import ngModule from '../../module';
import Input from '../../lib/input';
import './style.scss';

/**
 * Input with option selector.
 *
 * @property {String} valueField The data field name that should be shown
 * @property {String} showFiled The data field name that should be used as value
 * @property {Array} data Static data for the autocomplete
 * @property {Object} intialData A initial data to avoid the server request used to get the selection
 * @property {Boolean} multiple Wether to allow multiple selection
 */
export default class Autocomplete extends Input {
    constructor($element, $scope, $http, $transclude) {
        super($element, $scope);
        this.$http = $http;
        this.$transclude = $transclude;

        this._field = undefined;
        this._selection = null;
        this.valueField = 'id';
        this.showField = 'name';
        this._multiField = [];
        this.readonly = true;
        this.form = null;
        this.input = this.element.querySelector('.mdl-textfield__input');

        componentHandler.upgradeElement(
            this.element.querySelector('.mdl-textfield'));
    }

    /**
     * @type {any} The autocomplete value.
     */
    get field() {
        return this._field;
    }

    set field(value) {
        if (angular.equals(value, this._field))
            return;

        this._field = value;
        this.refreshSelection();

        if (this.onChange)
            this.onChange({value});
    }

    /**
     * @type {Object} The selected data object, you can use this property
     * to prevent requests to display the initial value.
     */
    get selection() {
        return this._selection;
    }

    set selection(value) {
        this._selection = value;
        this.refreshDisplayed();
    }

    selectionIsValid(selection) {
        return selection
            && selection[this.valueField] == this._field
            && selection[this.showField] != null;
    }

    refreshSelection() {
        if (this.selectionIsValid(this._selection))
            return;

        let value = this._field;

        if (value && this.valueField && this.showField) {
            if (this.selectionIsValid(this.initialData)) {
                this.selection = this.initialData;
                return;
            }

            let data = this.data;

            if (!data && this.$.dropDown)
                data = this.$.dropDown.$.model.data;

            if (data)
                for (let i = 0; i < data.length; i++)
                    if (data[i][this.valueField] === value) {
                        this.selection = data[i];
                        return;
                    }

            if (this.url) {
                this.requestSelection(value);
                return;
            }
        } else
            this.selection = null;
    }

    requestSelection(value) {
        let where = {};

        if (this.multiple)
            where[this.valueField] = {inq: this.field};
        else
            where[this.valueField] = value;

        let filter = {
            fields: this.getFields(),
            where: where
        };

        let json = encodeURIComponent(JSON.stringify(filter));
        this.$http.get(`${this.url}?filter=${json}`).then(
            json => this.onSelectionRequest(json.data),
            () => this.onSelectionRequest(null)
        );
    }

    onSelectionRequest(data) {
        if (data && data.length > 0) {
            if (this.multiple)
                this.selection = data;
            else
                this.selection = data[0];
        } else
            this.selection = null;
    }

    refreshDisplayed() {
        let display = '';

        if (this._selection && this.showField) {
            if (this.multiple && Array.isArray(this._selection)) {
                for (var item of this._selection) {
                    if (display.length > 0) display += ', ';
                    display += item[this.showField];
                }
            } else {
                display = this._selection[this.showField];
            }
        }

        this.input.value = display;
        this.mdlUpdate();
    }

    getFields() {
        let fields = [];
        fields.push(this.valueField);
        fields.push(this.showField);

        if (this.selectFields)
            for (let field of this.selectFields)
                fields.push(field);

        return fields;
    }

    mdlUpdate() {
        let field = this.element.querySelector('.mdl-textfield');
        let mdlField = field.MaterialTextfield;
        if (mdlField) mdlField.updateClasses_();
    }

    setValue(value) {
        this.field = value;
        if (this.form) this.form.$setDirty();
    }

    onDropDownSelect(value) {
        this.setValue(value);
        this.field = value;
    }

    onClearClick(event) {
        event.preventDefault();
        this.setValue(null);
    }

    onKeyDown(event) {
        if (event.defaultPrevented) return;

        switch (event.keyCode) {
        case 38: // Up
        case 40: // Down
        case 13: // Enter
            this.showDropDown();
            break;
        default:
            if (event.key.length == 1)
                this.showDropDown(event.key);
            else
                return;
        }

        event.preventDefault();
    }

    onMouseDown(event) {
        event.preventDefault();
        this.showDropDown();
    }

    showDropDown(search) {
        Object.assign(this.$.dropDown.$.model, {
            url: this.url,
            staticData: this.data
        });

        Object.assign(this.$.dropDown, {
            valueField: this.valueField,
            showField: this.showField,
            selectFields: this.getFields(),
            where: this.where,
            order: this.order,
            parent: this.input,
            multiple: this.multiple,
            limit: this.limit,
            $transclude: this.$transclude
        });
        this.$.dropDown.show(search);
    }
}
Autocomplete.$inject = ['$element', '$scope', '$http', '$transclude'];

ngModule.component('vnAutocomplete', {
    template: require('./autocomplete.html'),
    controller: Autocomplete,
    bindings: {
        url: '@?',
        data: '<?',
        showField: '@?',
        valueField: '@?',
        selectFields: '<?',
        disabled: '<?',
        where: '@?',
        order: '@?',
        label: '@',
        initialData: '<?',
        field: '=?',
        limit: '<?',
        showFilter: '<?',
        selection: '<?',
        multiple: '<?',
        onChange: '&?'
    },
    transclude: {
        tplItem: '?tplItem'
    },
    require: {
        form: '?^form'
    }
});