// Leaderboard integration tests: GET /api/leaderboard?type=level|gold|kills&page=1
const { describe, it, before, after } = require('node:test');
const assert = require('node:assert/strict');
const { setup, teardown, cleanup } = require('../helpers');

/**
 * Register a user and log them in, returning the session cookie string.
 */
async function registerAndLogin(baseUrl, username, password) {
  await fetch(`${baseUrl}/api/auth/register`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ username, password }),
  });

  const res = await fetch(`${baseUrl}/api/auth/login`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ username, password }),
  });
  assert.equal(res.status, 200);
  const json = await res.json();
  assert.equal(json.ok, true);

  const setCookie = res.headers.get('set-cookie');
  assert.ok(setCookie, 'Login should set a session cookie');
  const cookie = setCookie.split(';')[0];
  return cookie;
}

function authHeaders(cookie) {
  return { Cookie: cookie };
}

describe('leaderboard', () => {
  let baseUrl, userSeq = 0;

  before(async () => {
    baseUrl = await setup();
  });

  after(async () => {
    await teardown(); cleanup();
  });

  /**
   * Register, login, create a character, optionally tweak DB fields, return cookie + characterId.
   */
  async function setupHero(overrides = {}) {
    userSeq += 1;
    const username = `lbu${userSeq}`;
    const cookie = await registerAndLogin(baseUrl, username, 'password123');

    const charRes = await fetch(`${baseUrl}/api/character`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ name: `LbHero${userSeq}`, class: 'warrior' }),
    });
    assert.equal(charRes.status, 201);
    const charJson = await charRes.json();
    const characterId = charJson.data.character.id;

    const db = require('../../src/db').getDb();
    const cols = Object.keys(overrides);
    if (cols.length) {
      db.prepare(`UPDATE characters SET ${cols.map((c) => `${c} = ?`).join(', ')} WHERE id = ?`)
        .run(...Object.values(overrides), characterId);
    }

    return { cookie, characterId };
  }

  // ─── GET /api/leaderboard?type=level ──────────────────────────────────

  it('returns heroes sorted by level descending, then xp descending', async () => {
    // Create 3 heroes with different levels.
    const heroes = [];
    for (let i = 0; i < 3; i++) {
      heroes.push(await setupHero({ level: i + 1 }));
    }

    // Create a 4th hero for the auth cookie.
    const { cookie } = await setupHero();

    const res = await fetch(`${baseUrl}/api/leaderboard?type=level`, {
      headers: authHeaders(cookie),
    });
    const body = await res.json();

    assert.equal(res.status, 200);
    assert.equal(body.ok, true);
    assert.ok(Array.isArray(body.data.entries));
    assert.ok(body.data.entries.length >= 3);
    // First entry should be the highest level (3).
    assert.equal(body.data.entries[0].level, 3);
    assert.ok(body.data.pagination, 'should have pagination');
    assert.ok(body.data.pagination.page === 1);
  });

  it('returns heroes sorted by gold descending', async () => {
    const heroes = [];
    heroes.push(await setupHero({ level: 1, gold: 500 }));
    heroes.push(await setupHero({ level: 1, gold: 1000 }));
    heroes.push(await setupHero({ level: 1, gold: 250 }));

    const { cookie } = await setupHero({ level: 1, gold: 50 });

    const res = await fetch(`${baseUrl}/api/leaderboard?type=gold`, {
      headers: authHeaders(cookie),
    });
    const body = await res.json();

    assert.equal(res.status, 200);
    const entries = body.data.entries;
    assert.equal(entries[0].gold, 1000);
    assert.equal(entries[1].gold, 500);
    assert.equal(entries[2].gold, 250);
  });

  it('returns heroes sorted by kills descending', async () => {
    await setupHero({ level: 1, kills: 50 });
    await setupHero({ level: 1, kills: 100 });
    await setupHero({ level: 1, kills: 10 });

    const { cookie } = await setupHero({ level: 1, kills: 5 });

    const res = await fetch(`${baseUrl}/api/leaderboard?type=kills`, {
      headers: authHeaders(cookie),
    });
    const body = await res.json();

    assert.equal(res.status, 200);
    const entries = body.data.entries;
    assert.equal(entries[0].kills, 100);
    assert.equal(entries[1].kills, 50);
    assert.equal(entries[2].kills, 10);
  });

  // ─── Pagination ───────────────────────────────────────────────────────

  it('paginates correctly with page and limit', async () => {
    // Create 4 heroes at different levels.
    await setupHero({ level: 1 });
    await setupHero({ level: 2 });
    await setupHero({ level: 3 });
    await setupHero({ level: 4 });

    const { cookie } = await setupHero({ level: 1 });

    const res = await fetch(`${baseUrl}/api/leaderboard?type=level&page=1&limit=2`, {
      headers: authHeaders(cookie),
    });
    const body = await res.json();

    assert.equal(res.status, 200);
    assert.equal(body.data.entries.length, 2);
    assert.equal(body.data.pagination.page, 1);
    assert.equal(body.data.pagination.limit, 2);
    assert.ok(body.data.pagination.total >= 5, 'should have at least 5 total');
    assert.ok(body.data.pagination.totalPages >= 3, 'should have at least 3 pages');
    assert.equal(body.data.entries[0].rank, 1);
    assert.equal(body.data.entries[1].rank, 2);
  });

  it('page 2 returns subsequent entries with correct ranks', async () => {
    await setupHero({ level: 1 });
    await setupHero({ level: 2 });
    await setupHero({ level: 3 });

    const { cookie } = await setupHero({ level: 1 });

    const res = await fetch(`${baseUrl}/api/leaderboard?type=level&page=2&limit=2`, {
      headers: authHeaders(cookie),
    });
    const body = await res.json();

    assert.equal(res.status, 200);
    assert.equal(body.data.entries.length, 2);
    assert.equal(body.data.pagination.page, 2);
    // Ranks should be 3, 4.
    assert.equal(body.data.entries[0].rank, 3);
    assert.equal(body.data.entries[1].rank, 4);
  });

  // ─── Validation ───────────────────────────────────────────────────────

  it('rejects invalid type', async () => {
    const { cookie } = await setupHero();

    const res = await fetch(`${baseUrl}/api/leaderboard?type=invalid`, {
      headers: authHeaders(cookie),
    });
    const body = await res.json();

    assert.equal(res.status, 400);
    assert.equal(body.ok, false);
    assert.equal(body.error.code, 'VALIDATION_ERROR');
  });

  it('rejects negative page number', async () => {
    const { cookie } = await setupHero();

    const res = await fetch(`${baseUrl}/api/leaderboard?type=level&page=-1`, {
      headers: authHeaders(cookie),
    });
    const body = await res.json();

    assert.equal(res.status, 400);
    assert.equal(body.ok, false);
    assert.equal(body.error.code, 'VALIDATION_ERROR');
  });

  it('rejects request without authentication', async () => {
    const res = await fetch(`${baseUrl}/api/leaderboard?type=level`);
    const body = await res.json();

    assert.equal(res.status, 401);
    assert.equal(body.ok, false);
  });

  // ─── Entry shape ──────────────────────────────────────────────────────

  it('returns correct entry shape with all fields', async () => {
    const { cookie } = await setupHero({
      level: 7, xp: 1000, gold: 500, kills: 25,
    });

    // Create one more hero so there are multiple entries.
    await setupHero({ level: 1 });

    const res = await fetch(`${baseUrl}/api/leaderboard?type=level`, {
      headers: authHeaders(cookie),
    });
    const body = await res.json();

    assert.equal(res.status, 200);
    const entry = body.data.entries.find(e => e.name === `LbHero${userSeq - 1}`);
    assert.ok(entry, 'should find the hero');
    assert.equal(entry.name, `LbHero${userSeq - 1}`);
    assert.equal(entry.class, 'warrior');
    assert.equal(entry.level, 7);
    assert.equal(entry.xp, 1000);
    assert.equal(entry.gold, 500);
    assert.equal(entry.kills, 25);
    assert.ok(typeof entry.rank === 'number', 'rank should be a number');
  });
});