package config

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

var (
	globalConfig       structs.SysConfig
	logger             = slog.New(slog.NewJSONHandler(os.Stdout, nil))
	BasePath           string
	Version            = "v2.0.0"
	Ready              = false
	VersionServerReady = false
	VersionInfo        structs.Version
	Ram                int
	Cpu                int
	CoreTemp           int
	Disk               int
	WifiEnabled        = false
	ActiveNetwork      string
	WifiNetworks       []string
	HttpOpen           = false
	UploadSecret       string
	checkInterval	   = 5 * time.Minute
	confMutex          sync.Mutex
	versMutex          sync.Mutex
)

// try initializing from system.json on disk
func init() {
	// try loading existing config
	BasePath, err := os.Getwd()
	if err != nil {
		errmsg := fmt.Sprintf("Couldn't get cwd: %v", err)
		logger.Error(errmsg)
	}
	confPath := filepath.Join(BasePath, "settings", "system.json")
	file, err := os.Open(confPath)
	if err != nil {
		// create a default if it doesn't exist
		err = createDefaultConf()
		if err != nil {
			errmsg := fmt.Sprintf("Unable to create config! %v", err)
			logger.Error(errmsg)
		}
	}
	defer file.Close()
	decoder := json.NewDecoder(file)
	err = decoder.Decode(&globalConfig)
	if err != nil {
		errmsg := fmt.Sprintf("Error decoding JSON: %v", err)
		logger.Error(errmsg)
	}
}

// return the global conf var
func Conf() structs.SysConfig {
	confMutex.Lock()
	defer confMutex.Unlock()
	return globalConfig
}

// update by passing in a map of key:values you want to modify
func UpdateConf(values map[string]interface{}) error {
	// mutex lock to avoid race conditions
	confMutex.Lock()
	defer confMutex.Unlock()
	confPath := filepath.Join(BasePath, "settings", "system.json")
	file, err := ioutil.ReadFile(confPath)
	if err != nil {
		errmsg := fmt.Sprintf("Unable to load config: %v", err)
		logger.Error(errmsg)
		return err
	}
	// unmarshal the config to struct
	var configMap map[string]interface{}
	if err := json.Unmarshal(file, &configMap); err != nil {
		errmsg := fmt.Sprintf("Error decoding JSON: %v", err)
		logger.Error(errmsg)
		return err
	}
	// update our unmarshaled struct
	for key, value := range values {
		configMap[key] = value
	}
	// marshal and persist it
	updatedJSON, err := json.MarshalIndent(configMap, "", "    ")
	if err != nil {
		errmsg := fmt.Sprintf("Error encoding JSON: %v", err)
		logger.Error(errmsg)
		return err
	}
	// update the globalConfig var
	if err := json.Unmarshal(updatedJSON, &globalConfig); err != nil {
		errmsg := fmt.Sprintf("Error updating global config: %v", err)
		logger.Error(errmsg)
		return err
	}
	if err := ioutil.WriteFile(confPath, updatedJSON, 0644); err != nil {
		errmsg := fmt.Sprintf("Error writing to file: %v", err)
		logger.Error(errmsg)
		return err
	}
	return nil
}

// write a default conf to disk
func createDefaultConf() error {
	defaultConfig := structs.SysConfig{
		Setup:        "start",
		EndpointUrl:  "api.startram.io",
		ApiVersion:   "v1",
		Piers:        []string{},
		NetCheck:     "1.1.1.1:53",
		UpdateMode:   "auto",
		UpdateUrl:    "https://version.groundseg.app",
		UpdateBranch: "latest",
		SwapVal:      16,
		SwapFile:     filepath.Join(BasePath, "settings", "swapfile"),
		KeyFile:      filepath.Join(BasePath, "settings", "session.key"),
		Sessions: struct {
			Authorized   map[string]structs.SessionInfo `json:"authorized"`
			Unauthorized map[string]structs.SessionInfo `json:"unauthorized"`
		}{
			Authorized:   make(map[string]structs.SessionInfo),
			Unauthorized: make(map[string]structs.SessionInfo),
		},
		LinuxUpdates: struct {
			Value    int    `json:"value"`
			Interval string `json:"interval"`
			Previous bool   `json:"previous"`
		}{
			Value:    1,
			Interval: "week",
			Previous: false,
		},
		DockerData:     "/var/lib/docker",
		WgOn:           false,
		WgRegistered:   false,
		PwHash:         "",
		C2cInterval:    0,
		FirstBoot:      false,
		WgRegisterd:    false,
		GsVersion:      Version,
		CfgDir:         "",
		UpdateInterval: 0,
		BinHash:        "",
		Pubkey:         "",
		Privkey:        "",
		Salt:           "",
	}
	path := filepath.Join(BasePath, "settings", "system.json")
	if err := os.MkdirAll(filepath.Dir(path), os.ModePerm); err != nil {
		return err
	}
	file, err := os.Create(path)
	if err != nil {
		return err
	}
	defer file.Close()
	encoder := json.NewEncoder(file)
	encoder.SetIndent("", "    ")
	if err := encoder.Encode(&defaultConfig); err != nil {
		return err
	}
	return nil
}

// check outbound tcp connectivity
// takes ip:port
func NetCheck(netCheck string) bool {
	logger.Info("Checking internet access")
	internet := false
	timeout := 3 * time.Second
	conn, err := net.DialTimeout("tcp", netCheck, timeout)
	if err != nil {
		errmsg := fmt.Sprintf("Check internet access error: %v", err)
		logger.Error(errmsg)
	} else {
		internet = true
		_ = conn.Close()
	}
	return internet
}

// check the version server and return unmarshaled result
func CheckVersion() (structs.Version, bool) {
	versMutex.Lock()
	defer versMutex.Unlock()
	const retries = 10
	const delay = time.Second
	url := globalConfig.UpdateUrl
	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 {
				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 {
				return VersionInfo, false
			}
		}
		// unmarshal values into Version struct
		err = json.Unmarshal(body, &VersionInfo)
		if err != nil {
			errmsg := fmt.Sprintf("Error unmarshalling JSON: %v", err)
			logger.Warn(errmsg)
			if i < retries-1 {
				time.Sleep(delay)
				continue
			} else {
				return VersionInfo, false
			}
		}
		// debug: re-marshal and write 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)
			return VersionInfo, false
		}
		defer file.Close()
		encoder := json.NewEncoder(file)
		encoder.SetIndent("", "    ")
		if err := encoder.Encode(&VersionInfo); err != nil {
			errmsg := fmt.Sprintf("Failed to write JSON: %v", err)
			logger.Error(errmsg)
		}
		return VersionInfo, true
	}
	return VersionInfo, false
}

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