//============== Http操作=========================
//Copyright 2018 何镇汐
//Licensed under the MIT license
//================================================
import { HttpClient, HttpHeaders, HttpParams, HttpErrorResponse } from '@angular/common/http';
import { IocHelper as ioc } from './ioc-helper';
import { formatDate, uuid } from '../common/helper';

/**
 * Http操作
 */
export class HttpHelper {
    /**
     * 发送请求
     * @param url 请求地址
     * @param httpMethod http方法
     * @param data 数据
     */
    static send<T>(url: string, httpMethod: HttpMethod, data?): HttpRequest<T> {
        switch (httpMethod) {
            case HttpMethod.Get:
                return this.get<T>(url).param(data);
            case HttpMethod.Post:
                return this.post<T>(url, data);
            case HttpMethod.Put:
                return this.put<T>(url, data);
            case HttpMethod.Delete:
                return this.delete<T>(url).param(data);
            default:
                return this.get<T>(url).param(data);
        }
    }

    /**
     * get请求
     * @param url 请求地址
     */
    static get<T>(url: string): HttpRequest<T> {
        return new HttpRequest<T>(HttpMethod.Get, url);
    }

    /**
     * post请求
     * @param url 请求地址
     * @param body Http主体
     */
    static post<T>(url: string, body?): HttpRequest<T> {
        return new HttpRequest<T>(HttpMethod.Post, url, body);
    }

    /**
     * put请求
     * @param url 请求地址
     * @param body Http主体
     */
    static put<T>(url: string, body?): HttpRequest<T> {
        return new HttpRequest<T>(HttpMethod.Put, url, body);
    }

    /**
     * delete请求
     * @param url 请求地址
     */
    static delete<T>(url: string): HttpRequest<T> {
        return new HttpRequest<T>(HttpMethod.Delete, url);
    }
}

/**
 * Http请求操作
 */
export class HttpRequest<T> {
    /**
     * Http头集合
     */
    private headers: HttpHeaders;
    /**
     * 内容类型
     */
    private httpContentType: HttpContentType;
    /**
     * Http参数集合
     */
    private parameters: HttpParams;

    /**
     * 初始化Http请求操作
     * @param httpMethod Http方法
     * @param url 请求地址
     * @param body Http主体
     */
    constructor(private httpMethod: HttpMethod, private url: string, private body?) {
        this.headers = new HttpHeaders();
        this.parameters = new HttpParams();
    }

    /**
     * 添加Http头
     * @param name 名称
     * @param value 值
     */
    header(name: string, value): HttpRequest<T> {
        let stringValue = "";
        if (value !== undefined && value !== null)
            stringValue = String(value);
        this.headers = this.headers.append(name, stringValue);
        return this;
    }

    /**
     * 设置内容类型
     * @param contentType 内容类型
     */
    contentType(contentType: HttpContentType): HttpRequest<T> {
        this.httpContentType = contentType;
        return this;
    }

    /**
    * 添加Http参数,添加到url查询字符串
    * @param data 参数对象
    */
    param(data): HttpRequest<T>;
    /**
     * 添加Http参数,添加到url查询字符串
     * @param name 名称
     * @param value 值
     */
    param(name: string, value: string): HttpRequest<T>;
    param(data, value?: string): HttpRequest<T> {
        if (typeof data === "object") {
            this.paramByObject(data);
            return this;
        }
        if (typeof data === "string" && value)
            this.parameters = this.parameters.append(data, value);
        return this;
    }

    /**
     * 添加Http参数
     */
    private paramByObject(data) {
        for (let key in data) {
            if (data.hasOwnProperty(key)) {
                let value = this.getValue(data[key]);
                if (value == null)
                    value = "";
                this.parameters = this.parameters.append(key, value);
            }
        }
    }

    /**
     * 获取值
     * @param data 数据
     */
    private getValue(data): string {
        if (!data)
            return data;
        if (data.getYear)
            return formatDate(data, "YYYY-MM-DD HH:mm:ss");
        return data;
    }

    /**
     * 处理响应
     * @param handler 响应处理函数
     * @param errorHandler 错误处理函数
     * @param beforeHandler 发送前处理函数，返回false则取消发送
     * @param completeHandler 请求完成处理函数
     */
    handle(handler: (value: T) => void, errorHandler?: (error: HttpErrorResponse) => void, beforeHandler?: () => boolean, completeHandler?: () => void) {
        if (beforeHandler && beforeHandler() === false)
            return;
        this.request().subscribe(handler, errorHandler, completeHandler);
    }

    /**
     * 处理响应
     * @param handler 响应处理函数
     * @param errorHandler 错误处理函数
     * @param beforeHandler 发送前处理函数，返回false则取消发送
     * @param completeHandler 请求完成处理函数
     */
    async handleAsync(handler: (value: T) => void, errorHandler?: (error: HttpErrorResponse) => void, beforeHandler?: () => boolean, completeHandler?: () => void): Promise<void> {
        if (beforeHandler && beforeHandler() === false)
            return;
        return await this.request().toPromise().then(handler).catch(errorHandler).then(completeHandler);
    }

    /**
     * 发送请求
     */
    private request() {
        this.setContentType();
        let httpClient = ioc.get<HttpClient>(HttpClient);
        this.initParameters();
        let options = { headers: this.headers, params: this.parameters };
        switch (this.httpMethod) {
            case HttpMethod.Get:
                return httpClient.get<T>(this.url, options);
            case HttpMethod.Post:
                return httpClient.post<T>(this.url, this.getBody(), options);
            case HttpMethod.Put:
                return httpClient.put<T>(this.url, this.getBody(), options);
            case HttpMethod.Delete:
                return httpClient.delete<T>(this.url, options);
            default:
                return httpClient.get<T>(this.url, options);
        }
    }

    /**
     * 初始化请求参数
     */
    private initParameters() {
        if (this.httpMethod === HttpMethod.Get)
            this.param("no-cache-tag", uuid());
    }

    /**
     * 获取body
     */
    private getBody() {
        if (typeof this.body === "string")
            return JSON.stringify(this.body);
        return this.body;
    }

    /**
     * 设置内容类型
     */
    private setContentType() {
        return this.header("Content-Type", this.getContentType(this.httpContentType));
    }

    /**
     * 获取内容类型
     * @param contentType
     */
    private getContentType(contentType: HttpContentType) {
        switch (contentType) {
            case HttpContentType.FormUrlEncoded:
                return "application/x-www-form-urlencoded";
            case HttpContentType.Json:
                return "application/json";
            default:
                return "application/json";
        }
    }
}

/**
 * Http方法
 */
export enum HttpMethod {
    Get,
    Post,
    Put,
    Delete
}

/**
 * Http内容类型
 */
export enum HttpContentType {
    /**
     * application/x-www-form-urlencoded
     */
    FormUrlEncoded,
    /**
     * application/json
     */
    Json
}