import { describe, it, expect } from 'vitest'
import Database from 'better-sqlite3'
import { openDatabase, migrateUpgrades } from '../src/db.js'

/** Builds a pre-v2 database (plan-1 schema, no version row, no new columns). */
function legacyDb(): Database.Database {
  const db = new Database(':memory:')
  db.pragma('journal_mode = WAL')
  db.pragma('foreign_keys = ON')
  db.exec(`
    CREATE TABLE app_meta (key TEXT PRIMARY KEY, value TEXT NOT NULL);
    CREATE TABLE users (id INTEGER PRIMARY KEY AUTOINCREMENT, username TEXT NOT NULL UNIQUE, password_hash TEXT NOT NULL, is_admin INTEGER NOT NULL DEFAULT 0, created_at TEXT NOT NULL DEFAULT (datetime('now')));
    CREATE TABLE sessions (token TEXT PRIMARY KEY, user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE, created_at TEXT NOT NULL DEFAULT (datetime('now')), expires_at TEXT NOT NULL);
    CREATE TABLE settings (user_id INTEGER PRIMARY KEY REFERENCES users(id) ON DELETE CASCADE, discogs_token TEXT, subsonic_url TEXT, subsonic_username TEXT, subsonic_password TEXT);
    CREATE TABLE collection_items (id INTEGER PRIMARY KEY AUTOINCREMENT, user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE, discogs_release_id INTEGER NOT NULL, title TEXT NOT NULL, artist TEXT NOT NULL, year INTEGER, formats TEXT NOT NULL DEFAULT '[]', genres TEXT NOT NULL DEFAULT '[]', labels TEXT NOT NULL DEFAULT '[]', tracklist TEXT NOT NULL DEFAULT '[]', catno TEXT, country TEXT, cover_url TEXT, local_artwork_path TEXT, barcodes TEXT NOT NULL DEFAULT '[]', rip_override INTEGER, date_added TEXT NOT NULL DEFAULT (datetime('now')), UNIQUE (user_id, discogs_release_id));
    CREATE TABLE digital_albums (id INTEGER PRIMARY KEY AUTOINCREMENT, user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE, subsonic_id TEXT NOT NULL, title TEXT NOT NULL, artist TEXT NOT NULL, UNIQUE (user_id, subsonic_id));
    CREATE TABLE match_links (user_id INTEGER NOT NULL, item_id INTEGER NOT NULL REFERENCES collection_items(id) ON DELETE CASCADE, album_id INTEGER NOT NULL REFERENCES digital_albums(id) ON DELETE CASCADE, PRIMARY KEY (user_id, item_id));
    INSERT INTO users (id, username, password_hash, is_admin) VALUES (1, 'sam', 'x', 1);
    INSERT INTO digital_albums (id, user_id, subsonic_id, title, artist) VALUES (1, 1, 'a1', 'Motion', 'The Cinematic Orchestra');
  `)
  return db
}

function columns(db: Database.Database, table: string): string[] {
  return (db.prepare(`PRAGMA table_info(${table})`).all() as { name: string }[]).map((c) => c.name)
}

describe('schema migration v2', () => {
  it('migrates a legacy database: loans table, last_played_at, version row', () => {
    const db = legacyDb()
    migrateUpgrades(db)
    expect(columns(db, 'digital_albums')).toContain('last_played_at')
    expect(columns(db, 'loans')).toEqual([
      'id',
      'user_id',
      'item_id',
      'borrower',
      'lent_at',
      'returned_at',
    ])
    const version = db.prepare("SELECT value FROM app_meta WHERE key = 'schema_version'").get()
    expect(version).toEqual({ value: '2' })
    // existing data survives
    expect(db.prepare('SELECT title FROM digital_albums').get()).toEqual({ title: 'Motion' })
  })

  it('openDatabase creates a fresh v2 database directly', () => {
    const db = openDatabase(':memory:')
    expect(columns(db, 'digital_albums')).toContain('last_played_at')
    expect(columns(db, 'loans')).toContain('borrower')
    const version = db.prepare("SELECT value FROM app_meta WHERE key = 'schema_version'").get()
    expect(version).toEqual({ value: '2' })
  })

  it('migrations are idempotent', () => {
    const db = openDatabase(':memory:')
    expect(() => migrateUpgrades(db)).not.toThrow()
    expect(
      (db.prepare("SELECT value FROM app_meta WHERE key = 'schema_version'").get() as { value: string }).value
    ).toBe('2')
  })
})