import { readFileSync } from 'node:fs';

// Reading an Omarchy theme's `colors.toml`.
//
// Omarchy 4 ships a genuinely semantic palette rather than sixteen ANSI slots: three background depths,
// four foreground weights, an accent, a selection and a muted, plus the named hues. That is why this port
// can be a mapping at all — the previous one had to guess, and the guessing is what produced themes with
// no surfaces and unreadable highlights.
//
// Verified across all 22 themes in basecamp/omarchy@master: every one declares the 24 keys below.

export type Palette = {
  mode: 'dark' | 'light';
  accent: string;
  selection: string;
  muted: string;
  background: string;
  darkBackground: string;
  darkerBackground: string;
  lighterBackground: string;
  foreground: string;
  darkForeground: string;
  lightForeground: string;
  brightForeground: string;
  red: string;
  yellow: string;
  green: string;
  cyan: string;
  blue: string;
  magenta: string;
  /** Not in every theme — 19 of 22. Falls back to yellow-red mid, which is what orange is. */
  orange: string;
  brightRed: string;
  brightYellow: string;
  brightGreen: string;
  brightCyan: string;
  brightBlue: string;
  brightMagenta: string;
};

/**
 * A deliberately small TOML reader: this file is flat `key = "value"` and nothing else.
 *
 * Exported (not just used by `loadPalette` below) because a community theme can ship this exact shape
 * too — see `port-community-themes.ts`, which reads it from a fetched string rather than a file path.
 */
export function parseTomlText(text: string): Record<string, string> {
  const out: Record<string, string> = {};
  for (const line of text.split('\n')) {
    const m = line.match(/^\s*([a-z_0-9]+)\s*=\s*"([^"]*)"/i);
    // basecamp/omarchy's own files are already lowercase hex; a community `colors.toml` isn't guaranteed
    // to be, so normalize here rather than leaving the two sources visibly inconsistent.
    if (m) out[m[1]!] = m[2]!.toLowerCase();
  }
  return out;
}

/** The 24-key contract, given an already-parsed record rather than a path — see `parseTomlText`. */
export function paletteFromRecord(t: Record<string, string>, label: string): Palette {
  const need = (key: string): string => {
    const v = t[key];
    if (!v) throw new Error(`${label}: missing "${key}"`);
    return v;
  };

  return {
    mode: t.mode === 'light' ? 'light' : 'dark',
    accent: need('accent'),
    selection: need('selection'),
    muted: need('muted'),
    background: need('background'),
    darkBackground: need('dark_background'),
    darkerBackground: need('darker_background'),
    lighterBackground: need('lighter_background'),
    foreground: need('foreground'),
    darkForeground: need('dark_foreground'),
    lightForeground: need('light_foreground'),
    brightForeground: need('bright_foreground'),
    red: need('red'),
    yellow: need('yellow'),
    green: need('green'),
    cyan: need('cyan'),
    blue: need('blue'),
    magenta: need('magenta'),
    orange: t.orange ?? need('yellow'),
    brightRed: need('bright_red'),
    brightYellow: need('bright_yellow'),
    brightGreen: need('bright_green'),
    brightCyan: need('bright_cyan'),
    brightBlue: need('bright_blue'),
    brightMagenta: need('bright_magenta'),
  };
}

export function loadPalette(tomlPath: string): Palette {
  return paletteFromRecord(parseTomlText(readFileSync(tomlPath, 'utf8')), tomlPath);
}