trmnl_server_cpp/main.cpp

#include <iostream>
#include <list>
#include <map>
#include <memory>
#include <random>
#include <string>
#include <vector>

#include <stdint.h>

#include "httplib.h"
#include "json.hpp"

#include "helpers.h"
#include "TRMNL.h"

using nlohmann::json;

using namespace std;

int main(int argc, char **argv)
{
	string config_filename = "config.json";
	string devices_filename = "devices.json";
	string host = "";
	string folder_images = "images";
	string cert_file = "";
	string key_file = "";
	uint16_t port = 0;
	shared_ptr<httplib::Server> server = nullptr;

	bool ok;
	json cfg;
	json devs;
	TRMNLContainer container;

	if (argc > 2)
	{
		config_filename = argv[1];
	}

	ok = read_file_json(cfg, config_filename, &cout);
	if (!ok)
	{
		return -1;
	}

	json_extract(cfg, "devices_filename", devices_filename);
	json_extract(cfg, "host", host);
	json_extract(cfg, "port", port);
	json_extract(cfg, "folder_images", folder_images);
	// json_extract(cfg, "cert_file", cert_file);
	// json_extract(cfg, "key_file", cert_file);

	if (host.empty())
	{
		cout << "host not provided" << endl;
		return -1;
	}

	if (0 == port)
	{
		cout << "port number not provided" << endl;
		return -1;
	}

	if (folder_images.empty())
	{
		cout << "folder for images is empty" << endl;
		return -1;
	}

	if (!cert_file.empty() && !key_file.empty())
	{
		// TODO: Implement SSL Server Properly
	}
	else
	{
		server = make_shared<httplib::Server>();
	}

	ok = read_file_json(devs, devices_filename, &cout);
	if (!ok)
	{
		return -1;
	}

	container.clear();
	container = devs;

	auto setup_handler = [&container, &devices_filename](const httplib::Request& req, httplib::Response& res)
	{
		if (req.has_header("ID"))
		{
			json response;
			string id = req.get_header_value("ID");
			TRMNL* trmnl = container.get_device_by_id(id);

			// Refresh date from file
			// Someone might have put the new device in
			if (nullptr == trmnl)
			{
				json j;
				read_file_json(j, devices_filename, &cout);
				container.clear();
				container = j;
				trmnl = container.get_device_by_id(id);
			}

			if (nullptr == trmnl)
			{
				res.status = 404;

				response["status"] = 404;
				response["api_key"] = nullptr;
				response["friendly_id"] = nullptr;
				response["image_url"] = nullptr;
				response["filename"] = nullptr;

				res.body = response.dump();
			}
			else
			{
				bool should_dump = false;

				res.status = 200;
				if (trmnl->friendly_id().empty())
				{
					should_dump = true;
					trmnl->friendly_id(TRMNL::friendly_from_id(id));
				}

				if (trmnl->api_key().empty())
				{
					should_dump = true;
					trmnl->api_key("nullptr");
				}

				response["status"] = 200;
				response["api_key"] = trmnl->api_key();
				response["friendly_id"] = trmnl->friendly_id();
				// TODO: Check for image in folder
				response["image_url"] = "https://trmnl.com/images/setup/setup-logo.bmp";
				response["filename"] = "welcome";

				res.body = response.dump();

				if (should_dump)
				{
					write_file_json(container, devices_filename, &cout);
				}
			}
		}
		else
		{
			// Bad Request - No ID header
			res.status = 400;
		}
	};

	auto display_handler = [&container, &devices_filename](const httplib::Request& req, httplib::Response& res)
	{
		res.status = 500;

		for (auto header : res.headers)
		{
			cout << header.first << ": " << header.second << endl;
		}
	};

	auto log_handler = [](const httplib::Request& req, httplib::Response& res)
	{
		try
		{
			json j = json::parse(req.body);
			cout << j.dump(4) << endl;
		}
		catch (const exception& e)
		{
			cout << req.body << endl;
		}
		res.status = 200;
	};


	server->Get("/api/setup/*", setup_handler);
	server->Get("/api/display/*", display_handler);
	server->Post("/api/log/*", log_handler);

	ok = server->set_mount_point("/images", folder_images);
	if (!ok)
	{
		cout << "Could not mount images folder" << endl;
		return -1;
	}

	cout << "Server listening on " << host << ":" << port << endl;
	server->listen(host, port);

	return 0;
}