package global

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
	"os"
	"os/signal"
	"strconv"
	"strings"
	"syscall"
	"time"

	"github.com/hiddify/libcore/config"

	"github.com/sagernet/sing-box/option"
)

func RunStandalone(hiddifySettingPath string, configPath string) error {
	fmt.Println("Running in standalone mode")
	current, err := readAndBuildConfig(hiddifySettingPath, configPath)
	if err != nil {
		fmt.Printf("Error in read and build config %v", err)
		return err
	}

	go StartServiceC(false, current.Config)
	go updateConfigInterval(current, hiddifySettingPath, configPath)
	fmt.Printf("Press CTRL+C to stop\n")
	fmt.Printf("Open http://localhost:6756/?secret=hiddify in your browser\n")
	sigChan := make(chan os.Signal, 1)
	signal.Notify(sigChan, os.Interrupt, syscall.SIGTERM)

	<-sigChan
	err = StopServiceC()

	return err
}

type ConfigResult struct {
	Config          string
	RefreshInterval int
}

func readAndBuildConfig(hiddifySettingPath string, configPath string) (ConfigResult, error) {
	var result ConfigResult

	result, err := readConfigContent(configPath)
	if err != nil {
		return result, err
	}
	hiddifyconfig := config.DefaultConfigOptions()
	if hiddifySettingPath != "" {
		hiddifyconfig, err = readConfigOptionsAt(hiddifySettingPath)
		if err != nil {
			return result, err
		}
	}
	result.Config, err = buildConfig(result.Config, *hiddifyconfig)
	if err != nil {
		return result, err
	}

	return result, nil
}

func readConfigContent(configPath string) (ConfigResult, error) {
	var content string
	var refreshInterval int

	if strings.HasPrefix(configPath, "http://") || strings.HasPrefix(configPath, "https://") {
		resp, err := http.Get(configPath)
		if err != nil {
			return ConfigResult{}, fmt.Errorf("failed to get config from URL: %w", err)
		}
		defer resp.Body.Close()

		body, err := ioutil.ReadAll(resp.Body)
		if err != nil {
			return ConfigResult{}, fmt.Errorf("failed to read config body: %w", err)
		}
		content = string(body)
		refreshInterval, _ = extractRefreshInterval(resp.Header, content)
		fmt.Printf("Refresh interval: %d\n", refreshInterval)
	} else {
		data, err := ioutil.ReadFile(configPath)
		if err != nil {
			return ConfigResult{}, fmt.Errorf("failed to read config file: %w", err)
		}
		content = string(data)
	}

	return ConfigResult{
		Config:          content,
		RefreshInterval: refreshInterval,
	}, nil
}

func extractRefreshInterval(header http.Header, bodyStr string) (int, error) {
	refreshIntervalStr := header.Get("profile-update-interval")
	if refreshIntervalStr != "" {
		refreshInterval, err := strconv.Atoi(refreshIntervalStr)
		if err != nil {
			return 0, fmt.Errorf("failed to parse refresh interval from header: %w", err)
		}
		return refreshInterval, nil
	}

	lines := strings.Split(bodyStr, "\n")
	for _, line := range lines {
		line = strings.TrimSpace(line)
		if strings.HasPrefix(line, "//profile-update-interval:") || strings.HasPrefix(line, "#profile-update-interval:") {
			parts := strings.SplitN(line, ":", 2)
			str := strings.TrimSpace(parts[1])
			refreshInterval, err := strconv.Atoi(str)
			if err != nil {
				return 0, fmt.Errorf("failed to parse refresh interval from body: %w", err)
			}
			return refreshInterval, nil
		}
	}
	return 0, nil
}
func buildConfig(configContent string, options config.ConfigOptions) (string, error) {
	parsedContent, err := config.ParseConfigContent(configContent, true)
	if err != nil {
		return "", fmt.Errorf("failed to parse config content: %w", err)
	}
	singconfigs, err := readConfigBytes([]byte(parsedContent))
	if err != nil {
		return "", err
	}

	finalconfig, err := config.BuildConfig(options, *singconfigs)
	if err != nil {
		return "", fmt.Errorf("failed to build config: %w", err)
	}

	finalconfig.Log.Output = ""
	finalconfig.Experimental.ClashAPI.ExternalUI = "webui"
	finalconfig.Experimental.ClashAPI.ExternalController = "0.0.0.0:6756"
	if finalconfig.Experimental.ClashAPI.Secret == "" {
		// finalconfig.Experimental.ClashAPI.Secret = "hiddify"
	}

	if err := SetupC("./", "./", "./tmp", false); err != nil {
		return "", fmt.Errorf("failed to set up global configuration: %w", err)
	}

	configStr, err := config.ToJson(*finalconfig)
	if err != nil {
		return "", fmt.Errorf("failed to convert config to JSON: %w", err)
	}

	return configStr, nil
}

func updateConfigInterval(current ConfigResult, hiddifySettingPath string, configPath string) {
	if current.RefreshInterval <= 0 {
		return
	}

	for {
		<-time.After(time.Duration(current.RefreshInterval) * time.Hour)
		new, err := readAndBuildConfig(hiddifySettingPath, configPath)
		if err != nil {
			continue
		}
		if new.Config != current.Config {
			go StopServiceC()
			go StartServiceC(false, new.Config)
		}
		current = new
	}

}

func readConfigBytes(content []byte) (*option.Options, error) {
	var options option.Options
	err := options.UnmarshalJSON(content)
	if err != nil {
		return nil, err
	}
	return &options, nil
}

func readConfigOptionsAt(path string) (*config.ConfigOptions, error) {
	content, err := os.ReadFile(path)
	if err != nil {
		return nil, err
	}
	var options config.ConfigOptions
	err = json.Unmarshal(content, &options)

	if err != nil {
		return nil, err
	}
	if options.Warp.WireguardConfigStr != "" {
		err := json.Unmarshal([]byte(options.Warp.WireguardConfigStr), &options.Warp.WireguardConfig)
		if err != nil {
			return nil, err
		}
	}

	return &options, nil
}