package de.pixart.messenger.ui;

import android.app.ActionBar;
import android.content.Intent;
import android.os.Bundle;
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.Button;
import android.widget.CompoundButton;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

import com.google.zxing.integration.android.IntentIntegrator;

import org.whispersystems.libsignal.IdentityKey;

import java.util.ArrayList;
import java.util.Arrays;
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.axolotl.AxolotlService;
import de.pixart.messenger.crypto.axolotl.FingerprintStatus;
import de.pixart.messenger.entities.Account;
import de.pixart.messenger.entities.Conversation;
import de.pixart.messenger.utils.CryptoHelper;
import de.pixart.messenger.utils.XmppUri;
import de.pixart.messenger.xmpp.OnKeyStatusUpdated;
import de.pixart.messenger.xmpp.jid.InvalidJidException;
import de.pixart.messenger.xmpp.jid.Jid;

public class TrustKeysActivity extends OmemoActivity implements OnKeyStatusUpdated {
    private List<Jid> contactJids;

    private Account mAccount;
    private Conversation mConversation;
    private TextView keyErrorMessage;
    private LinearLayout keyErrorMessageCard;
    private TextView ownKeysTitle;
    private LinearLayout ownKeys;
    private LinearLayout ownKeysCard;
    private LinearLayout foreignKeys;
    private Button mSaveButton;
    private Button mCancelButton;

    private AtomicBoolean mUseCameraHintShown = new AtomicBoolean(false);

    private AxolotlService.FetchStatus lastFetchReport = AxolotlService.FetchStatus.SUCCESS;

    private final Map<String, Boolean> ownKeysToTrust = new HashMap<>();
    private final Map<Jid, Map<String, Boolean>> foreignKeysToTrust = new HashMap<>();

    private final OnClickListener mSaveButtonListener = new OnClickListener() {
        @Override
        public void onClick(View v) {
            commitTrusts();
            finishOk();
        }
    };

    private final OnClickListener mCancelButtonListener = new OnClickListener() {
        @Override
        public void onClick(View v) {
            setResult(RESULT_CANCELED);
            finish();
        }
    };

    private XmppUri mPendingFingerprintVerificationUri = null;
    private Toast mUseCameraHintToast = null;

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

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

        keyErrorMessageCard = findViewById(R.id.key_error_message_card);
        keyErrorMessage = findViewById(R.id.key_error_message);
        ownKeysTitle = findViewById(R.id.own_keys_title);
        ownKeys = findViewById(R.id.own_keys_details);
        ownKeysCard = findViewById(R.id.own_keys_card);
        foreignKeys = findViewById(R.id.foreign_keys);
        mCancelButton = findViewById(R.id.cancel_button);
        mCancelButton.setOnClickListener(mCancelButtonListener);
        mSaveButton = findViewById(R.id.save_button);
        mSaveButton.setOnClickListener(mSaveButtonListener);


        if (getActionBar() != null) {
            getActionBar().setHomeButtonEnabled(true);
            getActionBar().setDisplayHomeAsUpEnabled(true);
        }

        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());
        return super.onCreateOptionsMenu(menu);
    }

    private void showCameraToast() {
        mUseCameraHintToast = Toast.makeText(this,R.string.use_camera_icon_to_scan_barcode,Toast.LENGTH_LONG);
        ActionBar actionBar = getActionBar();
        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 {
                    new IntentIntegrator(this).initiateScan(Arrays.asList("AZTEC","QR_CODE"));
                    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();
                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));
        ownKeys.removeAllViews();
        foreignKeys.removeAllViews();
        boolean hasOwnKeys = false;
        boolean hasForeignKeys = false;
        for (final String fingerprint : ownKeysToTrust.keySet()) {
            hasOwnKeys = true;
            addFingerprintRowWithListeners(ownKeys, mAccount, fingerprint, false,
                    FingerprintStatus.createActive(ownKeysToTrust.get(fingerprint)), false, false,
                    new CompoundButton.OnCheckedChangeListener() {
                        @Override
                        public void onCheckedChanged(CompoundButton buttonView, boolean 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;
                final LinearLayout layout = (LinearLayout) getLayoutInflater().inflate(R.layout.keys_card, foreignKeys, false);
                final Jid jid = entry.getKey();
                final TextView header = layout.findViewById(R.id.foreign_keys_title);
                final LinearLayout keysContainer = layout.findViewById(R.id.foreign_keys_details);
                final TextView informNoKeys = layout.findViewById(R.id.no_keys_to_accept);
                header.setText(jid.toString());
                header.setOnClickListener(new OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        switchToContactDetails(mAccount.getRoster().getContact(jid));
                    }
                });
                final Map<String, Boolean> fingerprints = entry.getValue();
                for (final String fingerprint : fingerprints.keySet()) {
                    addFingerprintRowWithListeners(keysContainer, mAccount, fingerprint, false,
                            FingerprintStatus.createActive(fingerprints.get(fingerprint)), false, false,
                            new CompoundButton.OnCheckedChangeListener() {
                                @Override
                                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                                    fingerprints.put(fingerprint, isChecked);
                                    lockOrUnlockAsNeeded();
                                }
                            }
                    );
                }
                if (fingerprints.size() == 0) {
                    informNoKeys.setVisibility(View.VISIBLE);
                    if (hasNoOtherTrustedKeys(jid)) {
                        if (!mAccount.getRoster().getContact(jid).mutualPresenceSubscription()) {
                            informNoKeys.setText(R.string.error_no_keys_to_trust_presence);
                        } else {
                            informNoKeys.setText(R.string.error_no_keys_to_trust_server_error);
                        }
                    } else {
                        informNoKeys.setText(getString(R.string.no_keys_just_confirm, mAccount.getRoster().getContact(jid).getDisplayName()));
                    }
                } else {
                    informNoKeys.setVisibility(View.GONE);
                }
                foreignKeys.addView(layout);
            }
        }

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

        ownKeysTitle.setText(mAccount.getJid().toBareJid().toString());
        ownKeysCard.setVisibility(hasOwnKeys ? View.VISIBLE : View.GONE);
        foreignKeys.setVisibility(hasForeignKeys ? View.VISIBLE : View.GONE);
        if (hasPendingKeyFetches()) {
            setFetching();
            lock();
        } else {
            if (!hasForeignKeys && hasNoOtherTrustedKeys()) {
                keyErrorMessageCard.setVisibility(View.VISIBLE);
                if (lastFetchReport == AxolotlService.FetchStatus.ERROR
                        || mAccount.getAxolotlService().fetchMapHasErrors(contactJids)) {
                    if (anyWithoutMutualPresenceSubscription(contactJids)) {
                        keyErrorMessage.setText(R.string.error_no_keys_to_trust_presence);
                    } else {
                        keyErrorMessage.setText(R.string.error_no_keys_to_trust_server_error);
                    }
                } else {
                    keyErrorMessage.setText(R.string.error_no_keys_to_trust);
                }
                ownKeys.removeAllViews();
                ownKeysCard.setVisibility(View.GONE);
                foreignKeys.removeAllViews();
                foreignKeys.setVisibility(View.GONE);
            }
            lockOrUnlockAsNeeded();
            setDone();
        }
    }

    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<Jid>() : mConversation.getAcceptedCryptoTargets();
        ownKeysToTrust.clear();
        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 {
                reloadFingerprints();
                populateView();
                invalidateOptionsMenu();
            }
        }
    }

    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(mAccount, contactJids);
    }


    @Override
    public void onKeyStatusUpdated(final AxolotlService.FetchStatus report) {
        final boolean keysToTrust = reloadFingerprints();
        if (report != null) {
            lastFetchReport = report;
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    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(new Runnable() {
                @Override
                public void run() {
                    finishOk();
                }
            });

        }
    }

    private void finishOk() {
        Intent data = new Intent();
        data.putExtra("choice", getIntent().getIntExtra("choice", ConversationActivity.ATTACHMENT_CHOICE_INVALID));
        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<Jid>() : 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() {
        mSaveButton.setEnabled(true);
        mSaveButton.setTextColor(getPrimaryTextColor());
    }

    private void lock() {
        mSaveButton.setEnabled(false);
        mSaveButton.setTextColor(getSecondaryTextColor());
    }

    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() {
        mSaveButton.setText(getString(R.string.done));
    }

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