package de.pixart.messenger.ui;

import android.app.AlertDialog;
import android.content.Intent;
import android.databinding.DataBindingUtil;
import android.os.Bundle;
import android.support.v7.app.ActionBar;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.Gravity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Toast;

import org.whispersystems.libsignal.IdentityKey;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;

import de.pixart.messenger.Config;
import de.pixart.messenger.R;
import de.pixart.messenger.crypto.OmemoSetting;
import de.pixart.messenger.crypto.axolotl.AxolotlService;
import de.pixart.messenger.crypto.axolotl.FingerprintStatus;
import de.pixart.messenger.databinding.ActivityTrustKeysBinding;
import de.pixart.messenger.databinding.KeysCardBinding;
import de.pixart.messenger.entities.Account;
import de.pixart.messenger.entities.Contact;
import de.pixart.messenger.entities.Conversation;
import de.pixart.messenger.entities.Message;
import de.pixart.messenger.utils.CryptoHelper;
import de.pixart.messenger.utils.IrregularUnicodeDetector;
import de.pixart.messenger.utils.XmppUri;
import de.pixart.messenger.xmpp.OnKeyStatusUpdated;
import rocks.xmpp.addr.Jid;

public class TrustKeysActivity extends OmemoActivity implements OnKeyStatusUpdated {
    private final Map<String, Boolean> ownKeysToTrust = new HashMap<>();
    private final Map<Jid, Map<String, Boolean>> foreignKeysToTrust = new HashMap<>();
    private final OnClickListener mCancelButtonListener = v -> {
        setResult(RESULT_CANCELED);
        finish();
    };
    private List<Jid> contactJids;
    private Account mAccount;
    private Conversation mConversation;
    private final OnClickListener mSaveButtonListener = v -> {
        commitTrusts();
        finishOk(false);
    };
    private AtomicBoolean mUseCameraHintShown = new AtomicBoolean(false);
    private AxolotlService.FetchStatus lastFetchReport = AxolotlService.FetchStatus.SUCCESS;
    private Toast mUseCameraHintToast = null;
    private ActivityTrustKeysBinding binding;

    @Override
    protected void refreshUiReal() {
        invalidateOptionsMenu();
        populateView();
    }

    @Override
    protected void onCreate(final Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.binding = DataBindingUtil.setContentView(this, R.layout.activity_trust_keys);
        this.contactJids = new ArrayList<>();
        for (String jid : getIntent().getStringArrayExtra("contacts")) {
            try {
                this.contactJids.add(Jid.of(jid));
            } catch (IllegalArgumentException e) {
                e.printStackTrace();
            }
        }

        binding.cancelButton.setOnClickListener(mCancelButtonListener);
        binding.saveButton.setOnClickListener(mSaveButtonListener);

        setSupportActionBar((Toolbar) binding.toolbar);
        configureActionBar(getSupportActionBar());

        if (savedInstanceState != null) {
            mUseCameraHintShown.set(savedInstanceState.getBoolean("camera_hint_shown", false));
        }
    }

    @Override
    public void onSaveInstanceState(Bundle savedInstanceState) {
        savedInstanceState.putBoolean("camera_hint_shown", mUseCameraHintShown.get());
        super.onSaveInstanceState(savedInstanceState);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.trust_keys, menu);
        MenuItem scanQrCode = menu.findItem(R.id.action_scan_qr_code);
        scanQrCode.setVisible((ownKeysToTrust.size() > 0 || foreignActuallyHasKeys()) && isCameraFeatureAvailable());
        return super.onCreateOptionsMenu(menu);
    }

    private void showCameraToast() {
        mUseCameraHintToast = Toast.makeText(this, R.string.use_camera_icon_to_scan_barcode, Toast.LENGTH_LONG);
        ActionBar actionBar = getSupportActionBar();
        mUseCameraHintToast.setGravity(Gravity.TOP | Gravity.END, 0, actionBar == null ? 0 : actionBar.getHeight());
        mUseCameraHintToast.show();
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.action_scan_qr_code:
                if (hasPendingKeyFetches()) {
                    Toast.makeText(this, R.string.please_wait_for_keys_to_be_fetched, Toast.LENGTH_SHORT).show();
                } else {
                    ScanActivity.scan(this);
                    return true;
                }
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    protected void onStop() {
        super.onStop();
        if (mUseCameraHintToast != null) {
            mUseCameraHintToast.cancel();
        }
    }

    @Override
    protected void processFingerprintVerification(XmppUri uri) {
        if (mConversation != null
                && mAccount != null
                && uri.hasFingerprints()
                && mAccount.getAxolotlService().getCryptoTargets(mConversation).contains(uri.getJid())) {
            boolean performedVerification = xmppConnectionService.verifyFingerprints(mAccount.getRoster().getContact(uri.getJid()), uri.getFingerprints());
            boolean keys = reloadFingerprints();
            if (performedVerification && !keys && !hasNoOtherTrustedKeys() && !hasPendingKeyFetches()) {
                Toast.makeText(this, R.string.all_omemo_keys_have_been_verified, Toast.LENGTH_SHORT).show();
                finishOk(false);
                return;
            } else if (performedVerification) {
                Toast.makeText(this, R.string.verified_fingerprints, Toast.LENGTH_SHORT).show();
            }
        } else {
            reloadFingerprints();
            Log.d(Config.LOGTAG, "xmpp uri was: " + uri.getJid() + " has Fingerprints: " + Boolean.toString(uri.hasFingerprints()));
            Toast.makeText(this, R.string.barcode_does_not_contain_fingerprints_for_this_conversation, Toast.LENGTH_SHORT).show();
        }
        populateView();
    }

    private void populateView() {
        setTitle(getString(R.string.trust_omemo_fingerprints));
        binding.ownKeysDetails.removeAllViews();
        binding.foreignKeys.removeAllViews();
        boolean hasOwnKeys = false;
        boolean hasForeignKeys = false;
        for (final String fingerprint : ownKeysToTrust.keySet()) {
            hasOwnKeys = true;
            addFingerprintRowWithListeners(binding.ownKeysDetails, mAccount, fingerprint, false,
                    FingerprintStatus.createActive(ownKeysToTrust.get(fingerprint)), false, false,
                    (buttonView, isChecked) -> {
                        ownKeysToTrust.put(fingerprint, isChecked);
                        // own fingerprints have no impact on locked status.
                    }
            );
        }

        synchronized (this.foreignKeysToTrust) {
            for (Map.Entry<Jid, Map<String, Boolean>> entry : foreignKeysToTrust.entrySet()) {
                hasForeignKeys = true;
                KeysCardBinding keysCardBinding = DataBindingUtil.inflate(getLayoutInflater(), R.layout.keys_card, binding.foreignKeys, false);
                final Jid jid = entry.getKey();
                keysCardBinding.foreignKeysTitle.setText(IrregularUnicodeDetector.style(this, jid));
                keysCardBinding.foreignKeysTitle.setOnClickListener(v -> switchToContactDetails(mAccount.getRoster().getContact(jid)));
                final Map<String, Boolean> fingerprints = entry.getValue();
                for (final String fingerprint : fingerprints.keySet()) {
                    addFingerprintRowWithListeners(keysCardBinding.foreignKeysDetails, mAccount, fingerprint, false,
                            FingerprintStatus.createActive(fingerprints.get(fingerprint)), false, false,
                            (buttonView, isChecked) -> {
                                fingerprints.put(fingerprint, isChecked);
                                lockOrUnlockAsNeeded();
                            }
                    );
                }
                if (fingerprints.size() == 0) {
                    keysCardBinding.noKeysToAccept.setVisibility(View.VISIBLE);
                    if (hasNoOtherTrustedKeys(jid)) {
                        if (!mAccount.getRoster().getContact(jid).mutualPresenceSubscription()) {
                            keysCardBinding.noKeysToAccept.setText(R.string.error_no_keys_to_trust_presence);
                        } else {
                            keysCardBinding.noKeysToAccept.setText(R.string.error_no_keys_to_trust_server_error);
                        }
                    } else {
                        keysCardBinding.noKeysToAccept.setText(getString(R.string.no_keys_just_confirm, mAccount.getRoster().getContact(jid).getDisplayName()));
                    }
                } else {
                    keysCardBinding.noKeysToAccept.setVisibility(View.GONE);
                }
                binding.foreignKeys.addView(keysCardBinding.foreignKeysCard);
            }
        }

        if ((hasOwnKeys || foreignActuallyHasKeys()) && isCameraFeatureAvailable() && mUseCameraHintShown.compareAndSet(false, true)) {
            showCameraToast();
        }

        binding.ownKeysTitle.setText(mAccount.getJid().asBareJid().toString());
        binding.ownKeysCard.setVisibility(hasOwnKeys ? View.VISIBLE : View.GONE);
        binding.foreignKeys.setVisibility(hasForeignKeys ? View.VISIBLE : View.GONE);
        if (hasPendingKeyFetches()) {
            setFetching();
            lock();
        } else {
            if (!hasForeignKeys && hasNoOtherTrustedKeys()) {
                binding.keyErrorMessageCard.setVisibility(View.VISIBLE);
                boolean lastReportWasError = lastFetchReport == AxolotlService.FetchStatus.ERROR;
                boolean errorFetchingBundle = mAccount.getAxolotlService().fetchMapHasErrors(contactJids);
                boolean errorFetchingDeviceList = mAccount.getAxolotlService().hasErrorFetchingDeviceList(contactJids);
                boolean anyWithoutMutualPresenceSubscription = anyWithoutMutualPresenceSubscription(contactJids);
                if (errorFetchingDeviceList) {
                    binding.keyErrorMessage.setVisibility(View.VISIBLE);
                    binding.keyErrorMessage.setText(R.string.error_trustkey_device_list);
                } else if (errorFetchingBundle || lastReportWasError) {
                    binding.keyErrorMessage.setVisibility(View.VISIBLE);
                    binding.keyErrorMessage.setText(R.string.error_trustkey_bundle);
                } else {
                    binding.keyErrorMessage.setVisibility(View.GONE);
                }
                this.binding.keyErrorHintMutual.setVisibility(anyWithoutMutualPresenceSubscription ? View.VISIBLE : View.GONE);
                Contact contact = mAccount.getRoster().getContact(contactJids.get(0));
                binding.keyErrorGeneral.setText(getString(R.string.error_trustkey_general, contact.getDisplayName()));
                binding.ownKeysDetails.removeAllViews();
                if (OmemoSetting.isAlways()) {
                    binding.disableButton.setVisibility(View.GONE);
                } else {
                    binding.disableButton.setVisibility(View.VISIBLE);
                    binding.disableButton.setOnClickListener(this::disableEncryptionDialog);
                }
                binding.ownKeysCard.setVisibility(View.GONE);
                binding.foreignKeys.removeAllViews();
                binding.foreignKeys.setVisibility(View.GONE);
            }
            lockOrUnlockAsNeeded();
            setDone();
        }
    }

    private void disableEncryptionDialog(View view) {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle(R.string.disable_encryption);
        builder.setMessage(R.string.disable_encryption_message);
        builder.setPositiveButton(R.string.disable_now, (dialog, which) -> {
            mConversation.setNextEncryption(Message.ENCRYPTION_NONE);
            xmppConnectionService.updateConversation(mConversation);
            finishOk(true);
        });
        builder.setNegativeButton(R.string.cancel, null);
        builder.create().show();
    }

    private boolean anyWithoutMutualPresenceSubscription(List<Jid> contactJids) {
        for (Jid jid : contactJids) {
            if (!mAccount.getRoster().getContact(jid).mutualPresenceSubscription()) {
                return true;
            }
        }
        return false;
    }

    private boolean foreignActuallyHasKeys() {
        synchronized (this.foreignKeysToTrust) {
            for (Map.Entry<Jid, Map<String, Boolean>> entry : foreignKeysToTrust.entrySet()) {
                if (entry.getValue().size() > 0) {
                    return true;
                }
            }
        }
        return false;
    }

    private boolean reloadFingerprints() {
        List<Jid> acceptedTargets = mConversation == null ? new ArrayList<>() : mConversation.getAcceptedCryptoTargets();
        ownKeysToTrust.clear();
        if (this.mAccount == null) {
            return false;
        }
        AxolotlService service = this.mAccount.getAxolotlService();
        Set<IdentityKey> ownKeysSet = service.getKeysWithTrust(FingerprintStatus.createActiveUndecided());
        for (final IdentityKey identityKey : ownKeysSet) {
            final String fingerprint = CryptoHelper.bytesToHex(identityKey.getPublicKey().serialize());
            if (!ownKeysToTrust.containsKey(fingerprint)) {
                ownKeysToTrust.put(fingerprint, false);
            }
        }
        synchronized (this.foreignKeysToTrust) {
            foreignKeysToTrust.clear();
            for (Jid jid : contactJids) {
                Set<IdentityKey> foreignKeysSet = service.getKeysWithTrust(FingerprintStatus.createActiveUndecided(), jid);
                if (hasNoOtherTrustedKeys(jid) && ownKeysSet.size() == 0) {
                    foreignKeysSet.addAll(service.getKeysWithTrust(FingerprintStatus.createActive(false), jid));
                }
                Map<String, Boolean> foreignFingerprints = new HashMap<>();
                for (final IdentityKey identityKey : foreignKeysSet) {
                    final String fingerprint = CryptoHelper.bytesToHex(identityKey.getPublicKey().serialize());
                    if (!foreignFingerprints.containsKey(fingerprint)) {
                        foreignFingerprints.put(fingerprint, false);
                    }
                }
                if (foreignFingerprints.size() > 0 || !acceptedTargets.contains(jid)) {
                    foreignKeysToTrust.put(jid, foreignFingerprints);
                }
            }
        }
        return ownKeysSet.size() + foreignKeysToTrust.size() > 0;
    }

    public void onBackendConnected() {
        Intent intent = getIntent();
        this.mAccount = extractAccount(intent);
        if (this.mAccount != null && intent != null) {
            String uuid = intent.getStringExtra("conversation");
            this.mConversation = xmppConnectionService.findConversationByUuid(uuid);
            if (this.mPendingFingerprintVerificationUri != null) {
                processFingerprintVerification(this.mPendingFingerprintVerificationUri);
                this.mPendingFingerprintVerificationUri = null;
            } else {
                final boolean keysToTrust = reloadFingerprints();
                if (keysToTrust || hasPendingKeyFetches() || hasNoOtherTrustedKeys()) {
                    populateView();
                    invalidateOptionsMenu();
                } else {
                    finishOk(false);
                }
            }
        }
    }

    private boolean hasNoOtherTrustedKeys() {
        return mAccount == null || mAccount.getAxolotlService().anyTargetHasNoTrustedKeys(contactJids);
    }

    private boolean hasNoOtherTrustedKeys(Jid contact) {
        return mAccount == null || mAccount.getAxolotlService().getNumTrustedKeys(contact) == 0;
    }

    private boolean hasPendingKeyFetches() {
        return mAccount != null && mAccount.getAxolotlService().hasPendingKeyFetches(contactJids);
    }


    @Override
    public void onKeyStatusUpdated(final AxolotlService.FetchStatus report) {
        final boolean keysToTrust = reloadFingerprints();
        if (report != null) {
            lastFetchReport = report;
            runOnUiThread(() -> {
                if (mUseCameraHintToast != null && !keysToTrust) {
                    mUseCameraHintToast.cancel();
                }
                switch (report) {
                    case ERROR:
                        Toast.makeText(TrustKeysActivity.this, R.string.error_fetching_omemo_key, Toast.LENGTH_SHORT).show();
                        break;
                    case SUCCESS_TRUSTED:
                        Toast.makeText(TrustKeysActivity.this, R.string.blindly_trusted_omemo_keys, Toast.LENGTH_LONG).show();
                        break;
                    case SUCCESS_VERIFIED:
                        Toast.makeText(TrustKeysActivity.this,
                                Config.X509_VERIFICATION ? R.string.verified_omemo_key_with_certificate : R.string.all_omemo_keys_have_been_verified,
                                Toast.LENGTH_LONG).show();
                        break;
                }
            });

        }
        if (keysToTrust || hasPendingKeyFetches() || hasNoOtherTrustedKeys()) {
            refreshUi();
        } else {
            runOnUiThread(() -> finishOk(false));

        }
    }

    private void finishOk(boolean disabled) {
        Intent data = new Intent();
        data.putExtra("choice", getIntent().getIntExtra("choice", ConversationFragment.ATTACHMENT_CHOICE_INVALID));
        data.putExtra("disabled", disabled);
        setResult(RESULT_OK, data);
        finish();
    }

    private void commitTrusts() {
        for (final String fingerprint : ownKeysToTrust.keySet()) {
            mAccount.getAxolotlService().setFingerprintTrust(
                    fingerprint,
                    FingerprintStatus.createActive(ownKeysToTrust.get(fingerprint)));
        }
        List<Jid> acceptedTargets = mConversation == null ? new ArrayList<>() : mConversation.getAcceptedCryptoTargets();
        synchronized (this.foreignKeysToTrust) {
            for (Map.Entry<Jid, Map<String, Boolean>> entry : foreignKeysToTrust.entrySet()) {
                Jid jid = entry.getKey();
                Map<String, Boolean> value = entry.getValue();
                if (!acceptedTargets.contains(jid)) {
                    acceptedTargets.add(jid);
                }
                for (final String fingerprint : value.keySet()) {
                    mAccount.getAxolotlService().setFingerprintTrust(
                            fingerprint,
                            FingerprintStatus.createActive(value.get(fingerprint)));
                }
            }
        }
        if (mConversation != null && mConversation.getMode() == Conversation.MODE_MULTI) {
            mConversation.setAcceptedCryptoTargets(acceptedTargets);
            xmppConnectionService.updateConversation(mConversation);
        }
    }

    private void unlock() {
        binding.saveButton.setEnabled(true);
    }

    private void lock() {
        binding.saveButton.setEnabled(false);
    }

    private void lockOrUnlockAsNeeded() {
        synchronized (this.foreignKeysToTrust) {
            for (Jid jid : contactJids) {
                Map<String, Boolean> fingerprints = foreignKeysToTrust.get(jid);
                if (hasNoOtherTrustedKeys(jid) && (fingerprints == null || !fingerprints.values().contains(true))) {
                    lock();
                    return;
                }
            }
        }
        unlock();

    }

    private void setDone() {
        binding.saveButton.setText(getString(R.string.done));
    }

    private void setFetching() {
        binding.saveButton.setText(getString(R.string.fetching_keys));
    }
}