#include <Arduino.h>
#include <Update.h>
#include "config.h"
#include "updater.h"
#include "http_client_wrapper.h"

void Updater::run() {
	DEBUG("Updater is running...\n");
	HTTPClientWrapper* http = new HTTPClientWrapper();
	DEBUG("Requesting update info...\n");
	bool result = http->get(OTA_UPDATE_URL);
	if (!result) {
		ERROR("Updater failed requesting %s.\n", OTA_UPDATE_URL);
		return;
	}

	String line_str = "";
	if (!read_line(&line_str, http, "VERSION")) {
		return;
	}
	uint16_t version = line_str.toInt();
	if (version==0) {
		ERROR("Could not parse version number.\n");
		return;
	}
	DEBUG("Found version %d. My version is %d.\n", version, OTA_VERSION);
	if (version <= OTA_VERSION) {
		return;
	}
	
	String image_path = "";
	if (!read_line(&image_path, http, "IMAGE_PATH")) {
		return;
	}
	
	String image_md5 = "";
	if (!read_line(&image_md5, http, "IMAGE_MD5")) {
		return;
	}

	http->close();
	delete http;
	
	if(do_update(U_FLASH, image_path, image_md5)) {
		DEBUG("Update done. Rebooting...\n");
	} else {
		DEBUG("Update failed. Rebooting...\n");
	}
	delay(1000);
	ESP.restart();
}

bool Updater::read_line(String* dst, HTTPClientWrapper* http, String expected_key) {
	expected_key += "=";
	String line = http->readUntil("\n");
	if (!line.startsWith(expected_key)) {
		ERROR("Expected line start with '%s', but it started with '%s'.\n", expected_key.c_str(), line.c_str());
		return false;
	}
	line = line.substring(expected_key.length());
	line.trim();
	dst->concat(line);
	return true;
}

bool Updater::do_update(int command, String url, String expected_md5) {
	HTTPClientWrapper* http = new HTTPClientWrapper();
	bool result = http->get(url);
	if (!result) {
		ERROR("Updater failed requesting %s.\n", url.c_str());
		return false;
	}
	
	result = Update.begin(http->getSize(), command);
	if (!result) {
		ERROR("Update could not be started.\n");
		return false;
	}
	Update.setMD5(expected_md5.c_str());
	uint8_t buf[512];
	uint16_t len;
	while((len = http->read(buf, 512))) {
		Update.write(buf, len);
	}
	
	http->close();
	delete http;
	
	result = Update.end();
	if (!result) {
		const char* error = Update.errorString();
		ERROR("Writing the update failed. The error was: %s\n", error);
		return false;
	}
	return true;
}