/**
 * A small abstract class that contains the shared behaviour for any summary
 * calculations to be used in the grid.
 */
Ext.define('Ext.grid.feature.AbstractSummary', {

    extend: 'Ext.grid.feature.Feature',

    alias: 'feature.abstractsummary',

    summaryRowCls: Ext.baseCSSPrefix + 'grid-row-summary',
    summaryTableCls: Ext.plainTableCls + ' ' + Ext.baseCSSPrefix + 'grid-table',
    summaryRowSelector: '.' + Ext.baseCSSPrefix + 'grid-row-summary',

    // High priority rowTpl interceptor which sees summary rows early, and renders them correctly and then aborts the row rendering chain.
    // This will only see action when summary rows are being updated and Table.onUpdate->Table.bufferRender renders the individual updated sumary row.
    summaryRowTpl: {
        before: function(values, out) {
            // If a summary record comes through the rendering pipeline, render it simply, and return false from the
            // before method which aborts the tpl chain
            if (values.record.isSummary && this.summaryFeature.showSummaryRow) {
                this.summaryFeature.outputSummaryRecord(values.record, values, out);
                return false;
            }
        },
        priority: 1000
    },

   /**
    * @cfg {Boolean}
    * True to show the summary row.
    */
    showSummaryRow: true,

    // Listen for store updates. Eg, from an Editor.
    init: function() {
        var me = this;
        me.view.summaryFeature = me;
        me.rowTpl = me.view.self.prototype.rowTpl;

        // Add a high priority interceptor which renders summary records simply
        // This will only see action ona bufferedRender situation where summary records are updated.
        me.view.addRowTpl(me.summaryRowTpl).summaryFeature = me;

        // Define on the instance to store info needed by summary renderers.
        me.summaryData = {};
    },

    /**
     * Toggle whether or not to show the summary row.
     * @param {Boolean} visible True to show the summary row
     */
    toggleSummaryRow: function(visible) {
        this.showSummaryRow = !!visible;
    },

    createRenderer: function (column, record) {
        var me = this,
            ownerGroup = record.ownerGroup,
            summaryData = ownerGroup ? me.summaryData[ownerGroup] : me.summaryData,
            // Use the column.id for columns without a dataIndex. The populateRecord method does the same.
            dataIndex = column.dataIndex || column.id;

        return function () {
             return column.summaryRenderer ?
                column.summaryRenderer(record.get(dataIndex), summaryData, dataIndex) :
                // For no summaryRenderer, return the field value in the Feature record.
                record.get(dataIndex);
        };
    },

    outputSummaryRecord: function(summaryRecord, contextValues, out) {
        var view = contextValues.view,
            savedRowValues = view.rowValues,
            columns = contextValues.columns || view.headerCt.getVisibleGridColumns(),
            colCount = columns.length, i, column,
            // Set up a row rendering values object so that we can call the rowTpl directly to inject
            // the markup of a grid row into the output stream.
            values = {
                view: view,
                record: summaryRecord,
                rowStyle: '',
                rowClasses: [ this.summaryRowCls ],
                itemClasses: [],
                recordIndex: -1,
                rowId: view.getRowId(summaryRecord),
                columns: columns
            };

        // Because we are using the regular row rendering pathway, temporarily swap out the renderer for the summaryRenderer
        for (i = 0; i < colCount; i++) {
            column = columns[i];
            column.savedRenderer = column.renderer;

            if (column.summaryType || column.summaryRenderer) {
                column.renderer = this.createRenderer(column, summaryRecord);
            } else {
                column.renderer = Ext.emptyFn;
            }
        }

        // Use the base template to render a summary row
        view.rowValues = values;
        view.self.prototype.rowTpl.applyOut(values, out);
        view.rowValues = savedRowValues;

        // Restore regular column renderers
        for (i = 0; i < colCount; i++) {
            column = columns[i];
            column.renderer = column.savedRenderer;
            column.savedRenderer = null;
        }
    },

    /**
     * Get the summary data for a field.
     * @private
     * @param {Ext.data.Store} store The store to get the data from
     * @param {String/Function} type The type of aggregation. If a function is specified it will
     * be passed to the stores aggregate function.
     * @param {String} field The field to aggregate on
     * @param {Boolean} group True to aggregate in grouped mode 
     * @return {Number/String/Object} See the return type for the store functions.
     * if the group parameter is `true` An object is returned with a property named for each group who's
     * value is the summary value.
     */
    getSummary: function (store, type, field, group) {
        // Note `group` will either be an instance of Ext.data.Group or a list of records.
        var records = group.records;

        if (type) {
            if (Ext.isFunction(type)) {
                return store.getAggregate(type, null, records, [field]);
            }

            switch (type) {
                case 'count':
                    return records.length;
                case 'min':
                    return store.getMin(records, field);
                case 'max':
                    return store.getMax(records, field);
                case 'sum':
                    return store.getSum(records, field);
                case 'average':
                    return store.getAverage(records, field);
                default:
                    return '';

            }
        }
    },

    /**
     * Used by the Grouping Feature when {@link #showSummaryRow} is `true`.
     * 
     * Generates group summary data for the whole store.
     * @private
     * @return {Object} An object hash keyed by group name containing summary records.
     */
    generateSummaryData: function(){
        var me = this,
            store = me.view.store,
            groups = store.groups.items,
            reader = store.proxy.reader,
            len = groups.length,
            groupField = me.getGroupField(),
            data = {},
            lockingPartner = me.lockingPartner,
            i, group, record,
            root, summaryRows, hasRemote,
            convertedSummaryRow, remoteData;

        /**
         * @cfg {String} [remoteRoot=undefined]
         * The name of the property which contains the Array of summary objects.
         * It allows to use server-side calculated summaries.
         */
        if (me.remoteRoot && reader.rawData) {
            hasRemote = true;
            remoteData = {};
            // reset reader root and rebuild extractors to extract summaries data
            root = reader.root;
            reader.root = me.remoteRoot;
            reader.buildExtractors(true);
            summaryRows = reader.getRoot(reader.rawData)||[];
            len = summaryRows.length;

            // Ensure the Reader has a data conversion function to convert a raw data row into a Record data hash
            if (!reader.convertRecordData) {
                reader.buildExtractors();
            }

            for (i = 0; i < len; ++i) {
                convertedSummaryRow = {};

                // Convert a raw data row into a Record's hash object using the Reader
                reader.convertRecordData(convertedSummaryRow, summaryRows[i]);
                remoteData[convertedSummaryRow[groupField]] = convertedSummaryRow;
            }

            // restore initial reader configuration
            reader.root = root;
            reader.buildExtractors(true);
        }

        for (i = 0; i < len; ++i) {
            group = groups[i];
            // Something has changed or it doesn't exist, populate it
            if (hasRemote || group.isDirty() || !group.hasAggregate()) {
                record = me.populateRecord(group, remoteData);

                // Clear the dirty state of the group if this is the only Summary, or this is the right hand (normal grid's) summary
                if (!lockingPartner || (me.view.ownerCt === me.view.ownerCt.ownerLockable.normalGrid)) {
                    group.commit();
                }
            } else {
                record = group.getAggregateRecord();
            }

            data[group.key] = record;
        }

        return data;
    },

    setSummaryData: function (record, colId, summaryValue, groupName) {
        if (groupName) {
            if (!this.summaryData[groupName]) {
                this.summaryData[groupName] = {};
            }
            this.summaryData[groupName][colId] = summaryValue;
        } else {
            this.summaryData[colId] = summaryValue;
        }
    },

    populateRecord: function (group, remoteData) {
        var me = this,
            view = me.grid.ownerLockable ? me.grid.ownerLockable.view : me.view,
            store = me.view.store,
            record = group.getAggregateRecord(),
            // Use the full column set, regardless of locking
            columns = view.headerCt.getGridColumns(),
            len = columns.length,
            groupName = group.key,
            groupData, field, i, column, fieldName, summaryValue;

        record.beginEdit();

        if (remoteData) {
            // Remote summary grouping provides the grouping totals so there's no need to
            // iterate throught the columns to map the column's dataIndex to the field name.
            // Instead, enumerate the grouping record and set the field in the aggregate
            // record for each one.
            groupData = remoteData[groupName];
            for (field in groupData) {
                if (groupData.hasOwnProperty(field)) {
                    if (field !== record.idProperty) {
                        record.set(field, groupData[field]);
                    }
                }
            }
        }

        // Here we iterate through the columns with two objectives:
        //    1. For local grouping, get the summary for each column and update the record.
        //    2. For both local and remote grouping, set the summary data object
        //       which is passed to the summaryRenderer (if defined).
        for (i = 0; i < len; ++i) {
            column = columns[i];
            // Use the column id if there's no mapping, could be a calculated field.
            fieldName = column.dataIndex || column.id;

            // We need to capture the summary value because it could get overwritten when
            // setting on the model if there is a convert() method on the model.
            if (!remoteData) {
                summaryValue = me.getSummary(store, column.summaryType, fieldName, group);
                record.set(fieldName, summaryValue);
            } else {
                // For remote groupings, just get the value from the model.
                summaryValue = record.get(fieldName);
            }

            // Capture the columnId:value for the summaryRenderer in the summaryData object.
            me.setSummaryData(record, column.id, summaryValue, groupName);
        }

        // Poke on the owner group for easy lookup in this.createRenderer().
        record.ownerGroup = groupName;

        record.endEdit(true);
        record.commit();

        return record;
    }
});