const { describe, it, before, after } = require('node:test');
const assert = require('node:assert');
const fs = require('fs');
const path = require('path');
const os = require('os');
const express = require('express');

const configRoutes = require('../config');

function request(app, method, urlPath, body, headers = {}) {
  return new Promise((resolve, reject) => {
    const server = app.listen(0, '127.0.0.1', async () => {
      const port = server.address().port;
      try {
        const res = await fetch(`http://127.0.0.1:${port}${urlPath}`, {
          method,
          body,
          headers,
        });
        server.close(() => resolve(res));
      } catch (err) {
        server.close(() => reject(err));
      }
    });
  });
}

describe('config routes', () => {
  let app;
  const realDb = path.resolve(__dirname, '..', '..', '..', 'data', 'studyos.db');
  const backupDb = path.resolve(__dirname, '..', '..', '..', 'data', 'studyos.db.bak');

  before(() => {
    app = express();
    app.use(express.json());
    app.use('/api/config', configRoutes);
    if (fs.existsSync(realDb)) {
      fs.renameSync(realDb, backupDb);
    }
  });

  after(() => {
    if (fs.existsSync(backupDb)) {
      if (fs.existsSync(realDb)) fs.unlinkSync(realDb);
      fs.renameSync(backupDb, realDb);
    } else if (fs.existsSync(realDb)) {
      fs.unlinkSync(realDb);
    }
  });

  it('GET /api/config/backup returns 404 when DB missing', async () => {
    const res = await request(app, 'GET', '/api/config/backup');
    assert.strictEqual(res.status, 404);
    const body = await res.json();
    assert.strictEqual(body.error, 'No database');
  });

  it('POST /api/config/restore rejects invalid file', async () => {
    const form = new FormData();
    const blob = new Blob(['not-a-db']);
    form.append('file', blob, 'bad.db');

    const res = await request(app, 'POST', '/api/config/restore', form);
    assert.strictEqual(res.status, 400);
    const body = await res.json();
    assert.strictEqual(body.error, 'Not a valid SQLite database');
  });

  it('POST /api/config/restore accepts valid SQLite file', async () => {
    const header = Buffer.from('SQLite format 3\0');
    const dbContent = Buffer.concat([header, Buffer.alloc(100)]);

    const form = new FormData();
    const blob = new Blob([dbContent]);
    form.append('file', blob, 'studyos.db');

    const res = await request(app, 'POST', '/api/config/restore', form);
    assert.strictEqual(res.status, 200);
    const body = await res.json();
    assert.strictEqual(body.ok, true);
  });
});