/*!
 * Ext JS Library 3.0.0
 * Copyright(c) 2006-2009 Ext JS, LLC
 * licensing@extjs.com
 * http://www.extjs.com/license
 */
/**
 * @class Ext.data.DataReader
 * Abstract base class for reading structured data from a data source and converting
 * it into an object containing {@link Ext.data.Record} objects and metadata for use
 * by an {@link Ext.data.Store}.  This class is intended to be extended and should not
 * be created directly. For existing implementations, see {@link Ext.data.ArrayReader},
 * {@link Ext.data.JsonReader} and {@link Ext.data.XmlReader}.
 * @constructor Create a new DataReader
 * @param {Object} meta Metadata configuration options (implementation-specific).
 * @param {Array/Object} recordType
 * <p>Either an Array of {@link Ext.data.Field Field} definition objects (which
 * will be passed to {@link Ext.data.Record#create}, or a {@link Ext.data.Record Record}
 * constructor created using {@link Ext.data.Record#create}.</p>
 */
Ext.data.DataReader = function(meta, recordType){
    /**
     * This DataReader's configured metadata as passed to the constructor.
     * @type Mixed
     * @property meta
     */
    this.meta = meta;
    /**
     * @cfg {Array/Object} fields
     * <p>Either an Array of {@link Ext.data.Field Field} definition objects (which
     * will be passed to {@link Ext.data.Record#create}, or a {@link Ext.data.Record Record}
     * constructor created from {@link Ext.data.Record#create}.</p>
     */
    this.recordType = Ext.isArray(recordType) ?
        Ext.data.Record.create(recordType) : recordType;
};

Ext.data.DataReader.prototype = {

    /**
     * Abstract method, overridden in {@link Ext.data.JsonReader}
     */
    buildExtractors : Ext.emptyFn,

    /**
     * Used for un-phantoming a record after a successful database insert.  Sets the records pk along with new data from server.
     * You <b>must</b> return at least the database pk using the idProperty defined in your DataReader configuration.  The incoming
     * data from server will be merged with the data in the local record.
     * In addition, you <b>must</b> return record-data from the server in the same order received.
     * Will perform a commit as well, un-marking dirty-fields.  Store's "update" event will be suppressed.
     * @param {Record/Record[]} record The phantom record to be realized.
     * @param {Object/Object[]} data The new record data to apply.  Must include the primary-key from database defined in idProperty field.
     */
    realize: function(rs, data){
        if (Ext.isArray(rs)) {
            for (var i = rs.length - 1; i >= 0; i--) {
                // recurse
                if (Ext.isArray(data)) {
                    this.realize(rs.splice(i,1).shift(), data.splice(i,1).shift());
                }
                else {
                    // weird...rs is an array but data isn't??  recurse but just send in the whole invalid data object.
                    // the else clause below will detect !this.isData and throw exception.
                    this.realize(rs.splice(i,1).shift(), data);
                }
            }
        }
        else {
            // If rs is NOT an array but data IS, see if data contains just 1 record.  If so extract it and carry on.
            if (Ext.isArray(data) && data.length == 1) {
                data = data.shift();
            }
            if (!this.isData(data)) {
                // TODO: Let exception-handler choose to commit or not rather than blindly rs.commit() here.
                //rs.commit();
                throw new Ext.data.DataReader.Error('realize', rs);
            }
            this.buildExtractors();
            var values = this.extractValues(data, rs.fields.items, rs.fields.items.length);
            rs.phantom = false; // <-- That's what it's all about
            rs._phid = rs.id;  // <-- copy phantom-id -> _phid, so we can remap in Store#onCreateRecords
            rs.id = data[this.meta.idProperty];
            rs.data = values;
            rs.commit();
        }
    },

    /**
     * Used for updating a non-phantom or "real" record's data with fresh data from server after remote-save.
     * You <b>must</b> return a complete new record from the server.  If you don't, your local record's missing fields
     * will be populated with the default values specified in your Ext.data.Record.create specification.  Without a defaultValue,
     * local fields will be populated with empty string "".  So return your entire record's data after both remote create and update.
     * In addition, you <b>must</b> return record-data from the server in the same order received.
     * Will perform a commit as well, un-marking dirty-fields.  Store's "update" event will be suppressed as the record receives
     * a fresh new data-hash.
     * @param {Record/Record[]} rs
     * @param {Object/Object[]} data
     */
    update : function(rs, data) {
        if (Ext.isArray(rs)) {
            for (var i=rs.length-1; i >= 0; i--) {
                if (Ext.isArray(data)) {
                    this.update(rs.splice(i,1).shift(), data.splice(i,1).shift());
                }
                else {
                    // weird...rs is an array but data isn't??  recurse but just send in the whole data object.
                    // the else clause below will detect !this.isData and throw exception.
                    this.update(rs.splice(i,1).shift(), data);
                }
            }
        }
        else {
                     // If rs is NOT an array but data IS, see if data contains just 1 record.  If so extract it and carry on.
            if (Ext.isArray(data) && data.length == 1) {
                data = data.shift();
            }
            if (!this.isData(data)) {
                // TODO: create custom Exception class to return record in thrown exception.  Allow exception-handler the choice
                // to commit or not rather than blindly rs.commit() here.
                rs.commit();
                throw new Ext.data.DataReader.Error('update', rs);
            }
            this.buildExtractors();
            rs.data = this.extractValues(Ext.apply(rs.data, data), rs.fields.items, rs.fields.items.length);
            rs.commit();
        }
    },

    /**
     * Returns true if the supplied data-hash <b>looks</b> and quacks like data.  Checks to see if it has a key
     * corresponding to idProperty defined in your DataReader config containing non-empty pk.
     * @param {Object} data
     * @return {Boolean}
     */
    isData : function(data) {
        return (data && Ext.isObject(data) && !Ext.isEmpty(data[this.meta.idProperty])) ? true : false;
    }
};

/**
 * @class Ext.data.DataReader.Error
 * @extends Ext.Error
 * General error class for Ext.data.DataReader
 */
Ext.data.DataReader.Error = Ext.extend(Ext.Error, {
    constructor : function(message, arg) {
        this.arg = arg;
        Ext.Error.call(this, message);
    },
    name: 'Ext.data.DataReader'
});
Ext.apply(Ext.data.DataReader.Error.prototype, {
    lang : {
        'update': "#update received invalid data from server.  Please see docs for DataReader#update and review your DataReader configuration.",
        'realize': "#realize was called with invalid remote-data.  Please see the docs for DataReader#realize and review your DataReader configuration.",
        'invalid-response': "#readResponse received an invalid response from the server."
    }
});


