/*
 * Copyright (C) 2008 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.settings;

import android.content.ComponentName;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Bundle;
import android.preference.PreferenceActivity;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

import java.util.HashMap;
import java.util.List;

/**
 * Top-level settings activity to handle single pane and double pane UI layout.
 */
public class Settings extends PreferenceActivity implements ButtonBarHandler {

    private static final String META_DATA_KEY_HEADER_ID =
            "com.android.settings.TOP_LEVEL_HEADER_ID";
    private static final String META_DATA_KEY_FRAGMENT_CLASS =
            "com.android.settings.FRAGMENT_CLASS";
    private static final String META_DATA_KEY_PARENT_TITLE =
        "com.android.settings.PARENT_FRAGMENT_TITLE";
    private static final String META_DATA_KEY_PARENT_FRAGMENT_CLASS =
        "com.android.settings.PARENT_FRAGMENT_CLASS";

    private static final String SAVE_KEY_CURRENT_HEADER = "com.android.settings.CURRENT_HEADER";
    private static final String SAVE_KEY_PARENT_HEADER = "com.android.settings.PARENT_HEADER";

    private String mFragmentClass;
    private int mTopLevelHeaderId;
    private Header mFirstHeader;
    private Header mCurrentHeader;
    private Header mParentHeader;
    private boolean mInLocalHeaderSwitch;

    // TODO: Update Call Settings based on airplane mode state.

    protected HashMap<Integer, Integer> mHeaderIndexMap = new HashMap<Integer, Integer>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        getMetaData();
        mInLocalHeaderSwitch = true;
        super.onCreate(savedInstanceState);
        mInLocalHeaderSwitch = false;

        if (!onIsHidingHeaders() && onIsMultiPane()) {
            highlightHeader();
            // Force the title so that it doesn't get overridden by a direct launch of
            // a specific settings screen.
            setTitle(R.string.settings_label);
        }

        // Retrieve any saved state
        if (savedInstanceState != null) {
            mCurrentHeader = savedInstanceState.getParcelable(SAVE_KEY_CURRENT_HEADER);
            mParentHeader = savedInstanceState.getParcelable(SAVE_KEY_PARENT_HEADER);
        }

        // If the current header was saved, switch to it
        if (savedInstanceState != null && mCurrentHeader != null) {
            //switchToHeaderLocal(mCurrentHeader);
            showBreadCrumbs(mCurrentHeader.title, null);
        }

        if (mParentHeader != null) {
            setParentTitle(mParentHeader.title, null, new OnClickListener() {
                public void onClick(View v) {
                    switchToParent(mParentHeader.fragment);
                }
            });
        }
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);

        // Save the current fragment, if it is the same as originally launched
        if (mCurrentHeader != null) {
            outState.putParcelable(SAVE_KEY_CURRENT_HEADER, mCurrentHeader);
        }
        if (mParentHeader != null) {
            outState.putParcelable(SAVE_KEY_PARENT_HEADER, mParentHeader);
        }
    }

    private void switchToHeaderLocal(Header header) {
        mInLocalHeaderSwitch = true;
        switchToHeader(header);
        mInLocalHeaderSwitch = false;
    }

    @Override
    public void switchToHeader(Header header) {
        if (!mInLocalHeaderSwitch) {
            mCurrentHeader = null;
            mParentHeader = null;
        }
        super.switchToHeader(header);
    }

    /**
     * Switch to parent fragment and store the grand parent's info
     * @param className name of the activity wrapper for the parent fragment.
     */
    private void switchToParent(String className) {
        final ComponentName cn = new ComponentName(this, className);
        try {
            final PackageManager pm = getPackageManager();
            final ActivityInfo parentInfo = pm.getActivityInfo(cn, PackageManager.GET_META_DATA);

            if (parentInfo != null && parentInfo.metaData != null) {
                String fragmentClass = parentInfo.metaData.getString(META_DATA_KEY_FRAGMENT_CLASS);
                CharSequence fragmentTitle = parentInfo.loadLabel(pm);
                Header parentHeader = new Header();
                parentHeader.fragment = fragmentClass;
                parentHeader.title = fragmentTitle;
                mCurrentHeader = parentHeader;

                switchToHeaderLocal(parentHeader);

                mParentHeader = new Header();
                mParentHeader.fragment
                        = parentInfo.metaData.getString(META_DATA_KEY_PARENT_FRAGMENT_CLASS);
                mParentHeader.title = parentInfo.metaData.getString(META_DATA_KEY_PARENT_TITLE);
            }
        } catch (NameNotFoundException nnfe) {
            Log.w("Settings", "Could not find parent activity : " + className);
        }
    }

    @Override
    public void onNewIntent(Intent intent) {
        super.onNewIntent(intent);

        // If it is not launched from history, then reset to top-level
        if ((intent.getFlags() & Intent.FLAG_ACTIVITY_LAUNCHED_FROM_HISTORY) == 0
                && mFirstHeader != null) {
            switchToHeaderLocal(mFirstHeader);
        }
    }

    private void highlightHeader() {
        if (mTopLevelHeaderId != 0) {
            Integer index = mHeaderIndexMap.get(mTopLevelHeaderId);
            if (index != null) {
                getListView().setItemChecked(index, true);
            }
        }
    }

    @Override
    public Intent getIntent() {
        String startingFragment = getStartingFragmentClass(super.getIntent());
        if (startingFragment != null && !onIsMultiPane()) {
            Intent modIntent = new Intent(super.getIntent());
            modIntent.putExtra(EXTRA_SHOW_FRAGMENT, startingFragment);
            Bundle args = super.getIntent().getExtras();
            if (args != null) {
                args = new Bundle(args);
            } else {
                args = new Bundle();
            }
            args.putParcelable("intent", super.getIntent());
            modIntent.putExtra(EXTRA_SHOW_FRAGMENT_ARGUMENTS, super.getIntent().getExtras());
            return modIntent;
        }
        return super.getIntent();
    }

    /**
     * Checks if the component name in the intent is different from the Settings class and
     * returns the class name to load as a fragment.
     */
    protected String getStartingFragmentClass(Intent intent) {
        if (mFragmentClass != null) return mFragmentClass;

        String intentClass = intent.getComponent().getClassName();
        if (intentClass.equals(getClass().getName())) return null;

        if ("com.android.settings.ManageApplications".equals(intentClass)
                || "com.android.settings.RunningServices".equals(intentClass)
                || "com.android.settings.applications.StorageUse".equals(intentClass)) {
            // Old name of manage apps.
            intentClass = com.android.settings.applications.ManageApplications.class.getName();
        }

        return intentClass;
    }

    /**
     * Override initial header when an activity-alias is causing Settings to be launched
     * for a specific fragment encoded in the android:name parameter.
     */
    @Override
    public Header onGetInitialHeader() {
        String fragmentClass = getStartingFragmentClass(super.getIntent());
        if (fragmentClass != null) {
            Header header = new Header();
            header.fragment = fragmentClass;
            header.title = getTitle();
            header.fragmentArguments = getIntent().getExtras();
            mCurrentHeader = header;
            return header;
        }
        return super.onGetInitialHeader();
    }

    /**
     * Populate the activity with the top-level headers.
     */
    @Override
    public void onBuildHeaders(List<Header> target) {
        loadHeadersFromResource(R.xml.settings_headers, target);

        updateHeaderList(target);
    }

    private void updateHeaderList(List<Header> target) {
        int i = 0;
        while (i < target.size()) {
            Header header = target.get(i);
            // Ids are integers, so downcasting
            int id = (int) header.id;
            if (id == R.id.dock_settings) {
                if (!needsDockSettings())
                    target.remove(header);
            } else if (id == R.id.operator_settings || id == R.id.manufacturer_settings) {
                Utils.updateHeaderToSpecificActivityFromMetaDataOrRemove(this, target, header);
            } else if (id == R.id.call_settings) {
                if (!Utils.isVoiceCapable(this))
                    target.remove(header);
            }
            // Increment if the current one wasn't removed by the Utils code.
            if (target.get(i) == header) {
                // Hold on to the first header, when we need to reset to the top-level
                if (i == 0) mFirstHeader = header;
                mHeaderIndexMap.put(id, i);
                i++;
            }
        }
    }

    private boolean needsDockSettings() {
        return getResources().getBoolean(R.bool.has_dock_settings);
    }

    private void getMetaData() {
        try {
            ActivityInfo ai = getPackageManager().getActivityInfo(getComponentName(),
                    PackageManager.GET_META_DATA);
            if (ai == null || ai.metaData == null) return;
            mTopLevelHeaderId = ai.metaData.getInt(META_DATA_KEY_HEADER_ID);
            mFragmentClass = ai.metaData.getString(META_DATA_KEY_FRAGMENT_CLASS);
            
            // Check if it has a parent specified and create a Header object
            final int parentHeaderTitleRes = ai.metaData.getInt(META_DATA_KEY_PARENT_TITLE);
            String parentFragmentClass = ai.metaData.getString(META_DATA_KEY_PARENT_FRAGMENT_CLASS);
            if (parentFragmentClass != null) {
                mParentHeader = new Header();
                mParentHeader.fragment = parentFragmentClass;
                if (parentHeaderTitleRes != 0) {
                    mParentHeader.title = getResources().getString(parentHeaderTitleRes);
                }
            }
        } catch (NameNotFoundException nnfe) {
        }
    }

    @Override
    public boolean hasNextButton() {
        return super.hasNextButton();
    }

    @Override
    public Button getNextButton() {
        return super.getNextButton();
    }

    /*
     * Settings subclasses for launching independently.
     */

    public static class BluetoothSettingsActivity extends Settings { }
    public static class WirelessSettingsActivity extends Settings { }
    public static class TetherSettingsActivity extends Settings { }
    public static class VpnSettingsActivity extends Settings { }
    public static class DateTimeSettingsActivity extends Settings { }
    public static class StorageSettingsActivity extends Settings { }
    public static class WifiSettingsActivity extends Settings { }
    public static class InputMethodAndLanguageSettingsActivity extends Settings { }
    public static class InputMethodConfigActivity extends Settings { }
    public static class InputMethodAndSubtypeEnablerActivity extends Settings { }
    public static class LocalePickerActivity extends Settings { }
    public static class UserDictionarySettingsActivity extends Settings { }
    public static class SoundSettingsActivity extends Settings { }
    public static class DisplaySettingsActivity extends Settings { }
    public static class DeviceInfoSettingsActivity extends Settings { }
    public static class ApplicationSettingsActivity extends Settings { }
    public static class ManageApplicationsActivity extends Settings { }
    public static class StorageUseActivity extends Settings { }
    public static class DevelopmentSettingsActivity extends Settings { }
    public static class AccessibilitySettingsActivity extends Settings { }
    public static class SecuritySettingsActivity extends Settings { }
    public static class PrivacySettingsActivity extends Settings { }
    public static class DockSettingsActivity extends Settings { }
    public static class RunningServicesActivity extends Settings { }
    public static class ManageAccountsSettingsActivity extends Settings { }
    public static class PowerUsageSummaryActivity extends Settings { }
    public static class AccountSyncSettingsActivity extends Settings { }
    public static class AccountSyncSettingsInAddAccountActivity extends Settings { }
    public static class CryptKeeperSettingsActivity extends Settings { }
    public static class DeviceAdminSettingsActivity extends Settings { }
}