import ngModule from '../module';

export default class Template {
    constructor(vnInterpolate) {
        this.vnInterpolate = vnInterpolate;
    }
    get(template, $attrs, defaults) {
        let scope = Object.assign({}, defaults, $attrs);
        return template && this.vnInterpolate(template)(scope);
    }
    getNormalized(template, $attrs, defaults) {
        this.normalizeInputAttrs($attrs);
        return this.get(template, $attrs, defaults);
    }
    normalizeInputAttrs($attrs) {
        const field = $attrs.field || $attrs.model;
        const split = field.split('.');
        const len = split.length;

        let i = len - 1;
        const fieldName = split[i--];
        const entity = i >= 0 ? split[i--] : 'model';
        const ctrl = i >= 0 ? split[i--] : '$ctrl';

        if ($attrs.field) {
            if (len == 0)
                throw new Error(`Attribute 'field' can not be empty`);
            if (len > 3)
                throw new Error(`Attribute 'field' must have this syntax: [ctrl].[entity].[field]`);

            if ($attrs.model === undefined)
                $attrs.model = `${ctrl}.${entity}.${fieldName}`;
            if ($attrs.rule === undefined && len >= 2)
                $attrs.rule = `${entity}.${fieldName}`;
            if ($attrs.label === undefined && len >= 2)
                $attrs.label = `${entity}.${fieldName}`;
        }

        if ($attrs.name === undefined)
            $attrs.name = fieldName;

        if ($attrs.focus !== undefined)
            $attrs.focus = 'vn-focus';
    }
}
Template.$inject = ['vnInterpolate'];

ngModule.service('vnTemplate', Template);