odoo.define('web.mixins', function (require) {
"use strict";

var Class = require('web.Class');
var utils = require('web.utils');

/**
 * Mixin to structure objects' life-cycles folowing a parent-children
 * relationship. Each object can a have a parent and multiple children.
 * When an object is destroyed, all its children are destroyed too releasing
 * any resource they could have reserved before.
 */
var ParentedMixin = {
    __parentedMixin : true,
    init: function() {
        this.__parentedDestroyed = false;
        this.__parentedChildren = [];
        this.__parentedParent = null;
    },
    /**
     * Set the parent of the current object. When calling this method, the
     * parent will also be informed and will return the current object
     * when its getChildren() method is called. If the current object did
     * already have a parent, it is unregistered before, which means the
     * previous parent will not return the current object anymore when its
     * getChildren() method is called.
     */
    setParent : function(parent) {
        if (this.getParent()) {
            if (this.getParent().__parentedMixin) {
                this.getParent().__parentedChildren = _.without(this
                        .getParent().getChildren(), this);
            }
        }
        this.__parentedParent = parent;
        if (parent && parent.__parentedMixin) {
            parent.__parentedChildren.push(this);
        }
    },
    /**
     * Return the current parent of the object (or null).
     */
    getParent : function() {
        return this.__parentedParent;
    },
    /**
     * Return a list of the children of the current object.
     */
    getChildren : function() {
        return _.clone(this.__parentedChildren);
    },
    /**
     * Returns true if destroy() was called on the current object.
     */
    isDestroyed : function() {
        return this.__parentedDestroyed;
    },
    /**
        Utility method to only execute asynchronous actions if the current
        object has not been destroyed.

        @param {$.Deferred} promise The promise representing the asynchronous
                                    action.
        @param {bool} [reject=false] If true, the returned promise will be
                                     rejected with no arguments if the current
                                     object is destroyed. If false, the
                                     returned promise will never be resolved
                                     or rejected.
        @returns {$.Deferred} A promise that will mirror the given promise if
                              everything goes fine but will either be rejected
                              with no arguments or never resolved if the
                              current object is destroyed.
    */
    alive: function(promise, reject) {
        var self = this;
        return $.Deferred(function (def) {
            promise.then(function () {
                if (!self.isDestroyed()) {
                    def.resolve.apply(def, arguments);
                }
            }, function () {
                if (!self.isDestroyed()) {
                    def.reject.apply(def, arguments);
                }
            }).always(function () {
                if (reject) {
                    // noop if def already resolved or rejected
                    def.reject();
                }
                // otherwise leave promise in limbo
            });
        }).promise();
    },
    /**
     * Inform the object it should destroy itself, releasing any
     * resource it could have reserved.
     */
    destroy : function() {
        _.each(this.getChildren(), function(el) {
            el.destroy();
        });
        this.setParent(undefined);
        this.__parentedDestroyed = true;
    },
    /**
     * Find the closest ancestor matching predicate
     */
    findAncestor: function (predicate) {
        var ancestor = this;
        while (ancestor && !(predicate(ancestor)) && ancestor.getParent) {
            ancestor = ancestor.getParent();
        }
        return ancestor;
    },
};

function OdooEvent (target, name, data) {
    this.target = target;
    this.name = name;
    this.data = Object.create(null);
    _.extend(this.data, data);
    this.stopped = false;
}

OdooEvent.prototype.stop_propagation = function () {
    this.stopped = true;
};

OdooEvent.prototype.is_stopped = function () {
    return this.stopped;
};

/**
 * Backbone's events. Do not ever use it directly, use EventDispatcherMixin instead.
 *
 * This class just handle the dispatching of events, it is not meant to be extended,
 * nor used directly. All integration with parenting and automatic unregistration of
 * events is done in EventDispatcherMixin.
 *
 * Copyright notice for the following Class:
 *
 * (c) 2010-2012 Jeremy Ashkenas, DocumentCloud Inc.
 * Backbone may be freely distributed under the MIT license.
 * For all details and documentation:
 * http://backbonejs.org
 *
 */
var Events = Class.extend({
    on : function(events, callback, context) {
        var ev;
        events = events.split(/\s+/);
        var calls = this._callbacks || (this._callbacks = {});
        while ((ev = events.shift())) {
            var list = calls[ev] || (calls[ev] = {});
            var tail = list.tail || (list.tail = list.next = {});
            tail.callback = callback;
            tail.context = context;
            list.tail = tail.next = {};
        }
        return this;
    },

    off : function(events, callback, context) {
        var ev, calls, node;
        if (!events) {
            delete this._callbacks;
        } else if ((calls = this._callbacks)) {
            events = events.split(/\s+/);
            while ((ev = events.shift())) {
                node = calls[ev];
                delete calls[ev];
                if (!callback || !node)
                    continue;
                while ((node = node.next) && node.next) {
                    if (node.callback === callback
                            && (!context || node.context === context))
                        continue;
                    this.on(ev, node.callback, node.context);
                }
            }
        }
        return this;
    },

    callbackList: function() {
        var lst = [];
        _.each(this._callbacks || {}, function(el, eventName) {
            var node = el;
            while ((node = node.next) && node.next) {
                lst.push([eventName, node.callback, node.context]);
            }
        });
        return lst;
    },

    trigger : function(events) {
        var event, node, calls, tail, args, all, rest;
        if (!(calls = this._callbacks))
            return this;
        all = calls.all;
        (events = events.split(/\s+/)).push(null);
        // Save references to the current heads & tails.
        while ((event = events.shift())) {
            if (all)
                events.push({
                    next : all.next,
                    tail : all.tail,
                    event : event
                });
            if (!(node = calls[event]))
                continue;
            events.push({
                next : node.next,
                tail : node.tail
            });
        }
        rest = Array.prototype.slice.call(arguments, 1);
        while ((node = events.pop())) {
            tail = node.tail;
            args = node.event ? [ node.event ].concat(rest) : rest;
            while ((node = node.next) !== tail) {
                node.callback.apply(node.context || this, args);
            }
        }
        return this;
    }
});

/**
    Mixin containing an event system. Events are also registered by specifying the target object
    (the object which will receive the event when it is raised). Both the event-emitting object
    and the target object store or reference to each other. This is used to correctly remove all
    reference to the event handler when any of the object is destroyed (when the destroy() method
    from ParentedMixin is called). Removing those references is necessary to avoid memory leak
    and phantom events (events which are raised and sent to a previously destroyed object).
*/
var EventDispatcherMixin = _.extend({}, ParentedMixin, {
    __eventDispatcherMixin: true,
    init: function() {
        ParentedMixin.init.call(this);
        this.__edispatcherEvents = new Events();
        this.__edispatcherRegisteredEvents = [];
    },
    on: function(events, dest, func) {
        var self = this;
        if (typeof func !== "function") {
            throw new Error("Event handler must be a function.");
        }
        events = events.split(/\s+/);
        _.each(events, function(eventName) {
            self.__edispatcherEvents.on(eventName, func, dest);
            if (dest && dest.__eventDispatcherMixin) {
                dest.__edispatcherRegisteredEvents.push({name: eventName, func: func, source: self});
            }
        });
        return this;
    },
    off: function(events, dest, func) {
        var self = this;
        events = events.split(/\s+/);
        _.each(events, function(eventName) {
            self.__edispatcherEvents.off(eventName, func, dest);
            if (dest && dest.__eventDispatcherMixin) {
                dest.__edispatcherRegisteredEvents = _.filter(dest.__edispatcherRegisteredEvents, function(el) {
                    return !(el.name === eventName && el.func === func && el.source === self);
                });
            }
        });
        return this;
    },
    trigger: function() {
        this.__edispatcherEvents.trigger.apply(this.__edispatcherEvents, arguments);
        return this;
    },
    trigger_up: function(name, info) {
        var event = new OdooEvent(this, name, info);
        this._trigger_up(event);
    },
    _trigger_up: function(event) {
        var parent;
        this.__edispatcherEvents.trigger(event.name, event);
        if (!event.is_stopped() && (parent = this.getParent())) {
            parent._trigger_up(event);
        }
    },
    destroy: function() {
        var self = this;
        _.each(this.__edispatcherRegisteredEvents, function(event) {
            event.source.__edispatcherEvents.off(event.name, event.func, self);
        });
        this.__edispatcherRegisteredEvents = [];
        _.each(this.__edispatcherEvents.callbackList(), function(cal) {
            this.off(cal[0], cal[2], cal[1]);
        }, this);
        this.__edispatcherEvents.off();
        ParentedMixin.destroy.call(this);
    }
});

var PropertiesMixin = _.extend({}, EventDispatcherMixin, {
    init: function() {
        EventDispatcherMixin.init.call(this);
        this.__getterSetterInternalMap = {};
    },
    set: function(arg1, arg2, arg3) {
        var map;
        var options;
        if (typeof arg1 === "string") {
            map = {};
            map[arg1] = arg2;
            options = arg3 || {};
        } else {
            map = arg1;
            options = arg2 || {};
        }
        var self = this;
        var changed = false;
        _.each(map, function(val, key) {
            var tmp = self.__getterSetterInternalMap[key];
            if (tmp === val)
                return;
            // seriously, why are you doing this? it is obviously a stupid design.
            // the properties mixin should not be concerned with handling fields details.
            // this also has the side effect of introducing a dependency on utils.  Todo:
            // remove this, or move it elsewhere.  Also, learn OO programming.
            if (key === 'value' && self.field && self.field.type === 'float' && tmp && val){
                var digits = self.field.digits;
                if (_.isArray(digits)) {
                    if (utils.float_is_zero(tmp - val, digits[1])) {
                        return;
                    }
                }
            }
            changed = true;
            self.__getterSetterInternalMap[key] = val;
            if (! options.silent)
                self.trigger("change:" + key, self, {
                    oldValue: tmp,
                    newValue: val
                });
        });
        if (changed)
            self.trigger("change", self);
    },
    get: function(key) {
        return this.__getterSetterInternalMap[key];
    }
});

return {
    ParentedMixin: ParentedMixin,
    EventDispatcherMixin: EventDispatcherMixin,
    PropertiesMixin: PropertiesMixin,
};

});