/* 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/. */

Components.utils.import("resource://calendar/modules/calUtils.jsm");
Components.utils.import("resource://calendar/modules/calItipUtils.jsm");
Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");

function calTransactionManager() {
    this.wrappedJSObject = this;
    if (!this.transactionManager) {
        this.transactionManager =
            Components.classes["@mozilla.org/transactionmanager;1"]
                      .createInstance(Components.interfaces.nsITransactionManager);
    }
}

var calTransactionManagerClassID = Components.ID("{40a1ccf4-5f54-4815-b842-abf06f84dbfd}");
var calTransactionManagerInterfaces = [Components.interfaces.calITransactionManager];
calTransactionManager.prototype = {

    classID: calTransactionManagerClassID,
    QueryInterface: XPCOMUtils.generateQI(calTransactionManagerInterfaces),
    classInfo: XPCOMUtils.generateCI({
        classID: calTransactionManagerClassID,
        classDescription: "Calendar Transaction Manager",
        contractID: "mozilla.org/calendar/transactionmanager;1",
        interfaces: calTransactionManagerInterfaces,
        flags: Components.interfaces.nsIClassInfo.SINGLETON
    }),

    transactionManager: null,
    createAndCommitTxn: function(aAction, aItem, aCalendar, aOldItem, aListener) {
        let txn = new calTransaction(aAction,
                                     aItem,
                                     aCalendar,
                                     aOldItem,
                                     aListener);
        this.transactionManager.doTransaction(txn);
    },

    beginBatch: function() {
        this.transactionManager.beginBatch(null);
    },

    endBatch: function() {
        this.transactionManager.endBatch(false);
    },

    checkWritable: function(transaction) {
        function checkItem(item) {
            return item && item.calendar &&
                   cal.isCalendarWritable(item.calendar) &&
                   cal.userCanAddItemsToCalendar(item.calendar);
        }

        let trans = transaction && transaction.wrappedJSObject;
        return trans && checkItem(trans.mItem) && checkItem(trans.mOldItem);
    },

    undo: function() {
        this.transactionManager.undoTransaction();
    },

    canUndo: function() {
        return this.transactionManager.numberOfUndoItems > 0 &&
               this.checkWritable(this.transactionManager.peekUndoStack());
    },

    redo: function() {
        this.transactionManager.redoTransaction();
    },

    canRedo: function() {
        return this.transactionManager.numberOfRedoItems > 0 &&
               this.checkWritable(this.transactionManager.peekRedoStack());
    }
};

function calTransaction(aAction, aItem, aCalendar, aOldItem, aListener) {
    this.wrappedJSObject = this;
    this.mAction = aAction;
    this.mItem = aItem;
    this.mCalendar = aCalendar;
    this.mOldItem = aOldItem;
    this.mListener = aListener;
}

var calTransactionClassID = Components.ID("{fcb54c82-2fb9-42cb-bf44-1e197a55e520}");
var calTransactionInterfaces = [
    Components.interfaces.nsITransaction,
    Components.interfaces.calIOperationListener
];
calTransaction.prototype = {
    classID: calTransactionClassID,
    QueryInterface: XPCOMUtils.generateQI(calTransactionInterfaces),
    classInfo: XPCOMUtils.generateCI({
        classID: calTransactionClassID,
        classDescription: "Calendar Transaction",
        contractID: "mozilla.org/calendar/transaction;1",
        interfaces: calTransactionInterfaces,
    }),

    mAction: null,
    mCalendar: null,
    mItem: null,
    mOldItem: null,
    mOldCalendar: null,
    mListener: null,
    mIsDoTransaction: false,

    onOperationComplete: function(aCalendar, aStatus, aOperationType, aId, aDetail) {
        if (Components.isSuccessCode(aStatus)) {
            cal.itip.checkAndSend(aOperationType,
                                  aDetail,
                                  this.mIsDoTransaction ? this.mOldItem : this.mItem);

            if (aOperationType == Components.interfaces.calIOperationListener.ADD ||
                aOperationType == Components.interfaces.calIOperationListener.MODIFY) {
                if (this.mIsDoTransaction) {
                    this.mItem = aDetail;
                } else {
                    this.mOldItem = aDetail;
                }
            }
        }
        if (this.mListener) {
            this.mListener.onOperationComplete(aCalendar,
                                               aStatus,
                                               aOperationType,
                                               aId,
                                               aDetail);
        }
    },

    onGetResult: function(aCalendar, aStatus, aItemType, aDetail, aCount, aItems) {
        if (this.mListener) {
            this.mListener.onGetResult(aCalendar,
                                       aStatus,
                                       aItemType,
                                       aDetail,
                                       aCount,
                                       aItems);
        }
    },

    doTransaction: function() {
        this.mIsDoTransaction = true;
        switch (this.mAction) {
            case "add":
                this.mCalendar.addItem(this.mItem, this);
                break;
            case "modify":
                if (this.mItem.calendar.id == this.mOldItem.calendar.id) {
                    this.mCalendar.modifyItem(cal.itip.prepareSequence(this.mItem, this.mOldItem),
                                              this.mOldItem,
                                              this);
                } else {
                    let self = this;
                    let addListener = {
                        onOperationComplete: function(aCalendar, aStatus, aOperationType, aId, aDetail) {
                            self.onOperationComplete(...arguments);
                            if (Components.isSuccessCode(aStatus)) {
                                self.mOldItem.calendar.deleteItem(self.mOldItem, self);
                            }
                        }
                    };

                    this.mOldCalendar = this.mOldItem.calendar;
                    this.mCalendar.addItem(this.mItem, addListener);
                }
                break;
            case "delete":
                this.mCalendar.deleteItem(this.mItem, this);
                break;
            default:
                throw new Components.Exception("Invalid action specified",
                                               Components.results.NS_ERROR_ILLEGAL_VALUE);
        }
    },

    undoTransaction: function() {
        this.mIsDoTransaction = false;
        switch (this.mAction) {
            case "add":
                this.mCalendar.deleteItem(this.mItem, this);
                break;
            case "modify":
                if (this.mOldItem.calendar.id == this.mItem.calendar.id) {
                    this.mCalendar.modifyItem(cal.itip.prepareSequence(this.mOldItem, this.mItem),
                                              this.mItem, this);
                } else {
                    this.mCalendar.deleteItem(this.mItem, this);
                    this.mOldCalendar.addItem(this.mOldItem, this);
                }
                break;
            case "delete":
                this.mCalendar.addItem(this.mItem, this);
                break;
            default:
                throw new Components.Exception("Invalid action specified",
                                               Components.results.NS_ERROR_ILLEGAL_VALUE);
        }
    },

    redoTransaction: function() {
        this.doTransaction();
    },

    isTransient: false,

    merge: function(aTransaction) {
        // No support for merging
        return false;
    }
};
