/* eslint-disable no-console */
import { IField, IOptionManager, IOptionManagerOptionsAction, IOptionManagerOptionsArray, IOptionManagerParams } from '@wowpic/xform-types';
import fetch from './fetch';
import { isNull, strEval } from './utils';

export default class OptionManager implements IOptionManager {

    public nameProperty: string;

    public valueProperty: string;

    public action: IOptionManagerOptionsAction;

    public path: string;

    public watch: string[];

    public defaultIndex?: number;

    public initialOptions: IOptionManagerOptionsArray;

    private context: IField;

    constructor(context: IField, params: IOptionManagerParams) {
        this.context = context;
        this.initialize(params);
    }

    public async initialize(params: IOptionManagerParams) {
        const { options } = params;
        const field = this.context;
        if (typeof options === 'string') {
            this.action = options || '';
            this.nameProperty = 'name';
            this.valueProperty = 'value';
            this.path = '';
            this.watch = [];
            field.options = [];
            await Promise.resolve();
            this.initialOptions = await this.getOptions();
        } else if (Array.isArray(options)) {
            this.action = '';
            this.nameProperty = 'name';
            this.valueProperty = 'value';
            this.path = '';
            this.watch = [];
            field.options = options;
            this.initialOptions = options;
            this.triggerEvent();
        } else if (typeof options === 'object') {
            this.action = options.action;
            this.nameProperty = options.nameProperty || 'name';
            this.valueProperty = options.valueProperty || 'value';
            this.path = options.path || '';
            this.watch = options.watch || [];
            this.defaultIndex = options.defaultIndex;
            field.options = [];
            await Promise.resolve();
            this.initialOptions = await this.getOptions();
        }
    }

    private setDefaultItem() {
        const field = this.context;
        const defaultIndex = this.defaultIndex;
        const options = field.options;
        const value = field.value;
        if (Number.isInteger(defaultIndex) && options.length > defaultIndex && (isNull(field.value) || !options.find(item => item.value === value))) {
            const item = options[defaultIndex];
            field.setValue(item.value);
        }
    }

    public async getOptions() {
        const { path, nameProperty, valueProperty, action } = this;
        const field = this.context;
        const form = field.context;
        if (typeof action === 'function') {
            const options = await action(field, form);
            field.options = options;
            this.setDefaultItem();
            this.triggerEvent();
            return options;
        }
        if (typeof action === 'string') {
            const formPurified = form.purify();
            const url = strEval(action, formPurified);
            try {
                const data = await fetch(url);
                const list = path.split('.').reduce((result, index) => {
                    return index ? result[index] : result;
                }, data);
                const options = list.map((item: { [key: string]: any }) => {
                    return {
                        ...item,
                        name: item[nameProperty],
                        value: item[valueProperty]
                    };
                });
                field.options = options;
                this.setDefaultItem();
                this.triggerEvent();
                return options;
            } catch (e) {
                console.error(e);
                throw e;
            }
        }
        return [];
    }

    public reset() {
        const field = this.context;
        field.options = this.initialOptions;
        field.triggerEvent('OPTIONS_CHANGE');
    }

    private triggerEvent() {
        const field = this.context;
        field.triggerEvent('OPTIONS_CHANGE');
    }
};