import { Application, Router } from "@oak/oak";
import {
  addWebhookSubscription,
  deleteWebhooksByDid,
  getNotes,
  getNotesByDid,
  getNotesByDids,
  type WebhookVerb,
} from "./src/data/db.ts";
import { authenticateRequest } from "./src/auth/verify.ts";
import { log } from "./src/log.ts";

const router = new Router();

const PAGINATION = 20;
const GITHUB_CLIENT_ID = Deno.env.get("GITHUB_CLIENT_ID") ?? "";
const GITHUB_CLIENT_SECRET = Deno.env.get("GITHUB_CLIENT_SECRET") ?? "";

router.get("/", (ctx) => {
  ctx.response.body = "Hello world";
});

router.get("/auth/github", async (ctx) => {
  const code = ctx.request.url.searchParams.get("code");
  const type = ctx.request.url.searchParams.get("type");

  if (!code) {
    ctx.response.status = 400;
    ctx.response.body = { error: "code is required" };
    return;
  }

  const params: Record<string, string> = {
    client_id: GITHUB_CLIENT_ID,
    client_secret: GITHUB_CLIENT_SECRET,
  };

  if (type === "refresh") {
    params.grant_type = "refresh_token";
    params.refresh_token = code;
  } else {
    params.code = code;
  }

  const response = await fetch(
    "https://github.com/login/oauth/access_token",
    {
      method: "POST",
      headers: {
        "Accept": "application/json",
        "Content-Type": "application/json",
      },
      body: JSON.stringify(params),
    },
  );

  ctx.response.status = response.status;
  ctx.response.body = await response.json();
});

router.get("/health", (ctx) => {
  ctx.response.body = { status: "ok" };
});

router.get("/notes", (ctx) => {
  const cursor = ctx.request.url.searchParams.get("cursor") ?? undefined;
  const limit = Number(ctx.request.url.searchParams.get("limit")) || PAGINATION;
  ctx.response.body = getNotes(cursor, limit);
});

router.get("/:did/notes", (ctx) => {
  const { did } = ctx.params;
  const cursor = ctx.request.url.searchParams.get("cursor") ?? undefined;
  const limit = Number(ctx.request.url.searchParams.get("limit")) || PAGINATION;
  ctx.response.body = getNotesByDid(did, cursor, limit);
});

router.post("/notes/feed", async (ctx) => {
  const body = await ctx.request.body.json();
  const { dids, cursor, limit } = body ?? {};
  if (!Array.isArray(dids) || dids.length === 0) {
    ctx.response.status = 400;
    ctx.response.body = { error: "dids must be a non-empty array" };
    return;
  }
  ctx.response.body = getNotesByDids(dids, cursor, Number(limit) || PAGINATION);
});

const ALLOWED_VERBS = ["create", "delete", "bulk-create"] as const;

router.post("/:did/webhooks", async (ctx) => {
  const { did } = ctx.params;
  let verifiedDid: string;
  try {
    verifiedDid = await authenticateRequest(
      ctx.request.headers.get("Authorization"),
    );
  } catch {
    ctx.response.status = 401;
    ctx.response.body = { error: "Unauthorized" };
    return;
  }
  if (verifiedDid !== did) {
    ctx.response.status = 403;
    ctx.response.body = { error: "You can only manage your own webhooks" };
    return;
  }
  const body = await ctx.request.body.json();
  const { method, url, token, verb } = body ?? {};
  if (!method || !url) {
    ctx.response.status = 400;
    ctx.response.body = { error: "method and url are required" };
    return;
  }
  if (verb !== undefined && !ALLOWED_VERBS.includes(verb)) {
    ctx.response.status = 400;
    ctx.response.body = {
      error: `verb must be one of ${ALLOWED_VERBS.join(", ")}`,
    };
    return;
  }
  const verbsToInsert: WebhookVerb[] = verb ? [verb] : ["create", "delete"];
  const subscriptions = verbsToInsert.map((v) =>
    addWebhookSubscription({ did, method, url, token, verb: v })
  );
  ctx.response.status = 201;
  ctx.response.body = subscriptions;
});

router.delete("/:did/webhooks", async (ctx) => {
  const { did } = ctx.params;
  let verifiedDid: string;
  try {
    verifiedDid = await authenticateRequest(
      ctx.request.headers.get("Authorization"),
    );
  } catch {
    ctx.response.status = 401;
    ctx.response.body = { error: "Unauthorized" };
    return;
  }
  if (verifiedDid !== did) {
    ctx.response.status = 403;
    ctx.response.body = { error: "You can only manage your own webhooks" };
    return;
  }
  deleteWebhooksByDid(did);
  ctx.response.status = 204;
});

// router.delete("/:did/:rkey", async (ctx) => {
//   const { did, rkey } = ctx.params;
//   let verifiedDid: string;
//   try {
//     verifiedDid = await authenticateRequest(
//       ctx.request.headers.get("Authorization"),
//     );
//   } catch {
//     ctx.response.status = 401;
//     ctx.response.body = { error: "Unauthorized" };
//     return;
//   }
//   if (verifiedDid !== did) {
//     ctx.response.status = 403;
//     ctx.response.body = { error: "You can only delete your own notes" };
//     return;
//   }
//   deleteNote({ did, rkey });
//   ctx.response.status = 204;
// })

const app = new Application();

app.use(async (ctx, next) => {
  ctx.response.headers.set("Access-Control-Allow-Origin", "*");
  ctx.response.headers.set(
    "Access-Control-Allow-Methods",
    "GET, POST, PUT, DELETE, OPTIONS",
  );
  ctx.response.headers.set(
    "Access-Control-Allow-Headers",
    "Content-Type, Authorization",
  );
  if (ctx.request.method === "OPTIONS") {
    ctx.response.status = 204;
    return;
  }
  await next();
});

app.use(router.routes());
app.use(router.allowedMethods());

log("[server] listening on port 8080");
app.listen({ port: 8080 });