package config

import (
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"sig-pub/pkg/zlog"
	"strings"

	"github.com/spf13/viper"
)

func parseConfPath(confPath string) (filePath, fileName, confType string) {
	filePath, fileName = filepath.Split(confPath)
	ext := filepath.Ext(fileName)
	fileName, _ = strings.CutSuffix(fileName, ext)
	confType, _ = strings.CutPrefix(ext, ".")
	confType = strings.ToLower(confType)
	return
}

func LoadConfig[T any](conf T, confPathArg ...string) (T, error) {
	v, err := loadViper(confPathArg...)
	if err != nil {
		return conf, err
	}
	if err := v.Unmarshal(conf); err != nil {
		err = errors.New("viper unmarshal config failed: " + err.Error())
		return conf, err
	}
	return conf, nil
}

func MustLoadConfig[T any](conf T, confPathArg ...string) T {
	v, err := loadViper(confPathArg...)
	if err != nil {
		panic(err)
	}
	if err := v.Unmarshal(conf); err != nil {
		panic(errors.New("viper unmarshal config failed: " + err.Error()))
	}
	return conf
}

// loadViper load config.toml
// appConf service custom config
// return common service configuration
func loadViper(confPathArg ...string) (v *viper.Viper, err error) {
	confPath := ""
	confName := "config"
	confType := "toml"
	envPrefix := "SIG"

	if len(confPathArg) > 0 {
		confPath = confPathArg[0]
	}

	confPath, confName, confType = parseConfPath(confPath)
	if confPath == "" {
		confPath = "./"
	}

	filePath := fmt.Sprintf("%s%s.%s", confPath, confName, confType)
	dir, err := os.Getwd()
	if err != nil {
		zlog.Warning(err)
	} else {
		filePath = filepath.Join(dir, filePath)
	}
	zlog.Infof("use config file: %s, env prefix=%s\n", filePath, envPrefix)

	v = viper.New()
	v.AddConfigPath(confPath)
	v.SetConfigName(confName)
	v.SetConfigType(confType)
	v.SetEnvPrefix(envPrefix)
	v.AutomaticEnv()
	v.AllowEmptyEnv(true)

	if err := v.ReadInConfig(); err != nil {
		return nil, errors.New("viper read config fail: " + err.Error())
	}
	return v, nil
}