import { mkdir, rm, writeFile } from "node:fs/promises";
import path from "node:path";
import { createRequire } from "node:module";
import { fileURLToPath } from "node:url";
import { emojis as tiptapEmojis, type EmojiItem } from "@tiptap/extension-emoji";

const require = createRequire(import.meta.url);

interface EmojibaseItem {
  emoji?: string;
  group?: number;
}

const APPLE_ASSET_PREFIX = "https://cdn.jsdelivr.net/npm/emoji-datasource-apple/img/apple/64/";
const VARIATION_SELECTOR_RE = /[\uFE0E\uFE0F]/gu;
const __dirname = path.dirname(fileURLToPath(import.meta.url));
const sharedGeneratedDir = path.resolve(__dirname, "../src/shared/emoji/generated");
const clientGeneratedDir = path.resolve(__dirname, "../src/client/lib/emoji/generated");

function normalizeEmoji(emoji: string): string {
  return emoji.replace(VARIATION_SELECTOR_RE, "");
}

function getAppleAssetName(item: EmojiItem): string | null {
  if (!item.fallbackImage?.startsWith(APPLE_ASSET_PREFIX)) {
    return null;
  }

  return item.fallbackImage.slice(APPLE_ASSET_PREFIX.length);
}

function renderModule(header: string, value: unknown): string {
  return `${header}${JSON.stringify(value, null, 2)} as const;\n`;
}

async function main() {
  const emojibaseData = require("emojibase-data/en/data.json") as EmojibaseItem[];
  const emojibaseMessages = require("emojibase-data/en/messages.json") as {
    groups: Record<string, { message?: string }>;
  };
  const iconData: Record<string, string> = {};
  const groupOverrides: Record<string, string> = {};
  const baseEmojiMap = new Map<string, EmojiItem>();

  for (const item of tiptapEmojis) {
    if (!item.emoji) continue;

    const normalizedEmoji = normalizeEmoji(item.emoji);
    baseEmojiMap.set(normalizedEmoji, item);

    const asset = getAppleAssetName(item);
    if (asset) {
      iconData[normalizedEmoji] = asset;
    }
  }

  for (const emojibaseItem of emojibaseData) {
    if (!emojibaseItem.emoji) {
      continue;
    }

    const baseEmoji = normalizeEmoji(emojibaseItem.emoji);
    const baseItem = baseEmojiMap.get(baseEmoji);
    if (!baseItem) continue;

    const groupMessage =
      typeof emojibaseItem.group === "number"
        ? (emojibaseMessages.groups[String(emojibaseItem.group)]?.message ?? "")
        : "";
    if (!baseItem.group && groupMessage) {
      groupOverrides[baseEmoji] = groupMessage;
    }
  }

  await mkdir(sharedGeneratedDir, { recursive: true });
  await mkdir(clientGeneratedDir, { recursive: true });

  await writeFile(
    path.join(sharedGeneratedDir, "emoji-icon-data.ts"),
    renderModule(
      `// This file is generated by scripts/generate-emoji-data.ts\n\nexport const EMOJI_ICON_DATA = `,
      iconData,
    ),
  );

  await writeFile(
    path.join(clientGeneratedDir, "emoji-group-overrides.ts"),
    renderModule(
      `// This file is generated by scripts/generate-emoji-data.ts\n\nexport const EMOJI_GROUP_OVERRIDES = `,
      groupOverrides,
    ),
  );

  // Older versions of this script wrote both maps under the client directory.
  // Clean up the stale icon-data file if a previous checkout still has it so
  // it does not shadow the shared module via tsconfig path resolution.
  await rm(path.join(clientGeneratedDir, "emoji-icon-data.ts"), { force: true });
  await rm(path.join(clientGeneratedDir, "emoji-tone-variants.ts"), { force: true });
}

await main();