import { cloneDeep } from 'lodash-es';
/*
 * @Author: 疯狂秀才(Lucas Huang)
 * @Date: 2019-06-16 13:44:59
 * @LastEditors: 疯狂秀才(Lucas Huang)
 * @LastEditTime: 2019-08-15 09:47:34
 * @QQ: 1055818239
 * @Version: v0.0.1
 */
import { BehaviorSubject, Observable } from 'rxjs';
import { Injectable } from '@angular/core';
import {merge} from 'lodash-es';
import { map } from 'rxjs/operators';
import { CommonUtils } from './../common.utils';


export interface RuntimeState {
    form?: { [key: string]: any};
    model?: { [key: string]: any};
}

const DefaultRuntimeState: RuntimeState = {
    form: {},
    model: {}
};


@Injectable({
    providedIn: 'root'
})
export class RuntimeStateService {

    private _state: RuntimeState;

    private stateSubject = new BehaviorSubject<RuntimeState>({});

    state$: Observable<RuntimeState> = this.stateSubject.asObservable();

    form$:Observable<any> = this.state$.pipe(
                    map((state: RuntimeState) => state.form));

    lookupIsPending$: Observable<boolean> = this.form$.pipe( map(f => f.lookup.pending) );

    private _formState: any;
    private _lookupState: any;

    constructor(private utils: CommonUtils) {
        this._state = cloneDeep(DefaultRuntimeState);
        this._formState = this._state.form;
        this._lookupState = this._formState.lookup;
    }

    private setValue(newVal: { [key: string]: any }) {
        if (newVal) {
            this._state = merge(this._state, newVal);
            this.stateSubject.next(this._state);
        }
    }

    private getValue(keyPath: string) {
        return this.utils.getValue(keyPath, this._state);
    }

    destroy() {
        this._state = {
            form: {},
            model: {}
        };
        this._formState = this._state.form;
        this._lookupState = this._formState.lookup;
        this.stateSubject.next(this._state);
    }

    setLookupInstance(el: any) {
        this.setValue({form: { lookup: { instance: el }}});
    }

    updateFormState(newVal: {[key: string]: any}) {
        this.setValue({ form: newVal });
    }

    getFormState(keyPath: string) {
        return this.getValue('form.' + keyPath);
    }

    eventPath(evt: any) {
        const path = (evt.composedPath && evt.composedPath()) || evt.path, target = evt.target;

        if (path != null) {
            return (path.indexOf(window) < 0) ? path.concat(window) : path;
        }

        if (target === window) {
            return [window];
        }

        const getParents = (node, memo = undefined) => {
            memo = memo || [];
            const parentNode = node.parentNode;

            if (!parentNode) {
                return memo;
            } else {
                return getParents(parentNode, memo.concat(parentNode));
            }
        };

        return [target].concat(getParents(target), window);
    }
}