package config

import (
	"fmt"
	"log"
	"os"
	"path/filepath"

	"github.com/glebarez/sqlite"
	"gorm.io/driver/mysql"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"

	"github.com/spf13/viper"
)

// 获取项目根目录
func getProjectRoot() string {
	// 从当前工作目录向上查找 .env 文件
	dir, _ := os.Getwd()
	for i := 0; i < 5; i++ {
		if _, err := os.Stat(filepath.Join(dir, ".env")); err == nil {
			return dir
		}
		dir = filepath.Dir(dir)
	}
	// 默认返回当前目录
	return "."
}

type Config struct {
	Port              string
	JWTSecret         string
	DatabaseType      string // 数据库类型: mysql 或 sqlite
	DatabaseHost      string
	DatabasePort      string
	DatabaseUser      string
	DatabasePassword  string
	DatabaseName      string
	DatabaseURL       string // 拼接后的完整连接字符串
	SQLitePath        string // SQLite 数据库文件路径
	PythonServiceURL  string
	AICoreServiceAddr string // AI-Core gRPC 服务地址，如 "localhost:50051"
	// 文件上传配置
	UploadMode        string // "local" 或 "minio"
	UploadLocalPath   string // 本地存储路径，如 "resource/files"
	ServerBaseURL     string // 服务器基础 URL，用于生成本地文件 URL
	MarkdownLocalPath string // Markdown 文件存储路径，如 "resource/markdown"
	// MinIO 配置
	MinIOEndpoint   string
	MinIOAccessKey  string
	MinIOSecretKey  string
	MinIOBucket     string
	MinIOUseSSL    bool
}

func Load() *Config {
	// 重新初始化 viper，避免之前的状态影响
	viper.Reset()

	// 第一步：设置默认值
	viper.SetDefault("port", "8080")
	viper.SetDefault("jwt_secret", "your-secret-key-change-in-production")
	viper.SetDefault("python_service_url", "http://localhost:8081")
	viper.SetDefault("ai_core_service_addr", "localhost:50051")
	// 数据库默认配置
	viper.SetDefault("database_type", "mysql")
	viper.SetDefault("database_host", "localhost")
	viper.SetDefault("database_port", "3306")
	viper.SetDefault("database_user", "root")
	viper.SetDefault("database_password", "root")
	viper.SetDefault("database_name", "x_agents")
	viper.SetDefault("sqlite_path", "./data/x_agents.db")
	// 文件上传默认配置
	viper.SetDefault("upload_mode", "local")
	viper.SetDefault("upload_local_path", "resource/files")
	viper.SetDefault("server_base_url", "http://localhost:8080")
	viper.SetDefault("markdown_local_path", "resource/markdown")
	viper.SetDefault("minio_endpoint", "localhost:9000")
	viper.SetDefault("minio_access_key", "")
	viper.SetDefault("minio_secret_key", "")
	viper.SetDefault("minio_bucket", "x-agents")
	viper.SetDefault("minio_use_ssl", false)

	// 第二步：读取 config.yaml（优先级低）
	viper.SetConfigName("config")
	viper.SetConfigType("yaml")
	viper.AddConfigPath("./config")
	viper.AddConfigPath("../config")
	viper.AddConfigPath("../../config")
	_ = viper.MergeInConfig() // 忽略错误，可能没有 config.yaml

	// 第三步：读取 .env 文件（优先级最高）
	projectRoot := getProjectRoot()
	log.Printf("Project root: %s", projectRoot)

	viper.SetConfigName(".env")
	viper.SetConfigType("env")
	viper.AddConfigPath(projectRoot)  // 项目根目录 (X-Agents)
	viper.AddConfigPath(".")          // 当前目录
	viper.AddConfigPath("..")         // 父目录
	viper.AddConfigPath("../..")      // 上两级目录
	viper.SetEnvPrefix("GO")          // 环境变量前缀 GO_xxx (仅对环境变量生效)
	viper.AutomaticEnv()
	_ = viper.MergeInConfig() // 忽略错误，可能没有 .env

	// 处理 .env 文件中的键名（去掉 GO_ 前缀映射）
	envToConfig := map[string]string{
		"GO_PORT":              "port",
		"GO_DATABASE_TYPE":     "database_type",
		"GO_DATABASE_HOST":     "database_host",
		"GO_DATABASE_PORT":     "database_port",
		"GO_DATABASE_NAME":     "database_name",
		"GO_DATABASE_USER":     "database_user",
		"GO_DATABASE_PASSWORD": "database_password",
		"GO_SQLITE_PATH":      "sqlite_path",
	}
	for envKey, configKey := range envToConfig {
		if val := viper.GetString(envKey); val != "" {
			viper.Set(configKey, val)
		}
	}

	log.Printf("Loaded config: database_type=%s, port=%s",
		viper.GetString("database_type"), viper.GetString("port"))

	// 获取数据库类型
	dbType := viper.GetString("database_type")
	var databaseURL string

	if dbType == "sqlite" {
		sqlitePath := viper.GetString("sqlite_path")
		// 确保 SQLite 数据目录存在 (跨平台处理)
		dir := filepath.Dir(sqlitePath)
		if dir != "." && dir != "" {
			os.MkdirAll(dir, 0755)
		}
		databaseURL = sqlitePath
	} else {
		// MySQL 连接字符串
		dbHost := viper.GetString("database_host")
		dbPort := viper.GetString("database_port")
		dbUser := viper.GetString("database_user")
		dbPassword := viper.GetString("database_password")
		dbName := viper.GetString("database_name")
		databaseURL = fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?charset=utf8mb4&parseTime=True&loc=Local",
			dbUser, dbPassword, dbHost, dbPort, dbName)
	}

	return &Config{
		Port:              viper.GetString("port"),
		JWTSecret:         viper.GetString("jwt_secret"),
		DatabaseType:      dbType,
		DatabaseURL:       databaseURL,
		DatabaseHost:      viper.GetString("database_host"),
		DatabasePort:      viper.GetString("database_port"),
		DatabaseUser:      viper.GetString("database_user"),
		DatabasePassword:  viper.GetString("database_password"),
		DatabaseName:      viper.GetString("database_name"),
		SQLitePath:        viper.GetString("sqlite_path"),
		PythonServiceURL:  viper.GetString("python_service_url"),
		AICoreServiceAddr: viper.GetString("ai_core_service_addr"),
		// 文件上传配置
		UploadMode:        viper.GetString("upload_mode"),
		UploadLocalPath:   viper.GetString("upload_local_path"),
		ServerBaseURL:     viper.GetString("server_base_url"),
		MarkdownLocalPath: viper.GetString("markdown_local_path"),
		// MinIO 配置
		MinIOEndpoint:  viper.GetString("minio_endpoint"),
		MinIOAccessKey: viper.GetString("minio_access_key"),
		MinIOSecretKey: viper.GetString("minio_secret_key"),
		MinIOBucket:    viper.GetString("minio_bucket"),
		MinIOUseSSL:    viper.GetBool("minio_use_ssl"),
	}
}

func InitDB(cfg *Config) (*gorm.DB, error) {
	dsn := cfg.DatabaseURL
	if dsn == "" {
		return nil, fmt.Errorf("database URL is empty")
	}

	var db *gorm.DB
	var err error

	if cfg.DatabaseType == "sqlite" {
		// SQLite 不需要创建目录逻辑，因为 Load 函数已经处理了
		db, err = gorm.Open(sqlite.Open(dsn), &gorm.Config{
			Logger: logger.Default.LogMode(logger.Silent),
		})
		log.Printf("Using SQLite database: %s", dsn)
	} else {
		db, err = gorm.Open(mysql.Open(dsn), &gorm.Config{
			Logger: logger.Default.LogMode(logger.Silent),
		})
		log.Printf("Using MySQL database: %s:%s/%s",
			cfg.DatabaseHost, cfg.DatabasePort, cfg.DatabaseName)
	}

	if err != nil {
		return nil, fmt.Errorf("failed to connect database: %w", err)
	}

	log.Println("Database connected successfully")
	return db, nil
}