package config

import (
	"encoding/json"
	"fmt"
	"log"
	"os"
	"reflect"
	"strconv"
	"strings"
)

const configFilePath = "/etc/PixelRidge/BackGo/config.json"

type LogLevel int

const (
	LogLevelDebug LogLevel = iota
	LogLevelInfo
	LogLevelWarning
	LogLevelError
)

type Config struct {
	LogLevel                     LogLevel
	S3Enabled                    bool
	S3ConnectionAddress          string
	S3AuthorizationInfo          string
	S3Region                     string
	S3BucketInfo                 string
	SMBEnabled                   bool
	SMBConnectionAddress         string
	SMBAuthorizationInfo         string
	B2Enabled                    bool
	B2ConnectionAddress          string
	B2AuthorizationInfo          string
	B2BucketInfo                 string
	LocalStorageEnabled          bool
	LocalStorageDirectory        string
	APIServerBindAddress         string
	APIServerPort                string
	TransportServerBindAddress   string
	TransportServerPort          string
	Nodes                        []string
}

func LoadConfig() *Config {
	return &Config{
		LogLevel:                     getEnvAsLogLevel("LOG_LEVEL", LogLevelInfo),
		S3Enabled:                    getEnvAsBool("S3_ENABLED", false),
		S3ConnectionAddress:          os.Getenv("S3_CONNECTION_ADDRESS"),
		S3AuthorizationInfo:          os.Getenv("S3_AUTHORIZATION_INFO"),
		S3Region:                     os.Getenv("S3_REGION"),
		S3BucketInfo:                 os.Getenv("S3_BUCKET_INFO"),
		SMBEnabled:                   getEnvAsBool("SMB_ENABLED", false),
		SMBConnectionAddress:         os.Getenv("SMB_CONNECTION_ADDRESS"),
		SMBAuthorizationInfo:         os.Getenv("SMB_AUTHORIZATION_INFO"),
		B2Enabled:                    getEnvAsBool("BACKBLAZE_B2_ENABLED", false),
		B2ConnectionAddress:          os.Getenv("B2_CONNECTION_ADDRESS"),
		B2AuthorizationInfo:          os.Getenv("B2_AUTHORIZATION_INFO"),
		B2BucketInfo:                 os.Getenv("BACKBLAZE_B2_BUCKET_INFO"),
		LocalStorageEnabled:          getEnvAsBool("LOCAL_STORAGE_ENABLED", false),
		LocalStorageDirectory:        os.Getenv("LOCAL_STORAGE_DIRECTORY"),
		APIServerBindAddress:         os.Getenv("API_SERVER_BIND_ADDRESS"),
		APIServerPort:                os.Getenv("API_SERVER_PORT"),
		TransportServerBindAddress:   os.Getenv("TRANSPORT_SERVER_BIND_ADDRESS"),
		TransportServerPort:          os.Getenv("TRANSPORT_SERVER_PORT"),
		Nodes:                        getEnvAsSlice("NODES", ",", []string{}),
	}
}

func getEnvAsBool(name string, defaultVal bool) bool {
	valStr := os.Getenv(name)
	if valStr == "" {
		return defaultVal
	}
	val, err := strconv.ParseBool(valStr)
	if err != nil {
		log.Printf("Error parsing boolean for %s: %v\n", name, err)
		return defaultVal
	}
	return val
}

func getEnvAsSlice(name, sep string, defaultVal []string) []string {
	valStr := os.Getenv(name)
	if valStr == "" {
		return defaultVal
	}
	return strings.Split(valStr, sep)
}

func getEnvAsLogLevel(name string, defaultVal LogLevel) LogLevel {
	valStr := os.Getenv(name)
	if valStr == "" {
		return defaultVal
	}
	if strings.EqualFold(valStr, "debug") {
		return LogLevelDebug
	} else if strings.EqualFold(valStr, "info") {
		return LogLevelInfo
	} else if strings.EqualFold(valStr, "warning") {
		return LogLevelWarning
	} else if strings.EqualFold(valStr, "error") {
		return LogLevelError
	}
	log.Printf("Unknown LOG_LEVEL '%s', defaulting to INFO.\n", valStr)
	return LogLevelInfo
}

func UpdateConfig(key, value string) error {
	config, err := LoadConfigFromFile()
	if err != nil {
		return fmt.Errorf("loading config: %v", err)
	}

	rConfig := reflect.ValueOf(config).Elem()
	field := rConfig.FieldByNameFunc(func(s string) bool {
		return strings.EqualFold(s, key)
	})

	if !field.IsValid() {
		return fmt.Errorf("unknown configuration key: %s", key)
	}

	if !field.CanSet() {
		return fmt.Errorf("cannot set configuration key: %s", key)
	}

	switch field.Kind() {
	case reflect.String:
		field.SetString(value)
	case reflect.Bool:
		boolVal, err := strconv.ParseBool(value)
		if err != nil {
			return fmt.Errorf("parsing boolean value for %s: %v", key, err)
		}
		field.SetBool(boolVal)
	case reflect.Int:
		intVal, err := strconv.Atoi(value)
		if err != nil {
			return fmt.Errorf("parsing integer value for %s: %v", key, err)
		}
		field.SetInt(int64(intVal))
	default:
		return fmt.Errorf("unsupported configuration type for: %s", key)
	}

	return SaveConfigToFile(config)
}

func LoadConfigFromFile() (*Config, error) {
	file, err := os.ReadFile(configFilePath)
	if err != nil {
		return nil, err
	}

	var config Config
	if err := json.Unmarshal(file, &config); err != nil {
		return nil, err
	}

	return &config, nil
}

func SaveConfigToFile(config *Config) error {
	data, err := json.MarshalIndent(config, "", "    ")
	if err != nil {
		return err
	}

	return os.WriteFile(configFilePath, data, 0644)
}

func ReloadConfig() {
	fmt.Println("Configuration reloaded")
}