/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

package org.mozilla.gecko.db;

import java.io.File;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.mozilla.gecko.GeckoProfile;
import org.mozilla.gecko.db.BrowserContract.Clients;
import org.mozilla.gecko.db.BrowserContract.Tabs;
import org.mozilla.gecko.db.BrowserContract;
import org.mozilla.gecko.db.DBUtils;
import org.mozilla.gecko.util.ThreadUtils;

import android.content.ContentProvider;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteQueryBuilder;
import android.net.Uri;
import android.os.Build;
import android.text.TextUtils;
import android.util.Log;

public class TabsProvider extends ContentProvider {
    private static final String LOGTAG = "GeckoTabsProvider";
    private Context mContext;

    static final String DATABASE_NAME = "tabs.db";

    static final int DATABASE_VERSION = 2;

    static final String TABLE_TABS = "tabs";
    static final String TABLE_CLIENTS = "clients";

    static final int TABS = 600;
    static final int TABS_ID = 601;
    static final int CLIENTS = 602;
    static final int CLIENTS_ID = 603;

    static final String DEFAULT_TABS_SORT_ORDER = Clients.LAST_MODIFIED + " DESC, " + Tabs.LAST_USED + " DESC";
    static final String DEFAULT_CLIENTS_SORT_ORDER = Clients.LAST_MODIFIED + " DESC";

    static final String INDEX_TABS_GUID = "tabs_guid_index";
    static final String INDEX_TABS_POSITION = "tabs_position_index";
    static final String INDEX_CLIENTS_GUID = "clients_guid_index";

    static final UriMatcher URI_MATCHER = new UriMatcher(UriMatcher.NO_MATCH);

    static final Map<String, String> TABS_PROJECTION_MAP;
    static final Map<String, String> CLIENTS_PROJECTION_MAP;

    static {
        URI_MATCHER.addURI(BrowserContract.TABS_AUTHORITY, "tabs", TABS);
        URI_MATCHER.addURI(BrowserContract.TABS_AUTHORITY, "tabs/#", TABS_ID);
        URI_MATCHER.addURI(BrowserContract.TABS_AUTHORITY, "clients", CLIENTS);
        URI_MATCHER.addURI(BrowserContract.TABS_AUTHORITY, "clients/#", CLIENTS_ID);

        HashMap<String, String> map;

        map = new HashMap<String, String>();
        map.put(Tabs._ID, Tabs._ID);
        map.put(Tabs.TITLE, Tabs.TITLE);
        map.put(Tabs.URL, Tabs.URL);
        map.put(Tabs.HISTORY, Tabs.HISTORY);
        map.put(Tabs.FAVICON, Tabs.FAVICON);
        map.put(Tabs.LAST_USED, Tabs.LAST_USED);
        map.put(Tabs.POSITION, Tabs.POSITION);
        map.put(Clients.GUID, Clients.GUID);
        map.put(Clients.NAME, Clients.NAME);
        map.put(Clients.LAST_MODIFIED, Clients.LAST_MODIFIED);
        TABS_PROJECTION_MAP = Collections.unmodifiableMap(map);

        map = new HashMap<String, String>();
        map.put(Clients.GUID, Clients.GUID);
        map.put(Clients.NAME, Clients.NAME);
        map.put(Clients.LAST_MODIFIED, Clients.LAST_MODIFIED);
        CLIENTS_PROJECTION_MAP = Collections.unmodifiableMap(map);
    }

    private HashMap<String, DatabaseHelper> mDatabasePerProfile;

    static final String selectColumn(String table, String column) {
        return table + "." + column + " = ?";
    }

    // Calculate these once, at initialization. isLoggable is too expensive to
    // have in-line in each log call.
    private static boolean logDebug   = Log.isLoggable(LOGTAG, Log.DEBUG);
    private static boolean logVerbose = Log.isLoggable(LOGTAG, Log.VERBOSE);
    protected static void trace(String message) {
        if (logVerbose) {
            Log.v(LOGTAG, message);
        }
    }

    protected static void debug(String message) {
        if (logDebug) {
            Log.d(LOGTAG, message);
        }
    }

    final class DatabaseHelper extends SQLiteOpenHelper {
        public DatabaseHelper(Context context, String databasePath) {
            super(context, databasePath, null, DATABASE_VERSION);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            debug("Creating tabs.db: " + db.getPath());
            debug("Creating " + TABLE_TABS + " table");

            // Table for each tab on any client.
            db.execSQL("CREATE TABLE " + TABLE_TABS + "(" +
                    Tabs._ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
                    Tabs.CLIENT_GUID + " TEXT," +
                    Tabs.TITLE + " TEXT," +
                    Tabs.URL + " TEXT," +
                    Tabs.HISTORY + " TEXT," +
                    Tabs.FAVICON + " TEXT," +
                    Tabs.LAST_USED + " INTEGER," +
                    Tabs.POSITION + " INTEGER" +
                    ");");

            // Indices on CLIENT_GUID and POSITION.
            db.execSQL("CREATE INDEX " + INDEX_TABS_GUID + " ON " + TABLE_TABS + "("
                    + Tabs.CLIENT_GUID + ")");

            db.execSQL("CREATE INDEX " + INDEX_TABS_POSITION + " ON " + TABLE_TABS + "("
                    + Tabs.POSITION + ")");

            debug("Creating " + TABLE_CLIENTS + " table");

            // Table for client's name-guid mapping.
            db.execSQL("CREATE TABLE " + TABLE_CLIENTS + "(" +
                    Clients.GUID + " TEXT PRIMARY KEY," +
                    Clients.NAME + " TEXT," +
                    Clients.LAST_MODIFIED + " INTEGER" +
                    ");");

            // Index on GUID.
            db.execSQL("CREATE INDEX " + INDEX_CLIENTS_GUID + " ON " + TABLE_CLIENTS + "("
                    + Clients.GUID + ")");

            createLocalClient(db);
        }

        // Insert a client row for our local Fennec client.
        private void createLocalClient(SQLiteDatabase db) {
            debug("Inserting local Fennec client into " + TABLE_CLIENTS + " table");

            ContentValues values = new ContentValues();
            values.put(BrowserContract.Clients.LAST_MODIFIED, System.currentTimeMillis());
            db.insertOrThrow(TABLE_CLIENTS, null, values);
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            debug("Upgrading tabs.db: " + db.getPath() + " from " +
                    oldVersion + " to " + newVersion);

            // We have to do incremental upgrades until we reach the current
            // database schema version.
            for (int v = oldVersion + 1; v <= newVersion; v++) {
                switch(v) {
                    case 2:
                        createLocalClient(db);
                        break;
                 }
             }
        }

        @Override
        public void onOpen(SQLiteDatabase db) {
            debug("Opening tabs.db: " + db.getPath());

            Cursor cursor = null;
            try {
                cursor = db.rawQuery("PRAGMA synchronous=OFF", null);
            } finally {
                if (cursor != null)
                    cursor.close();
            }

            // From Honeycomb on, it's possible to run several db
            // commands in parallel using multiple connections.
            if (Build.VERSION.SDK_INT >= 11) {
                db.enableWriteAheadLogging();
                db.setLockingEnabled(false);
            } else {
                // Pre-Honeycomb, we can do some lesser optimizations.
                cursor = null;
                try {
                    cursor = db.rawQuery("PRAGMA journal_mode=PERSIST", null);
                } finally {
                    if (cursor != null)
                        cursor.close();
                }
            }
        }
    }

    private DatabaseHelper getDatabaseHelperForProfile(String profile) {
        // Each profile has a separate tabs.db database. The target
        // profile is provided using a URI query argument in each request
        // to our content provider.

        // Always fallback to default profile if none has been provided.
        if (TextUtils.isEmpty(profile)) {
            profile = GeckoProfile.get(getContext()).getName();
        }

        DatabaseHelper dbHelper;
        synchronized (this) {
            dbHelper = mDatabasePerProfile.get(profile);
            if (dbHelper != null) {
                return dbHelper;
            }

            String databasePath = getDatabasePath(profile);

            // Before bug 768532, the database was located outside if the
            // profile on Android 2.2. Make sure it is moved inside the profile
            // directory.
            if (Build.VERSION.SDK_INT == 8) {
                File oldPath = mContext.getDatabasePath("tabs-" + profile + ".db");
                if (oldPath.exists()) {
                    oldPath.renameTo(new File(databasePath));
                }
            }

            dbHelper = new DatabaseHelper(getContext(), databasePath);
            mDatabasePerProfile.put(profile, dbHelper);

            DBUtils.ensureDatabaseIsNotLocked(dbHelper, databasePath);
        }

        debug("Created database helper for profile: " + profile);
        return dbHelper;
    }

    private String getDatabasePath(String profile) {
        trace("Getting database path for profile: " + profile);

        File profileDir = GeckoProfile.get(mContext, profile).getDir();
        if (profileDir == null) {
            debug("Couldn't find directory for profile: " + profile);
            return null;
        }

        String databasePath = new File(profileDir, DATABASE_NAME).getAbsolutePath();
        debug("Successfully created database path for profile: " + databasePath);

        return databasePath;
    }

    private SQLiteDatabase getReadableDatabase(Uri uri) {
        trace("Getting readable database for URI: " + uri);

        String profile = null;

        if (uri != null)
            profile = uri.getQueryParameter(BrowserContract.PARAM_PROFILE);

        return getDatabaseHelperForProfile(profile).getReadableDatabase();
    }

    private SQLiteDatabase getWritableDatabase(Uri uri) {
        trace("Getting writable database for URI: " + uri);

        String profile = null;

        if (uri != null)
            profile = uri.getQueryParameter(BrowserContract.PARAM_PROFILE);

        return getDatabaseHelperForProfile(profile).getWritableDatabase();
    }

    @Override
    public boolean onCreate() {
        debug("Creating TabsProvider");

        synchronized (this) {
            mContext = getContext();
            mDatabasePerProfile = new HashMap<String, DatabaseHelper>();
        }

        return true;
    }

    @Override
    public String getType(Uri uri) {
        final int match = URI_MATCHER.match(uri);

        trace("Getting URI type: " + uri);

        switch (match) {
            case TABS:
                trace("URI is TABS: " + uri);
                return Tabs.CONTENT_TYPE;

            case TABS_ID:
                trace("URI is TABS_ID: " + uri);
                return Tabs.CONTENT_ITEM_TYPE;

            case CLIENTS:
                trace("URI is CLIENTS: " + uri);
                return Clients.CONTENT_TYPE;

            case CLIENTS_ID:
                trace("URI is CLIENTS_ID: " + uri);
                return Clients.CONTENT_ITEM_TYPE;
        }

        debug("URI has unrecognized type: " + uri);

        return null;
    }

    @Override
    public int delete(Uri uri, String selection, String[] selectionArgs) {
        trace("Calling delete on URI: " + uri);

        final SQLiteDatabase db = getWritableDatabase(uri);
        int deleted = 0;

        if (Build.VERSION.SDK_INT >= 11) {
            trace("Beginning delete transaction: " + uri);
            db.beginTransaction();
            try {
                deleted = deleteInTransaction(uri, selection, selectionArgs);
                db.setTransactionSuccessful();
                trace("Successful delete transaction: " + uri);
            } finally {
                db.endTransaction();
            }
        } else {
            deleted = deleteInTransaction(uri, selection, selectionArgs);
        }

        if (deleted > 0)
            getContext().getContentResolver().notifyChange(uri, null);

        return deleted;
    }

    @SuppressWarnings("fallthrough")
    public int deleteInTransaction(Uri uri, String selection, String[] selectionArgs) {
        trace("Calling delete in transaction on URI: " + uri);

        final int match = URI_MATCHER.match(uri);
        int deleted = 0;

        switch (match) {
            case CLIENTS_ID:
                trace("Delete on CLIENTS_ID: " + uri);
                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_CLIENTS, Clients.ROWID));
                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
                        new String[] { Long.toString(ContentUris.parseId(uri)) });
                // fall through
            case CLIENTS:
                trace("Delete on CLIENTS: " + uri);
                // Delete from both TABLE_TABS and TABLE_CLIENTS.
                deleteValues(uri, selection, selectionArgs, TABLE_TABS);
                deleted = deleteValues(uri, selection, selectionArgs, TABLE_CLIENTS);
                break;

            case TABS_ID:
                trace("Delete on TABS_ID: " + uri);
                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_TABS, Tabs._ID));
                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
                        new String[] { Long.toString(ContentUris.parseId(uri)) });
                // fall through
            case TABS:
                trace("Deleting on TABS: " + uri);
                deleted = deleteValues(uri, selection, selectionArgs, TABLE_TABS);
                break;

            default:
                throw new UnsupportedOperationException("Unknown delete URI " + uri);
        }

        debug("Deleted " + deleted + " rows for URI: " + uri);

        return deleted;
    }

    @Override
    public Uri insert(Uri uri, ContentValues values) {
        trace("Calling insert on URI: " + uri);

        final SQLiteDatabase db = getWritableDatabase(uri);
        Uri result = null;

        if (Build.VERSION.SDK_INT >= 11) {
            trace("Beginning insert transaction: " + uri);
            db.beginTransaction();
            try {
                result = insertInTransaction(uri, values);
                db.setTransactionSuccessful();
                trace("Successful insert transaction: " + uri);
            } finally {
                db.endTransaction();
            }
        } else {
            result = insertInTransaction(uri, values);
        }

        if (result != null)
            getContext().getContentResolver().notifyChange(uri, null);

        return result;
    }

    public Uri insertInTransaction(Uri uri, ContentValues values) {
        trace("Calling insert in transaction on URI: " + uri);

        final SQLiteDatabase db = getWritableDatabase(uri);
        int match = URI_MATCHER.match(uri);
        long id = -1;

        switch (match) {
            case CLIENTS:
                String guid = values.getAsString(Clients.GUID);
                debug("Inserting client in database with GUID: " + guid);
                id = db.insertOrThrow(TABLE_CLIENTS, Clients.GUID, values);
                break;

            case TABS:
                String url = values.getAsString(Tabs.URL);
                debug("Inserting tab in database with URL: " + url);
                id = db.insertOrThrow(TABLE_TABS, Tabs.TITLE, values);
                break;

            default:
                throw new UnsupportedOperationException("Unknown insert URI " + uri);
        }

        debug("Inserted ID in database: " + id);

        if (id >= 0)
            return ContentUris.withAppendedId(uri, id);

        return null;
    }

    @Override
    public int update(Uri uri, ContentValues values, String selection,
            String[] selectionArgs) {
        trace("Calling update on URI: " + uri);

        final SQLiteDatabase db = getWritableDatabase(uri);
        int updated = 0;

        if (Build.VERSION.SDK_INT >= 11) {
            trace("Beginning update transaction: " + uri);
            db.beginTransaction();
            try {
                updated = updateInTransaction(uri, values, selection, selectionArgs);
                db.setTransactionSuccessful();
                trace("Successful update transaction: " + uri);
            } finally {
                db.endTransaction();
            }
        } else {
            updated = updateInTransaction(uri, values, selection, selectionArgs);
        }

        if (updated > 0)
            getContext().getContentResolver().notifyChange(uri, null);

        return updated;
    }

    public int updateInTransaction(Uri uri, ContentValues values, String selection,
            String[] selectionArgs) {
        trace("Calling update in transaction on URI: " + uri);

        int match = URI_MATCHER.match(uri);
        int updated = 0;

        switch (match) {
            case CLIENTS_ID:
                trace("Update on CLIENTS_ID: " + uri);
                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_CLIENTS, Clients.ROWID));
                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
                        new String[] { Long.toString(ContentUris.parseId(uri)) });
                // fall through
            case CLIENTS:
                trace("Update on CLIENTS: " + uri);
                updated = updateValues(uri, values, selection, selectionArgs, TABLE_CLIENTS);
                break;

            case TABS_ID:
                trace("Update on TABS_ID: " + uri);
                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_TABS, Tabs._ID));
                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
                        new String[] { Long.toString(ContentUris.parseId(uri)) });
                // fall through
            case TABS:
                trace("Update on TABS: " + uri);
                updated = updateValues(uri, values, selection, selectionArgs, TABLE_TABS);
                break;

            default:
                throw new UnsupportedOperationException("Unknown update URI " + uri);
        }

        debug("Updated " + updated + " rows for URI: " + uri);

        return updated;
    }

    @Override
    @SuppressWarnings("fallthrough")
    public Cursor query(Uri uri, String[] projection, String selection,
            String[] selectionArgs, String sortOrder) {
        SQLiteDatabase db = getReadableDatabase(uri);
        final int match = URI_MATCHER.match(uri);

        SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
        String limit = uri.getQueryParameter(BrowserContract.PARAM_LIMIT);

        switch (match) {
            case TABS_ID:
                trace("Query is on TABS_ID: " + uri);
                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_TABS, Tabs._ID));
                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
                        new String[] { Long.toString(ContentUris.parseId(uri)) });
                // fall through
            case TABS:
                trace("Query is on TABS: " + uri);
                if (TextUtils.isEmpty(sortOrder)) {
                    sortOrder = DEFAULT_TABS_SORT_ORDER;
                } else {
                    debug("Using sort order " + sortOrder + ".");
                }

                qb.setProjectionMap(TABS_PROJECTION_MAP);
                qb.setTables(TABLE_TABS + " LEFT OUTER JOIN " + TABLE_CLIENTS + " ON (" + TABLE_TABS + "." + Tabs.CLIENT_GUID + " = " + TABLE_CLIENTS + "." + Clients.GUID + ")");
                break;

            case CLIENTS_ID:
                trace("Query is on CLIENTS_ID: " + uri);
                selection = DBUtils.concatenateWhere(selection, selectColumn(TABLE_CLIENTS, Clients.ROWID));
                selectionArgs = DBUtils.appendSelectionArgs(selectionArgs,
                        new String[] { Long.toString(ContentUris.parseId(uri)) });
                // fall through
            case CLIENTS:
                trace("Query is on CLIENTS: " + uri);
                if (TextUtils.isEmpty(sortOrder)) {
                    sortOrder = DEFAULT_CLIENTS_SORT_ORDER;
                } else {
                    debug("Using sort order " + sortOrder + ".");
                }

                qb.setProjectionMap(CLIENTS_PROJECTION_MAP);
                qb.setTables(TABLE_CLIENTS);
                break;

            default:
                throw new UnsupportedOperationException("Unknown query URI " + uri);
        }

        trace("Running built query.");
        Cursor cursor = qb.query(db, projection, selection, selectionArgs, null,
                null, sortOrder, limit);
        cursor.setNotificationUri(getContext().getContentResolver(),
                BrowserContract.TABS_AUTHORITY_URI);

        return cursor;
    }

    int updateValues(Uri uri, ContentValues values, String selection, String[] selectionArgs, String table) {
        trace("Updating tabs on URI: " + uri);

        final SQLiteDatabase db = getWritableDatabase(uri);

        return db.update(table, values, selection, selectionArgs);
    }

    int deleteValues(Uri uri, String selection, String[] selectionArgs, String table) {
        debug("Deleting tabs for URI: " + uri);

        final SQLiteDatabase db = getWritableDatabase(uri);

        return db.delete(table, selection, selectionArgs);
    }

    @Override
    public int bulkInsert(Uri uri, ContentValues[] values) {
        if (values == null)
            return 0;

        int numValues = values.length;
        int successes = 0;

        final SQLiteDatabase db = getWritableDatabase(uri);

        db.beginTransaction();
        try {
            for (int i = 0; i < numValues; i++) {
                try {
                    insertInTransaction(uri, values[i]);
                    successes++;
                } catch (SQLException e) {
                    Log.e(LOGTAG, "SQLException in bulkInsert", e);

                    // Restart the transaction to continue insertions.
                    db.setTransactionSuccessful();
                    db.endTransaction();
                    db.beginTransaction();
                }
            }
            trace("Flushing DB bulkinsert...");
            db.setTransactionSuccessful();
        } finally {
            db.endTransaction();
        }

        if (successes > 0)
            mContext.getContentResolver().notifyChange(uri, null);

        return successes;
    }
}