/* 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/. */

"use strict";

const EXPORTED_SYMBOLS = ['ContactDB'];

let DEBUG = 0;
/* static functions */
if (DEBUG)
    debug = function (s) { dump("-*- ContactDB component: " + s + "\n"); }
else
    debug = function (s) {}

const Cu = Components.utils; 
const Cc = Components.classes;
const Ci = Components.interfaces;

Cu.import("resource://gre/modules/Services.jsm");

const DB_NAME = "contacts";
const DB_VERSION = 1;
const STORE_NAME = "contacts";

function ContactDB(aGlobal) {
  debug("Constructor");
  this._indexedDB = aGlobal.mozIndexedDB;
}

ContactDB.prototype = {

  // Cache the DB
  db: null,

  close: function close() {
    debug("close");
    if (this.db)
      this.db.close();
  },

  /**
   * Prepare the database. This may include opening the database and upgrading
   * it to the latest schema version.
   * 
   * @return (via callback) a database ready for use.
   */
  ensureDB: function ensureDB(callback, failureCb) {
    if (this.db) {
      debug("ensureDB: already have a database, returning early.");
      callback(this.db);
      return;
    }

    let self = this;
    debug("try to open database:" + DB_NAME + " " + DB_VERSION);
    let request = this._indexedDB.open(DB_NAME, DB_VERSION);
    request.onsuccess = function (event) {
      debug("Opened database:", DB_NAME, DB_VERSION);
      self.db = event.target.result;
      self.db.onversionchange = function(event) {
        debug("WARNING: DB modified from a different window.");
      }
      callback(self.db);
    };
    request.onupgradeneeded = function (event) {
      debug("Database needs upgrade:" + DB_NAME + event.oldVersion + event.newVersion);
      debug("Correct new database version:" + event.newVersion == DB_VERSION);

      let db = event.target.result;
      switch (event.oldVersion) {
        case 0:
          debug("New database");
          self.createSchema(db);
          break;

        default:
          debug("No idea what to do with old database version:" + event.oldVersion);
          failureCb(event.target.errorMessage);
          break;
      }
    };
    request.onerror = function (event) {
      debug("Failed to open database:", DB_NAME);
      failureCb(event.target.errorMessage);
    };
    request.onblocked = function (event) {
      debug("Opening database request is blocked.");
    };
  },

  /**
   * Create the initial database schema.
   *
   * The schema of records stored is as follows:
   *
   * {id:            "...",       // UUID
   *  published:     Date(...),   // First published date.
   *  updated:       Date(...),   // Last updated date.
   *  properties:    {...}        // Object holding the ContactProperties
   * }
   */
  createSchema: function createSchema(db) {
    let objectStore = db.createObjectStore(STORE_NAME, {keyPath: "id"});

    // Metadata indexes
    objectStore.createIndex("published", "published", { unique: false });
    objectStore.createIndex("updated",   "updated",   { unique: false });

    // Properties indexes
    objectStore.createIndex("nickname",   "properties.nickname",   { unique: false, multiEntry: true });
    objectStore.createIndex("name",       "properties.name",       { unique: false, multiEntry: true });
    objectStore.createIndex("familyName", "properties.familyName", { unique: false, multiEntry: true });
    objectStore.createIndex("givenName",  "properties.givenName",  { unique: false, multiEntry: true });
    objectStore.createIndex("tel",        "properties.tel",        { unique: false, multiEntry: true });
    objectStore.createIndex("email",      "properties.email",      { unique: false, multiEntry: true });
    objectStore.createIndex("note",       "properties.note",       { unique: false, multiEntry: true });

    debug("Created object stores and indexes");
  },

  /**
   * Start a new transaction.
   * 
   * @param txn_type
   *        Type of transaction (e.g. IDBTransaction.READ_WRITE)
   * @param callback
   *        Function to call when the transaction is available. It will
   *        be invoked with the transaction and the 'contacts' object store.
   * @param successCb [optional]
   *        Success callback to call on a successful transaction commit.
   * @param failureCb [optional]
   *        Error callback to call when an error is encountered.
   */
  newTxn: function newTxn(txn_type, callback, successCb, failureCb) {
    this.ensureDB(function (db) {
      debug("Starting new transaction" + txn_type);
      let txn = db.transaction(STORE_NAME, txn_type);
      debug("Retrieving object store", STORE_NAME);
      let store = txn.objectStore(STORE_NAME);

      txn.oncomplete = function (event) {
        debug("Transaction complete. Returning to callback.");
        successCb(txn.result);
      };

      txn.onabort = function (event) {
        debug("Caught error on transaction" + event.target.errorCode);
        switch(event.target.errorCode) {
          case Ci.nsIIDBDatabaseException.ABORT_ERR:
          case Ci.nsIIDBDatabaseException.CONSTRAINT_ERR:
          case Ci.nsIIDBDatabaseException.DATA_ERR:
          case Ci.nsIIDBDatabaseException.TRANSIENT_ERR:
          case Ci.nsIIDBDatabaseException.NOT_ALLOWED_ERR:
          case Ci.nsIIDBDatabaseException.NOT_FOUND_ERR:
          case Ci.nsIIDBDatabaseException.QUOTA_ERR:
          case Ci.nsIIDBDatabaseException.READ_ONLY_ERR:
          case Ci.nsIIDBDatabaseException.TIMEOUT_ERR:
          case Ci.nsIIDBDatabaseException.TRANSACTION_INACTIVE_ERR:
          case Ci.nsIIDBDatabaseException.VERSION_ERR:
          case Ci.nsIIDBDatabaseException.UNKNOWN_ERR:
            failureCb("UnknownError");
            break;
          default:
            debug("Unknown errorCode", event.target.errorCode);
            failureCb("UnknownError");
            break;
        }
      };
      callback(txn, store);
    }, failureCb);
  },

  // Todo: add searchfields. "Tom" should be a result with T, t, To, to...
  makeImport: function makeImport(aContact) {
    let contact = {};
    contact.properties = {
      name:            [],
      honorificPrefix: [],
      givenName:       [],
      additionalName:  [],
      familyName:      [],
      honorificSuffix: [],
      nickname:        [],
      email:           [],
      photo:           [],
      url:             [],
      category:        [],
      adr:             [],
      tel:             [],
      org:             [],
      bday:            null,
      note:            [],
      impp:            [],
      anniversary:     null,
      sex:             null,
      genderIdentity:  null
    };

    for (let field in aContact.properties) {
      contact.properties[field] = aContact.properties[field];
    }

    contact.updated = aContact.updated;
    contact.published = aContact.published;
    contact.id = aContact.id;

    return contact;
  },

  // Needed to remove searchfields
  makeExport: function makeExport(aRecord) {
    let contact = {};
    contact.properties = aRecord.properties;

    for (let field in aRecord.properties)
      contact.properties[field] = aRecord.properties[field];

    contact.updated = aRecord.updated;
    contact.published = aRecord.published;
    contact.id = aRecord.id;
    return contact;
  },

  updateRecordMetadata: function updateRecordMetadata(record) {
    if (!record.id) {
      Cu.reportError("Contact without ID");
    }
    if (!record.published) {
      record.published = new Date();
    }
    record.updated = new Date();
  },

  saveContact: function saveContact(aContact, successCb, errorCb) {
    let contact = this.makeImport(aContact);
    this.newTxn(Ci.nsIIDBTransaction.READ_WRITE, function (txn, store) {
      debug("Going to update" + JSON.stringify(contact));

      // Look up the existing record and compare the update timestamp.
      // If no record exists, just add the new entry.
      let newRequest = store.get(contact.id);
      newRequest.onsuccess = function (event) {
        if (!event.target.result) {
          debug("new record!")
          this.updateRecordMetadata(contact);
          store.put(contact);
        } else {
          debug("old record!")
          if (new Date(typeof contact.updated === "undefined" ? 0 : contact.updated) < new Date(event.target.result.updated)) {
            debug("rev check fail!");
            txn.abort();
            return;
          } else {
            debug("rev check OK");
            contact.published = event.target.result.published;
            contact.updated = new Date();
            store.put(contact);
          }
        }
      }.bind(this);
    }.bind(this), successCb, errorCb);
  },

  removeContact: function removeContact(aId, aSuccessCb, aErrorCb) {
    this.newTxn(Ci.nsIIDBTransaction.READ_WRITE, function (txn, store) {
      debug("Going to delete" + aId);
      store.delete(aId);
    }, aSuccessCb, aErrorCb);
  },

  clear: function clear(aSuccessCb, aErrorCb) {
    this.newTxn(Ci.nsIIDBTransaction.READ_WRITE, function (txn, store) {
      debug("Going to clear all!");
      store.clear();
    }, aSuccessCb, aErrorCb);
  },

  /**
   * @param successCb
   *        Callback function to invoke with result array.
   * @param failureCb [optional]
   *        Callback function to invoke when there was an error.
   * @param options [optional]
   *        Object specifying search options. Possible attributes:
   *        - filterBy
   *        - filterOp
   *        - filterValue
   *        - count
   *        Possibly supported in the future:
   *        - fields
   *        - sortBy
   *        - sortOrder
   *        - startIndex
   */
  find: function find(aSuccessCb, aFailureCb, aOptions) {
    debug("ContactDB:find val:" + aOptions.filterValue + " by: " + aOptions.filterBy + " op: " + aOptions.filterOp + "\n");

    let self = this;
    this.newTxn(Ci.nsIIDBTransaction.READ_ONLY, function (txn, store) {
      if (aOptions && aOptions.filterOp == "equals") {
        self._findWithIndex(txn, store, aOptions);
      } else if (aOptions && aOptions.filterBy) {
        self._findWithSearch(txn, store, aOptions);
      } else {
        self._findAll(txn, store, aOptions);
      }
    }, aSuccessCb, aFailureCb);
  },

  _findWithIndex: function _findWithIndex(txn, store, options) {
    debug("_findWithIndex: " + options.filterValue +" " + options.filterOp + " " + options.filterBy + " ");
    let fields = options.filterBy;
    for (let key in fields) {
      debug("key: " + fields[key]);
      if (!store.indexNames.contains(fields[key]) && !fields[key] == "id") {
        debug("Key not valid!" + fields[key] + ", " + store.indexNames);
        txn.abort();
        return;
      }
    }

    // lookup for all keys
    if (options.filterBy.length == 0) {
      debug("search in all fields!" + JSON.stringify(store.indexNames));
      for(let myIndex = 0; myIndex < store.indexNames.length; myIndex++) {
        fields = Array.concat(fields, store.indexNames[myIndex])
      }
    }

    let filter_keys = fields.slice();
    for (let key = filter_keys.shift(); key; key = filter_keys.shift()) {
      let request;
      if (key == "id") {
        // store.get would return an object and not an array
        request = store.getAll(options.filterValue);
      } else {
        debug("Getting index: " + key);
        let index = store.index(key);
        request = index.getAll(options.filterValue, options.filterLimit);
      }
      if (!txn.result)
        txn.result = {};

      request.onsuccess = function (event) {
        debug("Request successful. Record count:" + event.target.result.length);
        for (let i in event.target.result)
          txn.result[event.target.result[i].id] = this.makeExport(event.target.result[i]);
      }.bind(this);
    }
  },

  // Will be replaced by _findWithIndex once all searchfields are added.
  _findWithSearch: function _findWithSearch(txn, store, options) {
    debug("_findWithSearch:" + options.filterValue + options.filterOp)
    store.getAll().onsuccess = function (event) {
      debug("Request successful." + event.target.result);
      txn.result = event.target.result.filter(function (record) {
        let properties = record.properties;
        for (let i = 0; i < options.filterBy.length; i++) {
          let field = options.filterBy[i];
          if (!properties[field])
              continue;
          let value = '';
          switch (field) {
            case "name":
            case "familyName":
            case "givenName":
            case "nickname":
            case "email":
            case "tel":
            case "note":
              value = [f for each (f in [properties[field]])].join("\n") || '';
              break;
            default:
              value = properties[field];
              debug("unknown field: " + field);
          }
          let match = false;
          switch (options.filterOp) {
            case "icontains":
              match = value.toLowerCase().indexOf(options.filterValue.toLowerCase()) != -1;
              break;
            case "contains":
              match = value.indexOf(options.filterValue) != -1;
              break;
            case "equals":
              match = value == options.filterValue;
              break
          }
          if (match)
            return true;
        }
        return false;
      }).map(this.makeExport.bind(this));
    }.bind(this);
  },

  _findAll: function _findAll(txn, store, options) {
    debug("ContactDB:_findAll:  " + JSON.stringify(options));
    if (!txn.result)
      txn.result = {};

    store.getAll(null, options.filterLimit).onsuccess = function (event) {
      debug("Request successful. Record count:", event.target.result.length);
      for (let i in event.target.result)
        txn.result[event.target.result[i].id] = this.makeExport(event.target.result[i]);
    }.bind(this);
  }
};