/**
 * Migration Script: V1 → V2 Database
 * -----------------------------------
 * This script migrates VTuber and VOD data from an old Postgres database (V1) into the new Prisma-backed database (V2).
 *
 * Usage:
 *   - Ensure environment variables are configured for both databases:
 *       V1_DB_HOST        Hostname of the V1 database (default: "localhost")
 *       V1_DB_PORT        Port of the V1 database (default: "5444")
 *       V1_DB_USER        Username for the V1 database (default: "postgres")
 *       V1_DB_PASS        Password for the V1 database (default: "password")
 *       V1_DB_NAME        Database name for V1 (default: "restoredb")
 *       DEFAULT_UPLOADER_ID
 *                        An existing user ID in the V2 database that will be set as the uploader for all migrated records.
 *
 * What it does:
 *   1. Migrates VTubers:
 *      - Reads all rows from `vtubers` in V1.
 *      - Inserts each into V2’s `vtuber` table using Prisma.
 *      - Maps all known fields (social links, images, themeColor, etc.).
 *      - Combines `description_1` and `description_2` into a single `description` field.
 *      - Assigns the `DEFAULT_UPLOADER_ID` to each migrated VTuber.
 *
 *   2. Migrates VODs:
 *      - Reads all rows from `vods` in V1.
 *      - Resolves associated VTubers via `vods_vtuber_links` → `vtubers.slug`.
 *      - Finds related thumbnails and source video links via `vods_thumbnail_links` and `vods_video_src_b_2_links`.
 *      - Inserts each VOD into V2’s `vod` table, connecting it to the corresponding VTubers by slug.
 *      - Assigns the `DEFAULT_UPLOADER_ID` to each migrated VOD.
 *
 * Notes:
 *   - This script assumes schema compatibility between V1 and V2 (field names may differ slightly).
 *   - Thumbnails and video source links fall back to `cdn_url` or `url` if available.
 *   - Any V1 records with missing or null values are gracefully handled with `null` fallbacks.
 *   - Run this script once; re-running may cause duplicate records unless unique constraints prevent it.
 *
 * Execution:
 *   Run with Node.js:
 *     $ npx @dotenvx/dotenvx run -f ./.env -- tsx ./migrate.ts
 *
 * Cleanup:
 *   - Connections to both the V1 database (pg.Pool) and Prisma client are properly closed at the end of execution.
 */



import { PrismaClient } from '../generated/prisma';
import pg from 'pg';

const prisma = new PrismaClient();

const v1 = new pg.Pool({
  host: process.env.V1_DB_HOST || 'localhost',
  port: +(process.env.V1_DB_PORT || '5444'),
  user: process.env.V1_DB_USER || 'postgres',
  password: process.env.V1_DB_PASS || 'password',
  database: process.env.V1_DB_NAME || 'restoredb'
});

// Set this to an existing user ID in v2
const DEFAULT_UPLOADER_ID = process.env.DEFAULT_UPLOADER_ID || 'REPLACE_WITH_V2_USER_ID';

async function migrateVtubers() {
  console.log('Migrating vtubers...');
  const res = await v1.query(`SELECT * FROM vtubers`);
  for (const vt of res.rows) {
    await prisma.vtuber.create({
      data: {
        slug: vt.slug,
        image: vt.image,
        displayName: vt.display_name,
        chaturbate: vt.chaturbate,
        twitter: vt.twitter,
        patreon: vt.patreon,
        twitch: vt.twitch,
        tiktok: vt.tiktok,
        onlyfans: vt.onlyfans,
        youtube: vt.youtube,
        linktree: vt.linktree,
        carrd: vt.carrd,
        fansly: vt.fansly,
        pornhub: vt.pornhub,
        discord: vt.discord,
        reddit: vt.reddit,
        throne: vt.throne,
        instagram: vt.instagram,
        facebook: vt.facebook,
        merch: vt.merch,
        description: `${vt.description_1 ?? ''}\n${vt.description_2 ?? ''}`.trim() || null,
        themeColor: vt.theme_color,
        uploaderId: DEFAULT_UPLOADER_ID
      }
    });
  }
  console.log(`Migrated ${res.rows.length} vtubers`);
}

async function migrateVods() {
  console.log('Migrating vods...');
  const vods = await v1.query(`SELECT * FROM vods`);

  for (const vod of vods.rows) {
    // Get linked vtubers
    const vtuberLinks = await v1.query(
      `SELECT vtuber_id FROM vods_vtuber_links WHERE vod_id = $1`,
      [vod.id]
    );

    let vtuberSlugs: string[] = [];
    if (vtuberLinks.rows.length > 0) {
      const vtuberRes = await v1.query(
        `SELECT slug FROM vtubers WHERE id = ANY($1)`,
        [vtuberLinks.rows.map(r => r.vtuber_id)]
      );
      vtuberSlugs = vtuberRes.rows.map(v => v.slug).filter(Boolean);
    }

    // Get thumbnail
    const thumbLink = await v1.query(
      `SELECT b2.cdn_url, b2.url FROM vods_thumbnail_links vtl
       JOIN b2_files b2 ON vtl.b_2_file_id = b2.id
       WHERE vtl.vod_id = $1 LIMIT 1`,
      [vod.id]
    );

    // Get source video
    const videoSrcLink = await v1.query(
      `SELECT b2.cdn_url, b2.url FROM vods_video_src_b_2_links vsl
       JOIN b2_files b2 ON vsl.b_2_file_id = b2.id
       WHERE vsl.vod_id = $1 LIMIT 1`,
      [vod.id]
    );

    await prisma.vod.create({
      data: {
        uploaderId: DEFAULT_UPLOADER_ID,
        streamDate: vod.date ?? new Date(),
        notes: vod.note,
        sourceVideo: videoSrcLink.rows[0]?.cdn_url || videoSrcLink.rows[0]?.url || null,
        thumbnail: thumbLink.rows[0]?.cdn_url || thumbLink.rows[0]?.url || null,
        vtubers: {
          connect: vtuberSlugs.map(slug => ({ slug }))
        }
      }
    });
  }

  console.log(`Migrated ${vods.rows.length} vods`);
}

async function main() {
  try {
    await migrateVtubers();
    await migrateVods();
  } catch (err) {
    console.error(err);
  } finally {
    await v1.end();
    await prisma.$disconnect();
  }
}

main();