GCDC-Server/src/main/java/io/github/norbipeti/gcdc/controller/DCController.java

package io.github.norbipeti.gcdc.controller;

import bell.oauth.discord.main.OAuthBuilder;
import bell.oauth.discord.main.Response;
import discord4j.core.object.entity.Message;
import discord4j.core.object.util.Snowflake;
import io.github.norbipeti.gcdc.model.Session;
import io.github.norbipeti.gcdc.service.DiscordService;
import io.github.norbipeti.gcdc.service.SessionService;
import lombok.RequiredArgsConstructor;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.context.request.async.DeferredResult;
import org.springframework.web.server.ResponseStatusException;

import javax.servlet.http.HttpServletRequest;
import javax.validation.Valid;
import java.security.Principal;
import java.util.Collections;
import java.util.Map;
import java.util.UUID;

@RestController
@RequiredArgsConstructor
public class DCController {
	private static final Map<String, String> RESULT_OK = Collections.singletonMap("response", "OK");
	private final SessionService service;
	private final DiscordService discordService;
	@Value("${discord.secret}")
	private String secret;
	private final OAuthBuilder builder = new OAuthBuilder("680138144812892371", secret);

	@GetMapping("/api/users/register")
	public Map<String, String> register(@RequestParam String state, @RequestParam String code, HttpServletRequest request) {
		if (state == null || code == null) throw new ResponseStatusException(HttpStatus.BAD_REQUEST);
		long channel;
		try { channel = Long.parseLong(state); } catch (NumberFormatException e) {
			throw new ResponseStatusException(HttpStatus.BAD_REQUEST);
		}
		builder.setRedirectURI(request.getRequestURL().toString());
		if (builder.exchange(code) == Response.ERROR)
			throw new ResponseStatusException(HttpStatus.BAD_REQUEST);
		long user = Snowflake.of(builder.getUser().getId()).asLong();
		service.deleteSession(user);
		service.insertSession(new Session(UUID.randomUUID().toString(), Snowflake.of(channel), user));
		return RESULT_OK;
	}

	@GetMapping("/api/users/get")
	public Map<String, String> getUser(@RequestParam String token) {
		getSession(token); //Returns unauthorized if needed
		return RESULT_OK;
	}

	@PostMapping("/api/messages/send")
	public Map<String, String> sendMessage(@RequestParam String token, @RequestParam String message) {
		var sess = getSession(token);
		discordService.sendMessage(sess.getChannel().asLong(), sess.getUser(), message);
		return RESULT_OK;
	}

	@GetMapping("/api/messages/get")
	public DeferredResult<Map<String, String>> getMessage(@RequestParam String token) {
		var sess = getSession(token);
		return discordService.getMessage(sess.getChannel().asLong());
	}

	private Session getSession(String token) {
		var sess = service.getSession(token);
		if (sess == null)
			throw new ResponseStatusException(HttpStatus.UNAUTHORIZED);
		return sess;
	}
}