package config

import (
	"encoding/json"
	"fmt"
	"goseg/defaults"
	"goseg/structs"
	"io/ioutil"
	"net/http"
	"os"
	"path/filepath"
	"time"
)

var (
	VersionServerReady = false
	VersionInfo        structs.Channel
)

// check the version server and return struct
func CheckVersion() (structs.Channel, bool) {
	versMutex.Lock()
	defer versMutex.Unlock()
	conf := Conf()
	releaseChannel := conf.UpdateBranch
	const retries = 10
	const delay = time.Second
	url := globalConfig.UpdateUrl
	var fetchedVersion structs.Version
	for i := 0; i < retries; i++ {
		resp, err := http.Get(url)
		if err != nil {
			errmsg := fmt.Sprintf("Unable to connect to update server: %v", err)
			logger.Warn(errmsg)
			if i < retries-1 {
				time.Sleep(delay)
				continue
			} else {
				VersionServerReady = false
				return VersionInfo, false
			}
		}
		// read the body bytes
		body, err := ioutil.ReadAll(resp.Body)
		resp.Body.Close()
		if err != nil {
			errmsg := fmt.Sprintf("Error reading version info: %v", err)
			logger.Warn(errmsg)
			if i < retries-1 {
				time.Sleep(delay)
				continue
			} else {
				VersionServerReady = false
				return VersionInfo, false
			}
		}
		// unmarshal values into Version struct
		err = json.Unmarshal(body, &fetchedVersion)
		if err != nil {
			errmsg := fmt.Sprintf("Error unmarshalling JSON: %v", err)
			logger.Warn(errmsg)
			if i < retries-1 {
				time.Sleep(delay)
				continue
			} else {
				VersionServerReady = false
				return VersionInfo, false
			}
		}
		VersionInfo = fetchedVersion.Groundseg[releaseChannel]
		// debug: re-marshal and write the entire fetched version to disk
		confPath := filepath.Join(BasePath, "settings", "version_info.json")
		file, err := os.Create(confPath)
		if err != nil {
			errmsg := fmt.Sprintf("Failed to create file: %v", err)
			logger.Error(errmsg)
			VersionServerReady = false
			return VersionInfo, false
		}
		defer file.Close()
		encoder := json.NewEncoder(file)
		encoder.SetIndent("", "    ")
		if err := encoder.Encode(&fetchedVersion); err != nil {
			errmsg := fmt.Sprintf("Failed to write JSON: %v", err)
			logger.Error(errmsg)
		}
		VersionServerReady = true
		return VersionInfo, true
	}
	VersionServerReady = false
	return VersionInfo, false
}

func CheckVersionLoop() {
	ticker := time.NewTicker(checkInterval)
	conf := Conf()
	releaseChannel := conf.UpdateBranch
	for {
		select {
		case <-ticker.C:
			latestVersion, _ := CheckVersion()
			currentChannelVersion := VersionInfo
			latestChannelVersion := latestVersion
			if latestChannelVersion != currentChannelVersion {
				fmt.Printf("New version available in %s channel! Current: %+v, Latest: %+v\n", releaseChannel, currentChannelVersion, latestChannelVersion)
				VersionInfo = latestVersion
				// Handle the update logic here
			}
		}
	}
}

// write the defaults.VersionInfo value to disk
func CreateDefaultVersion() error {
	var versionInfo structs.Version
	err := json.Unmarshal([]byte(defaults.DefaultVersionText), &versionInfo)
	if err != nil {
		return err
	}
	prettyJSON, err := json.MarshalIndent(versionInfo, "", "    ")
	if err != nil {
		return err
	}
	filePath := filepath.Join(BasePath, "settings", "version_info.json")
	err = ioutil.WriteFile(filePath, prettyJSON, 0644)
	if err != nil {
		return err
	}
	return nil
}