package protocol

import (
	"bytes"
	"context"
	"crypto/ecdsa"
	crand "crypto/rand"
	"errors"
	"reflect"
	"sort"

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

	"github.com/status-im/status-go/eth-node/crypto"
	"github.com/status-im/status-go/multiaccounts/accounts"
	"github.com/status-im/status-go/protocol/common"
	"github.com/status-im/status-go/protocol/communities"
	"github.com/status-im/status-go/protocol/identity"
	"github.com/status-im/status-go/protocol/protobuf"
)

var errorDecryptingPayloadEncryptionKey = errors.New("decrypting the payload encryption key resulted in no error and a nil key")

func (m *Messenger) toProfileShowcaseCommunityProto(preferences []*identity.ProfileShowcaseCommunityPreference, visibility identity.ProfileShowcaseVisibility) []*protobuf.ProfileShowcaseCommunity {
	entries := []*protobuf.ProfileShowcaseCommunity{}
	for _, preference := range preferences {
		if preference.ShowcaseVisibility != visibility {
			continue
		}

		entry := &protobuf.ProfileShowcaseCommunity{
			CommunityId: preference.CommunityID,
			Order:       uint32(preference.Order),
		}

		community, err := m.communitiesManager.GetByIDString(preference.CommunityID)
		if err != nil {
			m.logger.Warn("failed to get community for profile entry ", zap.Error(err))
		}

		if community != nil && community.Encrypted() {
			grant, _, err := m.communitiesManager.GetCommunityGrant(preference.CommunityID)
			if err != nil {
				m.logger.Warn("failed to get community for profile entry ", zap.Error(err))
			}

			entry.Grant = grant
		}

		entries = append(entries, entry)
	}
	return entries
}

func (m *Messenger) toProfileShowcaseAccountProto(preferences []*identity.ProfileShowcaseAccountPreference, visibility identity.ProfileShowcaseVisibility) []*protobuf.ProfileShowcaseAccount {
	entries := []*protobuf.ProfileShowcaseAccount{}
	for _, preference := range preferences {
		if preference.ShowcaseVisibility != visibility {
			continue
		}

		entries = append(entries, &protobuf.ProfileShowcaseAccount{
			Address: preference.Address,
			Name:    preference.Name,
			ColorId: preference.ColorID,
			Emoji:   preference.Emoji,
			Order:   uint32(preference.Order),
		})
	}
	return entries
}

func (m *Messenger) toProfileShowcaseCollectibleProto(preferences []*identity.ProfileShowcaseCollectiblePreference, visibility identity.ProfileShowcaseVisibility) []*protobuf.ProfileShowcaseCollectible {
	entries := []*protobuf.ProfileShowcaseCollectible{}
	for _, preference := range preferences {
		if preference.ShowcaseVisibility != visibility {
			continue
		}

		entries = append(entries, &protobuf.ProfileShowcaseCollectible{
			ContractAddress: preference.ContractAddress,
			ChainId:         preference.ChainID,
			TokenId:         preference.TokenID,
			CommunityId:     preference.CommunityID,
			AccountAddress:  preference.AccountAddress,
			Order:           uint32(preference.Order),
		})
	}
	return entries
}

func (m *Messenger) toProfileShowcaseVerifiedTokensProto(preferences []*identity.ProfileShowcaseVerifiedTokenPreference, visibility identity.ProfileShowcaseVisibility) []*protobuf.ProfileShowcaseVerifiedToken {
	entries := []*protobuf.ProfileShowcaseVerifiedToken{}
	for _, preference := range preferences {
		if preference.ShowcaseVisibility != visibility {
			continue
		}

		entries = append(entries, &protobuf.ProfileShowcaseVerifiedToken{
			Symbol: preference.Symbol,
			Order:  uint32(preference.Order),
		})
	}
	return entries
}

func (m *Messenger) toProfileShowcaseUnverifiedTokensProto(preferences []*identity.ProfileShowcaseUnverifiedTokenPreference, visibility identity.ProfileShowcaseVisibility) []*protobuf.ProfileShowcaseUnverifiedToken {
	entries := []*protobuf.ProfileShowcaseUnverifiedToken{}
	for _, preference := range preferences {
		if preference.ShowcaseVisibility != visibility {
			continue
		}

		entries = append(entries, &protobuf.ProfileShowcaseUnverifiedToken{
			ContractAddress: preference.ContractAddress,
			ChainId:         preference.ChainID,
			Order:           uint32(preference.Order),
		})
	}
	return entries
}

func (m *Messenger) fromProfileShowcaseCommunityProto(senderPubKey *ecdsa.PublicKey, messages []*protobuf.ProfileShowcaseCommunity) []*identity.ProfileShowcaseCommunity {
	entries := []*identity.ProfileShowcaseCommunity{}
	for _, message := range messages {
		entry := &identity.ProfileShowcaseCommunity{
			CommunityID:      message.CommunityId,
			Order:            int(message.Order),
			MembershipStatus: identity.ProfileShowcaseMembershipStatusUnproven,
		}

		community, err := m.FetchCommunity(&FetchCommunityRequest{
			CommunityKey:    message.CommunityId,
			Shard:           nil,
			TryDatabase:     true,
			WaitForResponse: true,
		})
		if err != nil {
			m.logger.Warn("failed to fetch community for profile entry ", zap.Error(err))
		}

		if community != nil && community.Encrypted() {
			grant, err := community.VerifyGrantSignature(message.Grant)
			if err != nil {
				m.logger.Warn("failed to verify grant signature ", zap.Error(err))
				entry.MembershipStatus = identity.ProfileShowcaseMembershipStatusNotAMember
			} else {
				if grant != nil && bytes.Equal(grant.MemberId, crypto.CompressPubkey(senderPubKey)) {
					entry.MembershipStatus = identity.ProfileShowcaseMembershipStatusProvenMember
				} else { // Show as not a member if membership can't be proven
					entry.MembershipStatus = identity.ProfileShowcaseMembershipStatusNotAMember
				}
			}
		} else if community != nil {
			// Use member list as a proof for unecrypted communities
			if community.HasMember(senderPubKey) {
				entry.MembershipStatus = identity.ProfileShowcaseMembershipStatusProvenMember
			} else {
				entry.MembershipStatus = identity.ProfileShowcaseMembershipStatusNotAMember
			}
		}

		entries = append(entries, entry)
	}
	return entries
}

func (m *Messenger) fromProfileShowcaseAccountProto(messages []*protobuf.ProfileShowcaseAccount) []*identity.ProfileShowcaseAccount {
	entries := []*identity.ProfileShowcaseAccount{}
	for _, entry := range messages {
		entries = append(entries, &identity.ProfileShowcaseAccount{
			Address: entry.Address,
			Name:    entry.Name,
			ColorID: entry.ColorId,
			Emoji:   entry.Emoji,
			Order:   int(entry.Order),
		})
	}
	return entries
}

func (m *Messenger) fromProfileShowcaseCollectibleProto(messages []*protobuf.ProfileShowcaseCollectible) []*identity.ProfileShowcaseCollectible {
	entries := []*identity.ProfileShowcaseCollectible{}
	for _, entry := range messages {
		entries = append(entries, &identity.ProfileShowcaseCollectible{
			ContractAddress: entry.ContractAddress,
			ChainID:         entry.ChainId,
			TokenID:         entry.TokenId,
			CommunityID:     entry.CommunityId,
			AccountAddress:  entry.AccountAddress,
			Order:           int(entry.Order),
		})
	}
	return entries
}

func (m *Messenger) fromProfileShowcaseVerifiedTokenProto(messages []*protobuf.ProfileShowcaseVerifiedToken) []*identity.ProfileShowcaseVerifiedToken {
	entries := []*identity.ProfileShowcaseVerifiedToken{}
	for _, entry := range messages {
		entries = append(entries, &identity.ProfileShowcaseVerifiedToken{
			Symbol: entry.Symbol,
			Order:  int(entry.Order),
		})
	}
	return entries
}

func (m *Messenger) fromProfileShowcaseUnverifiedTokenProto(messages []*protobuf.ProfileShowcaseUnverifiedToken) []*identity.ProfileShowcaseUnverifiedToken {
	entries := []*identity.ProfileShowcaseUnverifiedToken{}
	for _, entry := range messages {
		entries = append(entries, &identity.ProfileShowcaseUnverifiedToken{
			ContractAddress: entry.ContractAddress,
			ChainID:         entry.ChainId,
			Order:           int(entry.Order),
		})
	}
	return entries
}

func (m *Messenger) SetProfileShowcasePreferences(preferences *identity.ProfileShowcasePreferences, sync bool) error {
	clock, _ := m.getLastClockWithRelatedChat()
	preferences.Clock = clock
	return m.setProfileShowcasePreferences(preferences, sync)
}

func (m *Messenger) setProfileShowcasePreferences(preferences *identity.ProfileShowcasePreferences, sync bool) error {
	err := identity.Validate(preferences)
	if err != nil {
		return err
	}

	err = m.persistence.SaveProfileShowcasePreferences(preferences)
	if err != nil {
		return err
	}

	if sync {
		err = m.syncProfileShowcasePreferences(context.Background(), m.dispatchMessage)
		if err != nil {
			return err
		}
	}

	return m.DispatchProfileShowcase()
}

func (m *Messenger) DispatchProfileShowcase() error {
	err := m.publishContactCode()
	if err != nil {
		return err
	}
	return nil
}

func (m *Messenger) GetProfileShowcasePreferences() (*identity.ProfileShowcasePreferences, error) {
	return m.persistence.GetProfileShowcasePreferences()
}

func (m *Messenger) GetProfileShowcaseForContact(contactID string) (*identity.ProfileShowcase, error) {
	return m.persistence.GetProfileShowcaseForContact(contactID)
}

func (m *Messenger) GetProfileShowcaseAccountsByAddress(address string) ([]*identity.ProfileShowcaseAccount, error) {
	return m.persistence.GetProfileShowcaseAccountsByAddress(address)
}

func (m *Messenger) EncryptProfileShowcaseEntriesWithContactPubKeys(entries *protobuf.ProfileShowcaseEntries, contacts []*Contact) (*protobuf.ProfileShowcaseEntriesEncrypted, error) {
	// Make AES key
	AESKey := make([]byte, 32)
	_, err := crand.Read(AESKey)
	if err != nil {
		return nil, err
	}

	// Encrypt showcase entries with the AES key
	data, err := proto.Marshal(entries)
	if err != nil {
		return nil, err
	}

	encrypted, err := common.Encrypt(data, AESKey, crand.Reader)
	if err != nil {
		return nil, err
	}

	eAESKeys := [][]byte{}
	// Sign for each contact
	for _, contact := range contacts {
		var pubK *ecdsa.PublicKey
		var sharedKey []byte
		var eAESKey []byte

		pubK, err = contact.PublicKey()
		if err != nil {
			return nil, err
		}
		// Generate a Diffie-Helman (DH) between the sender private key and the recipient's public key
		sharedKey, err = common.MakeECDHSharedKey(m.identity, pubK)
		if err != nil {
			return nil, err
		}

		// Encrypt the main AES key with AES encryption using the DH key
		eAESKey, err = common.Encrypt(AESKey, sharedKey, crand.Reader)
		if err != nil {
			return nil, err
		}

		eAESKeys = append(eAESKeys, eAESKey)
	}

	return &protobuf.ProfileShowcaseEntriesEncrypted{
		EncryptedEntries: encrypted,
		EncryptionKeys:   eAESKeys,
	}, nil
}

func (m *Messenger) DecryptProfileShowcaseEntriesWithPubKey(senderPubKey *ecdsa.PublicKey, encrypted *protobuf.ProfileShowcaseEntriesEncrypted) (*protobuf.ProfileShowcaseEntries, error) {
	for _, eAESKey := range encrypted.EncryptionKeys {
		// Generate a Diffie-Helman (DH) between the recipient's private key and the sender's public key
		sharedKey, err := common.MakeECDHSharedKey(m.identity, senderPubKey)
		if err != nil {
			return nil, err
		}

		// Decrypt the main encryption AES key with AES encryption using the DH key
		dAESKey, err := common.Decrypt(eAESKey, sharedKey)
		if err != nil {
			if err.Error() == ErrCipherMessageAutentificationFailed {
				continue
			}
			return nil, err
		}
		if dAESKey == nil {
			return nil, errorDecryptingPayloadEncryptionKey
		}

		// Decrypt profile entries with the newly decrypted main encryption AES key
		entriesData, err := common.Decrypt(encrypted.EncryptedEntries, dAESKey)
		if err != nil {
			return nil, err
		}

		entries := &protobuf.ProfileShowcaseEntries{}
		err = proto.Unmarshal(entriesData, entries)
		if err != nil {
			return nil, err
		}

		return entries, nil
	}

	// Return empty if no matching key found
	return &protobuf.ProfileShowcaseEntries{}, nil
}

func (m *Messenger) GetProfileShowcaseForSelfIdentity() (*protobuf.ProfileShowcase, error) {
	preferences, err := m.GetProfileShowcasePreferences()
	if err != nil {
		return nil, err
	}

	forEveryone := &protobuf.ProfileShowcaseEntries{
		Communities:      m.toProfileShowcaseCommunityProto(preferences.Communities, identity.ProfileShowcaseVisibilityEveryone),
		Accounts:         m.toProfileShowcaseAccountProto(preferences.Accounts, identity.ProfileShowcaseVisibilityEveryone),
		Collectibles:     m.toProfileShowcaseCollectibleProto(preferences.Collectibles, identity.ProfileShowcaseVisibilityEveryone),
		VerifiedTokens:   m.toProfileShowcaseVerifiedTokensProto(preferences.VerifiedTokens, identity.ProfileShowcaseVisibilityEveryone),
		UnverifiedTokens: m.toProfileShowcaseUnverifiedTokensProto(preferences.UnverifiedTokens, identity.ProfileShowcaseVisibilityEveryone),
	}

	forContacts := &protobuf.ProfileShowcaseEntries{
		Communities:      m.toProfileShowcaseCommunityProto(preferences.Communities, identity.ProfileShowcaseVisibilityContacts),
		Accounts:         m.toProfileShowcaseAccountProto(preferences.Accounts, identity.ProfileShowcaseVisibilityContacts),
		Collectibles:     m.toProfileShowcaseCollectibleProto(preferences.Collectibles, identity.ProfileShowcaseVisibilityContacts),
		VerifiedTokens:   m.toProfileShowcaseVerifiedTokensProto(preferences.VerifiedTokens, identity.ProfileShowcaseVisibilityContacts),
		UnverifiedTokens: m.toProfileShowcaseUnverifiedTokensProto(preferences.UnverifiedTokens, identity.ProfileShowcaseVisibilityContacts),
	}

	forIDVerifiedContacts := &protobuf.ProfileShowcaseEntries{
		Communities:      m.toProfileShowcaseCommunityProto(preferences.Communities, identity.ProfileShowcaseVisibilityIDVerifiedContacts),
		Accounts:         m.toProfileShowcaseAccountProto(preferences.Accounts, identity.ProfileShowcaseVisibilityIDVerifiedContacts),
		Collectibles:     m.toProfileShowcaseCollectibleProto(preferences.Collectibles, identity.ProfileShowcaseVisibilityIDVerifiedContacts),
		VerifiedTokens:   m.toProfileShowcaseVerifiedTokensProto(preferences.VerifiedTokens, identity.ProfileShowcaseVisibilityIDVerifiedContacts),
		UnverifiedTokens: m.toProfileShowcaseUnverifiedTokensProto(preferences.UnverifiedTokens, identity.ProfileShowcaseVisibilityIDVerifiedContacts),
	}

	mutualContacts := []*Contact{}
	iDVerifiedContacts := []*Contact{}

	m.allContacts.Range(func(_ string, contact *Contact) (shouldContinue bool) {
		if contact.mutual() {
			mutualContacts = append(mutualContacts, contact)
			if contact.IsVerified() {
				iDVerifiedContacts = append(iDVerifiedContacts, contact)
			}
		}
		return true
	})

	forContactsEncrypted, err := m.EncryptProfileShowcaseEntriesWithContactPubKeys(forContacts, mutualContacts)
	if err != nil {
		return nil, err
	}

	forIDVerifiedContactsEncrypted, err := m.EncryptProfileShowcaseEntriesWithContactPubKeys(forIDVerifiedContacts, iDVerifiedContacts)
	if err != nil {
		return nil, err
	}

	return &protobuf.ProfileShowcase{
		ForEveryone:           forEveryone,
		ForContacts:           forContactsEncrypted,
		ForIdVerifiedContacts: forIDVerifiedContactsEncrypted,
	}, nil
}

func (m *Messenger) buildProfileShowcaseFromEntries(
	contactID string,
	communities []*identity.ProfileShowcaseCommunity,
	accounts []*identity.ProfileShowcaseAccount,
	collectibles []*identity.ProfileShowcaseCollectible,
	verifiedTokens []*identity.ProfileShowcaseVerifiedToken,
	unverifiedTokens []*identity.ProfileShowcaseUnverifiedToken) *identity.ProfileShowcase {
	sort.Slice(communities, func(i, j int) bool {
		return communities[j].Order > communities[i].Order
	})
	sort.Slice(accounts, func(i, j int) bool {
		return accounts[j].Order > accounts[i].Order
	})
	sort.Slice(collectibles, func(i, j int) bool {
		return collectibles[j].Order > collectibles[i].Order
	})
	sort.Slice(verifiedTokens, func(i, j int) bool {
		return verifiedTokens[j].Order > verifiedTokens[i].Order
	})
	sort.Slice(unverifiedTokens, func(i, j int) bool {
		return unverifiedTokens[j].Order > unverifiedTokens[i].Order
	})

	return &identity.ProfileShowcase{
		ContactID:        contactID,
		Communities:      communities,
		Accounts:         accounts,
		Collectibles:     collectibles,
		VerifiedTokens:   verifiedTokens,
		UnverifiedTokens: unverifiedTokens,
	}
}

func (m *Messenger) BuildProfileShowcaseFromIdentity(state *ReceivedMessageState, message *protobuf.ProfileShowcase) error {
	senderPubKey := state.CurrentMessageState.PublicKey
	contactID := state.CurrentMessageState.Contact.ID

	communities := []*identity.ProfileShowcaseCommunity{}
	accounts := []*identity.ProfileShowcaseAccount{}
	collectibles := []*identity.ProfileShowcaseCollectible{}
	verifiedTokens := []*identity.ProfileShowcaseVerifiedToken{}
	unverifiedTokens := []*identity.ProfileShowcaseUnverifiedToken{}

	communities = append(communities, m.fromProfileShowcaseCommunityProto(senderPubKey, message.ForEveryone.Communities)...)
	accounts = append(accounts, m.fromProfileShowcaseAccountProto(message.ForEveryone.Accounts)...)
	collectibles = append(collectibles, m.fromProfileShowcaseCollectibleProto(message.ForEveryone.Collectibles)...)
	verifiedTokens = append(verifiedTokens, m.fromProfileShowcaseVerifiedTokenProto(message.ForEveryone.VerifiedTokens)...)
	unverifiedTokens = append(unverifiedTokens, m.fromProfileShowcaseUnverifiedTokenProto(message.ForEveryone.UnverifiedTokens)...)

	forContacts, err := m.DecryptProfileShowcaseEntriesWithPubKey(senderPubKey, message.ForContacts)
	if err != nil {
		return err
	}

	if forContacts != nil {
		communities = append(communities, m.fromProfileShowcaseCommunityProto(senderPubKey, forContacts.Communities)...)
		accounts = append(accounts, m.fromProfileShowcaseAccountProto(forContacts.Accounts)...)
		collectibles = append(collectibles, m.fromProfileShowcaseCollectibleProto(forContacts.Collectibles)...)
		verifiedTokens = append(verifiedTokens, m.fromProfileShowcaseVerifiedTokenProto(forContacts.VerifiedTokens)...)
		unverifiedTokens = append(unverifiedTokens, m.fromProfileShowcaseUnverifiedTokenProto(forContacts.UnverifiedTokens)...)
	}

	forIDVerifiedContacts, err := m.DecryptProfileShowcaseEntriesWithPubKey(senderPubKey, message.ForIdVerifiedContacts)
	if err != nil {
		return err
	}

	if forIDVerifiedContacts != nil {
		communities = append(communities, m.fromProfileShowcaseCommunityProto(senderPubKey, forIDVerifiedContacts.Communities)...)
		accounts = append(accounts, m.fromProfileShowcaseAccountProto(forIDVerifiedContacts.Accounts)...)
		collectibles = append(collectibles, m.fromProfileShowcaseCollectibleProto(forIDVerifiedContacts.Collectibles)...)
		verifiedTokens = append(verifiedTokens, m.fromProfileShowcaseVerifiedTokenProto(forIDVerifiedContacts.VerifiedTokens)...)
		unverifiedTokens = append(unverifiedTokens, m.fromProfileShowcaseUnverifiedTokenProto(forIDVerifiedContacts.UnverifiedTokens)...)
	}

	newShowcase := m.buildProfileShowcaseFromEntries(
		contactID, communities, accounts, collectibles, verifiedTokens, unverifiedTokens)

	oldShowcase, err := m.persistence.GetProfileShowcaseForContact(contactID)
	if err != nil {
		return err
	}

	if reflect.DeepEqual(newShowcase, oldShowcase) {
		return nil
	}

	err = m.persistence.ClearProfileShowcaseForContact(contactID)
	if err != nil {
		return err
	}

	err = m.persistence.SaveProfileShowcaseForContact(newShowcase)
	if err != nil {
		return err
	}

	state.Response.AddProfileShowcase(newShowcase)
	return nil
}

func (m *Messenger) UpdateProfileShowcaseWalletAccount(account *accounts.Account) error {
	profileAccount, err := m.persistence.GetProfileShowcaseAccountPreference(account.Address.Hex())
	if err != nil {
		return err
	}

	if profileAccount == nil {
		// No corresponding profile entry, exit
		return nil
	}

	profileAccount.Name = account.Name
	profileAccount.ColorID = string(account.ColorID)
	profileAccount.Emoji = account.Emoji

	err = m.persistence.SaveProfileShowcaseAccountPreference(profileAccount)
	if err != nil {
		return err
	}

	return m.DispatchProfileShowcase()
}

func (m *Messenger) DeleteProfileShowcaseWalletAccount(account *accounts.Account) error {
	deleted, err := m.persistence.DeleteProfileShowcaseAccountPreference(account.Address.Hex())
	if err != nil {
		return err
	}

	if deleted {
		return m.DispatchProfileShowcase()
	}
	return nil
}

func (m *Messenger) DeleteProfileShowcaseCommunity(community *communities.Community) error {
	deleted, err := m.persistence.DeleteProfileShowcaseCommunityPreference(community.IDString())
	if err != nil {
		return err
	}

	if deleted {
		return m.DispatchProfileShowcase()
	}
	return nil
}

func (m *Messenger) saveProfileShowcasePreferencesProto(p *protobuf.SyncProfileShowcasePreferences, shouldSync bool) error {
	preferences := FromProfileShowcasePreferencesProto(p)
	return m.setProfileShowcasePreferences(preferences, shouldSync)
}

func (m *Messenger) syncProfileShowcasePreferences(ctx context.Context, rawMessageHandler RawMessageHandler) error {
	preferences, err := m.GetProfileShowcasePreferences()
	if err != nil {
		return err
	}

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

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

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