package protocol

import (
	"context"
	"errors"
	"time"

	"github.com/golang/protobuf/proto"
	"go.uber.org/zap"

	ethcommon "github.com/ethereum/go-ethereum/common"
	"github.com/status-im/status-go/account"
	"github.com/status-im/status-go/eth-node/types"
	"github.com/status-im/status-go/multiaccounts/accounts"
	"github.com/status-im/status-go/protocol/common"
	"github.com/status-im/status-go/protocol/encryption/multidevice"
	"github.com/status-im/status-go/protocol/protobuf"
)

var (
	checkBalancesInterval = time.Minute * 10

	ErrCannotChangeKeypairName = errors.New("cannot change profile keypair name")
)

func (m *Messenger) retrieveWalletBalances() error {
	if m.walletAPI == nil {
		m.logger.Warn("wallet api not enabled")
	}
	accounts, err := m.settings.GetAccounts()
	if err != nil {
		return err
	}

	if len(accounts) == 0 {
		m.logger.Info("no accounts to sync wallet balance")
	}

	var ethAccounts []ethcommon.Address

	for _, acc := range accounts {
		m.logger.Info("syncing wallet address", zap.String("account", acc.Address.Hex()))
		ethAccounts = append(ethAccounts, ethcommon.BytesToAddress(acc.Address.Bytes()))
	}

	ctx, cancel := context.WithTimeout(context.Background(), time.Minute*5)
	defer cancel()

	// TODO: publish tokens as a signal
	_, err = m.walletAPI.GetWalletToken(ctx, ethAccounts)
	if err != nil {
		return err
	}

	return nil
}

func (m *Messenger) watchWalletBalances() {
	m.logger.Info("watching wallet balances")

	if m.walletAPI == nil {
		m.logger.Warn("wallet service not enabled")
		return
	}
	go func() {
		for {
			select {
			case <-time.After(checkBalancesInterval):

				err := m.retrieveWalletBalances()
				if err != nil {
					m.logger.Error("failed to retrieve wallet balances", zap.Error(err))
				}
			case <-m.quit:
				return
			}
		}
	}()
}

func (m *Messenger) UpdateKeypairName(keyUID string, name string) error {
	if keyUID == m.account.KeyUID && name != m.account.Name {
		// profile keypair name must always follow profile display name
		return ErrCannotChangeKeypairName
	}
	clock, _ := m.getLastClockWithRelatedChat()
	err := m.settings.UpdateKeypairName(keyUID, name, clock, keyUID == m.account.KeyUID)
	if err != nil {
		return err
	}

	return m.resolveAndSyncKeypairOrJustWalletAccount(keyUID, types.Address{}, clock, m.dispatchMessage)
}

func (m *Messenger) UpdateAccountPosition(address types.Address, position int64) error {
	acc, err := m.settings.GetAccountByAddress(address)
	if err != nil {
		return err
	}

	clock, _ := m.getLastClockWithRelatedChat()
	acc.Clock = clock

	err = m.settings.UpdateAccountPosition(address, position, clock)
	if err != nil {
		return err
	}

	return m.resolveAndSyncKeypairOrJustWalletAccount(acc.KeyUID, acc.Address, acc.Clock, m.dispatchMessage)
}

func (m *Messenger) resolveAndSetAccountPropsMaintainedByBackend(acc *accounts.Account) error {
	// Account position is fully maintained by the backend, no need client to set it explicitly.
	// To support DragAndDrop feature for accounts there is exposed `UpdateAccountPosition` which
	// moves an account to the passed position.
	//
	// Account operability is fully maintained by the backend, for new accounts created on this device
	// it is always set to fully operable, while for accounts received by syncing process or fetched from waku
	// is set by logic placed in `resolveAccountOperability` function.
	//
	// TODO: making not or partially operable accounts fully operable will be added later, but for sure it will
	// be handled by the backend only, no need client to set it explicitly.

	dbAccount, err := m.settings.GetAccountByAddress(acc.Address)
	if err != nil && err != accounts.ErrDbAccountNotFound {
		return err
	}
	if dbAccount != nil {
		acc.Position = dbAccount.Position
		acc.Operable = dbAccount.Operable
	} else {
		pos, err := m.settings.GetPositionForNextNewAccount()
		if err != nil {
			return err
		}
		acc.Position = pos
		acc.Operable = accounts.AccountFullyOperable
	}
	return nil
}

func (m *Messenger) SaveOrUpdateKeypair(keypair *accounts.Keypair) error {
	if keypair.KeyUID == m.account.KeyUID && keypair.Name != m.account.Name {
		// profile keypair name must always follow profile display name
		return ErrCannotChangeKeypairName
	}
	clock, _ := m.getLastClockWithRelatedChat()
	keypair.Clock = clock

	for _, acc := range keypair.Accounts {
		acc.Clock = clock
		err := m.resolveAndSetAccountPropsMaintainedByBackend(acc)
		if err != nil {
			return err
		}
	}

	err := m.settings.SaveOrUpdateKeypair(keypair)
	if err != nil {
		return err
	}

	return m.resolveAndSyncKeypairOrJustWalletAccount(keypair.KeyUID, types.Address{}, keypair.Clock, m.dispatchMessage)
}

func (m *Messenger) SaveOrUpdateAccount(acc *accounts.Account) error {
	clock, _ := m.getLastClockWithRelatedChat()
	acc.Clock = clock

	err := m.resolveAndSetAccountPropsMaintainedByBackend(acc)
	if err != nil {
		return err
	}

	err = m.settings.SaveOrUpdateAccounts([]*accounts.Account{acc}, true)
	if err != nil {
		return err
	}

	return m.resolveAndSyncKeypairOrJustWalletAccount(acc.KeyUID, acc.Address, acc.Clock, m.dispatchMessage)
}

func (m *Messenger) deleteKeystoreFileForAddress(address types.Address) error {
	acc, err := m.settings.GetAccountByAddress(address)
	if err != nil {
		return err
	}

	if acc.Operable == accounts.AccountNonOperable || acc.Operable == accounts.AccountPartiallyOperable {
		return nil
	}

	if acc.Type != accounts.AccountTypeWatch {
		kp, err := m.settings.GetKeypairByKeyUID(acc.KeyUID)
		if err != nil {
			return err
		}

		lastAcccountOfKeypairWithTheSameKey := len(kp.Accounts) == 1

		knownKeycardsForKeyUID, err := m.settings.GetKeycardsWithSameKeyUID(acc.KeyUID)
		if err != nil {
			return err
		}

		if len(knownKeycardsForKeyUID) == 0 {
			err = m.accountsManager.DeleteAccount(address)
			var e *account.ErrCannotLocateKeyFile
			if err != nil && !errors.As(err, &e) {
				return err
			}

			if acc.Type != accounts.AccountTypeKey {
				if lastAcccountOfKeypairWithTheSameKey {
					err = m.accountsManager.DeleteAccount(types.Address(ethcommon.HexToAddress(kp.DerivedFrom)))
					var e *account.ErrCannotLocateKeyFile
					if err != nil && !errors.As(err, &e) {
						return err
					}
				}
			}
		}
	}

	return nil
}

func (m *Messenger) DeleteAccount(address types.Address) error {
	err := m.deleteKeystoreFileForAddress(address)
	if err != nil {
		return err
	}

	acc, err := m.settings.GetAccountByAddress(address)
	if err != nil {
		return err
	}

	clock, _ := m.getLastClockWithRelatedChat()

	err = m.settings.DeleteAccount(address, clock)
	if err != nil {
		return err
	}

	return m.resolveAndSyncKeypairOrJustWalletAccount(acc.KeyUID, acc.Address, clock, m.dispatchMessage)
}

func (m *Messenger) prepareSyncAccountMessage(acc *accounts.Account) *protobuf.SyncAccount {
	return &protobuf.SyncAccount{
		Clock:     acc.Clock,
		Address:   acc.Address.Bytes(),
		KeyUid:    acc.KeyUID,
		PublicKey: acc.PublicKey,
		Path:      acc.Path,
		Name:      acc.Name,
		ColorId:   string(acc.ColorID),
		Emoji:     acc.Emoji,
		Wallet:    acc.Wallet,
		Chat:      acc.Chat,
		Hidden:    acc.Hidden,
		Removed:   acc.Removed,
		Position:  acc.Position,
	}
}

func (m *Messenger) getMyInstallationMetadata() (*multidevice.InstallationMetadata, error) {
	installation, ok := m.allInstallations.Load(m.installationID)
	if !ok {
		return nil, errors.New("no installation found")
	}

	if installation.InstallationMetadata == nil {
		return nil, errors.New("no installation metadata")
	}

	return installation.InstallationMetadata, nil
}

func (m *Messenger) prepareSyncKeypairMessage(kp *accounts.Keypair) (*protobuf.SyncKeypair, error) {
	message := &protobuf.SyncKeypair{
		Clock:                   kp.Clock,
		KeyUid:                  kp.KeyUID,
		Name:                    kp.Name,
		Type:                    kp.Type.String(),
		DerivedFrom:             kp.DerivedFrom,
		LastUsedDerivationIndex: kp.LastUsedDerivationIndex,
		SyncedFrom:              kp.SyncedFrom,
		Removed:                 kp.Removed,
	}

	if kp.SyncedFrom == "" {
		installationMetadata, err := m.getMyInstallationMetadata()
		if err != nil {
			return nil, err
		}
		message.SyncedFrom = installationMetadata.Name
	}

	for _, acc := range kp.Accounts {
		sAcc := m.prepareSyncAccountMessage(acc)
		if sAcc == nil {
			continue
		}

		message.Accounts = append(message.Accounts, sAcc)
	}

	syncKcMsgs, err := m.prepareSyncKeycardsMessage(kp.KeyUID)
	if err != nil {
		return nil, err
	}
	message.Keycards = syncKcMsgs

	return message, nil
}

func (m *Messenger) syncWalletAccount(acc *accounts.Account, rawMessageHandler RawMessageHandler) error {
	if !m.hasPairedDevices() {
		return nil
	}

	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	_, chat := m.getLastClockWithRelatedChat()

	message := m.prepareSyncAccountMessage(acc)

	encodedMessage, err := proto.Marshal(message)
	if err != nil {
		return err
	}

	rawMessage := common.RawMessage{
		LocalChatID:         chat.ID,
		Payload:             encodedMessage,
		MessageType:         protobuf.ApplicationMetadataMessage_SYNC_ACCOUNT,
		ResendAutomatically: true,
	}

	_, err = rawMessageHandler(ctx, rawMessage)
	return err
}

func (m *Messenger) syncKeypair(keypair *accounts.Keypair, rawMessageHandler RawMessageHandler) (err error) {
	if !m.hasPairedDevices() {
		return nil
	}

	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	_, chat := m.getLastClockWithRelatedChat()
	rawMessage := common.RawMessage{
		LocalChatID:         chat.ID,
		ResendAutomatically: true,
		MessageType:         protobuf.ApplicationMetadataMessage_SYNC_KEYPAIR,
	}

	message, err := m.prepareSyncKeypairMessage(keypair)
	if err != nil {
		return err
	}

	rawMessage.Payload, err = proto.Marshal(message)
	if err != nil {
		return err
	}

	_, err = rawMessageHandler(ctx, rawMessage)
	return err
}

// This function resolves which protobuf message needs to be sent.
//
// If `KeyUID` is empty (means it's a watch only account) we send `protobuf.SyncAccount` message
// otherwise means the account belong to a keypai, hence we send `protobuf.SyncKeypair` message
func (m *Messenger) resolveAndSyncKeypairOrJustWalletAccount(keyUID string, address types.Address, clock uint64, rawMessageHandler RawMessageHandler) error {
	if !m.hasPairedDevices() {
		return nil
	}

	if keyUID == "" {
		dbAccount, err := m.settings.GetAccountByAddress(address)
		if err != nil && err != accounts.ErrDbAccountNotFound {
			return err
		}
		if dbAccount == nil {
			dbAccount = &accounts.Account{
				Address: address,
				Clock:   clock,
				Removed: true,
			}
		}
		err = m.syncWalletAccount(dbAccount, rawMessageHandler)
		if err != nil {
			return err
		}
	} else {
		dbKeypair, err := m.settings.GetKeypairByKeyUID(keyUID)
		if err != nil && err != accounts.ErrDbKeypairNotFound {
			return err
		}

		if dbKeypair == nil {
			// In case entire keypair was removed (happens if user removes the last account for a keypair).
			dbKeypair = &accounts.Keypair{
				KeyUID:  keyUID,
				Clock:   clock,
				Removed: true,
			}
		}

		err = m.syncKeypair(dbKeypair, rawMessageHandler)
		if err != nil {
			return err
		}
	}

	_, chat := m.getLastClockWithRelatedChat()
	chat.LastClockValue = clock
	return m.saveChat(chat)
}