package config

import (
	"fmt"
	"log/slog"
	"os"
	"time"

	"github.com/knadh/koanf"
	"github.com/knadh/koanf/parsers/yaml"
	"github.com/knadh/koanf/providers/file"
)

type Environment string

const (
	Development Environment = "development"
	Production  Environment = "production"
)

var K = koanf.New(".")

type Server struct {
	Port string `koanf:"port"`
	Host string `koanf:"host"`
	// TrustProxy 是否在受信反代后；true 时才信任代理头获取客户端 IP
	TrustProxy bool `koanf:"trust_proxy"`
}

type Database struct {
	Host     string `koanf:"host"`
	Port     int    `koanf:"port"`
	User     string `koanf:"user"`
	Password string `koanf:"password"`
	DBName   string `koanf:"dbname"`
	SSLMode  string `koanf:"sslMode"`
}

type Redis struct {
	Addr      string `koanf:"addr"`
	Password  string `koanf:"password"`
	DB        int    `koanf:"db"`
	KeyPrefix string `koanf:"key_prefix"`
}

type JWTConfig struct {
	Secret        string        `koanf:"secret"`
	SigningMethod string        `koanf:"signing_method"`
	Expire        time.Duration `koanf:"expire"`
	RefreshExpire time.Duration `koanf:"refresh_expire"`
	Issuer        string        `koanf:"issuer"`
	Audience      string        `koanf:"audience"`
	TokenHeader   string        `koanf:"token_header"`
	TokenPrefix   string        `koanf:"token_prefix"`
	CookieName    string        `koanf:"cookie_name"`
}

type LogConfig struct {
	Level      string `koanf:"level"`
	Filename   string `koanf:"filename"`
	MaxSize    int    `koanf:"max_size"`
	MaxBackups int    `koanf:"max_backups"`
	MaxAge     int    `koanf:"max_age"`
	Compress   bool   `koanf:"compress"`
	Console    bool   `koanf:"console"`
}

type FileConfig struct {
	BaseURL       string `koanf:"base_url"`
	UploadDir     string `koanf:"upload_dir"`
	MaxUploadSize int64  `koanf:"max_upload_size"` // 上传大小上限（字节），0 表示默认 10MB
}

type Config struct {
	Server    Server     `koanf:"server"`
	Database  Database   `koanf:"database"`
	Redis     Redis      `koanf:"redis"`
	JWTConfig JWTConfig  `koanf:"jwt"`
	Log       LogConfig  `koanf:"log"`
	File      FileConfig `koanf:"file"`
}

// GetEnv 获取环境变量，确保环境变量始终有效
func GetEnv() Environment {
	env := os.Getenv("APP_ENV")

	switch Environment(env) {
	case Development, Production:
		return Environment(env)
	default:
		return Development
	}
}

func IsDev() bool {
	return GetEnv() == Development
}

func NewConfig() (*Config, error) {
	env := GetEnv()
	filepath := fmt.Sprintf("%s.yaml", env)

	if err := K.Load(file.Provider(filepath), yaml.Parser()); err != nil {
		slog.Error("error loading config", "error", err)
		return nil, err
	}

	var cfg Config
	if err := K.Unmarshal("", &cfg); err != nil {
		slog.Error("error unmarshaling config", "error", err)
		return nil, err
	}

	return &cfg, nil
}

func GetString(key string) string {
	return K.String(key)
}

func GetInt(key string) int {
	return K.Int(key)
}

func GetBool(key string) bool {
	return K.Bool(key)
}