import type { CliStatusResult, RuntimeStatus } from '../../shared/runtime-types'
import { findTransport } from '../../shared/runtime-bootstrap'
import { tryReadMetadata } from './metadata'
import { sendRequest } from './transport'
import { RuntimeRpcFailureError, type RuntimeRpcSuccess } from './types'

export async function getCliStatus(
  userDataPath: string
): Promise<RuntimeRpcSuccess<CliStatusResult>> {
  const metadata = tryReadMetadata(userDataPath)
  const transport = metadata ? findTransport(metadata, 'unix', 'named-pipe') : null
  if (!transport || !metadata?.authToken) {
    return buildCliStatusResponse({
      app: {
        running: false,
        pid: null
      },
      runtime: {
        // Why: distinguishing "never started" from "was running but died"
        // gives the user a better signal about what happened. If the metadata
        // file exists, Orca was running at some point.
        state: metadata ? 'stale_bootstrap' : 'not_running',
        reachable: false,
        runtimeId: null
      },
      graph: {
        state: 'not_running'
      }
    })
  }

  try {
    const response = await sendRequest<RuntimeStatus>(metadata, 'status.get', undefined, 1000)
    if (response.ok === false) {
      throw new RuntimeRpcFailureError(response)
    }
    const graphState = response.result.graphStatus
    const desktopWindowStatus = resolveDesktopWindowStatus(response.result)
    return buildCliStatusResponse({
      app: {
        running: true,
        pid: metadata.pid,
        ...(desktopWindowStatus ? { desktopWindowStatus } : {})
      },
      runtime: {
        state: graphState === 'ready' ? 'ready' : 'graph_not_ready',
        reachable: true,
        runtimeId: response.result.runtimeId,
        ...(response.result.appVersion ? { appVersion: response.result.appVersion } : {}),
        ...(response.result.remoteUpdateSupport
          ? { remoteUpdateSupport: response.result.remoteUpdateSupport }
          : {}),
        ...(response.result.capabilities ? { capabilities: response.result.capabilities } : {})
      },
      graph: {
        state: graphState
      }
    })
  } catch {
    const running = isProcessRunning(metadata.pid)
    return buildCliStatusResponse({
      app: {
        running,
        pid: running ? metadata.pid : null
      },
      runtime: {
        state: running ? 'starting' : 'stale_bootstrap',
        reachable: false,
        runtimeId: null
      },
      graph: {
        state: running ? 'starting' : 'not_running'
      }
    })
  }
}

export function resolveDesktopWindowStatus(
  status: RuntimeStatus
): CliStatusResult['app']['desktopWindowStatus'] {
  if (status.desktopWindowStatus) {
    return status.desktopWindowStatus
  }
  // Why: older desktop runtimes predate the explicit status but a positive
  // Electron id still proves that a real window owns the graph.
  return status.authoritativeWindowId !== null && status.authoritativeWindowId > 0
    ? 'available'
    : undefined
}

function buildCliStatusResponse(result: CliStatusResult): RuntimeRpcSuccess<CliStatusResult> {
  return {
    id: 'local-status',
    ok: true,
    result,
    _meta: {
      runtimeId: result.runtime.runtimeId ?? 'none'
    }
  }
}

function isProcessRunning(pid: number | null | undefined): boolean {
  if (!pid || pid <= 0) {
    return false
  }
  try {
    process.kill(pid, 0)
    return true
  } catch {
    return false
  }
}