package client

import (
	"encoding/json"
	"errors"
	"os"
	"sync"

	"github.com/awnumar/memguard"
)

type Config struct {
	// UserConfig
	SavePassword      bool   `json:"save_password,omitempty"`
	SavedPassword     string `json:"saved_password,omitempty"`
	PasswordTip       string `json:"password_tip,omitempty"`
	PasswordTipUnlock string `json:"password_tip_unlock,omitempty"`
	// Technical
	IdentityFile       string `json:"identity_file,omitempty"`
	StoragePath        string `json:"storage_path,omitempty"`
	MaxIdsPerUser      int    `json:"max_ids_per_user,omitempty"`
	MsgDbRollingPeriod int    `json:"msg_db_rolling_period,omitempty"`
	Chunksize          int64  `json:"chunksize,omitempty"`
	DbSize             int    `json:"db_size,omitempty"`
	UserAgent          string `json:"user_agent,omitempty"`
	// Network
	ServerPollInterval int `json:"server_poll_interval,omitempty"`
	HttpTimeOut        int `json:"http_timeout,omitempty"`
	HttpLongPoll       int `json:"http_long_poll,omitempty"`
	// GUI
	LastOpenChat                   string `json:"last_open_chat,omitempty"`
	SoundNotificationEnable        bool   `json:"sound_notification_enable,omitempty"`
	DefaultNotificationSound       string `json:"default_notification_sound,omitempty"`
	NotificationVibeEnable         bool   `json:"notification_vibe_enable,omitempty"`
	DefaultNotificationVibe        string `json:"default_notification_vibe,omitempty"`
	NotificationLEDEnable          bool   `json:"notification_led_enable,omitempty"`
	DefaultNotificationLEDColor    string `json:"default_notification_led_color,omitempty"`
	VisualNotificationEnable       bool   `json:"visual_notification_enable,omitempty"`
	VisualNotificationModes        string `json:"visual_notifiaction_modes,omitempty"`
	PrivateChatNotificationsEnable bool   `json:"private_chat_notifiactions_enable,omitempty"`
	GroupChatNotificationsEnable   bool   `json:"group_chat_notifiactions_enable,omitempty"`
	ChannelNotificationsEnable     bool   `json:"channel_notifications_enable,omitempty"`
	Language                       string `json:"language,omitempty"`
	Theme                          string `json:"theme,omitempty"`
	FingerprintEnable              bool   `json:"fingerprint_enable,omitempty"`
	ShowFavoriteContacts           bool   `json:"show_favorite_contacts,omitempty"`
	NightModeEnable                bool   `json:"night_mode_enable,omitempty"`

	// Debug
	DbSuffix string `json:"db_suffix,omitempty"`

	// Inner
	memoryPassword      *memguard.LockedBuffer
	additionalPasswords []*memguard.LockedBuffer
	me                  *Identity
}

var instance *Config
var once sync.Once

func GetConfig() *Config {
	once.Do(func() {
		instance = &Config{}
	})
	return instance
}

func (c *Config) Load(filename string) error {
	data, err := os.ReadFile(filename)
	if err != nil {
		return err
	}
	err = json.Unmarshal(data, c)
	if err != nil {
		return err
	}
	// override values if not set or wrong
	if c.HttpTimeOut <= 0 {
		c.HttpTimeOut = 10
		c.Save(filename)
	}
	if c.HttpLongPoll <= 1 {
		c.HttpLongPoll = 300
		c.Save(filename)
	}
	return nil
}

func (c *Config) Save(filename string) error {
	data, err := json.Marshal(c)
	if err != nil {
		return err
	}
	err = os.WriteFile(filename, data, 0600)
	if err != nil {
		return err
	}
	return nil
}

func (c *Config) SetMemPass(pass string) error {
	if c.memoryPassword != nil {
		c.memoryPassword.Destroy()
	}
	c.memoryPassword = memguard.NewBufferFromBytes([]byte(pass))
	return nil
}

func (c *Config) GetMemPass() (string, error) {
	if c.memoryPassword == nil {
		return "", errors.New("password not set")
	}
	return string(c.memoryPassword.Bytes()), nil
}

func (c *Config) GetIdentity() *Identity {
	return c.me
}

func (c *Config) SetIdentity(id *Identity) {
	c.me = id
}

func (c *Config) SaveIdentity() error {
	return c.me.Save()
}

func (c *Config) Clean() {
	if c.memoryPassword != nil {
		c.memoryPassword.Destroy()
		c.memoryPassword = nil
	}
	for _, buf := range c.additionalPasswords {
		if buf != nil {
			buf.Destroy()
		}
	}
	c.additionalPasswords = []*memguard.LockedBuffer{}
}

// AddAdditionalPassword securely stores an additional password in protected memory
func (c *Config) AddAdditionalPassword(password string) {
	buf := memguard.NewBufferFromBytes([]byte(password))
	c.additionalPasswords = append(c.additionalPasswords, buf)
}

// GetAdditionalPasswords returns all additional passwords as strings
func (c *Config) GetAdditionalPasswords() ([]string, error) {
	passwords := make([]string, 0, len(c.additionalPasswords))
	for _, buf := range c.additionalPasswords {
		if buf == nil {
			continue
		}
		passwords = append(passwords, string(buf.Bytes()))
	}
	return passwords, nil
}

// GetAdditionalPasswordAt returns the password at the specified index
func (c *Config) GetAdditionalPasswordAt(index int) (string, error) {
	if index < 0 || index >= len(c.additionalPasswords) {
		return "", errors.New("index out of range")
	}
	if c.additionalPasswords[index] == nil {
		return "", errors.New("password at index is nil")
	}
	return string(c.additionalPasswords[index].Bytes()), nil
}

// RemoveAdditionalPasswordAt removes and destroys the password at the specified index
func (c *Config) RemoveAdditionalPasswordAt(index int) error {
	if index < 0 || index >= len(c.additionalPasswords) {
		return errors.New("index out of range")
	}
	if c.additionalPasswords[index] != nil {
		c.additionalPasswords[index].Destroy()
	}
	c.additionalPasswords = append(c.additionalPasswords[:index], c.additionalPasswords[index+1:]...)
	return nil
}

// ClearAdditionalPasswords removes and destroys all additional passwords
func (c *Config) ClearAdditionalPasswords() {
	for _, buf := range c.additionalPasswords {
		if buf != nil {
			buf.Destroy()
		}
	}
	c.additionalPasswords = []*memguard.LockedBuffer{}
}