import { test, before, after } from "node:test";
import assert from "node:assert/strict";
import { createServer } from "node:http";
import { readFileSync, mkdtempSync, rmSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { academicStartYear, todayIso } from "../shared/weeks.js";

// The API over HTTP, as the Android and iOS clients see it: the real server against a stand-in
// for the university's Nextcloud that serves the fixtures as a small catalog.
const SHARE = "/public.php/dav/files/no5zKbMrns6j5jQ/";
const fixture = (name) => readFileSync(new URL(`./fixtures/${name}`, import.meta.url));
const year = academicStartYear(todayIso());
const YEAR = `${year}-${year + 1}`;
const FOLDER = `${SHARE}${YEAR}/Финансово-экономический факультет/Дневная форма/`;
const MODIFIED = "Mon, 14 Sep 2026 13:05:15 GMT";
const files = {
  [`${SHARE}Расписание белых и зеленых недель.docx`]: fixture("weeks.docx"),
  [`${SHARE}Расписание звонков.docx`]: fixture("bells.docx"),
  [`${FOLDER}23-ЛГ_23-БА.docx`]: fixture("fef-23-ba.docx"),
  [`${FOLDER}24-ИТ.docx`]: fixture("fit-daily.docx"),
  // The university fails on one document and is too slow on another.
  [`${FOLDER}Сломанный.docx`]: 500,
  [`${FOLDER}Медленный.docx`]: "slow",
};
const folders = [SHARE, `${SHARE}${YEAR}/`, `${SHARE}${YEAR}/Финансово-экономический факультет/`, FOLDER];

const encode = (path) => path.split("/").map(encodeURIComponent).join("/");
const listing = (folder) => {
  const children = [...folders.filter((f) => f !== folder && f.startsWith(folder) && !f.slice(folder.length, -1).includes("/")),
    ...Object.keys(files).filter((f) => f.startsWith(folder) && !f.slice(folder.length).includes("/"))];
  const entry = (path) => {
    const folder = path.endsWith("/");
    const size = Buffer.isBuffer(files[path]) ? files[path].length : 1000;
    return `<d:response><d:href>${encode(path)}</d:href><d:propstat><d:prop>${
      folder ? "<d:resourcetype><d:collection/></d:resourcetype>" : `<d:resourcetype/><d:getcontentlength>${size}</d:getcontentlength>`
    }<d:getlastmodified>${MODIFIED}</d:getlastmodified></d:prop><d:status>HTTP/1.1 200 OK</d:status></d:propstat></d:response>`;
  };
  return `<?xml version="1.0"?><d:multistatus xmlns:d="DAV:">${[folder, ...children].map(entry).join("")}</d:multistatus>`;
};

let source, server, base, data;
const stats = { requests: 0, connections: 0 };

before(async () => {
  source = createServer((req, res) => {
    stats.requests++;
    const path = decodeURIComponent(req.url);
    if (req.method === "PROPFIND" && folders.includes(path)) {
      res.writeHead(207, { "Content-Type": "application/xml" });
      return res.end(listing(path));
    }
    const body = files[path];
    if (body === "slow") return setTimeout(() => res.end("late"), 2000);
    if (typeof body === "number" || !body) return res.writeHead(body || 404).end();
    res.end(body);
  });
  source.on("connection", () => stats.connections++);
  await new Promise((resolve) => source.listen(0, "127.0.0.1", resolve));
  data = mkdtempSync(join(tmpdir(), "psu-api-"));
  process.env.PSU_SOURCE_ORIGIN = `http://127.0.0.1:${source.address().port}`;
  process.env.PSU_DATA_DIR = data;
  process.env.PSU_SOURCE_TIMEOUT_MS = "500";
  const { app } = await import("../server/index.js");
  server = app.listen(0, "127.0.0.1");
  await new Promise((resolve) => server.on("listening", resolve));
  base = `http://127.0.0.1:${server.address().port}`;
});

after(() => {
  server?.close();
  server?.closeAllConnections();
  source?.closeAllConnections();
  source?.close();
  rmSync(data, { recursive: true, force: true });
});

const get = (path, headers = {}) => fetch(base + path, { headers });
const json = async (path) => {
  const response = await get(path);
  return { status: response.status, body: await response.json(), response };
};
const query = (params) => "?" + new URLSearchParams(params);
let doc;

test("API: до загрузки индекса сервер жив, но не готов", async () => {
  const health = await json("/api/health");
  assert.equal(health.status, 200);
  assert.equal(health.body.ok, true);
  assert.equal(health.body.ready, false);
  assert.equal(typeof health.body.apiVersion, "number");
  const ready = await json("/api/ready");
  assert.equal(ready.status, 503);
  assert.equal(ready.body.code, "not_ready");
  assert.ok(ready.body.waiting.includes("index"));
});

test("API: группы находятся по каталогу, после этого сервер готов", async () => {
  const { status, body } = await json("/api/groups" + query({ q: "23-БА" }));
  assert.equal(status, 200);
  const group = body.results.find((r) => r.group === "23-БА");
  assert.ok(group, JSON.stringify(body));
  assert.equal(group.file, "23-ЛГ_23-БА.docx");
  doc = group.fileId;
  // The calendar loads beside the index; the first timetable request waits for it.
  await get("/api/calendar");
  const ready = await json("/api/ready");
  assert.equal(ready.status, 200, JSON.stringify(ready.body));
  assert.equal(ready.body.ready, true);
  // Two broken documents of four do not keep the server from being ready.
  assert.equal(ready.body.documents, 2);
  assert.equal((await json("/api/health")).body.ready, true);
});

test("API: расписание группы — форма ответа для приложений", async () => {
  const { status, body, response } = await json("/api/timetable" + query({ doc, group: "23-БА", from: "2026-10-19", days: 7 }));
  assert.equal(status, 200);
  assert.equal(body.group, "23-БА");
  assert.equal(body.document.id, doc);
  assert.equal(body.document.name, "23-ЛГ_23-БА.docx");
  assert.ok(Array.isArray(body.days) && body.days.length === 7);
  assert.ok(Array.isArray(body.bells) && body.bells.length > 0);
  assert.ok(Array.isArray(body.subgroups));
  const lesson = body.days.flatMap((d) => d.lessons)[0];
  assert.ok(lesson, "на неделе есть занятия");
  for (const field of ["key", "subject", "type", "start", "end", "pair", "rooms", "teachers", "condition", "subgroup", "raw"])
    assert.ok(field in lesson, `поле ${field}`);
  assert.match(body.days[0].date, /^\d{4}-\d{2}-\d{2}$/);
  assert.equal(response.headers.get("cache-control"), "no-cache");
  assert.ok(response.headers.get("etag"));
});

test("API: неизменное расписание отдаётся пустым 304", async () => {
  const path = "/api/timetable" + query({ doc, group: "23-БА", from: "2026-10-19", days: 7 });
  const etag = (await get(path)).headers.get("etag");
  // fetch adds "Cache-Control: no-cache" to a request with its own If-None-Match, which forbids
  // a 304; OkHttp and URLCache revalidate without it, as this request does.
  const again = await get(path, { "If-None-Match": etag, "Cache-Control": "max-age=0" });
  assert.equal(again.status, 304);
  assert.equal(await again.text(), "");
  const other = await get("/api/timetable" + query({ doc, group: "23-ЛГ", from: "2026-10-19", days: 7 }), { "If-None-Match": etag, "Cache-Control": "max-age=0" });
  assert.equal(other.status, 200);
});

test("API: ошибки с машиночитаемым кодом", async () => {
  const cases = [
    ["/api/timetable" + query({ group: "23-БА" }), 400, "bad_request"],
    ["/api/timetable" + query({ doc, group: "23-БА", from: "19.10.2026" }), 400, "bad_request"],
    ["/api/timetable" + query({ doc: "нет-такого", group: "23-БА" }), 404, "document_not_found"],
    ["/api/timetable" + query({ doc, group: "99-ЯЯ" }), 404, "group_not_found"],
    ["/api/exams", 400, "bad_request"],
    ["/api/directory/day" + query({ date: "2026-10-19" }), 400, "bad_request"],
    ["/api/nope", 404, "unknown_endpoint"],
  ];
  for (const [path, status, code] of cases) {
    const result = await json(path);
    assert.equal(result.status, status, path);
    assert.equal(result.body.code, code, path);
    assert.equal(typeof result.body.error, "string", path);
  }
});

test("API: исходный документ, сбой и таймаут университета", async () => {
  const catalog = (await json("/api/catalog")).body;
  const id = (name) => catalog.files.find((f) => f.name === name).id;
  const original = await get(`/api/original/${id("23-ЛГ_23-БА.docx")}`);
  assert.equal(original.status, 200);
  assert.deepEqual(Buffer.from(await original.arrayBuffer()), fixture("fef-23-ba.docx"));
  const broken = await json(`/api/original/${id("Сломанный.docx")}`);
  assert.equal(broken.status, 502);
  assert.equal(broken.body.code, "source_unavailable");
  const slow = await json(`/api/original/${id("Медленный.docx")}`);
  assert.equal(slow.status, 504);
  assert.equal(slow.body.code, "source_timeout");
});

test("API: диагностика каталога и её фильтры", async () => {
  const all = await json("/api/diagnostics");
  assert.equal(all.status, 200);
  assert.equal(all.body.documents, 2);
  assert.equal(all.body.failed.length, 2);
  assert.equal(typeof all.body.counts, "object");
  // 23-БА's "2,6-12-16н" is a typo in Word that stays flagged.
  const ba = await json("/api/diagnostics" + query({ group: "23-БА" }));
  const problems = ba.body.items.flatMap((i) => i.problems);
  assert.ok(problems.some((p) => p.code === "weeks_unreadable"));
  assert.ok(problems.every((p) => p.groups.includes("23-БА")));
  const none = await json("/api/diagnostics" + query({ code: "нет-такого" }));
  assert.equal(none.body.problems, 0);
});

test("API: импорт Word и лимит 10 файлов", async () => {
  const send = (name, body) => {
    const form = new FormData();
    form.append("file", new Blob([body]), name);
    return fetch(base + "/api/import", { method: "POST", body: form });
  };
  const ok = await send("23-ЛГ_23-БА.docx", fixture("fef-23-ba.docx"));
  assert.equal(ok.status, 200);
  assert.ok((await ok.json()).groups.includes("23-БА"));
  const wrongType = await send("расписание.pdf", "%PDF");
  assert.equal(wrongType.status, 400);
  assert.equal((await wrongType.json()).code, "bad_request");
  const garbage = await send("расписание.docx", "не Word");
  assert.equal(garbage.status, 422);
  assert.equal((await garbage.json()).code, "unreadable_file");
  for (let i = 0; i < 7; i++) assert.equal((await send("23-ЛГ_23-БА.docx", fixture("fef-23-ba.docx"))).status, 200);
  const limited = await send("23-ЛГ_23-БА.docx", fixture("fef-23-ba.docx"));
  assert.equal(limited.status, 429);
  assert.equal((await limited.json()).code, "too_many_requests");
  assert.ok(Number(limited.headers.get("retry-after")) > 0);
});

test("API: запросы к университету идут по открытым соединениям", () => {
  // Listings, the week table, bells and four documents (some twice) over a handful of sockets.
  assert.ok(stats.requests >= 10, `запросов ${stats.requests}`);
  assert.ok(stats.connections < stats.requests / 2, `соединений ${stats.connections} на ${stats.requests} запросов`);
});