package database

import (
	"io/fs"
	"os"
	"path/filepath"
	"testing"

	"nex/backend/internal/config"
	"nex/backend/migrations"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"go.uber.org/zap"
)

func TestInit_SQLite(t *testing.T) {
	dir := t.TempDir()
	cfg := &config.DatabaseConfig{
		Driver:          "sqlite",
		Path:            filepath.Join(dir, "test.db"),
		MaxIdleConns:    5,
		MaxOpenConns:    10,
		ConnMaxLifetime: 0,
	}

	zapLogger := zap.NewNop()
	db, err := Init(cfg, zapLogger)
	require.NoError(t, err)
	require.NotNil(t, db)
	defer Close(db)

	sqlDB, err := db.DB()
	require.NoError(t, err)
	require.NotNil(t, sqlDB)
}

func TestClose(t *testing.T) {
	dir := t.TempDir()
	cfg := &config.DatabaseConfig{
		Driver:          "sqlite",
		Path:            filepath.Join(dir, "test.db"),
		MaxIdleConns:    5,
		MaxOpenConns:    10,
		ConnMaxLifetime: 0,
	}

	zapLogger := zap.NewNop()
	db, err := Init(cfg, zapLogger)
	require.NoError(t, err)
	require.NotNil(t, db)

	Close(db)
}

func TestBuildDSN(t *testing.T) {
	cfg := &config.DatabaseConfig{
		Driver:   "mysql",
		Host:     "db.example.com",
		Port:     3306,
		User:     "nexuser",
		Password: "secretpass",
		DBName:   "nexdb",
	}

	dsn := BuildDSN(cfg)
	assert.Equal(t, "nexuser:secretpass@tcp(db.example.com:3306)/nexdb?charset=utf8mb4&parseTime=true&loc=Local", dsn)
}

func TestBuildDSN_EmptyPassword(t *testing.T) {
	cfg := &config.DatabaseConfig{
		Driver: "mysql",
		Host:   "localhost",
		Port:   3306,
		User:   "root",
		DBName: "nex",
	}

	dsn := BuildDSN(cfg)
	assert.Equal(t, "root:@tcp(localhost:3306)/nex?charset=utf8mb4&parseTime=true&loc=Local", dsn)
}

func TestInit_SQLite_AnyCWD(t *testing.T) {
	dir := t.TempDir()

	origDir, err := os.Getwd()
	if err == nil {
		defer func() {
			if chdirErr := os.Chdir(origDir); chdirErr != nil {
				t.Logf("无法恢复工作目录: %v", chdirErr)
			}
		}()
	}
	if chdirErr := os.Chdir(dir); chdirErr != nil {
		t.Skipf("无法切换到临时目录: %v", chdirErr)
	}

	cfg := &config.DatabaseConfig{
		Driver:          "sqlite",
		Path:            filepath.Join(dir, "test.db"),
		MaxIdleConns:    5,
		MaxOpenConns:    10,
		ConnMaxLifetime: 0,
	}

	zapLogger := zap.NewNop()
	db, err := Init(cfg, zapLogger)
	require.NoError(t, err)
	require.NotNil(t, db)
	defer Close(db)

	sqlDB, err := db.DB()
	require.NoError(t, err)
	require.NotNil(t, sqlDB)
}

func TestForDriverDialect_SQLite(t *testing.T) {
	require.NoError(t, testMigrateWithDriver(t, "sqlite"))
}

func TestForDriverDialect_MySQL(t *testing.T) {
	dialect, fsys, err := migrations.ForDriver("mysql")
	require.NoError(t, err)
	assert.Equal(t, "mysql", string(dialect))
	entries, fsErr := fs.ReadDir(fsys, ".")
	require.NoError(t, fsErr)
	assert.NotEmpty(t, entries, "MySQL 迁移资源应至少包含一个文件")
}

func TestForDriverDialect_Invalid(t *testing.T) {
	dir := t.TempDir()
	cfg := &config.DatabaseConfig{
		Driver:          "postgres",
		Path:            filepath.Join(dir, "test.db"),
		MaxIdleConns:    5,
		MaxOpenConns:    10,
		ConnMaxLifetime: 0,
	}

	zapLogger := zap.NewNop()
	_, err := Init(cfg, zapLogger)
	assert.Error(t, err, "非法 driver 应返回错误")
	assert.Contains(t, err.Error(), "不支持的数据库驱动")
}

func testMigrateWithDriver(t *testing.T, driver string) error {
	t.Helper()

	dir := t.TempDir()
	cfg := &config.DatabaseConfig{
		Driver:          driver,
		Path:            filepath.Join(dir, "test.db"),
		MaxIdleConns:    5,
		MaxOpenConns:    10,
		ConnMaxLifetime: 0,
	}

	zapLogger := zap.NewNop()
	db, err := Init(cfg, zapLogger)
	if err != nil {
		return err
	}
	Close(db)
	return nil
}