/*
*******************************************************************************
* Copyright (c) 2021 by M5Stack
*                  Equipped with M5Core sample source code
*                          配套  M5Core 示例源代码
* Visit the website for more information：https://docs.m5stack.com/en/core/gray
* 获取更多资料请访问：https://docs.m5stack.com/zh_CN/core/gray
*
* describe：BasicHTTPClient.
* date：2021/8/4
******************************************************************************
*/
#include <M5Stack.h>
#include <Arduino.h>
#include <WiFi.h>
#include <WiFiMulti.h>
#include <HTTPClient.h>

WiFiMulti wifiMulti;
HTTPClient http;

void setup() {
  M5.begin(); //Init M5Core.  初始化 M5Core
  M5.Power.begin(); //Init power  初始化电源模块
  wifiMulti.addAP("M5-", "Of");  //Storage wifi configuration information.  存储wifi配置信息
  M5.Lcd.print("\nConnecting Wifi...\n"); //print format output string on lcd.  串口格式化输出字符串
}

void loop() {
  M5.Lcd.setCursor(0,0); //Set the cursor at (0,0).  设置光标位于(0,0)处
  if((wifiMulti.run() == WL_CONNECTED)) { // wait for WiFi connection.  等待连接至wifi
    M5.Lcd.print("[HTTP] begin...\n");
    http.begin("http://example.com/index.html");  // configure traged server and url.  配置被跟踪的服务器和URL
    M5.Lcd.print("[HTTP] GET...\n");
    int httpCode = http.GET();  // start connection and send HTTP header.  开始连接服务器并发送HTTP的标头
    if(httpCode > 0) {  // httpCode will be negative on error.  出错时httpCode将为负值
      M5.Lcd.printf("[HTTP] GET... code: %d\n", httpCode);

      if(httpCode == HTTP_CODE_OK) {  // file found at server.  在服务器上找到文件
        String payload = http.getString();
        M5.Lcd.println(payload);  //打印在服务器上读取的文件.  Print files read on the server
      }
    }else {
      M5.Lcd.printf("[HTTP] GET... failed, error: %s\n", http.errorToString(httpCode).c_str());
    }
    http.end();
  }else{
    M5.Lcd.print("connect failed");
  }
  delay(5000);
  M5.Lcd.createSprite(); //clear the screen.  清除屏幕
}