import { Pool, type PoolClient } from 'pg'
import { afterAll, beforeAll } from 'vitest'

// Shared pool for the pg-real project. DATABASE_URL must point at a Postgres
// instance that already has every migration from supabase/migrations/ applied
// and that includes the Supabase `auth` schema (supabase/postgres image).
const databaseUrl =
  process.env.DATABASE_URL ?? 'postgresql://postgres:postgres@localhost:5432/postgres'

let pool: Pool | null = null

export function getPool(): Pool {
  if (!pool) {
    pool = new Pool({ connectionString: databaseUrl, max: 8 })
  }
  return pool
}

// Acquire a fresh client. Caller must always .release().
export async function getClient(): Promise<PoolClient> {
  return getPool().connect()
}

// Run `fn` inside a role/JWT context that auth.uid() / user_company_ids() will
// observe. Uses SET LOCAL inside a transaction so the role reverts on commit
// or rollback. Always rolls back so the test's writes do not persist: tests
// that need to seed data must do that on the superuser connection first.
export async function withUserContext<T>(
  userId: string,
  fn: (client: PoolClient) => Promise<T>,
): Promise<T> {
  const client = await getClient()
  try {
    await client.query('BEGIN')
    // Set JWT claims BEFORE switching role: non-superuser set_config on a
    // namespaced GUC is fine, but keeping order explicit avoids surprises.
    // Set both the whole-claims object and the individual `sub` claim:
    // different versions of Supabase's auth.uid() read one or the other.
    await client.query(`SELECT set_config('request.jwt.claims', $1, true)`, [
      JSON.stringify({ sub: userId, role: 'authenticated' }),
    ])
    await client.query(`SELECT set_config('request.jwt.claim.sub', $1, true)`, [userId])
    await client.query(`SET LOCAL ROLE authenticated`)
    // Fail loudly and early if the JWT context did not land the way we
    // expect: otherwise RLS policies return empty and the real test
    // failure points at an unrelated assertion.
    const authCheck = await client.query<{ uid: string | null }>(
      `SELECT auth.uid()::text AS uid`,
    )
    if (authCheck.rows[0]?.uid !== userId) {
      throw new Error(
        `withUserContext: auth.uid() resolved to ${authCheck.rows[0]?.uid ?? 'NULL'}, ` +
          `expected ${userId}. Check request.jwt.claims setup.`,
      )
    }
    const result = await fn(client)
    await client.query('ROLLBACK')
    return result
  } catch (err) {
    await client.query('ROLLBACK').catch(() => {})
    throw err
  } finally {
    client.release()
  }
}

// Schema sanity: fail loud if migrations did not apply, rather than letting
// every test fail with a cryptic "relation does not exist". Runs once per
// test file (vitest invokes setupFiles per worker).
beforeAll(async () => {
  const client = await getClient()
  try {
    const result = await client.query<{ name: string; kind: 'trigger' | 'function' | 'table' }>(`
      SELECT 'trigger'::text AS kind, tgname AS name FROM pg_trigger
        WHERE tgname IN ('enforce_period_lock', 'audit_log_no_update')
      UNION ALL
      SELECT 'function'::text, proname FROM pg_proc
        WHERE proname IN ('commit_journal_entry', 'user_company_ids', 'audit_log_immutable')
      UNION ALL
      SELECT 'table'::text, tablename FROM pg_tables
        WHERE schemaname = 'public'
          AND tablename IN ('journal_entries', 'companies', 'company_members',
                            'fiscal_periods', 'audit_log', 'voucher_sequences')
    `)
    const found = new Set(result.rows.map((r) => `${r.kind}:${r.name}`))
    const required = [
      'trigger:enforce_period_lock',
      'trigger:audit_log_no_update',
      'function:commit_journal_entry',
      'function:user_company_ids',
      'function:audit_log_immutable',
      'table:journal_entries',
      'table:companies',
      'table:company_members',
      'table:fiscal_periods',
      'table:audit_log',
      'table:voucher_sequences',
    ]
    const missing = required.filter((r) => !found.has(r))
    if (missing.length > 0) {
      throw new Error(
        `pg-real schema sanity check failed. Missing: ${missing.join(', ')}. ` +
          `Did every migration in supabase/migrations/ apply cleanly to ${databaseUrl}?`,
      )
    }
  } finally {
    client.release()
  }
})

afterAll(async () => {
  if (pool) {
    await pool.end()
    pool = null
  }
})