/**
 * Terminal Fonts Configuration
 *
 * `family` is the raw CSS font-family string for the Latin glyphs only.
 * CJK and icon fallbacks are composed at runtime by composeFontFamilyStack()
 * in cjkFonts.ts, which lets users pick the CJK font independently or have
 * one chosen automatically per Latin font.
 */

export interface TerminalFont {
  id: string;
  name: string;
  family: string;
  description: string;
  category: 'monospace' | 'proportional';
}

const BASE_TERMINAL_FONTS: TerminalFont[] = [
  // Existing Latin monospace fonts (ids unchanged for sync compatibility)
  { id: 'menlo',            name: 'Menlo',            family: 'Menlo, monospace',                description: 'macOS system font, clean and professional', category: 'monospace' },
  { id: 'monaco',           name: 'Monaco',           family: 'Monaco, monospace',               description: 'Classic monospace, excellent readability', category: 'monospace' },
  { id: 'consolas',         name: 'Consolas',         family: 'Consolas, monospace',             description: 'Windows-style monospace, clear and compact', category: 'monospace' },
  { id: 'courier-new',      name: 'Courier New',      family: '"Courier New", monospace',        description: 'Classic typewriter style, universal support', category: 'monospace' },
  { id: 'source-code-pro',  name: 'Source Code Pro',  family: '"Source Code Pro", monospace',    description: "Adobe's professional programming font", category: 'monospace' },
  { id: 'fira-code',        name: 'Fira Code',        family: '"Fira Code", monospace',          description: 'Monospace font with programming ligatures', category: 'monospace' },
  { id: 'fira-mono',        name: 'Fira Mono',        family: '"Fira Mono", monospace',          description: 'Clean monospace without ligatures', category: 'monospace' },
  { id: 'inconsolata',      name: 'Inconsolata',      family: 'Inconsolata, monospace',          description: 'Elegant and readable monospace font', category: 'monospace' },
  { id: 'dejavu-sans-mono', name: 'DejaVu Sans Mono', family: '"DejaVu Sans Mono", monospace',   description: 'Wide character support, very readable', category: 'monospace' },
  { id: 'liberation-mono',  name: 'Liberation Mono',  family: '"Liberation Mono", monospace',    description: 'Open source monospace font, Courier alternative', category: 'monospace' },
  { id: 'jetbrains-mono',   name: 'JetBrains Mono',   family: '"JetBrains Mono", monospace',     description: 'Professional font designed for IDEs', category: 'monospace' },
  { id: 'victor-mono',      name: 'Victor Mono',      family: '"Victor Mono", monospace',        description: 'Stylish monospace with italic support', category: 'monospace' },
  { id: 'cascadia-code',    name: 'Cascadia Code',    family: '"Cascadia Code", monospace',      description: "Microsoft's modern monospace font", category: 'monospace' },
  { id: 'cascadia-mono',    name: 'Cascadia Mono',    family: '"Cascadia Mono", monospace',      description: 'Cascadia without ligatures', category: 'monospace' },
  { id: 'droid-sans-mono',  name: 'Droid Sans Mono',  family: '"Droid Sans Mono", monospace',    description: "Google's Droid monospace font", category: 'monospace' },
  { id: 'ubuntu-mono',      name: 'Ubuntu Mono',      family: '"Ubuntu Mono", monospace',        description: "Ubuntu's official monospace font", category: 'monospace' },
  { id: 'roboto-mono',      name: 'Roboto Mono',      family: '"Roboto Mono", monospace',        description: "Google's Roboto monospace variant", category: 'monospace' },
  { id: 'ibm-plex-mono',    name: 'IBM Plex Mono',    family: '"IBM Plex Mono", monospace',      description: "IBM's professional monospace font", category: 'monospace' },
  { id: 'space-mono',       name: 'Space Mono',       family: '"Space Mono", monospace',         description: 'Geometric monospace with strong personality', category: 'monospace' },
  { id: 'input-mono',       name: 'Input Mono',       family: '"Input Mono", monospace',         description: 'Designed specifically for coding', category: 'monospace' },
  { id: 'hack',             name: 'Hack',             family: 'Hack, monospace',                 description: 'Designed for source code, excellent in terminals', category: 'monospace' },
  { id: 'anonymous-pro',    name: 'Anonymous Pro',    family: '"Anonymous Pro", monospace',      description: 'Designed for coding and terminal use', category: 'monospace' },
  { id: 'programmer-fonts', name: 'Programmer Fonts', family: '"Programmer Fonts", monospace',   description: 'Optimized for programming with clear glyphs', category: 'monospace' },
  { id: 'pt-mono',          name: 'PT Mono',          family: '"PT Mono", monospace',            description: "ParaType's monospace font", category: 'monospace' },
  { id: 'iosevka',          name: 'Iosevka',          family: 'Iosevka, monospace',              description: 'Highly customizable monospace font', category: 'monospace' },
  { id: 'ioskeley-mono',    name: 'Ioskeley Mono',    family: '"Ioskeley Mono", monospace',      description: 'Iosevka variant mimicking Berkeley Mono style', category: 'monospace' },
  { id: 'mononoki',         name: 'Mononoki',         family: 'Mononoki, monospace',             description: 'Crisp and clear monospace with ligatures', category: 'monospace' },
  { id: 'go-mono',          name: 'Go Mono',          family: '"Go Mono", monospace',            description: "Google Go's monospace font", category: 'monospace' },
  { id: 'overpass-mono',    name: 'Overpass Mono',    family: '"Overpass Mono", monospace',      description: 'Open source monospace with good coverage', category: 'monospace' },

  // True monospace CJK-coverage fonts only. PingFang SC and Microsoft
  // YaHei UI (the OS system fonts) are deliberately omitted — they are
  // proportional sans-serif designs whose Latin glyphs render with
  // variable widths and whose CJK glyphs don't fit a terminal's 2x cell
  // grid. Picking one as the primary font produced visibly bloated
  // spacing for ASCII characters in #931.
  { id: 'sarasa-mono-sc',   name: 'Sarasa Mono SC',   family: '"Sarasa Mono SC", monospace',   description: 'Iosevka + Source Han Sans (Simplified Chinese), 2:1 monospace', category: 'monospace' },
  { id: 'sarasa-mono-tc',   name: 'Sarasa Mono TC',   family: '"Sarasa Mono TC", monospace',   description: 'Iosevka + Source Han Sans (Traditional Chinese), 2:1 monospace', category: 'monospace' },
  { id: 'maple-mono-cn',    name: 'Maple Mono CN',    family: '"Maple Mono CN", monospace',    description: 'Maple Mono with unified Latin + Simplified Chinese metrics', category: 'monospace' },
  { id: 'lxgw-wenkai-mono', name: 'LXGW WenKai Mono', family: '"LXGW WenKai Mono", monospace', description: 'Monospace Kaishu (regular-script) derived from Fontworks Klee One', category: 'monospace' },
];

export const TERMINAL_FONTS: TerminalFont[] = BASE_TERMINAL_FONTS;

export const DEFAULT_FONT_SIZE = 14;
export const MIN_FONT_SIZE = 10;
export const MAX_FONT_SIZE = 32;

export type FontPlatform = 'darwin' | 'win32' | 'linux' | (string & {});

/**
 * The default terminal font id for a given OS. Chosen so the primary
 * Latin glyphs render with a font that ships with the OS — avoiding the
 * cold-start cell-misalignment in #1647, where a bundled webfont
 * (JetBrains Mono, font-display: swap) swapped in *after* xterm measured
 * the cell grid and left ASCII garbled until a manual window resize.
 *
 *   - darwin: Menlo is a macOS system font (instant, no swap).
 *   - win32:  Consolas ships with every Windows since Vista.
 *   - linux:  DejaVu Sans Mono is the most widely pre-installed Linux
 *             monospace; if a given distro lacks it, the runtime font-ready
 *             remeasure (useTerminalEffects) still recovers any swap.
 *
 * Unknown platforms fall back to the macOS default.
 */
export function getDefaultTerminalFontIdForPlatform(platform: FontPlatform): string {
  if (platform === 'win32') return 'consolas';
  if (platform === 'linux') return 'dejavu-sans-mono';
  return 'menlo';
}

/**
 * Normalize a `navigator.platform` string to the coarse OS buckets used
 * by getDefaultTerminalFontIdForPlatform. Mirrors the detection already
 * used for the CJK fallback stack in Terminal.tsx (Mac/Win regex on
 * navigator.platform); anything else — including Linux — is `linux`.
 */
export function detectFontPlatform(navigatorPlatform: string): FontPlatform {
  if (/Win/i.test(navigatorPlatform)) return 'win32';
  if (/Mac|iPhone|iPad|iPod/i.test(navigatorPlatform)) return 'darwin';
  return 'linux';
}

/**
 * The stored sentinel meaning "follow the OS default font". It is
 * persisted and cloud-synced as-is (platform-neutral), so each device
 * resolves it to its own locally-installed default at render time —
 * unlike a concrete platform id, which would leak one OS's font to
 * another via sync and reintroduce #1647 on the receiving machine.
 */
export const TERMINAL_FONT_AUTO = 'auto';

/**
 * Resolve a stored terminal font id to a concrete font id. The `auto`
 * sentinel (and any empty/nullish value) resolves to the per-platform
 * default; an explicit user choice is returned unchanged.
 */
export function resolveTerminalFontFamilyId(
  id: string | null | undefined,
  navigatorPlatform: string,
): string {
  if (id && id !== TERMINAL_FONT_AUTO) return id;
  return getDefaultTerminalFontIdForPlatform(detectFontPlatform(navigatorPlatform));
}

/**
 * Whether two terminal font ids resolve to the same concrete font on this
 * platform. Font pickers display the resolved concrete font for an `auto`
 * value, so a click on the shown default arrives as that concrete id while
 * the stored value is still `auto`; comparing raw would treat it as a
 * change and pin a per-OS font (which then syncs across devices). Comparing
 * resolved ids makes that click a correct no-op.
 */
export function isSameResolvedTerminalFont(
  a: string | null | undefined,
  b: string | null | undefined,
  navigatorPlatform: string,
): boolean {
  return (
    resolveTerminalFontFamilyId(a, navigatorPlatform) ===
    resolveTerminalFontFamilyId(b, navigatorPlatform)
  );
}

// Font ids that earlier versions of netcatty exposed in the primary font
// dropdown but that are proportional (non-monospace) and produce broken
// cell-grid alignment when used as a terminal font. Reads should migrate
// these to a sane default.
const DEPRECATED_PRIMARY_FONT_IDS = new Set<string>([
  'pingfang-sc',
  'microsoft-yahei',
  'comic-sans-ms',
]);

export function isDeprecatedPrimaryFontId(fontId: string | null | undefined): boolean {
  return !!fontId && DEPRECATED_PRIMARY_FONT_IDS.has(fontId);
}

/**
 * In-place migration for any object carrying `fontFamily` /
 * `fontFamilyOverride` (Host, GroupConfig). When the saved id is one
 * we've since removed from TERMINAL_FONTS, drop the override so the
 * record inherits the global default rather than silently rendering
 * "fallback to fonts[0]" while still claiming an override is active.
 *
 * Returns the (possibly new) value to assign back. Caller decides
 * whether to mutate or copy; both are safe with this shape.
 */
export function migrateDeprecatedFontOverride<
  T extends { fontFamily?: string; fontFamilyOverride?: boolean },
>(record: T): T {
  if (!isDeprecatedPrimaryFontId(record.fontFamily)) return record;
  const next = { ...record };
  delete next.fontFamily;
  if (next.fontFamilyOverride === true) {
    next.fontFamilyOverride = false;
  }
  return next;
}