import assert from 'node:assert/strict';
import { mkdtemp, writeFile } from 'node:fs/promises';
import { tmpdir } from 'node:os';
import { join } from 'node:path';
import { test } from 'node:test';
import { LandingClient } from '../src/client.mjs';

const showPage = {
  method: 'GET',
  path: '/v1/pages/{page}',
  params: [{ name: 'page', in: 'path' }, { name: 'lang', in: 'query' }],
  hasBody: false,
  requiresAuth: true,
};

const publicProjects = {
  method: 'GET',
  path: '/public/v1/projects',
  params: [{ name: 'featured', in: 'query' }],
  hasBody: false,
  requiresAuth: false,
};

/** A fake fetch that answers from a list of handlers and records every call. */
function fakeFetch(handler) {
  const calls = [];

  const fetch = async (url, init) => {
    calls.push({ url, ...init });
    const { status = 200, body = {} } = handler(url, init, calls.length);

    return new Response(status === 204 ? null : JSON.stringify(body), { status });
  };

  return { fetch, calls };
}

const tokenResponse = (access, expiresInMs = 3_600_000) => ({
  access_token: access,
  refresh_token: `refresh-${access}`,
  expires_at: new Date(Date.now() + expiresInMs).toISOString(),
});

test('builds the URL from path and query parameters', async () => {
  const { fetch, calls } = fakeFetch(() => ({ body: { data: [] } }));
  const client = new LandingClient({ apiBase: 'http://app.test/api/', fetch });

  await client.call(publicProjects, { featured: true });

  assert.equal(calls[0].url, 'http://app.test/api/public/v1/projects?featured=1');
  assert.equal(calls[0].headers.Authorization, undefined);
});

test('sends the preview secret on public calls only', async () => {
  const { fetch, calls } = fakeFetch((url) => (
    url.endsWith('/auth/token') ? { body: tokenResponse('a') } : { body: {} }
  ));
  const client = new LandingClient({
    apiBase: 'http://app.test/api', username: 'u', password: 'p', previewToken: 'secret', fetch,
  });

  await client.call(publicProjects, {});
  await client.call(showPage, { page: 1 });

  assert.equal(calls[0].headers['X-Preview-Token'], 'secret');
  assert.equal(calls.at(-1).headers['X-Preview-Token'], undefined);
});

test('logs in once and reuses the token', async () => {
  const { fetch, calls } = fakeFetch((url) => (
    url.endsWith('/auth/token') ? { body: tokenResponse('a') } : { body: { data: {} } }
  ));
  const client = new LandingClient({ apiBase: 'http://app.test/api', username: 'u', password: 'p', fetch });

  await Promise.all([client.call(showPage, { page: 1 }), client.call(showPage, { page: 2 })]);
  await client.call(showPage, { page: 3 });

  assert.equal(calls.filter((c) => c.url.endsWith('/auth/token')).length, 1);
  assert.equal(calls.at(-1).url, 'http://app.test/api/v1/pages/3');
  assert.equal(calls.at(-1).headers.Authorization, 'Bearer a');
});

test('refreshes a token about to expire', async () => {
  let issued = 0;
  const { fetch, calls } = fakeFetch((url) => (
    url.endsWith('/auth/token') ? { body: tokenResponse(`t${++issued}`, 10_000) } : { body: {} }
  ));
  const client = new LandingClient({ apiBase: 'http://app.test/api', username: 'u', password: 'p', fetch });

  await client.call(showPage, { page: 1 });
  await client.call(showPage, { page: 1 });

  const grants = calls.filter((c) => c.url.endsWith('/auth/token')).map((c) => JSON.parse(c.body).grant_type);

  assert.deepEqual(grants, ['password', 'refresh_token']);
  assert.equal(calls.at(-1).headers.Authorization, 'Bearer t2');
});

test('retries once with a new token after a 401', async () => {
  let issued = 0;
  const { fetch, calls } = fakeFetch((url, init) => {
    if (url.endsWith('/auth/token')) return { body: tokenResponse(`t${++issued}`) };

    return init.headers.Authorization === 'Bearer t1' ? { status: 401, body: { message: 'Unauthenticated.' } } : { body: { ok: true } };
  });
  const client = new LandingClient({ apiBase: 'http://app.test/api', username: 'u', password: 'p', fetch });

  const response = await client.call(showPage, { page: 1 });

  assert.equal(response.status, 200);
  assert.equal(calls.at(-1).headers.Authorization, 'Bearer t2');
});

test('falls back to the password when the refresh token is refused', async () => {
  let issued = 0;
  const { fetch, calls } = fakeFetch((url, init) => {
    if (!url.endsWith('/auth/token')) return { body: {} };

    return JSON.parse(init.body).grant_type === 'refresh_token'
      ? { status: 422, body: { message: 'invalid' } }
      : { body: tokenResponse(`t${++issued}`, 10_000) };
  });
  const client = new LandingClient({ apiBase: 'http://app.test/api', username: 'u', password: 'p', fetch });

  await client.call(showPage, { page: 1 });
  await client.call(showPage, { page: 1 });

  const grants = calls.filter((c) => c.url.endsWith('/auth/token')).map((c) => JSON.parse(c.body).grant_type);

  assert.deepEqual(grants, ['password', 'refresh_token', 'password']);
});

test('a fixed token is used as is and never renewed', async () => {
  const { fetch, calls } = fakeFetch(() => ({ status: 401, body: {} }));
  const client = new LandingClient({ apiBase: 'http://app.test/api', token: 'fixed', fetch });

  const response = await client.call(showPage, { page: 1 });

  assert.equal(response.status, 401);
  assert.equal(calls.length, 1);
  assert.equal(calls[0].headers.Authorization, 'Bearer fixed');
});

test('refuses an authenticated call without credentials', async () => {
  const client = new LandingClient({ apiBase: 'http://app.test/api', fetch: async () => assert.fail('no request') });

  await assert.rejects(client.call(showPage, { page: 1 }), /LANDING_TOKEN/);
});

test('refuses a call missing a path parameter', async () => {
  const client = new LandingClient({ apiBase: 'http://app.test/api', token: 't', fetch: async () => assert.fail('no request') });

  await assert.rejects(client.call(showPage, {}), /"page"/);
});

const uploadMedia = {
  method: 'POST',
  path: '/v1/media',
  params: [],
  hasBody: true,
  files: ['file'],
  requiresAuth: true,
};

test('uploads a local file as multipart, never as JSON', async () => {
  const dir = await mkdtemp(join(tmpdir(), 'landing-mcp-'));
  const file = join(dir, 'hero.png');
  await writeFile(file, Buffer.from([0x89, 0x50, 0x4e, 0x47]));

  const { fetch, calls } = fakeFetch(() => ({ status: 201, body: { data: { path: 'pages/x.png' } } }));
  const client = new LandingClient({ apiBase: 'http://app.test/api', token: 't', fetch });

  const response = await client.call(uploadMedia, { file_path: file });
  const sent = calls[0].body;

  assert.equal(response.status, 201);
  assert.ok(sent instanceof FormData);
  assert.equal(sent.get('file').name, 'hero.png');
  assert.equal(sent.get('file').size, 4);
  // fetch has to write it, boundary and all.
  assert.equal(calls[0].headers['Content-Type'], undefined);
});

test('sends the JSON body when there is no file', async () => {
  const { fetch, calls } = fakeFetch(() => ({ status: 201, body: {} }));
  const client = new LandingClient({ apiBase: 'http://app.test/api', token: 't', fetch });

  await client.call(uploadMedia, { body: { url: 'https://images.example.org/a.png' } });

  assert.equal(calls[0].headers['Content-Type'], 'application/json');
  assert.equal(JSON.parse(calls[0].body).url, 'https://images.example.org/a.png');
});

test('says which file it could not read', async () => {
  const client = new LandingClient({ apiBase: 'http://app.test/api', token: 't', fetch: async () => assert.fail('no request') });

  await assert.rejects(client.call(uploadMedia, { file_path: '/nope/missing.png' }), /\/nope\/missing\.png/);
});