package config

import (
	"bytes"
	_ "embed"
	"encoding/json"
	"fmt"

	"os"

	"github.com/hiddify/ray2sing/ray2sing"
	"github.com/sagernet/sing-box/experimental/libbox"
	SJ "github.com/sagernet/sing/common/json"
	"github.com/xmdhs/clash2singbox/convert"
	"github.com/xmdhs/clash2singbox/model/clash"
	"gopkg.in/yaml.v3"
)

//go:embed config.json.template
var configByte []byte

func ParseConfig(path string, debug bool) ([]byte, error) {
	content, err := os.ReadFile(path)
	if err != nil {
		return nil, err
	}
	var jsonObj map[string]interface{}

	fmt.Printf("Convert using json\n")
	jsonDecoder := json.NewDecoder(SJ.NewCommentFilter(bytes.NewReader(content)))
	if err := jsonDecoder.Decode(&jsonObj); err == nil {
		if jsonObj["outbounds"] == nil {
			return nil, fmt.Errorf("[SingboxParser] no outbounds found")
		}
		newContent, _ := json.MarshalIndent(jsonObj, "", "  ")
		return validateResult(newContent, "SingboxParser")
	}
	fmt.Printf("Convert using v2ray\n")
	v2rayStr, err := ray2sing.Ray2Singbox(string(content))
	if err == nil {
		return validateResult([]byte(v2rayStr), "V2rayParser")
	}
	fmt.Printf("Convert using clash\n")
	clashObj := clash.Clash{}
	if err := yaml.Unmarshal(content, &clashObj); err == nil && clashObj.Proxies != nil {
		if len(clashObj.Proxies) == 0 {
			return nil, fmt.Errorf("[ClashParser] no outbounds found")
		}
		converted, err := convert.Clash2sing(clashObj)
		if err != nil {
			return nil, fmt.Errorf("[ClashParser] converting clash to sing-box error: %w", err)
		}
		output := configByte
		output, err = convert.Patch(output, converted, "", "", nil)
		if err != nil {
			return nil, fmt.Errorf("[ClashParser] patching clash config error: %w", err)
		}
		return validateResult(output, "ClashParser")
	}

	return nil, fmt.Errorf("unable to determine config format")
}

func validateResult(content []byte, name string) ([]byte, error) {
	err := libbox.CheckConfig(string(content))
	if err != nil {
		return nil, fmt.Errorf("[%s] invalid sing-box config: %w", name, err)
	}
	return content, nil
}