/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.email.activity;

import com.android.email.Email;
import com.android.email.R;
import com.android.email.Utility;

import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;

/**
 * Activity to show (non-EML) email messages.
 *
 * This activity shows regular email messages, which are not file-based.  (i.e. not *.eml or *.msg)
 *
 * TODO Test it!
 */
public class MessageView extends MessageViewBase implements View.OnClickListener,
        MessageOrderManager.Callback {
    private static final String EXTRA_MESSAGE_ID = "com.android.email.MessageView_message_id";
    private static final String EXTRA_MAILBOX_ID = "com.android.email.MessageView_mailbox_id";
    /* package */ static final String EXTRA_DISABLE_REPLY =
        "com.android.email.MessageView_disable_reply";

    // for saveInstanceState()
    private static final String STATE_MESSAGE_ID = "messageId";

    private long mMessageId;
    private long mMailboxId;

    private MessageOrderManager mOrderManager;

    private View mMoveToNewer;
    private View mMoveToOlder;

    // this is true when reply & forward are disabled, such as messages in the trash
    private boolean mDisableReplyAndForward;

    /**
     * View a specific message found in the Email provider.
     * @param messageId the message to view.
     * @param mailboxId identifies the sequence of messages used for newer/older navigation.
     * @param disableReplyAndForward set if reply/forward do not make sense for this message
     *        (e.g. messages in Trash).
     */
    public static void actionView(Context context, long messageId, long mailboxId,
            boolean disableReplyAndForward) {
        if (messageId < 0) {
            throw new IllegalArgumentException("MessageView invalid messageId " + messageId);
        }
        Intent i = new Intent(context, MessageView.class);
        i.putExtra(EXTRA_MESSAGE_ID, messageId);
        i.putExtra(EXTRA_MAILBOX_ID, mailboxId);
        i.putExtra(EXTRA_DISABLE_REPLY, disableReplyAndForward);
        context.startActivity(i);
    }

    public static void actionView(Context context, long messageId, long mailboxId) {
        actionView(context, messageId, mailboxId, false);
    }

    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);

        mMoveToNewer = findViewById(R.id.moveToNewer);
        mMoveToOlder = findViewById(R.id.moveToOlder);
        mMoveToNewer.setOnClickListener(this);
        mMoveToOlder.setOnClickListener(this);

        findViewById(R.id.reply).setOnClickListener(this);
        findViewById(R.id.reply_all).setOnClickListener(this);
        findViewById(R.id.delete).setOnClickListener(this);

        initFromIntent();
        if (icicle != null) {
            mMessageId = icicle.getLong(STATE_MESSAGE_ID, mMessageId);
        }
    }

    private void initFromIntent() {
        Intent intent = getIntent();
        mMessageId = intent.getLongExtra(EXTRA_MESSAGE_ID, -1);
        mMailboxId = intent.getLongExtra(EXTRA_MAILBOX_ID, -1);
        mDisableReplyAndForward = intent.getBooleanExtra(EXTRA_DISABLE_REPLY, false);
        if (mDisableReplyAndForward) {
            findViewById(R.id.reply).setEnabled(false);
            findViewById(R.id.reply_all).setEnabled(false);
        }
    }

    @Override
    protected void onSaveInstanceState(Bundle state) {
        super.onSaveInstanceState(state);
        if (mMessageId != -1) {
            state.putLong(STATE_MESSAGE_ID, mMessageId);
        }
    }

    @Override
    public void onResume() {
        super.onResume();

        // Exit immediately if the accounts list has changed (e.g. externally deleted)
        if (Email.getNotifyUiAccountsChanged()) {
            Welcome.actionStart(this);
            finish();
            return;
        }
        mOrderManager = new MessageOrderManager(this, mMailboxId, this);
        messageChanged();
    }

    @Override
    public void onPause() {
        if (mOrderManager != null) {
            mOrderManager.close();
            mOrderManager = null;
        }
        super.onPause();
    }

    @Override
    protected long getAccountId() {
        return getFragment().getAccountId();
    }

    private void onReply() {
        MessageCompose.actionReply(this, mMessageId, false);
        finish();
    }

    private void onReplyAll() {
        MessageCompose.actionReply(this, mMessageId, true);
        finish();
    }

    private void onForward() {
        MessageCompose.actionForward(this, mMessageId);
        finish();
    }

    private void onDeleteMessage() {
        // the delete triggers mCursorObserver in MessageOrderManager.
        // first move to older/newer before the actual delete
        long messageIdToDelete = mMessageId;
        boolean moved = moveToOlder() || moveToNewer();
        getController().deleteMessage(messageIdToDelete, -1);
        Utility.showToast(this,
                getResources().getQuantityString(R.plurals.message_deleted_toast, 1));
        if (!moved) {
            // this generates a benign warning "Duplicate finish request" because
            // MessageOrderManager detects that the current message is gone, and we finish() it
            // in the onMessageNotFound() callback.
            finish();
        }
    }

    private boolean moveToOlder() {
        if (mOrderManager != null && mOrderManager.moveToOlder()) {
            mMessageId = mOrderManager.getCurrentMessageId();
            messageChanged();
            return true;
        }
        return false;
    }

    private boolean moveToNewer() {
        if (mOrderManager != null && mOrderManager.moveToNewer()) {
            mMessageId = mOrderManager.getCurrentMessageId();
            messageChanged();
            return true;
        }
        return false;
    }

    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.reply:
                onReply();
                break;
            case R.id.reply_all:
                onReplyAll();
                break;
            case R.id.delete:
                onDeleteMessage();
                break;
            case R.id.moveToOlder:
                moveToOlder();
                break;
            case R.id.moveToNewer:
                moveToNewer();
                break;
        }
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        boolean handled = handleMenuItem(item.getItemId());
        if (!handled) {
            handled = super.onOptionsItemSelected(item);
        }
        return handled;
    }

    /**
     * This is the core functionality of onOptionsItemSelected() but broken out and exposed
     * for testing purposes (because it's annoying to mock a MenuItem).
     *
     * @param menuItemId id that was clicked
     * @return true if handled here
     */
    /* package */ boolean handleMenuItem(int menuItemId) {
        switch (menuItemId) {
            case R.id.delete:
                onDeleteMessage();
                break;
            case R.id.reply:
                onReply();
                break;
            case R.id.reply_all:
                onReplyAll();
                break;
            case R.id.forward:
                onForward();
                break;
            case R.id.mark_as_unread:
                getFragment().onMarkMessageAsRead(false);
                break;
            default:
                return false;
        }
        return true;
    }

    @Override
    public void onMessageSetUnread() {
        finish();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);
        getMenuInflater().inflate(R.menu.message_view_option, menu);
        if (mDisableReplyAndForward) {
            menu.findItem(R.id.forward).setEnabled(false);
            menu.findItem(R.id.reply).setEnabled(false);
            menu.findItem(R.id.reply_all).setEnabled(false);
        }
        return true;
    }

    /**
     * Sync the current message.
     * - Set message id to the fragment and the message order manager.
     * - Update the navigation arrows.
     */
    private void messageChanged() {
        getFragment().openMessage(mMessageId);
        if (mOrderManager != null) {
            mOrderManager.moveTo(mMessageId);
        }
        updateNavigationArrows();
    }

    /**
     * Update the arrows based on the current position of the older/newer cursor.
     */
    private void updateNavigationArrows() {
        mMoveToNewer.setEnabled((mOrderManager != null) && mOrderManager.canMoveToNewer());
        mMoveToOlder.setEnabled((mOrderManager != null) && mOrderManager.canMoveToOlder());
    }

    /** Implements {@link MessageOrderManager.Callback#onMessageNotFound()}. */
    // TODO Name too generic.  Rename this.
    @Override
    public void onMessageNotFound() {
        finish();
    }

    /** Implements {@link MessageOrderManager.Callback#onMessagesChanged()}. */
    // TODO Name too generic.  Rename this.
    @Override
    public void onMessagesChanged() {
        updateNavigationArrows();
    }

    @Override
    public void onRespondedToInvite(int response) {
        if (!moveToOlder()) {
            finish(); // if this is the last message, move up to message-list.
        }
    }

    @Override
    public void onCalendarLinkClicked(long epochEventStartTime) {
        Uri uri = Uri.parse("content://com.android.calendar/time/" + epochEventStartTime);
        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setData(uri);
        intent.putExtra("VIEW", "DAY");
        intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
        startActivity(intent);
    }
}