package config

import (
	"strings"

	"github.com/spf13/viper"
)

type Config struct {
	Server ServerConfig `mapstructure:"server"`
	Log    LogConfig    `mapstructure:"log"`
	Cors   CorsConfig   `mapstructure:"cors"`
}

type ServerConfig struct {
	Port         int    `mapstructure:"port"`
	Mode         string `mapstructure:"mode"`
	ReadTimeout  string `mapstructure:"read_timeout"`
	WriteTimeout string `mapstructure:"write_timeout"`
}

type LogConfig struct {
	Level    string `mapstructure:"level"`
	Encoding string `mapstructure:"encoding"`
}

type CorsConfig struct {
	AllowOrigins []string `mapstructure:"allow_origins"`
	AllowMethods []string `mapstructure:"allow_methods"`
	AllowHeaders []string `mapstructure:"allow_headers"`
}

var C *Config

func Load() (*Config, error) {
	viper.SetConfigName("config")
	viper.SetConfigType("yaml")
	viper.AddConfigPath("./config")
	viper.AddConfigPath(".")

	viper.SetDefault("server.port", 8080)
	viper.SetDefault("server.mode", "debug")
	viper.SetDefault("log.level", "debug")
	viper.SetDefault("log.encoding", "console")

	viper.AutomaticEnv()
	viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))

	// 允许 PORT 等环境变量直接覆盖
	_ = viper.BindEnv("server.port", "PORT")

	if err := viper.ReadInConfig(); err != nil {
		// 配置文件不存在时使用默认值+环境变量，不视为致命错误
		if _, ok := err.(viper.ConfigFileNotFoundError); !ok {
			return nil, err
		}
	}

	var cfg Config
	if err := viper.Unmarshal(&cfg); err != nil {
		return nil, err
	}
	C = &cfg
	return &cfg, nil
}