package config

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

	"gopkg.in/yaml.v2"
)

// Config 应用配置
type Config struct {
	Database DBConfig    `yaml:"database"`
	Redis    RedisConfig `yaml:"redis"`
	Doris    DorisConfig `yaml:"doris"`
	Auth     Auth        `yaml:"auth"`
	Service  Service     `yaml:"service"`
	HTTP     HTTPConfig  `yaml:"http"` // 新增 HTTP 配置
}

// HTTPConfig HTTP客户端配置
type HTTPConfig struct {
	Timeout             int  `yaml:"timeout"`                 // 请求超时时间（秒）
	MaxIdleConns        int  `yaml:"max_idle_conns"`          // 最大空闲连接数
	MaxIdleConnsPerHost int  `yaml:"max_idle_conns_per_host"` // 每个主机的最大空闲连接数
	IdleConnTimeout     int  `yaml:"idle_conn_timeout"`       // 空闲连接超时时间（秒）
	MaxConnsPerHost     int  `yaml:"max_conns_per_host"`      // 每个主机的最大连接数
	DisableCompression  bool `yaml:"disable_compression"`     // 是否禁用压缩
	DisableKeepAlives   bool `yaml:"disable_keep_alives"`     // 是否禁用长连接
}

// DBConfig 数据库配置
type DBConfig struct {
	Type            string `yaml:"type"`
	Host            string `yaml:"host"`
	Port            int    `yaml:"port"`
	Username        string `yaml:"username"`
	Password        string `yaml:"password"`
	Database        string `yaml:"database"`
	MaxOpenConns    int    `yaml:"max_open_conns"`
	MaxIdleConns    int    `yaml:"max_idle_conns"`
	ConnMaxLifetime int    `yaml:"conn_max_lifetime"` // 单位：秒
}

// RedisConfig Redis配置
type RedisConfig struct {
	Host     string `yaml:"host"`
	Port     int    `yaml:"port"`
	Password string `yaml:"password"`
	DB       int    `yaml:"db"`
	PoolSize int    `yaml:"pool_size"`
	// 连接超时和读写超时（秒）
	DialTimeout  int `yaml:"dial_timeout"`
	ReadTimeout  int `yaml:"read_timeout"`
	WriteTimeout int `yaml:"write_timeout"`
	// 连接池配置
	IdleTimeout int `yaml:"idle_timeout"` // 空闲连接超时（秒）
	MaxConnAge  int `yaml:"max_conn_age"` // 连接最大存活时间（秒）
}

// DorisConfig Doris配置
type DorisConfig struct {
	// FE节点配置
	FEHost     string `yaml:"fe_host"`
	FEPort     int    `yaml:"fe_port"`
	FEUsername string `yaml:"fe_username"`
	FEPassword string `yaml:"fe_password"`

	// MySQL协议配置
	MySQLHost string `yaml:"mysql_host"`
	MySQLPort int    `yaml:"mysql_port"`

	// 连接池配置
	MaxOpenConns    int `yaml:"max_open_conns"`
	MaxIdleConns    int `yaml:"max_idle_conns"`
	ConnMaxLifetime int `yaml:"conn_max_lifetime"` // 单位：秒

	// Stream Load配置
	StreamLoadTimeout int `yaml:"stream_load_timeout"` // 秒
	BatchSize         int `yaml:"batch_size"`          // 批量大小
}

// Auth 认证配置
type Auth struct {
	Token string `yaml:"token"`
}

// Service 微服务配置
type Service struct {
	ServiceName    string `yaml:"service_name"`
	Port           int    `yaml:"port"`
	ReadTimeout    int    `yaml:"read_timeout"`
	WriteTimeout   int    `yaml:"write_timeout"`
	IdleTimeout    int    `yaml:"idle_timeout"`
	TrustedProxies string `yaml:"trusted_proxies"`
}

// 导出接口，防止外部修改
type IConfig interface {
	GetDatabase() DBConfig
	GetRedis() RedisConfig
	GetDoris() DorisConfig
	GetAuth() Auth
	GetService() Service
	GetHTTP() HTTPConfig // 新增获取HTTP配置方法
	IsDatabaseConfigured() bool
	IsRedisConfigured() bool
	IsDorisConfigured() bool
	IsHTTPConfigured() bool // 新增检查HTTP配置方法
}

// 实现接口的具体类型
type configWrapper struct {
	config *Config
}

func (cw *configWrapper) GetDatabase() DBConfig {
	return cw.config.Database
}

func (cw *configWrapper) GetRedis() RedisConfig {
	return cw.config.Redis
}

func (cw *configWrapper) GetDoris() DorisConfig {
	return cw.config.Doris
}

func (cw *configWrapper) GetAuth() Auth {
	return cw.config.Auth
}

func (cw *configWrapper) GetService() Service {
	return cw.config.Service
}

func (cw *configWrapper) GetHTTP() HTTPConfig {
	return cw.config.HTTP
}

func (cw *configWrapper) IsDatabaseConfigured() bool {
	db := cw.config.Database
	return db.Type != "" &&
		db.Host != "" &&
		db.Port > 0 &&
		db.Username != "" &&
		db.Database != ""
}

func (cw *configWrapper) IsRedisConfigured() bool {
	redis := cw.config.Redis
	return redis.Host != "" && redis.Port > 0
}

func (cw *configWrapper) IsDorisConfigured() bool {
	doris := cw.config.Doris
	// 检查FE配置（HTTP API方式）
	return doris.FEHost != "" && doris.FEPort > 0
}

func (cw *configWrapper) IsHTTPConfigured() bool {
	httpCfg := cw.config.HTTP
	return httpCfg.Timeout > 0
}

func (cw *configWrapper) IsAuthConfigured() bool {
	return cw.config.Auth.Token != ""
}

var (
	instance IConfig
	once     sync.Once
	initErr  error
)

// GetConfig 获取配置单例实例
func GetConfig() IConfig {
	once.Do(func() {
		config, err := loadConfig()
		if err != nil {
			initErr = err
			// 创建一个空的配置实例，避免nil指针
			instance = &configWrapper{config: &Config{}}
			return
		}
		instance = &configWrapper{config: config}
	})
	return instance
}

// GetInitError 获取初始化错误（如果有）
func GetInitError() error {
	return initErr
}

// loadConfig 加载配置文件
func loadConfig() (*Config, error) {

	configFile, err := findConfigFile()
	if err != nil {
		return nil, err
	}

	fmt.Printf("✅ Using config file: %s\n", configFile)

	// 先创建带默认值的配置
	config := &Config{
		Service: Service{
			ServiceName:    "myService",
			Port:           8080,
			ReadTimeout:    30,
			WriteTimeout:   30,
			IdleTimeout:    60,
			TrustedProxies: "",
		},
		Redis: RedisConfig{
			Port:         6379,
			DB:           0,
			PoolSize:     10,
			DialTimeout:  5,
			ReadTimeout:  3,
			WriteTimeout: 3,
			IdleTimeout:  300,
			MaxConnAge:   0, // 0表示不限制
		},
		Doris: DorisConfig{
			FEPort:            8030,
			MySQLPort:         9030,
			MaxOpenConns:      20,
			MaxIdleConns:      10,
			ConnMaxLifetime:   3600,
			StreamLoadTimeout: 30,
			BatchSize:         1000,
		},
		HTTP: HTTPConfig{
			Timeout:             30,
			MaxIdleConns:        100,
			MaxIdleConnsPerHost: 10,
			IdleConnTimeout:     90,
			MaxConnsPerHost:     0, // 0表示不限制
			DisableCompression:  false,
			DisableKeepAlives:   false,
		},
	}
	// 读取配置文件
	data, err := os.ReadFile(configFile)
	if err != nil {
		return nil, fmt.Errorf("failed to read config file %s: %v", configFile, err)
	}

	err = yaml.Unmarshal(data, &config)
	if err != nil {
		return nil, fmt.Errorf("failed to parse config file: %v", err)
	}

	return config, nil
}

// findConfigFile 查找配置文件
func findConfigFile() (string, error) {
	// 1. 首先尝试可执行文件同目录
	exePath, err := os.Executable()
	if err == nil {
		exeDir := filepath.Dir(exePath)
		configFile := filepath.Join(exeDir, "db.yaml")
		if _, err := os.Stat(configFile); err == nil {
			return configFile, nil
		}
	}

	// 2. 尝试环境变量指定的路径
	envConfigPath := os.Getenv("DB_CONFIG_PATH")
	if envConfigPath != "" {
		if _, err := os.Stat(envConfigPath); err == nil {
			return envConfigPath, nil
		}
		return "", fmt.Errorf("DB_CONFIG_PATH file not found: %s", envConfigPath)
	}

	// 3. 如果都没有找到，返回错误
	exeDir := "unknown"
	if exePath, err := os.Executable(); err == nil {
		exeDir = filepath.Dir(exePath)
	}

	return "", fmt.Errorf(`no configuration file found!

Tried locations:
1. Executable directory: %s/db.yaml
2. Environment variable: DB_CONFIG_PATH

Solutions:
- Place db.yaml in the same directory as the executable  
- Or set DB_CONFIG_PATH environment variable to config file path

Example:
  export DB_CONFIG_PATH=/path/to/your/db.yaml`, exeDir)
}