/* eslint-disable max-lines -- Why: command routing, WSL translation, and
git/gh/glab wrappers must stay co-located so platform behavior remains
consistent across every repo-scoped subprocess call. */
/**
 * Centralized git/gh/command runner with transparent WSL support.
 *
 * Why: When a repo lives on a WSL filesystem (UNC path like \\wsl.localhost\Ubuntu\...),
 * native Windows binaries (git.exe, gh.exe, rg.exe) are either absent or extremely slow.
 * This module detects WSL paths and routes command execution through `wsl.exe -d <distro>`
 * with translated Linux paths, so every call site gets WSL support for free.
 */
import {
  execFile,
  execFileSync,
  spawn,
  type ChildProcess,
  type ExecFileOptions,
  type SpawnOptions
} from 'node:child_process'
import { StringDecoder } from 'node:string_decoder'
import { withGitSpan } from '../observability/instrumentation'
import { recordSubprocessSpawn } from '../diagnostics/main-thread-churn-probe'
import {
  classifyGhRateLimitBucket,
  createGhRateLimitBlockedError,
  getGhRateLimitBlockedUntilMs,
  isGhPrimaryRateLimitStderr,
  isGhRateLimitProbe,
  notifyGhPrimaryRateLimit
} from './gh-rate-limit-breaker'
import { getDefaultWslDistro, parseWslPath, toWindowsWslPath, type WslPathInfo } from '../wsl'
import { addWslEnvKeys } from '../wsl-env'
import { getSpawnArgsForWindows, isWindowsBatchScript, resolveWindowsCommand } from '../win32-utils'
import {
  buildWslLoginShellCommand,
  escapeWslShCommandForWindows,
  quotePosixShell
} from '../../shared/wsl-login-shell-command'
import { UNTRANSLATED_GIT_OUTPUT_ENV } from '../../shared/git-output-locale'

// ─── Core resolution ────────────────────────────────────────────────

// `LANGUAGE=en LC_ALL=en_US.UTF-8 LANG=en_US.UTF-8` — env-assignment prefix for
// WSL-routed git, where spawn env cannot cross the wsl.exe boundary. Values are
// shell-safe unquoted (alnum, dot, dash, underscore only).
const GIT_OUTPUT_LOCALE_SHELL_PREFIX = Object.entries(UNTRANSLATED_GIT_OUTPUT_ENV)
  .map(([key, value]) => `${key}=${value}`)
  .join(' ')

type ResolvedCommand = {
  binary: string
  args: string[]
  cwd: string | undefined
  /** Non-null when the command was routed through WSL. */
  wsl: WslPathInfo | null
}

/**
 * Translate any Windows-style paths in command arguments to Linux paths
 * when the command will execute inside WSL.
 *
 * Why: callers like worktree-create pass Windows paths (e.g. the workspace
 * directory) as git arguments. WSL git doesn't understand Windows paths,
 * so we must translate them. WSL UNC paths (\\wsl.localhost\...) are
 * converted to their native Linux form; regular Windows drive paths
 * (C:\Users\...) are converted to /mnt/c/Users/...
 */
function translateArgsForWsl(args: string[]): string[] {
  return args.map(translateArgForWsl)
}

function translateArgForWsl(arg: string): string {
  // WSL UNC path → native linux path
  const wslInfo = parseWslPath(arg)
  if (wslInfo) {
    return wslInfo.linuxPath
  }

  // Windows drive path (e.g. C:\Users\...) → /mnt/c/Users/...
  const driveMatch = arg.match(/^([A-Za-z]):[/\\](.*)$/)
  if (driveMatch) {
    const driveLetter = driveMatch[1].toLowerCase()
    const rest = driveMatch[2].replace(/\\/g, '/')
    return `/mnt/${driveLetter}/${rest}`
  }

  return arg
}

function hasExplicitRepoArg(args: string[]): boolean {
  for (let i = 0; i < args.length; i++) {
    if (
      (args[i] === '--repo' || args[i] === '-R') &&
      typeof args[i + 1] === 'string' &&
      args[i + 1].trim()
    ) {
      return true
    }
    if (args[i].startsWith('--repo=') || args[i].startsWith('-R=')) {
      return args[i].slice(args[i].indexOf('=') + 1).trim().length > 0
    }
    if (args[i].startsWith('-R') && args[i].length > 2) {
      return args[i].slice(2).trim().length > 0
    }
  }
  return false
}

function argsUseGhApiPlaceholders(args: string[]): boolean {
  return args.some(
    (arg) => arg.includes('{owner}') || arg.includes('{repo}') || arg.includes('{branch}')
  )
}

function canRunGitHubCliWithoutRepoCwd(args: string[]): boolean {
  if (hasExplicitRepoArg(args)) {
    return true
  }
  if (args[0] === 'api') {
    return !argsUseGhApiPlaceholders(args)
  }
  return args[0] === 'auth'
}

function isMissingCommandInWsl(stderr: string, command: string): boolean {
  const s = stderr.toLowerCase()
  const c = command.toLowerCase()
  return s.includes(`${c}: command not found`) || s.includes(`${c}: not found`)
}

function canFallBackToHostGitHubCli(
  command: 'gh',
  args: string[],
  resolved: ResolvedCommand,
  stderr: string
): boolean {
  return (
    process.platform === 'win32' &&
    resolved.wsl !== null &&
    isMissingCommandInWsl(stderr, command) &&
    canRunGitHubCliWithoutRepoCwd(args)
  )
}

function resolveHostGitHubCli(command: 'gh', args: string[]): ResolvedCommand {
  return {
    binary: command,
    args,
    // Why: host gh cannot use a WSL UNC cwd reliably. We only fall back
    // for commands with explicit repo/API context, so no repo cwd is required.
    cwd: undefined,
    wsl: null
  }
}

function resolveDefaultWslCli(command: 'gh' | 'glab', args: string[]): ResolvedCommand | null {
  const distro = getDefaultWslDistro()
  return distro ? resolveCommand(command, args, undefined, distro) : null
}

function isHostCommandMissing(err: unknown, command: 'gh' | 'glab'): boolean {
  if (!err || typeof err !== 'object') {
    return false
  }
  const e = err as { code?: unknown; message?: unknown; syscall?: unknown; path?: unknown }
  if (e.code === 'ENOENT') {
    return true
  }
  const message = typeof e.message === 'string' ? e.message.toLowerCase() : ''
  return (
    message.includes('enoent') &&
    (message.includes(command) || e.path === command || e.syscall === 'spawn')
  )
}

/**
 * Given a command, its arguments, and a working directory, resolve whether
 * the invocation should be routed through wsl.exe.
 *
 * Why `bash -c "cd ... && ..."` instead of `--cd`: wsl.exe's --cd flag
 * does not work reliably when invoked via Node's execFile/spawn (it fails
 * with ERROR_PATH_NOT_FOUND in some configurations). Using bash -c with
 * an explicit cd is universally supported.
 */
function resolveCommand(
  command: string,
  args: string[],
  cwd: string | undefined,
  wslDistroOverride?: string,
  options: { useWslLoginShell?: boolean } = {}
): ResolvedCommand {
  if (process.platform !== 'win32') {
    return { binary: command, args, cwd, wsl: null }
  }

  // Why: global gh callers (rate_limit, listAccessibleProjects) have no
  // meaningful cwd to derive a WSL distro from. On WSL-only Windows setups,
  // gh.exe isn't on the host PATH and the spawn fails with ENOENT. Allow
  // callers to pass a distro hint so we can route through wsl.exe regardless.
  // TODO(wsl-default-distro): the codebase currently has no persistent
  // "default WSL distro" setting — distros are derived from individual repo
  // paths. Until such a setting exists, global gh callers without an explicit
  // override silently fall back to host gh.exe, which on WSL-only Windows
  // installs will ENOENT. The wslDistroOverride parameter is the hook for
  // wiring a future setting in without re-plumbing the runner.
  const cwdWsl = cwd ? parseWslPath(cwd) : null
  const wsl: WslPathInfo | null =
    cwdWsl ?? (wslDistroOverride ? { distro: wslDistroOverride, linuxPath: '' } : null)
  if (!wsl) {
    return { binary: command, args, cwd, wsl: null }
  }

  const translatedArgs = translateArgsForWsl(args)
  // Why: env set on wsl.exe stays on the Windows side (WSLENV forwards only
  // named vars), so the untranslated-output locale must ride the command
  // string for git stderr parsers to work inside the distro (issue #7808).
  const localePrefix = command === 'git' ? `${GIT_OUTPUT_LOCALE_SHELL_PREFIX} ` : ''
  const escapedCommand = quotePosixShell(command)
  // Why: shell-escape each argument to prevent word splitting / glob expansion
  // inside the bash -c string. Single quotes are safe for all chars except
  // single quotes themselves, which we escape as '\'' (end quote, escaped
  // literal, reopen quote).
  const escapedArgs = translatedArgs.map(quotePosixShell)
  // Why: when cwd is supplied as a WSL UNC path, prepend `cd <linuxPath> &&`
  // so the command runs in the expected directory. When the caller only
  // supplied a distro override (no cwd), skip the cd entirely — the gh CLI
  // doesn't need a particular cwd for global calls like `api rate_limit`.
  const linuxCwd = cwdWsl?.linuxPath ?? (cwd && wslDistroOverride ? translateArgForWsl(cwd) : null)
  const shellCmd = linuxCwd
    ? `cd ${quotePosixShell(linuxCwd)} && ${localePrefix}${escapedCommand} ${escapedArgs.join(' ')}`
    : `${localePrefix}${escapedCommand} ${escapedArgs.join(' ')}`

  if (options.useWslLoginShell) {
    return {
      binary: 'wsl.exe',
      args: [
        '-d',
        wsl.distro,
        '--',
        'sh',
        '-lc',
        escapeWslShCommandForWindows(buildWslLoginShellCommand(shellCmd))
      ],
      cwd: undefined,
      wsl
    }
  }

  return {
    binary: 'wsl.exe',
    args: ['-d', wsl.distro, '--', 'bash', '-c', shellCmd],
    // Why: cwd is set to undefined because wsl.exe handles directory switching
    // via the cd inside bash -c. Setting a UNC cwd on the Node process would
    // be redundant and can cause issues with some Node internals.
    cwd: undefined,
    wsl
  }
}

// ─── Git-specific runners ───────────────────────────────────────────

// Why: Node's execFile only honors maxBuffer when it is a number — passing
// `undefined` (which happens whenever a caller omits the option) disables the
// cap entirely, so a command that prints more than V8's ~512MB max string
// length crashes the main process uncatchably inside execFile's exit handler
// (Array.join over the buffered chunks). Apply this floor so no git call can
// ever buffer without a bound. Matches the relay's MAX_GIT_BUFFER.
export const DEFAULT_GIT_MAX_BUFFER = 10 * 1024 * 1024

type GitExecOptions = {
  cwd: string
  encoding?: BufferEncoding | 'buffer'
  maxBuffer?: number
  timeout?: number
  stdin?: string
  env?: NodeJS.ProcessEnv
  signal?: AbortSignal
  wslDistro?: string
  useConfiguredSshCommandForNetwork?: boolean
}

type CommandExecOptions = {
  cwd?: string
  encoding?: BufferEncoding
  maxBuffer?: number
  timeout?: number
  env?: NodeJS.ProcessEnv
  signal?: AbortSignal
}

function isMissingCommandError(error: unknown): boolean {
  return Boolean(
    error && typeof error === 'object' && (error as { code?: unknown }).code === 'ENOENT'
  )
}

function hasPathSeparator(command: string): boolean {
  return command.includes('/') || command.includes('\\')
}

function shouldRetryWindowsCommandShim(error: unknown, resolved: ResolvedCommand): boolean {
  return (
    process.platform === 'win32' &&
    resolved.wsl === null &&
    isMissingCommandError(error) &&
    !hasPathSeparator(resolved.binary) &&
    !/\.[A-Za-z0-9]+$/.test(resolved.binary)
  )
}

function createAbortError(): Error {
  const error = new Error('The operation was aborted.')
  error.name = 'AbortError'
  return error
}

function killSpawnedCommandTree(child: ChildProcess): void {
  const pid = child.pid
  if (!pid || process.platform !== 'win32') {
    child.kill()
    return
  }
  try {
    // Why: Windows package-manager CLIs are often .cmd shims. Killing only
    // cmd.exe leaves the underlying node/npm/pnpm child running.
    const killer = spawn('taskkill', ['/pid', String(pid), '/t', '/f'], {
      stdio: 'ignore',
      windowsHide: true
    })
    killer.on('error', () => child.kill())
    killer.unref()
  } catch {
    child.kill()
  }
}

type ExecFileCaptureOptions = Omit<ExecFileOptions, 'timeout'> & {
  timeout?: number
  stdin?: string
}

function emptyExecFileOutput(options: ExecFileCaptureOptions): string | Buffer {
  return options.encoding === 'buffer' ? Buffer.alloc(0) : ''
}

function isExecFileResultObject(
  value: unknown
): value is { stdout: string | Buffer; stderr: string | Buffer } {
  return (
    value !== null &&
    typeof value === 'object' &&
    !Buffer.isBuffer(value) &&
    'stdout' in value &&
    'stderr' in value
  )
}

function execFileCapture(
  command: string,
  args: string[],
  options: ExecFileCaptureOptions
): Promise<{ stdout: string | Buffer; stderr: string | Buffer }> {
  return new Promise((resolve, reject) => {
    if (options.signal?.aborted) {
      reject(createAbortError())
      return
    }

    let settled = false
    let child: ChildProcess | null = null
    let timer: NodeJS.Timeout | null = null
    const cleanup = (): void => {
      if (timer) {
        clearTimeout(timer)
        timer = null
      }
      options.signal?.removeEventListener('abort', onAbort)
    }
    const finish = (
      error: Error | null,
      stdout: string | Buffer = emptyExecFileOutput(options),
      stderr: string | Buffer = emptyExecFileOutput(options)
    ): void => {
      if (settled) {
        return
      }
      settled = true
      cleanup()
      if (error) {
        const enriched = error as Error & { stdout?: string | Buffer; stderr?: string | Buffer }
        enriched.stdout ??= stdout
        enriched.stderr ??= stderr
        reject(enriched)
        return
      }
      resolve({ stdout, stderr })
    }
    const onAbort = (): void => {
      if (child) {
        killSpawnedCommandTree(child)
      }
      finish(createAbortError())
    }

    try {
      const spawnStartedAt = performance.now()
      child = execFile(
        command,
        args,
        {
          cwd: options.cwd,
          encoding: options.encoding,
          maxBuffer: options.maxBuffer ?? DEFAULT_GIT_MAX_BUFFER,
          env: options.env,
          signal: options.signal
        },
        (error, stdout, stderr) => {
          if (!error && stderr === undefined && isExecFileResultObject(stdout)) {
            finish(null, stdout.stdout, stdout.stderr)
            return
          }
          finish(error, stdout, stderr)
        }
      )
      recordSubprocessSpawn(command, args, performance.now() - spawnStartedAt)
    } catch (error) {
      finish(error instanceof Error ? error : new Error(String(error)))
      return
    }

    child.once('error', (error) => finish(error))

    if (options.stdin !== undefined) {
      child.stdin?.end(options.stdin)
    }

    // Why: Node's native execFile timeout waits for the child to exit after
    // signaling it. Some CLIs ignore that signal, so reject the UI operation
    // on our own timer and kill the child only as best effort.
    if (options.timeout && options.timeout > 0) {
      timer = setTimeout(() => {
        if (child) {
          killSpawnedCommandTree(child)
        }
        finish(new Error(`${command} timed out.`))
      }, options.timeout)
    }
    options.signal?.addEventListener('abort', onAbort, { once: true })
  })
}

async function spawnCommandCapture(
  command: string,
  args: string[],
  options: CommandExecOptions
): Promise<{ stdout: string; stderr: string }> {
  const { spawnCmd, spawnArgs } = getSpawnArgsForWindows(command, args)
  return new Promise((resolve, reject) => {
    if (options.signal?.aborted) {
      reject(createAbortError())
      return
    }
    let settled = false
    let stdout = ''
    let stderr = ''
    let stdoutBytes = 0
    let stderrBytes = 0
    const spawnStartedAt = performance.now()
    const child = spawn(spawnCmd, spawnArgs, {
      cwd: options.cwd,
      env: options.env,
      stdio: ['ignore', 'pipe', 'pipe'],
      windowsHide: true
    })
    recordSubprocessSpawn(spawnCmd, spawnArgs, performance.now() - spawnStartedAt)
    let timer: NodeJS.Timeout | null = null
    const onAbort = (): void => {
      killSpawnedCommandTree(child)
      finish(createAbortError())
    }
    const cleanupListeners = (): void => {
      if (timer) {
        clearTimeout(timer)
        timer = null
      }
      options.signal?.removeEventListener('abort', onAbort)
      child.stdout?.off('data', onStdoutData)
      child.stderr?.off('data', onStderrData)
      child.off('error', onError)
      child.off('close', onClose)
    }
    const finish = (error: Error | null): void => {
      if (settled) {
        return
      }
      settled = true
      cleanupListeners()
      if (error) {
        reject(Object.assign(error, { stdout, stderr }))
        return
      }
      resolve({ stdout, stderr })
    }
    timer = options.timeout
      ? setTimeout(() => {
          killSpawnedCommandTree(child)
          finish(new Error(`${command} timed out.`))
        }, options.timeout)
      : null
    options.signal?.addEventListener('abort', onAbort, { once: true })
    function onStdoutData(chunk: Buffer): void {
      stdoutBytes += chunk.byteLength
      if (options.maxBuffer && stdoutBytes > options.maxBuffer) {
        killSpawnedCommandTree(child)
        finish(new Error(`${command} stdout exceeded maxBuffer.`))
        return
      }
      stdout += chunk.toString(options.encoding ?? 'utf-8')
    }
    function onStderrData(chunk: Buffer): void {
      stderrBytes += chunk.byteLength
      if (options.maxBuffer && stderrBytes > options.maxBuffer) {
        killSpawnedCommandTree(child)
        finish(new Error(`${command} stderr exceeded maxBuffer.`))
        return
      }
      stderr += chunk.toString(options.encoding ?? 'utf-8')
    }
    function onError(error: Error): void {
      finish(error)
    }
    function onClose(code: number | null): void {
      if (code === 0) {
        finish(null)
        return
      }
      finish(new Error(`${command} exited with ${code}.`))
    }
    child.stdout?.on('data', onStdoutData)
    child.stderr?.on('data', onStderrData)
    child.on('error', onError)
    child.on('close', onClose)
  })
}

export function gitOptionalLocksDisabledEnv(
  env: NodeJS.ProcessEnv = process.env
): NodeJS.ProcessEnv {
  return {
    ...env,
    GIT_OPTIONAL_LOCKS: '0'
  }
}

/**
 * Append git config entries through the GIT_CONFIG_COUNT / GIT_CONFIG_KEY_n /
 * GIT_CONFIG_VALUE_n env protocol (git >= 2.31), composing with any count
 * already present in `env` so we never clobber config a caller injected the
 * same way.
 */
export function appendGitConfigEnv(
  env: NodeJS.ProcessEnv,
  entries: readonly (readonly [key: string, value: string])[]
): NodeJS.ProcessEnv {
  const parsed = Number.parseInt(env.GIT_CONFIG_COUNT ?? '', 10)
  const base = Number.isInteger(parsed) && parsed > 0 ? parsed : 0
  const next = { ...env }
  entries.forEach(([key, value], index) => {
    next[`GIT_CONFIG_KEY_${base + index}`] = key
    next[`GIT_CONFIG_VALUE_${base + index}`] = value
  })
  next.GIT_CONFIG_COUNT = String(base + entries.length)
  return next
}

/**
 * Pin Orca-spawned git to untranslated English output so stderr/progress
 * parsers keep working under any user locale (issue #7808; see
 * UNTRANSLATED_GIT_OUTPUT_ENV for the full rationale). Terminal git is
 * untouched. Injected by every git runner in this module; WSL-routed spawns
 * get the same values via GIT_OUTPUT_LOCALE_SHELL_PREFIX instead.
 */
export function untranslatedGitOutputEnv(env: NodeJS.ProcessEnv = process.env): NodeJS.ProcessEnv {
  return { ...env, ...UNTRANSLATED_GIT_OUTPUT_ENV }
}

const GIT_CONFIG_WSLENV_KEY_RE = /^GIT_CONFIG_(?:COUNT|KEY_\d+|VALUE_\d+)$/

export function promptGuardGitEnv(
  env: NodeJS.ProcessEnv = process.env,
  platform: NodeJS.Platform = process.platform
): NodeJS.ProcessEnv {
  const next = appendGitConfigEnv(
    {
      ...untranslatedGitOutputEnv(env),
      GIT_TERMINAL_PROMPT: '0',
      GIT_ASKPASS: env.GIT_ASKPASS ?? '',
      SSH_ASKPASS: env.SSH_ASKPASS ?? '',
      // Why: Git Credential Manager ignores GIT_TERMINAL_PROMPT / GIT_ASKPASS and
      // pops a GUI on first auth — the Windows worktree-create hang (STA-1292).
      // `never` suppresses the prompt while still serving cached credentials.
      GCM_INTERACTIVE: 'never'
    },
    // Why: disable only the *interactive* credential prompt, NOT the helper
    // itself — an empty credential.helper would break cached-credential auth for
    // private repos. Harmless on macOS/Linux (no GCM) and on the SSH path.
    [
      ['credential.interactive', 'false'],
      ['credential.guiPrompt', 'false']
    ]
  )
  if (platform === 'win32') {
    // Why: wsl.exe only imports env vars named in WSLENV, so WSL-routed git
    // would never see the guard — and WSL setups commonly use the Windows
    // credential manager as git's helper, which pops the same OAuth window
    // (issue #7652). Askpass vars are deliberately not forwarded: a Windows
    // askpass path is meaningless inside the distro. GIT_CONFIG_* must be
    // forwarded all-or-nothing (including caller-preexisting entries): a
    // GIT_CONFIG_COUNT that crosses without every KEY_n/VALUE_n below it makes
    // git error out on "bogus count".
    addWslEnvKeys(next, [
      'GIT_TERMINAL_PROMPT',
      'GCM_INTERACTIVE',
      ...Object.keys(next).filter((key) => GIT_CONFIG_WSLENV_KEY_RE.test(key))
    ])
  }
  return next
}

/**
 * Credential-prompt guard for a general-purpose shell environment (terminal
 * PTYs, hook scripts): everything promptGuardGitEnv does EXCEPT the issue-7808
 * locale pins. Those exist so Orca can parse stderr of git it spawns itself;
 * forcing LC_ALL/LANG/LANGUAGE onto a user's shell would change the locale of
 * every child process, not just git's.
 */
export function promptGuardShellEnv(
  env: NodeJS.ProcessEnv = process.env,
  platform: NodeJS.Platform = process.platform
): NodeJS.ProcessEnv {
  const next = promptGuardGitEnv(env, platform)
  for (const key of Object.keys(UNTRANSLATED_GIT_OUTPUT_ENV)) {
    if (env[key] === undefined) {
      delete next[key]
    } else {
      next[key] = env[key]
    }
  }
  return next
}

/**
 * Force git to be non-interactive so it fails fast instead of blocking forever
 * on a prompt. Without this, a git read-path call (status, worktree list, …)
 * that hits an auth/credential prompt or an SSH host-key confirmation hangs on
 * stdin with no terminal to answer it; on the headless `serve` runtime those
 * stuck calls pile up and the runtime stops answering all clients (issue #5308).
 *
 * - GIT_TERMINAL_PROMPT=0: git refuses to prompt for credentials and errors out.
 * - GIT_ASKPASS / SSH_ASKPASS: emptied when unset so no GUI/askpass helper can
 *   pop a prompt and block. A caller-provided askpass is preserved on purpose —
 *   custom askpass setups commonly *serve* credentials non-interactively, and
 *   blanking them would break those fetches.
 * - GIT_SSH_COMMAND BatchMode=yes: SSH fails instead of waiting on an
 *   interactive password/host-key prompt. BatchMode does NOT change host trust
 *   (an unknown host still errors, it just won't hang). Only added when the
 *   caller hasn't set its own GIT_SSH_COMMAND.
 */
export function nonInteractiveGitEnv(
  env: NodeJS.ProcessEnv = process.env,
  platform: NodeJS.Platform = process.platform
): NodeJS.ProcessEnv {
  const next = promptGuardGitEnv(env, platform)
  if (!next.GIT_SSH_COMMAND) {
    next.GIT_SSH_COMMAND = 'ssh -o BatchMode=yes'
    if (platform === 'win32') {
      // Why: forward across the WSL boundary only when we set the value —
      // plain `ssh` resolves inside the distro, whereas a caller's
      // Windows-specific GIT_SSH_COMMAND must not leak into Linux git.
      addWslEnvKeys(next, ['GIT_SSH_COMMAND'])
    }
  }
  return next
}

type GitSshPolicyMode =
  | 'default'
  | 'explicit-env'
  | 'fallback'
  | 'configured-openssh'
  | 'configured-wrapper-passthrough'

const CORE_SSH_COMMAND_PROBE_TIMEOUT_MS = 2500

function commandBasename(command: string): string {
  const pieces = command.split(/[\\/]+/)
  return pieces.at(-1)?.toLowerCase() ?? command.toLowerCase()
}

function isMergeableOpenSshCommand(command: string): boolean {
  const basename = commandBasename(command)
  return basename === 'ssh' || basename === 'ssh.exe'
}

function shellTokenize(command: string): string[] | null {
  const tokens: string[] = []
  let current = ''
  let quote: "'" | '"' | null = null
  let escaped = false

  for (let i = 0; i < command.length; i++) {
    const char = command[i]
    if (escaped) {
      current += char
      escaped = false
      continue
    }
    if (char === '\\') {
      const next = command[i + 1]
      if (next && /[\s'"\\]/.test(next)) {
        escaped = true
      } else {
        current += char
      }
      continue
    }
    if (quote) {
      if (char === quote) {
        quote = null
      } else {
        current += char
      }
      continue
    }
    if (char === "'" || char === '"') {
      quote = char
      continue
    }
    if (/\s/.test(char)) {
      if (current) {
        tokens.push(current)
        current = ''
      }
      continue
    }
    if (';&|<>()`'.includes(char)) {
      return null
    }
    current += char
  }

  if (escaped || quote) {
    return null
  }
  if (current) {
    tokens.push(current)
  }
  return tokens
}

function shellQuoteToken(token: string): string {
  return /^[A-Za-z0-9_@%+=:,./~-]+$/.test(token) ? token : quotePosixShell(token)
}

function containsShellExpansionSyntax(command: string): boolean {
  return command.includes('$')
}

function withoutBatchModeOptions(tokens: string[]): string[] {
  const next: string[] = []
  for (let i = 0; i < tokens.length; i++) {
    const token = tokens[i]
    const lower = token.toLowerCase()
    if (lower === '-o') {
      const option = tokens[i + 1]?.toLowerCase()
      if (option?.startsWith('batchmode')) {
        i += 1
        continue
      }
    }
    if (lower.startsWith('-obatchmode')) {
      continue
    }
    next.push(token)
  }
  return next
}

function buildOpenSshBatchModeCommand(configuredCommand: string): string | null {
  if (containsShellExpansionSyntax(configuredCommand)) {
    return null
  }
  const tokens = shellTokenize(configuredCommand)
  if (!tokens || tokens.length === 0 || !isMergeableOpenSshCommand(tokens[0])) {
    return null
  }
  return [...withoutBatchModeOptions(tokens), '-o', 'BatchMode=yes'].map(shellQuoteToken).join(' ')
}

async function buildNetworkSshPolicyEnv(options: GitExecOptions): Promise<{
  env: NodeJS.ProcessEnv
  mode: GitSshPolicyMode
}> {
  const promptEnv = promptGuardGitEnv(options.env)
  if (promptEnv.GIT_SSH_COMMAND) {
    return { env: promptEnv, mode: 'explicit-env' }
  }

  const resolved = resolveCommand(
    'git',
    ['config', '--get', 'core.sshCommand'],
    options.cwd,
    options.wslDistro,
    { useWslLoginShell: Boolean(options.wslDistro) }
  )
  let configuredCommand = ''
  try {
    const { stdout } = await execFileCapture(resolved.binary, resolved.args, {
      cwd: resolved.cwd,
      encoding: 'utf-8',
      maxBuffer: DEFAULT_GIT_MAX_BUFFER,
      timeout: CORE_SSH_COMMAND_PROBE_TIMEOUT_MS,
      env: promptEnv,
      signal: options.signal
    })
    configuredCommand = String(stdout).trim()
  } catch {
    configuredCommand = ''
  }

  if (!configuredCommand) {
    return { env: { ...promptEnv, GIT_SSH_COMMAND: 'ssh -o BatchMode=yes' }, mode: 'fallback' }
  }

  const batchModeCommand = buildOpenSshBatchModeCommand(configuredCommand)
  if (!batchModeCommand) {
    // Why: custom wrappers are executable user policy; rewriting their argv is
    // riskier than relying on prompt guards plus the caller's target timeout.
    return { env: promptEnv, mode: 'configured-wrapper-passthrough' }
  }

  return {
    env: { ...promptEnv, GIT_SSH_COMMAND: batchModeCommand },
    mode: 'configured-openssh'
  }
}

/**
 * Async git command execution. Drop-in replacement for
 * `execFileAsync('git', args, { cwd, encoding, ... })`.
 */
export async function gitExecFileAsync(
  args: string[],
  options: GitExecOptions
): Promise<{ stdout: string; stderr: string }> {
  // Why wrap here: the resolved binary path / WSL detection is internal
  // detail; the span attributes track the user-visible `git <subcommand>
  // <args…>` form so dashboards group cleanly by intent rather than by
  // platform-conditional binary path.
  return withGitSpan(
    { args, ...(options.cwd !== undefined ? { cwd: options.cwd } : {}) },
    async () => {
      const resolved = resolveCommand('git', args, options.cwd, options.wslDistro, {
        useWslLoginShell: Boolean(options.wslDistro)
      })
      const policy = options.useConfiguredSshCommandForNetwork
        ? await buildNetworkSshPolicyEnv(options)
        : { env: nonInteractiveGitEnv(options.env), mode: 'default' as const }
      let result: { stdout: string | Buffer; stderr: string | Buffer }
      try {
        result = await execFileCapture(resolved.binary, resolved.args, {
          cwd: resolved.cwd,
          encoding: (options.encoding ?? 'utf-8') as BufferEncoding,
          maxBuffer: options.maxBuffer,
          timeout: options.timeout,
          stdin: options.stdin,
          // Why: never let a git read-path call block on an interactive prompt
          // (issue #5308) — fail fast instead of hanging the runtime.
          env: policy.env,
          signal: options.signal
        })
      } catch (error) {
        if (options.useConfiguredSshCommandForNetwork && error && typeof error === 'object') {
          Object.assign(error, { gitSshPolicyMode: policy.mode })
        }
        throw error
      }
      const { stdout, stderr } = result
      return { stdout: stdout as string, stderr: stderr as string }
    }
  )
}

/**
 * Async command execution with the same WSL cwd translation as repo-scoped git.
 * Keep this for fixed binary+argv call sites; never pass shell fragments.
 */
export async function commandExecFileAsync(
  command: string,
  args: string[],
  options: CommandExecOptions = {}
): Promise<{ stdout: string; stderr: string }> {
  const resolved = resolveCommand(command, args, options.cwd)
  const binary =
    resolved.wsl === null ? resolveWindowsCommand(resolved.binary, options.env) : resolved.binary
  if (isWindowsBatchScript(binary)) {
    return spawnCommandCapture(binary, resolved.args, {
      ...options,
      cwd: resolved.cwd
    })
  }
  try {
    const { stdout, stderr } = await execFileCapture(binary, resolved.args, {
      cwd: resolved.cwd,
      encoding: options.encoding ?? 'utf-8',
      maxBuffer: options.maxBuffer,
      timeout: options.timeout,
      env: options.env,
      signal: options.signal
    })
    return { stdout: stdout as string, stderr: stderr as string }
  } catch (error) {
    if (shouldRetryWindowsCommandShim(error, resolved)) {
      return spawnCommandCapture(
        resolveWindowsCommand(`${resolved.binary}.cmd`, options.env),
        resolved.args,
        {
          ...options,
          cwd: resolved.cwd
        }
      )
    }
    throw error
  }
}

/**
 * Async git command execution that returns a Buffer.
 * Used for reading binary blobs (git show).
 */
export async function gitExecFileAsyncBuffer(
  args: string[],
  options: { cwd: string; maxBuffer?: number; wslDistro?: string }
): Promise<{ stdout: Buffer }> {
  const resolved = resolveCommand('git', args, options.cwd, options.wslDistro, {
    useWslLoginShell: Boolean(options.wslDistro)
  })
  const { stdout } = (await execFileCapture(resolved.binary, resolved.args, {
    cwd: resolved.cwd,
    encoding: 'buffer',
    maxBuffer: options.maxBuffer,
    env: untranslatedGitOutputEnv()
  })) as { stdout: Buffer }
  return { stdout }
}

/** Result of a streamed git command. `stoppedEarly` is true when the caller's
 * onStdout hook asked to stop and the child was killed before exiting. */
export type GitStreamResult = { stoppedEarly: boolean }

type GitStreamOptions = {
  cwd: string
  env?: NodeJS.ProcessEnv
  wslDistro?: string
  signal?: AbortSignal
  /** Byte backstop; defaults to DEFAULT_GIT_MAX_BUFFER. */
  maxBuffer?: number
  /**
   * Called for each decoded stdout chunk as it arrives. Return true to stop:
   * the child is killed and the promise resolves with stoppedEarly=true. This
   * lets a streaming parser bail out (e.g. once an entry limit is reached)
   * without ever buffering the full output.
   */
  onStdout: (chunk: string) => boolean | void
}

/**
 * Stream a git command's stdout incrementally instead of buffering it whole.
 *
 * Why: status on a repo with an enormous un-ignored folder can emit more output
 * than fits in a single string, crashing the process when buffered. Streaming
 * lets the parser count entries as they arrive and stop git the moment a limit
 * is crossed, so memory stays bounded. Built on gitSpawn so WSL routing is
 * preserved. stderr is bounded; a non-zero exit rejects (unless we stopped it).
 */
export async function gitStreamStdout(
  args: string[],
  options: GitStreamOptions
): Promise<GitStreamResult> {
  const maxBuffer = options.maxBuffer ?? DEFAULT_GIT_MAX_BUFFER
  return withGitSpan({ args, cwd: options.cwd }, async () => {
    return new Promise<GitStreamResult>((resolve, reject) => {
      if (options.signal?.aborted) {
        reject(createAbortError())
        return
      }
      const child = gitSpawn(args, {
        cwd: options.cwd,
        env: nonInteractiveGitEnv(options.env),
        stdio: ['ignore', 'pipe', 'pipe'],
        wslDistro: options.wslDistro,
        windowsHide: true
      })

      let settled = false
      let stoppedEarly = false
      let stdoutBytes = 0
      let stderr = ''
      let stderrBytes = 0
      // Why: decode statefully so a multibyte UTF-8 character split across two
      // chunks (common with non-ASCII filenames) isn't corrupted into
      // replacement characters and mis-parsed.
      const stdoutDecoder = new StringDecoder('utf8')
      const stderrDecoder = new StringDecoder('utf8')

      const cleanup = (): void => {
        child.stdout?.off('data', onStdoutData)
        child.stderr?.off('data', onStderrData)
        child.off('error', onError)
        child.off('close', onClose)
        options.signal?.removeEventListener('abort', onAbort)
        // Flush any bytes the decoders were holding for an incomplete sequence.
        stdoutDecoder.end()
        stderrDecoder.end()
      }
      const finish = (error: Error | null): void => {
        if (settled) {
          return
        }
        settled = true
        cleanup()
        if (error) {
          reject(Object.assign(error, { stderr }))
          return
        }
        resolve({ stoppedEarly })
      }

      function onStdoutData(chunk: Buffer): void {
        stdoutBytes += chunk.byteLength
        if (stdoutBytes > maxBuffer) {
          killSpawnedCommandTree(child)
          finish(new Error('git stdout exceeded maxBuffer.'))
          return
        }
        const decoded = stdoutDecoder.write(chunk)
        if (decoded.length === 0) {
          return
        }
        // Why: the parser callback is caller-supplied; a throw here would escape
        // the stream event handler and crash the main process (the exact failure
        // mode this streaming path exists to prevent). Convert it to a rejection.
        let shouldStop: boolean | void
        try {
          shouldStop = options.onStdout(decoded)
        } catch (error) {
          killSpawnedCommandTree(child)
          finish(error instanceof Error ? error : new Error(String(error)))
          return
        }
        if (shouldStop === true) {
          // Why: parser hit its limit. Kill git and resolve cleanly — the
          // partial output we already parsed is the intended result.
          stoppedEarly = true
          killSpawnedCommandTree(child)
          finish(null)
        }
      }
      function onStderrData(chunk: Buffer): void {
        stderrBytes += chunk.byteLength
        if (stderrBytes > maxBuffer) {
          killSpawnedCommandTree(child)
          finish(new Error('git stderr exceeded maxBuffer.'))
          return
        }
        stderr += stderrDecoder.write(chunk)
      }
      function onError(error: Error): void {
        finish(error)
      }
      function onClose(code: number | null): void {
        if (stoppedEarly || code === 0) {
          finish(null)
          return
        }
        finish(new Error(`git exited with ${code}: ${stderr}`))
      }
      function onAbort(): void {
        killSpawnedCommandTree(child)
        finish(createAbortError())
      }

      child.stdout?.on('data', onStdoutData)
      child.stderr?.on('data', onStderrData)
      child.on('error', onError)
      child.on('close', onClose)
      options.signal?.addEventListener('abort', onAbort, { once: true })
      if (options.signal?.aborted) {
        onAbort()
      }
    })
  })
}

// Why: sync git calls run on the Electron main thread. Local git is normally
// fast, but a repo on a dead network drive / cloud-placeholder path can hang
// git on filesystem timeouts for minutes with no timeout set — the leading
// explanation for issue #7225's 127s "Not Responding" freeze. Callers needing
// longer operations should use the async runners instead.
const GIT_EXEC_SYNC_TIMEOUT_MS = 15_000

/**
 * Sync git command execution. Drop-in replacement for
 * `execFileSync('git', args, { cwd, encoding, ... })`.
 *
 * Returns trimmed stdout as a string.
 */
export function gitExecFileSync(
  args: string[],
  options: {
    cwd: string
    encoding?: BufferEncoding
    stdio?: SpawnOptions['stdio']
    timeout?: number
  }
): string {
  const resolved = resolveCommand('git', args, options.cwd)
  const spawnStartedAt = performance.now()
  try {
    return execFileSync(resolved.binary, resolved.args, {
      cwd: resolved.cwd,
      encoding: options.encoding ?? 'utf-8',
      env: untranslatedGitOutputEnv(),
      stdio: options.stdio ?? ['pipe', 'pipe', 'pipe'],
      timeout: options.timeout ?? GIT_EXEC_SYNC_TIMEOUT_MS
    }) as string
  } finally {
    // Sync exec holds the main thread for its whole duration, so the entire
    // call is main-thread block time — the cost issue #7576 flags.
    recordSubprocessSpawn(resolved.binary, resolved.args, performance.now() - spawnStartedAt)
  }
}

/**
 * Spawn a git child process. Drop-in replacement for
 * `spawn('git', args, { cwd, stdio, ... })`.
 */
export function gitSpawn(
  args: string[],
  options: SpawnOptions & { cwd: string; wslDistro?: string }
): ChildProcess {
  const { wslDistro, ...spawnOptions } = options
  const resolved = resolveCommand('git', args, options.cwd, wslDistro, {
    useWslLoginShell: Boolean(wslDistro)
  })
  const spawnStartedAt = performance.now()
  const child = spawn(resolved.binary, resolved.args, {
    ...spawnOptions,
    env: untranslatedGitOutputEnv(spawnOptions.env ?? process.env),
    cwd: resolved.cwd
  })
  recordSubprocessSpawn(resolved.binary, resolved.args, performance.now() - spawnStartedAt)
  return child
}

// ─── gh CLI runners ─────────────────────────────────────────────────

// Why: non-repo-scoped gh calls (listAccessibleProjects, rate_limit, etc.)
// have no meaningful cwd. Allow it to be omitted so the one WSL-aware wrapper
// serves both repo-scoped and global callers and we stop having two spawn
// sites (the other one — a plain execFileAsync in project-view.ts — bypasses
// retry/backoff and any future quota tracker).
// Why: `wslDistro` is an explicit hint for global (cwd-less) gh callers on
// WSL-only Windows installs where gh.exe isn't on the host PATH. When set,
// resolveCommand routes the spawn through `wsl.exe -d <distro> -- gh ...`
// even without a UNC cwd to parse a distro from. Repo-scoped callers should
// keep using cwd — the distro derives from the path automatically there.
// Why: `idempotent` gates the transient-error retry. When undefined we
// auto-detect from argv (writes are detected by `-X POST/PATCH/PUT/DELETE`
// or a `query=mutation …` arg); callers can also pass an explicit override.
// A 5xx/socket reset after the request reaches GitHub but before the
// response returns is the canonical case where the server-side write
// succeeded; retrying would create a duplicate comment/issue/label addition.
// See bug-scan finding 1.
type GhExecOptions = Omit<GitExecOptions, 'cwd'> & {
  cwd?: string
  wslDistro?: string
  idempotent?: boolean
}

const NON_IDEMPOTENT_METHODS = new Set(['POST', 'PATCH', 'PUT', 'DELETE'])
// `gh <noun> <verb>` write subcommands. Reads (view/list/status/checks)
// are absent on purpose so the default of "retry" stays for them.
const NON_IDEMPOTENT_GH_VERBS = new Set([
  'create',
  'edit',
  'update',
  'delete',
  'close',
  'reopen',
  'merge',
  'comment',
  'review',
  'ready',
  'lock',
  'unlock',
  'pin',
  'unpin',
  'transfer',
  'develop'
])

function argsLookIdempotent(args: string[]): boolean {
  let explicitMethodSeen = false
  let hasApiBodyField = false
  let hasGraphQlQuery = false
  const isGraphQlApi = args[0] === 'api' && args[1] === 'graphql'
  for (let i = 0; i < args.length; i++) {
    const a = args[i]
    if (a === '-X' || a === '--method') {
      explicitMethodSeen = true
      const next = args[i + 1]
      if (typeof next === 'string' && NON_IDEMPOTENT_METHODS.has(next.toUpperCase())) {
        return false
      }
    }
    // Single-token form `--method=POST` (gh accepts this).
    if (a.startsWith('--method=')) {
      explicitMethodSeen = true
      const value = a.slice('--method='.length)
      if (NON_IDEMPOTENT_METHODS.has(value.toUpperCase())) {
        return false
      }
    }
    // `gh api` auto-switches GET→POST when -f/-F/--field/--raw-field body
    // fields are supplied without an explicit -X. Track those to classify
    // such calls as non-idempotent.
    if (a === '-f' || a === '-F' || a === '--field' || a === '--raw-field') {
      hasApiBodyField = true
    } else if (
      a.startsWith('-f=') ||
      a.startsWith('-F=') ||
      a.startsWith('--field=') ||
      a.startsWith('--raw-field=')
    ) {
      hasApiBodyField = true
    }
    // `gh api graphql -f query=mutation(...){ ... }` — detect mutation queries
    // so writes via the GraphQL endpoint also fail fast on transient errors.
    if (a.startsWith('query=')) {
      hasGraphQlQuery = true
      const trimmed = a.slice('query='.length).trimStart().toLowerCase()
      if (trimmed.startsWith('mutation')) {
        return false
      }
    }
  }
  // `gh api ... -f foo=bar` with no explicit method: gh switches to POST.
  // Treat as non-idempotent so a transient 5xx after the server applied
  // the write doesn't retry and duplicate it. GraphQL reads are the exception:
  // gh sends them as POST body fields, but a query operation is idempotent.
  if (
    args[0] === 'api' &&
    hasApiBodyField &&
    !explicitMethodSeen &&
    !(isGraphQlApi && hasGraphQlQuery)
  ) {
    return false
  }
  // `gh issue close`, `gh pr edit`, `gh pr merge`, etc. The first arg is the
  // noun (issue/pr/repo/label/...) and the second is the verb. Defaulting
  // `gh api` calls without an explicit -X to GET-equivalent (idempotent) is
  // intentional: callers that POST through `gh api` set `-X POST`.
  if (args.length >= 2 && args[0] !== 'api') {
    if (NON_IDEMPOTENT_GH_VERBS.has(args[1])) {
      return false
    }
  }
  return true
}

/**
 * Extract stderr from an execFile rejection.
 *
 * Why: Node's execFile rejects with an Error that has `.stdout` and `.stderr`
 * fields populated separately from `.message`. Reading `err.message` alone is
 * unreliable — it can truncate stderr or omit it entirely depending on Node
 * version and maxBuffer behavior. We prefer the explicit fields and fall
 * back to `.message` only when neither is present.
 */
export function extractExecError(err: unknown): { stderr: string; stdout: string } {
  if (err && typeof err === 'object') {
    const e = err as { stderr?: unknown; stdout?: unknown; message?: unknown }
    const stderr =
      typeof e.stderr === 'string'
        ? e.stderr
        : Buffer.isBuffer(e.stderr)
          ? e.stderr.toString('utf-8')
          : ''
    const stdout =
      typeof e.stdout === 'string'
        ? e.stdout
        : Buffer.isBuffer(e.stdout)
          ? e.stdout.toString('utf-8')
          : ''
    if (stderr || stdout) {
      return { stderr, stdout }
    }
    if (typeof e.message === 'string') {
      return { stderr: e.message, stdout: '' }
    }
  }
  return { stderr: String(err), stdout: '' }
}

/**
 * Detect a Retry-After hint in gh stderr and return the suggested delay in ms,
 * or null when the response includes no Retry-After.
 *
 * Why: gh forwards response headers when verbose, and prints "Retry-After:
 * <seconds>" in error output for primary rate-limit 429s. When present, the
 * caller is better served by propagating the error so the UI can surface the
 * real wait time — retrying on our own 250ms cadence just earns another 429
 * and burns the retry budget. Also supports HTTP-date Retry-After values.
 */
export function parseRetryAfterMs(stderr: string): number | null {
  const raw = findRetryAfterHeaderValue(stderr)
  if (raw === null) {
    return null
  }
  if (/^\d+$/.test(raw)) {
    const seconds = Number(raw)
    return Number.isFinite(seconds) ? seconds * 1000 : null
  }
  const ts = Date.parse(raw)
  if (Number.isNaN(ts)) {
    return null
  }
  return Math.max(0, ts - Date.now())
}

function findRetryAfterHeaderValue(stderr: string): string | null {
  const headerIndex = indexOfAsciiIgnoreCase(stderr, 'retry-after:', 0)
  if (headerIndex === -1) {
    return null
  }
  let valueStart = headerIndex + 'retry-after:'.length
  while (valueStart < stderr.length) {
    const code = stderr.charCodeAt(valueStart)
    if (code !== 9 && code !== 32) {
      break
    }
    valueStart++
  }
  let valueEnd = valueStart
  while (valueEnd < stderr.length) {
    const code = stderr.charCodeAt(valueEnd)
    if (code === 10 || code === 13) {
      break
    }
    valueEnd++
  }
  const value = stderr.slice(valueStart, valueEnd).trim()
  return value.length > 0 ? value : null
}

function indexOfAsciiIgnoreCase(value: string, search: string, fromIndex: number): number {
  const lastStart = value.length - search.length
  for (let index = Math.max(0, fromIndex); index <= lastStart; index++) {
    let matches = true
    for (let offset = 0; offset < search.length; offset++) {
      const code = value.charCodeAt(index + offset)
      const normalizedCode = code >= 65 && code <= 90 ? code + 32 : code
      if (normalizedCode !== search.charCodeAt(offset)) {
        matches = false
        break
      }
    }
    if (matches) {
      return index
    }
  }
  return -1
}

/**
 * Classify whether a gh execFile rejection is worth retrying.
 *
 * Why: gh surfaces HTTP status in stderr as "HTTP 504", "HTTP 502", etc.
 * Network resets and DNS hiccups also show up as stderr substrings. We retry
 * those and 429 (rate-limited) — but only 429s without an explicit
 * Retry-After (the caller is better off propagating so the UI can show the
 * actual wait time). The primary-rate-limit 403 branch is NOT retried: those
 * require the user to back off for minutes, which is not transient.
 */
export function isTransientGhError(stderr: string): boolean {
  const s = stderr.toLowerCase()
  if (
    s.includes('http 500') ||
    s.includes('http 502') ||
    s.includes('http 503') ||
    s.includes('http 504') ||
    s.includes('econnreset') ||
    s.includes('etimedout') ||
    s.includes('socket hang up')
  ) {
    return true
  }
  // 429 without Retry-After: retry. With Retry-After: propagate.
  if (s.includes('http 429')) {
    return parseRetryAfterMs(stderr) === null
  }
  return false
}

// Why: total of 3 attempts (original + 2 retries) with 250ms → 1s backoff.
// These are standard "transient 5xx" values. Longer waits push past user
// patience for an interactive action; shorter waits would hammer the same
// unhealthy upstream that just failed. The array length defines retry count;
// total attempts = length + 1.
const GH_RETRY_DELAYS_MS = [250, 1000] as const

// Why: the upstream Retry-After header is server-suggested but unbounded —
// GitHub has been observed to send tens-of-seconds values on rare incidents,
// and a malicious or misconfigured proxy could send anything. Cap the wait
// at 30s so a single transient gh call can never block the IPC main thread
// for longer than the user's patience budget for an interactive action.
const GH_RETRY_AFTER_MAX_MS = 30_000
const DEFAULT_GH_EXEC_TIMEOUT_MS = 30_000

async function sleep(ms: number): Promise<void> {
  return new Promise((resolve) => setTimeout(resolve, ms))
}

function defaultGhExecTimeoutMs(env: NodeJS.ProcessEnv = process.env): number {
  const raw = env.ORCA_GH_EXEC_TIMEOUT_MS
  if (!raw) {
    return DEFAULT_GH_EXEC_TIMEOUT_MS
  }
  const parsed = Number(raw)
  return Number.isFinite(parsed) && parsed > 0 ? parsed : DEFAULT_GH_EXEC_TIMEOUT_MS
}

function nonInteractiveGhEnv(env: NodeJS.ProcessEnv = process.env): NodeJS.ProcessEnv {
  return {
    ...env,
    GH_PROMPT_DISABLED: env.GH_PROMPT_DISABLED ?? '1'
  }
}

/**
 * Async gh CLI execution. Drop-in replacement for
 * `execFileAsync('gh', args, { cwd, encoding, ... })`.
 *
 * Retries transient 5xx / 429 (without Retry-After) / network-reset failures
 * with exponential backoff. Non-transient errors (auth, 404, rate-limit 403,
 * validation, 429-with-Retry-After) fail fast on the first attempt.
 */
export async function ghExecFileAsync(
  args: string[],
  options: GhExecOptions = {}
): Promise<{ stdout: string; stderr: string }> {
  // Why: while a bucket's primary rate limit is exhausted, every spawn would
  // return the same 403 — fail fast without paying the subprocess cost. The
  // rate_limit probe itself is exempt so the breaker can learn the reset time.
  const rateLimitBucket = classifyGhRateLimitBucket(args)
  if (!isGhRateLimitProbe(args)) {
    const blockedUntilMs = getGhRateLimitBlockedUntilMs(rateLimitBucket)
    if (blockedUntilMs !== null) {
      throw createGhRateLimitBlockedError(rateLimitBucket, blockedUntilMs)
    }
  }
  let resolved = resolveCommand('gh', args, options.cwd, options.wslDistro)
  let lastError: unknown
  let attemptedHostFallback = false
  let attemptedDefaultWslFallback = false
  for (let attempt = 0; attempt <= GH_RETRY_DELAYS_MS.length; attempt++) {
    try {
      const { stdout, stderr } = await execFileCapture(resolved.binary, resolved.args, {
        cwd: resolved.cwd,
        encoding: (options.encoding ?? 'utf-8') as BufferEncoding,
        maxBuffer: options.maxBuffer,
        // Why: GitHub detail IPC powers PR cards, Tasks, and URL worktree
        // creation; one stuck gh child must fail visibly, not wedge every lane.
        timeout: options.timeout ?? defaultGhExecTimeoutMs(options.env),
        env: nonInteractiveGhEnv(options.env)
      })
      return { stdout: stdout as string, stderr: stderr as string }
    } catch (err) {
      lastError = err
      const { stderr } = extractExecError(err)
      if (isGhPrimaryRateLimitStderr(stderr)) {
        notifyGhPrimaryRateLimit(rateLimitBucket)
      }
      if (
        process.platform === 'win32' &&
        !attemptedDefaultWslFallback &&
        resolved.wsl === null &&
        !options.cwd &&
        !options.wslDistro &&
        isHostCommandMissing(err, 'gh')
      ) {
        const wslResolved = resolveDefaultWslCli('gh', args)
        if (wslResolved) {
          // Why: WSL-only Windows installs have no gh.exe on the host PATH, but
          // global calls like rate_limit/auth do not carry a repo cwd to route by.
          resolved = wslResolved
          attemptedDefaultWslFallback = true
          attempt = -1
          continue
        }
      }
      if (!attemptedHostFallback && canFallBackToHostGitHubCli('gh', args, resolved, stderr)) {
        resolved = resolveHostGitHubCli('gh', args)
        attemptedHostFallback = true
        attempt = -1
        continue
      }
      const isLastAttempt = attempt >= GH_RETRY_DELAYS_MS.length
      // Why: only retry idempotent calls. A 5xx/socket reset can arrive
      // after the server already applied a POST/PATCH/PUT/DELETE; retrying
      // would duplicate the write (e.g. double-post a comment, double-add
      // a label). When the caller doesn't say, we auto-detect from argv —
      // explicit `-X <method>` and GraphQL `query=mutation …` are treated
      // as non-idempotent. See bug-scan finding 1.
      const idempotent = options.idempotent ?? argsLookIdempotent(args)
      if (idempotent && !isLastAttempt && isTransientGhError(stderr)) {
        // Why: when the upstream surfaced a Retry-After (e.g. on a transient
        // 5xx that GitHub explicitly recommends backing off for), honor it
        // instead of using our default backoff — sleeping less than the
        // server suggests just earns another failure and burns our retry
        // budget. Cap at GH_RETRY_AFTER_MAX_MS so a pathologically large
        // hint can't block IPC for minutes; if the real wait is longer, the
        // attempt will fail again and the error will propagate to the UI
        // where the user can see it.
        const retryAfterMs = parseRetryAfterMs(stderr)
        const delayMs =
          retryAfterMs !== null
            ? Math.min(retryAfterMs, GH_RETRY_AFTER_MAX_MS)
            : GH_RETRY_DELAYS_MS[attempt]
        await sleep(delayMs)
        continue
      }
      throw err
    }
  }
  // Unreachable: the loop either returns or throws. Here for TS exhaustiveness.
  throw lastError
}

// ─── glab CLI runner ────────────────────────────────────────────────
// Why: parallel to gh CLI runner above. GitLab support is added by
// cloning gh's surface rather than abstracting both behind a generic
// runner — keeping them as parallel implementations matches the
// project's clone-and-adapt approach for new providers and avoids
// touching the working gh path. Reuses the shared retry/transient
// helpers since HTTP-status- and TCP-error-based classification is
// provider-agnostic.

type GlabExecOptions = Omit<GitExecOptions, 'cwd'> & {
  cwd?: string
  wslDistro?: string
  idempotent?: boolean
  allowDefaultWslFallback?: boolean
}

/**
 * Async glab CLI execution. Drop-in replacement for
 * `execFileAsync('glab', args, { cwd, encoding, ... })`.
 *
 * Retry policy mirrors ghExecFileAsync.
 */
/**
 * glab's `--hostname` flag rejects a host that carries a port
 * ("error parsing --hostname: invalid hostname"). A self-hosted GitLab on a
 * non-default port (e.g. `gitlab.example.com:8443`) must instead be selected
 * via the `GITLAB_HOST` env var, which accepts `host:port`. Translate any
 * `--hostname host:port` pair into `GITLAB_HOST` so every call site (`api`,
 * `auth status`, …) works against ported self-hosted instances. Port-less
 * `--hostname` values are left untouched.
 *
 * @internal exported for tests.
 */
export function redirectPortedHostnameToEnv(
  args: string[],
  options: GlabExecOptions
): { args: string[]; options: GlabExecOptions } {
  const i = args.indexOf('--hostname')
  if (i === -1 || i + 1 >= args.length) {
    return { args, options }
  }
  const host = args[i + 1]
  if (!/^[^/\s]+:\d+$/.test(host)) {
    return { args, options }
  }
  return {
    args: [...args.slice(0, i), ...args.slice(i + 2)],
    options: { ...options, env: { ...(options.env ?? process.env), GITLAB_HOST: host } }
  }
}

export async function glabExecFileAsync(
  args: string[],
  options: GlabExecOptions = {}
): Promise<{ stdout: string; stderr: string }> {
  ;({ args, options } = redirectPortedHostnameToEnv(args, options))
  let resolved = resolveCommand('glab', args, options.cwd, options.wslDistro)
  let lastError: unknown
  let attemptedDefaultWslFallback = false
  for (let attempt = 0; attempt <= GH_RETRY_DELAYS_MS.length; attempt++) {
    try {
      const { stdout, stderr } = await execFileCapture(resolved.binary, resolved.args, {
        cwd: resolved.cwd,
        encoding: (options.encoding ?? 'utf-8') as BufferEncoding,
        maxBuffer: options.maxBuffer,
        timeout: options.timeout,
        env: options.env
      })
      return { stdout: stdout as string, stderr: stderr as string }
    } catch (err) {
      lastError = err
      const { stderr } = extractExecError(err)
      if (
        process.platform === 'win32' &&
        !attemptedDefaultWslFallback &&
        resolved.wsl === null &&
        !options.cwd &&
        !options.wslDistro &&
        options.allowDefaultWslFallback !== false &&
        isHostCommandMissing(err, 'glab')
      ) {
        const wslResolved = resolveDefaultWslCli('glab', args)
        if (wslResolved) {
          // Why: mirror gh's WSL-only fallback for global GitLab project/auth calls.
          resolved = wslResolved
          attemptedDefaultWslFallback = true
          attempt = -1
          continue
        }
      }
      const isLastAttempt = attempt >= GH_RETRY_DELAYS_MS.length
      // Why: mirror gh's write-safety gate. A transient error after GitLab
      // applies a POST/PATCH/PUT/DELETE must not create duplicate comments,
      // issues, or merge actions through an automatic retry.
      const idempotent = options.idempotent ?? argsLookIdempotent(args)
      if (idempotent && !isLastAttempt && isTransientGhError(stderr)) {
        const retryAfterMs = parseRetryAfterMs(stderr)
        const delayMs =
          retryAfterMs !== null
            ? Math.min(retryAfterMs, GH_RETRY_AFTER_MAX_MS)
            : GH_RETRY_DELAYS_MS[attempt]
        await sleep(delayMs)
        continue
      }
      throw err
    }
  }
  throw lastError
}

// ─── Generic command runner (for rg, etc.) ──────────────────────────

/**
 * Spawn any command with WSL awareness.
 * Used for non-git binaries like `rg` that also need WSL routing.
 */
export function wslAwareSpawn(
  command: string,
  args: string[],
  options: SpawnOptions & { cwd?: string; wslDistro?: string; useWslLoginShell?: boolean }
): ChildProcess {
  const { wslDistro, useWslLoginShell, ...spawnOptions } = options
  const resolved = resolveCommand(command, args, options.cwd, wslDistro, {
    useWslLoginShell
  })
  const spawnStartedAt = performance.now()
  const child = spawn(resolved.binary, resolved.args, {
    ...spawnOptions,
    cwd: resolved.cwd
  })
  recordSubprocessSpawn(resolved.binary, resolved.args, performance.now() - spawnStartedAt)
  return child
}

// ─── Path translation helpers ───────────────────────────────────────

/**
 * Translate absolute Linux paths in git output back to Windows UNC paths.
 *
 * Why: when git runs inside WSL, paths in output (e.g. `git worktree list`)
 * are Linux-native (/home/user/repo). The rest of Orca needs Windows UNC
 * paths (\\wsl.localhost\Ubuntu\home\user\repo) to read files via Node fs.
 */
export function translateWslOutputPaths(
  output: string,
  originalCwd: string,
  options: { wslDistro?: string } = {}
): string {
  const wsl = parseWslPath(originalCwd)
  const distro = wsl?.distro ?? options.wslDistro
  if (!distro) {
    return output
  }

  // Replace absolute Linux paths that start with / and look like filesystem
  // paths in structured git output (e.g. "worktree /home/user/repo/feature")
  return output.replace(/(?<=worktree )(\/.+)$/gm, (_match, linuxPath: string) =>
    toWindowsWslPath(linuxPath, distro)
  )
}

/**
 * Get the WSL info for a path, if applicable. Convenience re-export so
 * consumers don't need to import from wsl.ts directly.
 */
export { parseWslPath, toLinuxPath, toWindowsWslPath, isWslPath } from '../wsl'