import type { Database } from "sql.js";

const migrations = [m01_initial];

export default async function executeMigrations(db: Database) {
  // Check last migration status
  const migrationsWithNames = migrations.map<
    [string, (_: Database) => Promise<void>]
  >((func) => [func.name, func]);
  let startMigrationAt = 0;

  try {
    const rows = await db.exec("SELECT name FROM _migrations LIMIT 1");
    if (rows.length < 1) throw new Error("wtf");
    const migrationStatus = rows?.[0];
    const lastMigrationName = migrationStatus.values[0][0];
    console.log("status", migrationStatus);
    if (lastMigrationName) {
      const foundIndex = migrationsWithNames.findIndex(
        ([name]) => name === migrationStatus.values[0][0],
      );
      if (foundIndex >= 0) startMigrationAt = foundIndex + 1;
    }
  } catch (e) {
    // Don't have the table
    await db.run("BEGIN TRANSACTION");
    await db.run(`
      CREATE TABLE IF NOT EXISTS _migrations (name TEXT PRIMARY KEY);
      INSERT INTO _migrations (name) VALUES (NULL);

      CREATE TABLE IF NOT EXISTS _appDataVersion (version INTEGER PRIMARY KEY);
      INSERT INTO _appDataVersion (version) VALUES (0);
    `);
    await db.exec("COMMIT TRANSACTION");
    console.log("Created table.");
  }

  console.log(migrationsWithNames);
  console.log(startMigrationAt);

  const migrationsToRun = migrationsWithNames.slice(startMigrationAt);
  console.log(`Running ${migrationsToRun.length} migrations...`);
  for (const [name, migration] of migrationsToRun) {
    console.log("Running migration", name);
    await db.exec("BEGIN TRANSACTION");
    await migration(db);
    await db.exec("UPDATE _migrations SET name = $name", { $name: name });
    await db.exec("COMMIT TRANSACTION");
  }
}

async function m01_initial(db: Database) {
  db.exec(`
    CREATE TABLE charts (
      chart_id INTEGER PRIMARY KEY AUTOINCREMENT,
      artist TEXT,
      title TEXT,
      difficulty TEXT,
      banner_image TEXT
    );

    CREATE TABLE scores (
      score_id INTEGER PRIMARY KEY AUTOINCREMENT,
      chart_id INTEGER,
      
      FOREIGN KEY (chart_id) REFERENCES charts(chart_id)
    );

    CREATE TABLE banners (
      name TEXT PRIMARY KEY
    )
  `);
}