import FormUtils from '../form-utils';
import { getValue, setValue, isFunction, isEmpty } from '../../commons/utils';

/**
 * Initialize default properties in the document
 * @param  {[type]} form [description]
 * @return {[type]}      [description]
 */
export function initDefaultValues(form) {
    const schema = form.props.schema;
    const doc = form.props.doc;

    initFromSchema(schema, doc);
    initFromControls(schema, doc);
}

/**
 * Initialize default values from the form schema
 * @param  {Object} schema The form schema
 * @param  {Object} doc    The document being edited in the form
 */
function initFromSchema(schema, doc) {
    // set default properties of the document
    const defprops = schema.defaultProperties;
    if (!defprops) {
        return;
    }

    // browse the default properties
    Object.keys(defprops).forEach(prop => {
        // check if there is already a property value
        if (getValue(doc, prop) !== undefined) {
            return;
        }

        // get default value
        let val = defprops[prop];
        if (isFunction(val)) {
            val = val.call(doc, doc);
        }

        if (typeof val === 'object') {
            // create a copy of the object to avoid this object to be changed
            val = Object.assign({}, val);
        }

        // set default value
        setValue(doc, prop, val);
    });
}

/**
 * Initialize the default values from the controls,
 * in case the control assumes a default value
 * @param  {Object} schema The form schema
 * @param  {Object} doc    The document being edited in the form
 */
function initFromControls(schema, doc) {
    // set the default properties of the controls
    schema.controls.filter(elem => !!elem.property && getValue(doc, elem.property) === undefined).forEach(elem => {
        let val = elem.defaultValue;
        if (isEmpty(val)) {
            const control = FormUtils.getControl(elem);
            val = control.defaultValue();
        }

        if (!isEmpty(val)) {
            setValue(doc, elem.property, val, true);
        }
    });
}