// Go-live data carry-over: copies every row from the local SQLite dev database into the
// target (cloud) Postgres database, preserving values and ids as-is — this is a one-time
// full copy, not the "born in Postgres" empty-start path in docs/DEPLOY-HQ.md.
// Column types are a straight 1:1 map on this schema (money is bigint paise, flags stay
// integer, JSON payloads stay text — see migrations-pg.ts header), so no value conversion
// is needed; every column is copied through unchanged.
// Refuses to run if the target already has staff_user rows, so a re-run (or pointing at
// the wrong DATABASE_URL) can't silently duplicate or clobber data.
// stg_client/stg_invoice are APEX-import scratch tables, not real data — skipped.
//
// Run from repo root, source = local ./data/hq.db (or HQ_DATA_DIR), target = DATABASE_URL:
//   DATABASE_URL=postgres://postgres:<pw>@<host>:5432/hq npx tsx apps/hq/scripts/migrate-sqlite-to-pg.ts
import { openDb, type SqliteDb } from '../src/db'
import { openPgDb, type PgDb } from '../src/db-pg'

const SKIP_TABLES = new Set(['stg_client', 'stg_invoice', 'schema_migrations'])

async function main(): Promise<void> {
  const pgUrl = process.env['DATABASE_URL']
  if (pgUrl === undefined || pgUrl === '') {
    throw new Error('Set DATABASE_URL to the target (cloud) Postgres connection string.')
  }

  const sqlite = openDb(process.env['HQ_DATA_DIR']) as SqliteDb
  const pg = (await openPgDb(pgUrl)) as PgDb // schema is created by migrations here; seedIfEmpty is NOT called

  const existingStaff = (await pg.get<{ n: number }>(`SELECT COUNT(*) AS n FROM staff_user`))!.n
  if (existingStaff > 0) {
    throw new Error(
      `Target already has ${existingStaff} staff_user row(s) — refusing to import over existing data. ` +
        `Wrong DATABASE_URL, or this has already been migrated.`,
    )
  }

  const tables = sqlite.raw
    .prepare(`SELECT name FROM sqlite_master WHERE type='table' AND name NOT LIKE 'sqlite_%'`)
    .all() as { name: string }[]

  const client = await pg.pool.connect()
  try {
    await client.query('BEGIN')
    // Load in table-discovery order and ignore FK/trigger checks — safe here because the
    // whole load is one transaction into a database we just confirmed is empty.
    await client.query('SET LOCAL session_replication_role = replica')
    for (const { name } of tables) {
      if (SKIP_TABLES.has(name)) {
        console.log(`skip   ${name}`)
        continue
      }
      const rows = sqlite.raw.prepare(`SELECT * FROM ${name}`).all() as Record<string, unknown>[]
      if (rows.length === 0) {
        console.log(`${name}: 0 rows`)
        continue
      }
      const cols = Object.keys(rows[0]!)
      const placeholders = cols.map((_, i) => `$${i + 1}`).join(',')
      const insertSql = `INSERT INTO ${name} (${cols.join(',')}) VALUES (${placeholders})`
      for (const row of rows) {
        await client.query(insertSql, cols.map((c) => row[c]))
      }
      console.log(`${name}: ${rows.length} row(s) migrated`)
    }
    await client.query('COMMIT')
  } catch (err) {
    await client.query('ROLLBACK')
    throw err
  } finally {
    client.release()
  }
  console.log('Migration complete.')
}

main().catch((e: unknown) => {
  console.error(e)
  process.exit(1)
})