apps/Tag/src/com/android/apps/tag/TagDBHelper.java

/*
 * 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.apps.tag;

import com.google.common.annotations.VisibleForTesting;
import com.trustedlogic.trustednfc.android.NdefMessage;
import com.trustedlogic.trustednfc.android.NdefRecord;
import com.trustedlogic.trustednfc.android.NfcException;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteStatement;

import java.net.URI;
import java.util.Date;

/**
 * Database utilities for the saved tags.
 */
public class TagDBHelper extends SQLiteOpenHelper {

    private static final int DATABASE_VERSION = 1;

    private static final String NDEF_MSG = "create table NdefMessage ("
            + "_id INTEGER NOT NULL, "
            + "bytes BLOB NOT NULL, "
            + "date TEXT NOT NULL, "
            + "saved TEXT NOT NULL default 0,"  // boolean
            + "PRIMARY KEY(_id)"
            + ")";

    private static final String INSERT =
            "INSERT INTO NdefMessage (bytes, date, saved) values (?, ?, ?)";

    /**
     * A real NFC tag containing an NFC "smart poster".  This smart poster
     * consists of the text "NFC Forum Type 4 Tag" in english combined with
     * the URL "http://www.nxp.com/nfc"
     */
    public static final byte[] REAL_NFC_MSG = new byte[] {
            (byte) 0xd1,                   // MB=1 ME=1 CF=0 SR=1 IL=0 TNF=001
            (byte) 0x02,                   // Type Length = 2
            (byte) 0x2b,                   // Payload Length = 43
            (byte) 0x53, (byte) 0x70,      // Type = {'S', 'p'} (smart poster)

            // begin smart poster payload
            // begin smart poster record #1
            (byte) 0x91,                   // MB=1 ME=0 CF=0 SR=1 IL=0 TNF=001
            (byte) 0x01,                   // Type Length = 1
            (byte) 0x17,                   // Payload Length = 23
            (byte) 0x54,                   // Type = {'T'} (Text data)
            (byte) 0x02,                   // UTF-8 encoding, language code length = 2
            (byte) 0x65, (byte) 0x6e,      // language = {'e', 'n'} (english)

            // Begin text data within smart poster record #1
            (byte) 0x4e,                   // 'N'
            (byte) 0x46,                   // 'F'
            (byte) 0x43,                   // 'C'
            (byte) 0x20,                   // ' '
            (byte) 0x46,                   // 'F'
            (byte) 0x6f,                   // 'o'
            (byte) 0x72,                   // 'r'
            (byte) 0x75,                   // 'u'
            (byte) 0x6d,                   // 'm'
            (byte) 0x20,                   // ' '
            (byte) 0x54,                   // 'T'
            (byte) 0x79,                   // 'y'
            (byte) 0x70,                   // 'p'
            (byte) 0x65,                   // 'e'
            (byte) 0x20,                   // ' '
            (byte) 0x34,                   // '4'
            (byte) 0x20,                   // ' '
            (byte) 0x54,                   // 'T'
            (byte) 0x61,                   // 'a'
            (byte) 0x67,                   // 'g'
            // end Text data within smart poster record #1
            // end smart poster record #1

            // begin smart poster record #2
            (byte) 0x51,                   // MB=0 ME=1 CF=0 SR=1 IL=0 TNF=001
            (byte) 0x01,                   // Type Length = 1
            (byte) 0x0c,                   // Payload Length = 12
            (byte) 0x55,                   // Type = { 'U' } (URI)

            // begin URI data within smart poster record #2
            (byte) 0x01,                   // URI Prefix = 1 ("http://www.")
            (byte) 0x6e,                   // 'n'
            (byte) 0x78,                   // 'x'
            (byte) 0x70,                   // 'p'
            (byte) 0x2e,                   // '.'
            (byte) 0x63,                   // 'c'
            (byte) 0x6f,                   // 'o'
            (byte) 0x6d,                   // 'm'
            (byte) 0x2f,                   // '/'
            (byte) 0x6e,                   // 'n'
            (byte) 0x66,                   // 'f'
            (byte) 0x63                    // 'c'
            // end URI data within smart poster record #2
            // end smart poster record #2
            // end smart poster payload
    };

    public TagDBHelper(Context context) {
        this(context, "Tags.db");
    }

    @VisibleForTesting
    public TagDBHelper(Context context, String dbFile) {
        super(context, dbFile, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(NDEF_MSG);

        // A fake message containing 1 URL
        NdefMessage msg1 = new NdefMessage(new NdefRecord[] {
                NdefUtil.toUriRecord(URI.create("http://www.google.com"))
        });

        // A fake message containing 2 URLs
        NdefMessage msg2 = new NdefMessage(new NdefRecord[] {
                NdefUtil.toUriRecord(URI.create("http://www.youtube.com")),
                NdefUtil.toUriRecord(URI.create("http://www.android.com"))
        });

        insert(db, msg1, false);
        insert(db, msg2, true);

        try {
            // A real message obtained from an NFC Forum Type 4 tag.
            NdefMessage msg3 = new NdefMessage(REAL_NFC_MSG);
            insert(db, msg3, false);
        } catch (NfcException e) {
            throw new RuntimeException(e);
        }
    }

    private void insert(SQLiteDatabase db, NdefMessage msg, boolean isSaved) {
        SQLiteStatement stmt = db.compileStatement(INSERT);
        stmt.bindString(1, new String(msg.toByteArray())); // TODO: This should be a blob
        stmt.bindString(2, new Date().toString());
        String isSavedStr = isSaved ? "1" : "0";
        stmt.bindString(3, isSavedStr);
        stmt.executeInsert();
        stmt.close();
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    }
}