/*
 * Copyright (c) 2013, Stefan Brand <seiichiro@seiichiro0185.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this
 *    list of conditions and the following disclaimer in the documentation and/or other
 *    materials provided with the distribution.
 *
 * 3. The names of the contributors may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

.import QtQuick.LocalStorage 2.0 as LS

// Get DB Connection, Initialize or Upgrade DB
function getDB() {
  try {
    var db = LS.LocalStorage.openDatabaseSync("harbour-sailotp", "", "SailOTP Config Storage", 1000000);

    if (db.version == "") {
      // Initialize an empty DB, Create the Table
      db.changeVersion("", "2",
        function(tx) {
          tx.executeSql("CREATE TABLE IF NOT EXISTS OTPStorage(title TEXT, secret TEXT, type TEXT DEFAULT 'TOPT', counter INTEGER DEFAULT 0, fav INTEGER DEFAULT 0);");
      });
    } else if (db.version == "1.0") {
      // Upgrade DB Schema to Version 2
      db.changeVersion("1.0", "2",
        function(tx) {
          tx.executeSql("ALTER TABLE OTPStorage ADD COLUMN type TEXT DEFAULT 'TOTP';");
          tx.executeSql("ALTER TABLE OTPStorage ADD COLUMN counter INTEGER DEFAULT 0;");
          tx.executeSql("ALTER TABLE OTPStorage ADD COLUMN fav INTEGER DEFAULT 0;");
      });
    }
  } catch (e) {
    // DB Failed to open
    console.log("Could not open DB: " + e);
  }

  return db;
}

// Get all OTPs into the list model
function getOTP() {
  var db = getDB();

  db.transaction(
    function(tx) {
      var res = tx.executeSql("select * from OTPStorage;");
      for (var i=0; i < res.rows.length; i++) {
        mainPage.appendOTP(res.rows.item(i).title, res.rows.item(i).secret, res.rows.item(i).type, res.rows.item(i).counter, res.rows.item(i).fav);
        if (res.rows.item(i).fav) mainPage.setCoverOTP(res.rows.item(i).title, res.rows.item(i).secret, res.rows.item(i).type);
      }
  });
}

// Get all OTP Values and put them into a JSON-Object
function db2json() {
  var db = getDB();
  var otpList = [];

  db.transaction(
    function(tx) {
      var res = tx.executeSql("select * from OTPStorage;");
      for (var i=0; i < res.rows.length; i++) {
        otpList.push({
          "title": res.rows.item(i).title,
          "secret": res.rows.item(i).secret,
          "type": res.rows.item(i).type,
          "counter": res.rows.item(i).counter,
      });
    }
  });

  if (otpList.length > 0) {
    return(JSON.stringify({"app": "sailotp", "version": 1, "otplist": otpList}));
  } else {
    return("")
  }
}

// Read Values from JSON and put them into the DB
function json2db(jsonString) {
  var json = JSON.parse(jsonString);

  if (json.version != "1" && json.app != "sailotp" ) {
    console.log("Unrecognized JSON format");
    return(false);
  } else {
    var otpList = [];
    otpList = json.otplist;
    if (otpList.length > 0) {
      while(otpList.length > 0) {
        var otpItem = otpList.shift();
        if (otpItem.title != "" & otpItem.secret.length >= 16) {
          addOTP(otpItem.title, otpItem.secret, otpItem.type, otpItem.counter);
        }
      }
      parentPage.refreshOTPList();
    } else {
      console.log("File contains no Items");
      return(false);
    }
  }
}

// Add a new OTP
function addOTP(title, secret, type, counter) {
  var db = getDB();

  db.transaction(
    function(tx) {
      if (checkOTP(title, secret)) {
        console.log("Token " + title + " is already in DB");
      } else {
        tx.executeSql("INSERT INTO OTPStorage VALUES(?, ?, ?, ?, ?);", [title, secret, type, counter, 0]);
        console.log("Token " + title + " added.");
      }
  });
}

// Check if an OTP Token already exists in the DB
function checkOTP(title, secret) {
  var db = getDB();
  var res

  db.transaction(
    function(tx) {
      res = tx.executeSql("select title FROM OTPStorage WHERE title=? and secret=?;", [title, secret]);
  });

  return res.rows.length > 0 ? true : false
}

// Remove an existing OTP
function removeOTP(title, secret) {
  var db = getDB();

  db.transaction(
    function(tx) {
      tx.executeSql("DELETE FROM OTPStorage WHERE title=? and secret=?;", [title, secret]);
  });
}

// Set OTP to favourite
function setFav(title, secret) {
  var db = getDB();

  db.transaction(
    function(tx) {
      tx.executeSql("UPDATE OTPStorage set fav = 0");
      tx.executeSql("UPDATE OTPStorage set fav = 1 WHERE title=? and secret=?;", [title, secret]);
  });
}

// Reset favourite Flag for OTP
function resetFav(title, secret) {
  var db = getDB();

  db.transaction(
    function(tx) {
      tx.executeSql("UPDATE OTPStorage set fav = 0");
  });
}

// Change an existing OTP
function changeOTP(title, secret, type, counter, oldtitle, oldsecret) {
  var db = getDB();

  db.transaction(
    function(tx) {
      if (checkOTP(title, secret)) {
        console.log("Token " + title + " is already in DB");
      } else {
        tx.executeSql("UPDATE OTPStorage SET title=?, secret=?, type=?, counter=? WHERE title=? and secret=?;", [title, secret, type, counter, oldtitle, oldsecret]);
        console.log("Token " + title + " modified.");
      }
  });
}

// Get the counter for a HOTP value, incerment the counter on request
function getCounter(title, secret, increment) {
  var db = getDB();

  var res = "";

  db.transaction(
    function(tx) {
      res = tx.executeSql("SELECT counter FROM OTPStorage where title=? and secret=?;", [title, secret]);
      if (increment) tx.executeSql("UPDATE OTPStorage set counter=counter+1 WHERE title=? and secret=?;", [title, secret]);
  });

  return res.rows.item(0).counter;
}