import { mkdtempSync, rmSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join } from 'node:path';
import { createApp } from '../src/app';
import { loadConfig } from '../src/config';
import { createContext, type AppContext } from '../src/context';
import { silentLogger } from '../src/log';

export interface TestApp {
  ctx: AppContext;
  app: ReturnType<typeof createApp>;
  dir: string;
  cleanup(): void;
}

export async function makeApp(env: Record<string, string> = {}): Promise<TestApp> {
  const dir = mkdtempSync(join(tmpdir(), 'spendlight-test-'));
  const config = loadConfig({
    DATA_DIR: join(dir, 'data'),
    BACKUP_DIR: join(dir, 'backups'),
    WEB_DIST: join(dir, 'web'),
    APP_VERSION: '20261007.01',
    ...env,
  });
  const ctx = await createContext(config, { log: silentLogger });
  const app = createApp(ctx);
  return {
    ctx,
    app,
    dir,
    cleanup() {
      ctx.sqlite.close();
      rmSync(dir, { recursive: true, force: true });
    },
  };
}

/** A tiny browser: keeps cookies between calls and sends JSON. */
export class Client {
  private cookies = new Map<string, string>();

  constructor(
    private t: TestApp,
    private base = 'http://localhost',
    private extraHeaders: Record<string, string> = {},
  ) {}

  async call(method: string, path: string, body?: unknown, headers: Record<string, string> = {}) {
    const res = await this.t.app.request(`${this.base}${path}`, {
      method,
      headers: {
        ...(body !== undefined ? { 'Content-Type': 'application/json' } : {}),
        ...(this.cookies.size ? { Cookie: [...this.cookies].map(([k, v]) => `${k}=${v}`).join('; ') } : {}),
        ...this.extraHeaders,
        ...headers,
      },
      body: body !== undefined ? JSON.stringify(body) : undefined,
    });
    for (const line of res.headers.getSetCookie()) {
      const [pair] = line.split(';');
      const [name, ...rest] = pair!.split('=');
      const value = rest.join('=');
      if (!value || /max-age=0/i.test(line)) this.cookies.delete(name!);
      else this.cookies.set(name!, value);
    }
    const text = await res.text();
    let json: any = undefined;
    try {
      json = JSON.parse(text);
    } catch {
      /* not JSON */
    }
    return { status: res.status, json, text, headers: res.headers };
  }

  /** Send a file the way the browser's file picker does. */
  async upload(path: string, fileName: string, content: string) {
    const form = new FormData();
    form.append('file', new File([content], fileName, { type: 'text/csv' }));
    const res = await this.t.app.request(`${this.base}${path}`, {
      method: 'POST',
      headers: this.cookies.size ? { Cookie: [...this.cookies].map(([k, v]) => `${k}=${v}`).join('; ') } : {},
      body: form,
    });
    const text = await res.text();
    return { status: res.status, json: JSON.parse(text), text };
  }

  get = (path: string, headers?: Record<string, string>) => this.call('GET', path, undefined, headers);
  post = (path: string, body: unknown = {}, headers?: Record<string, string>) => this.call('POST', path, body, headers);
  patch = (path: string, body: unknown, headers?: Record<string, string>) => this.call('PATCH', path, body, headers);
  del = (path: string, headers?: Record<string, string>) => this.call('DELETE', path, undefined, headers);

  cookie(name: string) {
    return this.cookies.get(name);
  }
}

export async function setUpAdmin(t: TestApp) {
  const admin = new Client(t);
  const res = await admin.post('/api/v1/setup', { displayName: 'Chris', username: 'Chris', password: 'correct-horse' });
  if (res.status !== 200) throw new Error(`setup failed: ${res.text}`);
  return admin;
}