package db

import (
	"context"
	"os"
	"strings"
	"sync"
	"testing"

	"github.com/jackc/pgx/v5/pgxpool"
)

var (
	migrateOnceMu sync.Mutex
	migratedDSNs  = map[string]error{}
)

// RunMigrationsOnceForTest 同一 DSN 只迁一次，避免并行包抢同一隔离库。
func RunMigrationsOnceForTest(ctx context.Context, pool *pgxpool.Pool, dsn string) error {
	key := strings.TrimSpace(dsn)
	migrateOnceMu.Lock()
	defer migrateOnceMu.Unlock()
	if err, ok := migratedDSNs[key]; ok {
		return err
	}
	err := RunMigrations(ctx, pool, ResolveMigrationsDir())
	migratedDSNs[key] = err
	return err
}

const testDatabaseEnv = "TEST_DATABASE_URL"

// RequireTestDatabaseURL 集成测试必须显式提供隔离测试库，禁止默认连开发库。
func RequireTestDatabaseURL(t *testing.T) string {
	t.Helper()
	dsn := strings.TrimSpace(os.Getenv(testDatabaseEnv))
	if dsn == "" {
		t.Fatalf("%s must be set for PostgreSQL integration tests (refusing default dev database)", testDatabaseEnv)
	}
	return dsn
}

// SkipIfNoTestDatabaseURL 无隔离测试库时跳过（单元测试包内可选 PG 用例）。
func SkipIfNoTestDatabaseURL(t *testing.T) string {
	t.Helper()
	dsn := strings.TrimSpace(os.Getenv(testDatabaseEnv))
	if dsn == "" {
		t.Skipf("%s not set; skipping PostgreSQL integration test", testDatabaseEnv)
	}
	return dsn
}

// RefuseSharedEnvDSN fails if the DSN targets a shared env database.
func RefuseSharedEnvDSN(t *testing.T, dsn string) {
	t.Helper()
	if strings.Contains(dsn, "5433") || strings.Contains(dsn, "agent_system_dev") ||
		(strings.Contains(dsn, "5434") && strings.Contains(dsn, "agent_system_test")) ||
		strings.Contains(dsn, "5435") {
		t.Fatal("TEST_DATABASE_URL points at a shared env port; refuse agent_system_dev/test/main")
	}
}