package config

import (
	"fmt"
	"strings"

	"github.com/spf13/viper"
)

// Config 全局配置
type Config struct {
	Server ServerConfig `mapstructure:"server"`
	MySQL  MySQLConfig  `mapstructure:"mysql"`
	MinIO  MinIOConfig  `mapstructure:"minio"`
	JWT    JWTConfig    `mapstructure:"jwt"`
	WeChat WeChatConfig `mapstructure:"wechat"`
	Auth   AuthConfig   `mapstructure:"auth"`
	Admin  AdminConfig  `mapstructure:"admin"`
	AI     AIConfig     `mapstructure:"ai"`
}

// AIConfig 大模型配置（provider 中立，openai 兼容 base_url）
type AIConfig struct {
	Enabled     bool    `mapstructure:"enabled"`
	Provider    string  `mapstructure:"provider"` // openai(兼容) / mock
	BaseURL     string  `mapstructure:"base_url"` // 如 https://api.deepseek.com
	APIKey      string  `mapstructure:"api_key"`  // 用 PETS_AI_API_KEY 覆盖
	Model       string  `mapstructure:"model"`    // 如 deepseek-chat
	Temperature float64 `mapstructure:"temperature"`
	MaxTokens   int     `mapstructure:"max_tokens"`
	TimeoutSec  int     `mapstructure:"timeout_sec"`
}

type ServerConfig struct {
	Port int    `mapstructure:"port"`
	Mode string `mapstructure:"mode"`
}

type MySQLConfig struct {
	Host     string `mapstructure:"host"`
	Port     int    `mapstructure:"port"`
	User     string `mapstructure:"user"`
	Password string `mapstructure:"password"`
	Database string `mapstructure:"database"`
	Charset  string `mapstructure:"charset"`
}

// DSN 返回 GORM MySQL 连接串
func (m MySQLConfig) DSN() string {
	return fmt.Sprintf(
		"%s:%s@tcp(%s:%d)/%s?charset=%s&parseTime=True&loc=Local",
		m.User, m.Password, m.Host, m.Port, m.Database, m.Charset,
	)
}

type MinIOConfig struct {
	Endpoint      string `mapstructure:"endpoint"`
	AccessKey     string `mapstructure:"access_key"`
	SecretKey     string `mapstructure:"secret_key"`
	Bucket        string `mapstructure:"bucket"`
	UseSSL        bool   `mapstructure:"use_ssl"`
	PublicBaseURL string `mapstructure:"public_base_url"`
}

type JWTConfig struct {
	Secret      string `mapstructure:"secret"`
	ExpireHours int    `mapstructure:"expire_hours"`
}

type WeChatConfig struct {
	AppID     string `mapstructure:"app_id"`
	AppSecret string `mapstructure:"app_secret"`
}

type AuthConfig struct {
	DevLogin bool `mapstructure:"dev_login"`
}

type AdminConfig struct {
	Username string `mapstructure:"username"`
	Password string `mapstructure:"password"`
}

// Load 载入配置：configs/config.yaml + 环境变量覆盖（PETS_ 前缀，点转下划线）
// 例如 PETS_MYSQL_PASSWORD 覆盖 mysql.password
func Load() (*Config, error) {
	v := viper.New()
	v.SetConfigName("config")
	v.SetConfigType("yaml")
	v.AddConfigPath("./configs")
	v.AddConfigPath("../../configs")
	v.AddConfigPath(".")

	v.SetEnvPrefix("PETS")
	v.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
	v.AutomaticEnv()

	if err := v.ReadInConfig(); err != nil {
		return nil, fmt.Errorf("read config: %w", err)
	}

	var cfg Config
	if err := v.Unmarshal(&cfg); err != nil {
		return nil, fmt.Errorf("unmarshal config: %w", err)
	}
	return &cfg, nil
}