elysium/apps/api/src/routes/auth.ts

/**
 * @file Authentication routes for Discord OAuth.
 * @copyright nhcarrigan
 * @license Naomi's Public License
 * @author Naomi Carrigan
 */
/* eslint-disable max-lines-per-function -- Auth callback requires many steps */
/* eslint-disable max-statements -- Auth callback requires many statements */
import { Hono } from "hono";
import { initialGameState } from "../data/initialState.js";
import { prisma } from "../db/client.js";
import {
  buildOAuthUrl,
  exchangeCode,
  fetchDiscordUser,
} from "../services/discord.js";
import { signToken } from "../services/jwt.js";
import { logger } from "../services/logger.js";
import type { Player } from "@elysium/types";

const authRouter = new Hono();

authRouter.get("/url", (context) => {
  try {
    const url = buildOAuthUrl();
    return context.json({ url });
  } catch {
    return context.json({ error: "Failed to build OAuth URL" }, 500);
  }
});

authRouter.get("/callback", async(context) => {
  const code = context.req.query("code");

  if (code === undefined || code === "") {
    return context.json({ error: "Missing code parameter" }, 400);
  }

  try {
    const tokenData = await exchangeCode(code);
    const discordUser = await fetchDiscordUser(tokenData.access_token);

    const existing = await prisma.player.findUnique({
      where: { discordId: discordUser.id },
    });

    const now = Date.now();

    if (!existing) {
      const player = await prisma.player.create({
        data: {
          avatar:          discordUser.avatar,
          characterName:   discordUser.username,
          createdAt:       now,
          discordId:       discordUser.id,
          discriminator:   discordUser.discriminator,
          lastSavedAt:     now,
          totalClicks:     0,
          totalGoldEarned: 0,
          username:        discordUser.username,
        },
      });

      const playerShape: Player = {
        avatar:                       player.avatar ?? null,
        characterName:                player.characterName,
        createdAt:                    player.createdAt,
        discordId:                    player.discordId,
        discriminator:                player.discriminator,
        lastSavedAt:                  player.lastSavedAt,
        lifetimeAchievementsUnlocked: player.lifetimeAchievementsUnlocked,
        lifetimeAdventurersRecruited: player.lifetimeAdventurersRecruited,
        lifetimeBossesDefeated:       player.lifetimeBossesDefeated,
        lifetimeClicks:               player.lifetimeClicks,
        lifetimeGoldEarned:           player.lifetimeGoldEarned,
        lifetimeQuestsCompleted:      player.lifetimeQuestsCompleted,
        totalClicks:                  player.totalClicks,
        totalGoldEarned:              player.totalGoldEarned,
        username:                     player.username,
      };

      const freshState = initialGameState(
        playerShape,
        playerShape.characterName,
      );
      await prisma.gameState.create({
        data: {
          discordId: player.discordId,
          /* eslint-disable-next-line @typescript-eslint/consistent-type-assertions -- Prisma requires never type */
          state:     freshState as unknown as never,
          updatedAt: now,
        },
      });

      const jwtToken = signToken(player.discordId);
      void logger.log("info", `New player registered: ${player.discordId}`);
      void logger.metric("user_registered", 1, { discordId: player.discordId });

      // eslint-disable-next-line capitalized-comments -- v8 ignore
      /* v8 ignore next -- @preserve */
      const clientUrl = process.env.CORS_ORIGIN ?? "http://localhost:5173";
      return context.redirect(
        `${clientUrl}/auth/callback?token=${jwtToken}&isNew=true`,
      );
    }

    const updated = await prisma.player.update({
      data: {
        avatar:        discordUser.avatar,
        discriminator: discordUser.discriminator,
        username:      discordUser.username,
      },
      where: { discordId: discordUser.id },
    });

    const jwtToken = signToken(updated.discordId);
    void logger.log("info", `Player logged in: ${updated.discordId}`);
    void logger.metric("user_login", 1, { discordId: updated.discordId });

    // eslint-disable-next-line capitalized-comments -- v8 ignore
    /* v8 ignore next -- @preserve */
    const clientUrl = process.env.CORS_ORIGIN ?? "http://localhost:5173";
    return context.redirect(
      `${clientUrl}/auth/callback?token=${jwtToken}&isNew=false`,
    );
  } catch (error) {
    void logger.error(
      "auth_callback",
      error instanceof Error
        ? error
        : new Error(String(error)),
    );
    // eslint-disable-next-line capitalized-comments -- v8 ignore
    /* v8 ignore next -- @preserve */
    const clientUrl = process.env.CORS_ORIGIN ?? "http://localhost:5173";
    return context.redirect(`${clientUrl}/auth/callback?error=auth_failed`);
  }
});

export { authRouter };