package client

import (
	"encoding/json"
	"errors"
	"math/rand"
	"os"
	"time"

	"forge.redroom.link/yves/meowlib"
	"github.com/ProtonMail/gopenpgp/v2/helper"
	"github.com/google/uuid"
)

const maxHiddenCount = 30

type Identity struct {
	Nickname             string          `json:"nickname,omitempty"`
	DefaultAvatar        string          `json:"default_avatar,omitempty"`
	RootKp               meowlib.KeyPair `json:"id_kp,omitempty"`
	Status               string          `json:"status,omitempty"`
	Peers                PeerList        `json:"peers,omitempty"`
	HiddenPeers          [][]byte        `json:"hiddend_peers,omitempty"`
	Device               meowlib.KeyPair `json:"device,omitempty"`
	KnownServers         ServerList      `json:"known_servers,omitempty"`
	MessageServers       ServerList      `json:"message_servers,omitempty"`
	DefaultDbPassword    string          `json:"default_db_password,omitempty"`
	DbPasswordStore      bool            `json:"db_password_store,omitempty"`
	OwnedDevices         PeerList        `json:"owned_devices,omitempty"`
	StaticMtkServerPaths []ServerList    `json:"static_mtk_server_paths,omitempty"`
	DynamicMtkServeRules []string        `json:"dynamic_mtk_serve_rules,omitempty"`
	InvitationTimeout    int             `json:"invitation_timeout,omitempty"`
	unlockedHiddenPeers  PeerList
}

func CreateIdentity(nickname string) *Identity {
	var id Identity
	id.Nickname = nickname
	id.RootKp = meowlib.NewKeyPair()
	GetConfig().me = &id
	id.generateRandomHiddenStuff()
	return &id
}

// Creates an invitation for a peer, returns the peer containing
func (id *Identity) InvitePeer(MyName string, ContactName string, MessageServerIdxs []int) (*Peer, *meowlib.ContactCard, error) {
	var peer Peer
	var myContactCard meowlib.ContactCard
	peer.MyIdentity = meowlib.NewKeyPair()
	peer.MyEncryptionKp = meowlib.NewKeyPair()
	peer.MyLookupKp = meowlib.NewKeyPair()
	peer.Name = ContactName
	peer.InvitationId = uuid.New().String()
	if id.MessageServers.Servers == nil {
		return nil, nil, errors.New("no message servers defined in your identity")
	}
	for _, i := range MessageServerIdxs {
		if i > len(id.MessageServers.Servers)-1 {
			return nil, nil, errors.New("requested server out of range of defined message servers")
		}
	}
	for _, i := range MessageServerIdxs {
		srv := &id.MessageServers.Servers[i].ServerData
		myContactCard.PullServers = append(myContactCard.PullServers, srv)
	}
	myContactCard.Name = MyName
	myContactCard.ContactPublicKey = peer.MyIdentity.Public
	myContactCard.EncryptionPublicKey = peer.MyEncryptionKp.Public
	myContactCard.LookupPublicKey = peer.MyLookupKp.Public
	myContactCard.InvitationId = peer.InvitationId
	id.Peers = append(id.Peers, peer)

	return &peer, &myContactCard, nil
}

func (id *Identity) CheckInvitation(ReceivedContact *meowlib.ContactCard) (isAnswer bool, proposedNick string, receivedNick string) {
	for _, p := range id.Peers {
		if p.InvitationId == ReceivedContact.InvitationId {
			return true, p.Name, ReceivedContact.Name
		}
	}
	return false, "", ReceivedContact.Name
}

func (id *Identity) AnswerInvitation(MyName string, ContactName string, MessageServerIdxs []int, ReceivedContact *meowlib.ContactCard) *meowlib.ContactCard {
	var peer Peer
	var myContactCard meowlib.ContactCard
	peer.MyIdentity = meowlib.NewKeyPair()
	peer.MyEncryptionKp = meowlib.NewKeyPair()
	peer.MyLookupKp = meowlib.NewKeyPair()
	if ContactName != "" {
		peer.Name = ContactName
	} else {
		peer.Name = ReceivedContact.Name
	}
	peer.Contact = *ReceivedContact
	for _, i := range MessageServerIdxs {
		srv := id.MessageServers.Servers[i].ServerData
		myContactCard.PullServers = append(myContactCard.PullServers, &srv)
	}
	myContactCard.Name = MyName
	myContactCard.ContactPublicKey = peer.MyIdentity.Public
	myContactCard.EncryptionPublicKey = peer.MyEncryptionKp.Public
	myContactCard.LookupPublicKey = peer.MyLookupKp.Public
	myContactCard.InvitationId = ReceivedContact.InvitationId

	id.Peers = append(id.Peers, peer)

	return &myContactCard
}

func (id *Identity) FinalizeInvitation(ReceivedContact *meowlib.ContactCard) error {
	for i, p := range id.Peers {
		if p.InvitationId == ReceivedContact.InvitationId {
			id.Peers[i].Contact = *ReceivedContact
			return nil
		}
	}
	return errors.New("no matching contact found for invitationId " + ReceivedContact.InvitationId)
}

func LoadIdentity(filename string, password string) (*Identity, error) {
	var id Identity
	GetConfig().memoryPassword = password
	GetConfig().IdentityFile = filename
	indata, err := os.ReadFile(filename)
	if err != nil {
		return nil, err
	}
	pass, err := helper.DecryptMessageWithPassword([]byte(password), string(indata))
	if err != nil {
		return nil, err
	}
	err = json.Unmarshal([]byte(pass), &id)
	GetConfig().me = &id
	return &id, err
}

func (id *Identity) Save() error {
	if GetConfig().IdentityFile == "" {
		return errors.New("identity filename empty")
	}
	b, _ := json.Marshal(id)
	armor, err := helper.EncryptMessageWithPassword([]byte(GetConfig().memoryPassword), string(b))
	if err != nil {
		return err
	}
	err = os.WriteFile(GetConfig().IdentityFile, []byte(armor), 0600)
	return err
}

func (id *Identity) TryUnlockHidden(password string) error {
	found := false
	for _, encPeer := range id.HiddenPeers {
		p := Peer{}
		jsonPeer, err := meowlib.SymDecrypt(password, encPeer)
		if err == nil {
			err = json.Unmarshal(jsonPeer, &p)
			if err != nil {
				return err
			}
			p.dbPassword = password
			id.unlockedHiddenPeers = append(id.unlockedHiddenPeers, p)
			found = true
		}
	}
	if found {
		return nil
	}
	return errors.New("no peer found")
}

func (id *Identity) HidePeer(peerIdx int, password string) error {
	serializedPeer, err := json.Marshal(id.Peers[peerIdx])
	if err != nil {
		return err
	}
	encrypted, err := meowlib.SymEncrypt(password, serializedPeer)
	if err != nil {
		return err
	}
	// add encrypted peer data
	id.HiddenPeers = append(id.HiddenPeers, encrypted)
	// remove clear text peer
	id.Peers = append(id.Peers[:peerIdx], id.Peers[peerIdx+1:]...)
	return nil
}

func (id *Identity) generateRandomHiddenStuff() {
	rand.Seed(time.Now().UnixNano())
	count := rand.Intn(maxHiddenCount) + 1
	for i := 1; i < count; i++ {
		var p Peer
		p.Name = randomLenString(4, 20)
		p.MyEncryptionKp = meowlib.NewKeyPair()
		p.MyIdentity = meowlib.NewKeyPair()
		p.MyLookupKp = meowlib.NewKeyPair()
		p.Contact.Name = randomLenString(4, 20)
		p.Contact.ContactPublicKey = p.MyLookupKp.Public
		p.Contact.EncryptionPublicKey = p.MyIdentity.Public
		p.Contact.LookupPublicKey = p.MyEncryptionKp.Public
		p.Contact.AddUrls([]string{randomLenString(14, 60), randomLenString(14, 60)})
		id.Peers = append(id.Peers, p)
		id.HidePeer(0, randomLenString(8, 14))
		// TODO Add conversations
	}
}

func randomLenString(min int, max int) string {
	rand.Seed(time.Now().UnixNano())
	n := rand.Intn(max-min) + min
	return randomString(n)
}

func randomString(n int) string {
	var letters = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")
	s := make([]rune, n)
	for i := range s {
		s[i] = letters[rand.Intn(len(letters))]
	}
	return string(s)
}