package client

import (
	"fmt"
	"io"
	"os"
	"time"

	"forge.redroom.link/yves/meowlib"
	"github.com/google/uuid"
	"google.golang.org/protobuf/proto"
)

// Peer manages the peer messaging functions
//   - Building simple user messages
//   - Utility functions for packing/unpacking, encrypting/decrypting messages for peer communication
type Peer struct {
	Uid      string `json:"uid,omitempty"`
	Name     string `json:"name,omitempty"`
	Avatar   string `json:"avatar,omitempty"`
	MyName   string `json:"my_name,omitempty"`
	MyAvatar string `json:"my_avatar,omitempty"`
	//	Conversation        []InternalMessage `json:"conversation,omitempty"`
	// My own keys for that peer
	MyIdentity     meowlib.KeyPair `json:"my_identity,omitempty"`
	MyEncryptionKp meowlib.KeyPair `json:"my_encryption_kp,omitempty"`
	MyLookupKp     meowlib.KeyPair `json:"my_lookup_kp,omitempty"`
	MyPullServers  []string        `json:"my_pull_servers,omitempty"`
	// Peer keys and infos
	//Contact            meowlib.ContactCard `json:"contact,omitempty"` // todo : remove
	ContactPublicKey   string               `json:"contact_public_key,omitempty"`
	ContactLookupKey   string               `json:"contact_lookup_key,omitempty"`
	ContactEncryption  string               `json:"contact_encryption,omitempty"`
	ContactPullServers []string             `json:"contact_pull_servers,omitempty"`
	InvitationId       string               `json:"invitation_id,omitempty"`
	InvitationUrl      string               `json:"invitation_url,omitempty"`
	InvitationMessage  string               `json:"invitation_message,omitempty"`
	InvitationExpiry   time.Time            `json:"invitation_expiry,omitempty"`
	LastMessage        *InternalUserMessage `json:"last_message,omitempty"`
	// Internal management attributes
	Visible             bool     `json:"visible,omitempty"`
	VisiblePassword     string   `json:"visible_password,omitempty"`
	PasswordType        string   `json:"password_type,omitempty"`
	Blocked             bool     `json:"blocked,omitempty"`
	MessageNotification string   `json:"message_notification,omitempty"`
	MatriochkaMode      bool     `json:"matriochka_mode,omitempty"`
	DirectMode          bool     `json:"direct_mode,omitempty"`
	DbIds               []string `json:"db_ids,omitempty"`
	IsDevice            bool     `json:"is_device,omitempty"`
	dbPassword          string
}

//
// getters and setters
//

func (p *Peer) GetMyContact() *meowlib.ContactCard {
	var c meowlib.ContactCard
	c.ContactPublicKey = p.MyIdentity.Public
	c.LookupPublicKey = p.MyLookupKp.Public
	c.EncryptionPublicKey = p.MyEncryptionKp.Public
	srvCards, err := GetConfig().GetIdentity().MessageServers.LoadServerCardsFromUids(p.MyPullServers)
	if err == nil {
		c.PullServers = srvCards
	}
	c.InvitationId = p.InvitationId
	c.InvitationMessage = p.InvitationMessage
	c.Name = p.MyName
	return &c
}

func (p *Peer) GetContact() *meowlib.ContactCard {
	var c meowlib.ContactCard
	c.ContactPublicKey = p.ContactPublicKey
	c.LookupPublicKey = p.ContactLookupKey
	c.EncryptionPublicKey = p.ContactEncryption
	srvCards, err := GetConfig().GetIdentity().MessageServers.LoadServerCardsFromUids(p.ContactPullServers)
	if err == nil {
		c.PullServers = srvCards
	}
	c.InvitationId = p.InvitationId
	c.InvitationMessage = p.InvitationMessage
	c.Name = p.Name
	return &c
}

func (p *Peer) InvitationPending() bool {
	if p.ContactPublicKey == "" {
		return true
	}
	return false
}

//
// Messages building
//

func (p *Peer) BuildSimpleUserMessage(message []byte) (*meowlib.UserMessage, error) {
	var msg meowlib.UserMessage
	msg.Destination = p.ContactLookupKey
	msg.From = p.MyIdentity.Public
	msg.Data = message
	msg.Type = "1"
	msg.Status = &meowlib.ConversationStatus{}
	msg.Status.Uuid = uuid.New().String()

	return &msg, nil
}

func (p *Peer) BuildSingleFileMessage(filename string, message []byte) ([]meowlib.UserMessage, error) {
	var msgs []meowlib.UserMessage
	fi, err := os.Stat(filename)
	if err != nil {
		return nil, err
	}
	file, err := os.Open(filename)
	if err != nil {
		return nil, err
	}
	defer file.Close()
	// declare chunk size
	maxSz := GetConfig().Chunksize
	// create buffer
	b := make([]byte, maxSz)
	chunk := 0
	for {
		// read content to buffer
		readTotal, err := file.Read(b)
		if err != nil {
			if err != io.EOF {
				return nil, err
			}
			break
		}
		var msg meowlib.UserMessage
		var file meowlib.File
		msg.Destination = p.ContactLookupKey
		msg.From = p.MyIdentity.Public
		file.Filename = fi.Name()
		file.Chunk = uint32(chunk)
		file.Data = b[:readTotal]
		file.Size = uint64(fi.Size())
		msg.Files = append(msg.Files, &file)
		msg.Type = "1"
		if chunk == 0 {
			msg.Status = &meowlib.ConversationStatus{}
			msg.Status.Uuid = uuid.New().String()
		}
		msgs = append(msgs, msg)
		chunk++
	}
	return msgs, nil
}

// Builds an invitation answer user message.
// it takes as input a contactcard generated by Identity.AnswerInvitation
func (p *Peer) BuildInvitationAnswerMessage(myContactCard *meowlib.ContactCard) (*meowlib.UserMessage, error) {
	var msg meowlib.UserMessage
	var invitation meowlib.Invitation
	invitation.Step = 3
	out, err := proto.Marshal(myContactCard)
	if err != nil {
		return nil, err
	}
	invitation.Uuid = p.InvitationId
	invitation.Payload = out
	msg.Destination = p.ContactLookupKey
	msg.Invitation = &invitation
	msg.From = p.MyIdentity.Public
	msg.Type = "1"
	return &msg, nil
}

//
// Messages encryption and packaging
//

func (p *Peer) SerializeUserMessage(msg *meowlib.UserMessage) ([]byte, error) {
	out, err := proto.Marshal(msg)
	if err != nil {
		return nil, err
	}
	return out, nil
}

func (p *Peer) DeserializeUserMessage(data []byte) (*meowlib.UserMessage, error) {
	var msg meowlib.UserMessage
	err := proto.Unmarshal(data, &msg)
	if err != nil {
		return nil, err
	}
	return &msg, nil
}

// AsymEncryptMessage prepares a message to send to a specific peer contact
func (p *Peer) AsymEncryptMessage(Message []byte) (*meowlib.EncryptedMessage, error) {
	var enc *meowlib.EncryptedMessage
	// fmt.Println("[AsymEncryptMessage] Destination is:", p.ContactLookupKey)
	// fmt.Println("[AsymEncryptMessage] Contact encryption key is:", p.ContactEncryption)
	// fmt.Println("[AsymEncryptMessage] My signing key is:", p.MyIdentity.Private)
	// fmt.Println("[AsymEncryptMessage] Signature should be verified with:", p.MyIdentity.Public)
	enc, err := meowlib.AsymEncryptAndSign(p.ContactEncryption, p.MyIdentity.Private, Message)
	if err != nil {
		fmt.Println(err.Error())
		return enc, err
	}
	return enc, err
}

// AsymDecryptMessage reads a message from a specific peer contact
func (p *Peer) AsymDecryptMessage(Message []byte, Signature []byte) (DecryptedMessage []byte, err error) {
	// fmt.Println("[AsymDecryptMessage] Decrypting key is:", p.MyEncryptionKp.Private)
	// fmt.Println("[AsymDecryptMessage] Should have been encrypted with:", p.MyEncryptionKp.Public)
	// fmt.Println("[AsymDecryptMessage] Signature will be verified with:", p.ContactPublicKey)
	DecryptedMessage, err = meowlib.AsymDecryptAndCheck(p.MyEncryptionKp.Private, p.ContactPublicKey, Message, Signature)
	if err != nil {
		fmt.Println(err.Error())
		return nil, err
	}
	return DecryptedMessage, err
}

// PackUserMessage will package the previously encrypted message
func (p *Peer) PackUserMessage(message []byte, signature []byte) *meowlib.PackedUserMessage {
	var msg meowlib.PackedUserMessage
	msg.Destination = p.ContactLookupKey
	msg.Payload = message
	msg.Signature = signature
	return &msg
}

// UnPackUserMessage unpacks a user message
func (p *Peer) UnPackUserMessage(protoPackedMessage []byte) (payload []byte, signature []byte, err error) {
	msg := &meowlib.PackedServerMessage{}
	if err := proto.Unmarshal(protoPackedMessage, msg); err != nil {
		return nil, nil, err
	}
	return msg.Payload, msg.Signature, nil
}

func (p *Peer) GetConversationRequest() *meowlib.ConversationRequest {
	var cr meowlib.ConversationRequest
	return &cr
}

// ProcessOutboundUserMessage is a helper function that serializes, encrypts and packs a user message
func (p *Peer) ProcessOutboundUserMessage(usermessage *meowlib.UserMessage) (*meowlib.PackedUserMessage, error) {
	serializedMessage, err := p.SerializeUserMessage(usermessage)
	if err != nil {
		return nil, err
	}
	// Encrypting it
	enc, err := p.AsymEncryptMessage(serializedMessage)
	if err != nil {
		return nil, err
	}
	// Packing it
	packedMsg := p.PackUserMessage(enc.Data, enc.Signature)
	return packedMsg, nil
}

// ProcessInboundUserMessage is a helper function that decrypts and deserializes a user message
func (p *Peer) ProcessInboundUserMessage(message []byte, signature []byte) (*meowlib.UserMessage, error) {
	dec, err := p.AsymDecryptMessage(message, signature)
	if err != nil {
		return nil, err
	}
	msg, err := p.DeserializeUserMessage(dec)
	if err != nil {
		return nil, err
	}
	return msg, nil
}

//
// Messages database
//

// SetDbPassword sets a specific password for a hidden user, it won't be saved, but kept in memory only for the next operations
func (p *Peer) SetDbPassword(password string) {
	p.dbPassword = password
}

func (p *Peer) GetDbPassword() string {
	if p.dbPassword == "" {
		return GetConfig().memoryPassword
	}
	return p.dbPassword
}

func (p *Peer) StoreMessage(msg *meowlib.UserMessage, filenames []string) error {
	return StoreMessage(p, msg, filenames, p.GetDbPassword())
}

func (p *Peer) GetFilePreview(filename string) ([]byte, error) {
	return FilePreview(filename, p.GetDbPassword())
}

func (p *Peer) UpdateMessage(msg InternalUserMessage) error {
	return nil
}

func (p *Peer) LoadMessagesHistory(alreadyLoadedCount int, oldestMessageId int, qty int) ([]InternalUserMessage, error) {
	return GetMessagesHistory(p, alreadyLoadedCount, oldestMessageId, qty, p.GetDbPassword())

}

func (p *Peer) LoadNewMessages(lastMessageId int) ([]*InternalUserMessage, error) {
	return GetNewMessages(p, lastMessageId, p.GetDbPassword())
}

func (p *Peer) LoadMessage(uid string) (*InternalUserMessage, error) {
	return nil, nil
}

func (p *Peer) GetLastMessageUuid(msg []byte) {

}