import {
  completePluginAppThemeTokens,
  PLUGIN_APP_THEME_REQUIRED_TOKENS,
  PLUGIN_APP_THEME_TOKENS
} from './plugin-theme-artifact'
import { pluginAppThemeCssFallback } from './plugin-theme-css-fallbacks'

const REQUIRED = new Set<string>(PLUGIN_APP_THEME_REQUIRED_TOKENS)

type PluginAppThemeToken = (typeof PLUGIN_APP_THEME_TOKENS)[number]

// Why a full record: a public token added without saying what it paints fails typecheck.
const TOKEN_ROLES: Record<PluginAppThemeToken, string> = {
  '--background': 'App canvas',
  '--editor-surface': 'Code editor and notebook background',
  '--foreground': 'Body text',
  '--card': 'Cards and panels',
  '--card-foreground': 'Text on `--card`',
  '--popover': 'Menus, popovers and dialogs',
  '--popover-foreground': 'Text on `--popover`',
  '--primary': 'Primary buttons',
  '--primary-foreground': 'Text on `--primary`',
  '--secondary': 'Secondary buttons',
  '--secondary-foreground': 'Text on `--secondary`',
  '--muted': 'Quiet fills',
  '--muted-foreground': 'Secondary text',
  '--accent': 'Hover and selected fills',
  '--accent-foreground': 'Text on `--accent`',
  '--border': 'Borders and separators',
  '--input': 'Input borders',
  '--ring': 'Focus rings',
  '--chart-1': 'Chart series 1',
  '--chart-2': 'Chart series 2',
  '--chart-3': 'Chart series 3',
  '--chart-4': 'Chart series 4',
  '--chart-5': 'Chart series 5',
  '--sidebar': 'Right sidebar and settings navigation',
  '--sidebar-foreground': 'Text on `--sidebar`',
  '--sidebar-primary': 'Primary controls in sidebars',
  '--sidebar-primary-foreground': 'Text on `--sidebar-primary`',
  '--sidebar-accent': 'Hover and selected rows in sidebars',
  '--sidebar-accent-foreground': 'Text on `--sidebar-accent`',
  '--sidebar-border': 'Sidebar borders',
  '--sidebar-ring': 'Focus rings in sidebars',
  '--worktree-sidebar': 'Left workspace sidebar',
  '--worktree-sidebar-foreground': 'Text on `--worktree-sidebar`',
  '--worktree-sidebar-accent': 'Hover and multi-selected rows in the workspace sidebar',
  '--worktree-sidebar-accent-foreground': 'Text on `--worktree-sidebar-accent`',
  '--worktree-sidebar-border': 'Workspace sidebar borders',
  '--worktree-sidebar-ring': 'Focus rings in the workspace sidebar',
  '--worktree-sidebar-active':
    'The current workspace row; may be translucent, it paints over `--worktree-sidebar`',
  '--worktree-sidebar-active-border': 'Border of the current workspace row',
  '--host-badge': 'Execution-host badge on workspaces (for example `Local`, an SSH host)',
  '--host-badge-foreground': 'Text on `--host-badge`',
  '--tab-bar': 'Strip behind tabs, including the title bar when tabs sit in it',
  '--tab-active': 'Active tab',
  '--tab-active-foreground': 'Active tab text, and inactive tab text on hover',
  '--tab-active-indicator': 'Line under the active tab',
  '--tab-inactive': 'Inactive tabs',
  '--tab-inactive-foreground': 'Inactive tab text',
  '--split-divider': 'Divider between split tab groups',
  '--split-divider-hover': 'Split divider while hovered or dragged',
  '--chat-user-message': 'Your messages in chat; may be translucent, it paints over the chat',
  '--text-link': 'Links in Markdown previews and editors',
  '--diff-added': 'Added-line hue: Monaco overview ruler and chat diff text',
  '--diff-added-background': 'Added lines in diffs',
  '--diff-added-emphasis': 'Added characters within a changed line',
  '--diff-added-gutter': 'Gutter beside added lines',
  '--diff-removed': 'Removed-line hue: Monaco overview ruler and chat diff text',
  '--diff-removed-background': 'Removed lines in diffs',
  '--diff-removed-emphasis': 'Removed characters within a changed line',
  '--diff-removed-gutter': 'Gutter beside removed lines',
  '--git-decoration-added': 'Added files in the file explorer and source control',
  '--git-decoration-modified': 'Modified files',
  '--git-decoration-deleted': 'Deleted files',
  '--git-decoration-renamed': 'Renamed files',
  '--git-decoration-untracked': 'Untracked files',
  '--git-decoration-copied': 'Copied files',
  '--git-decoration-ignored': 'Git-ignored files'
}

// Why: these mix per mode in main.css, which the derivation rules cannot express.
const MODE_MIXES: Partial<Record<PluginAppThemeToken, string>> = {
  '--worktree-sidebar-active': 'a translucent wash of `--worktree-sidebar-foreground`',
  '--worktree-sidebar-active-border': 'a mix of `--worktree-sidebar-border`',
  '--chat-user-message': '`--foreground` mixed lightly into the chat background'
}

/** What an omitted token becomes, read back from the real derivation with every other token
 *  standing in as `var(<name>)`, so the table cannot drift from what Orca applies. */
function omittedValueFor(token: PluginAppThemeToken, base: 'light' | 'dark'): string {
  const others = Object.fromEntries(
    PLUGIN_APP_THEME_TOKENS.filter((other) => other !== token).map((other) => [
      other,
      `var(${other})`
    ])
  )
  const cssFallback = pluginAppThemeCssFallback(token, base)
  if (cssFallback && 'tint' in cssFallback) {
    return `\`${cssFallback.tint}\` at ${cssFallback.percent}% opacity`
  }
  const derived = cssFallback
    ? 'mixForeground' in cssFallback
      ? `color-mix(in srgb, var(--foreground) ${cssFallback.mixForeground}%, var(${cssFallback.into ?? '--background'}))`
      : `var(${cssFallback[0]})`
    : completePluginAppThemeTokens(others)[token]
  if (derived === undefined) {
    return MODE_MIXES[token] ?? "Orca's built-in color"
  }
  const mix = /^color-mix\(in srgb, var\((--[\w-]+)\) (\d+)%, var\((--[\w-]+)\)\)$/.exec(derived)
  if (mix) {
    return `\`${mix[1]}\` mixed ${mix[2]}% into \`${mix[3]}\``
  }
  return derived.replace(/^var\((--[\w-]+)\)$/, 'same as `$1`')
}

function omittedValue(token: PluginAppThemeToken): string {
  const light = omittedValueFor(token, 'light')
  const dark = omittedValueFor(token, 'dark')
  return light === dark ? light : `light: ${light}; dark: ${dark}`
}

/** Colour token list for theme authors, rendered from the public token set. */
export function renderPluginThemeTokenReference(): string {
  const lines = [
    '# Orca app theme tokens',
    '',
    '<!-- Generated by `pnpm generate:plugin-schemas` from src/shared/plugins. Do not edit. -->',
    '',
    'Every key an app theme may set in `tokens` (see [plugin themes](plugin-themes.md)). Any other key is refused. An omitted token falls back as listed; when that source is omitted too, it falls back the same way in turn.',
    '',
    '| Token | Paints | Required | When omitted |',
    '| --- | --- | --- | --- |',
    ...PLUGIN_APP_THEME_TOKENS.map(
      (token) =>
        `| \`${token}\` | ${TOKEN_ROLES[token]} | ${REQUIRED.has(token) ? 'yes' : 'no'} | ${REQUIRED.has(token) ? '' : omittedValue(token)} |`
    )
  ]
  return `${lines.join('\n')}\n`
}