import { EventEmitter } from 'node:events';
import type { IncomingMessage, ServerResponse } from 'node:http';
import { describe, expect, it, vi } from 'vitest';
import { handleDataServiceRoutes } from '@electron/api/routes/data-service';
import type { HostApiContext } from '@electron/api/context';
import type { DataServiceOperations } from '@electron/services/data-service-client';

function request(
  method: string,
  body?: unknown,
  headers: Record<string, string> = {},
): IncomingMessage {
  const req = new EventEmitter();
  const raw = body === undefined ? undefined : typeof body === 'string' ? body : JSON.stringify(body);
  Object.assign(req, {
    method,
    headers: {
      ...(raw === undefined ? {} : { 'content-length': String(Buffer.byteLength(raw, 'utf8')) }),
      ...headers,
    },
    [Symbol.asyncIterator]: async function* () {
      if (raw !== undefined) yield Buffer.from(raw, 'utf8');
    },
  });
  return req as IncomingMessage;
}

function response() {
  const chunks: string[] = [];
  const headers = new Map<string, string>();
  const res = new EventEmitter();
  Object.assign(res, {
    statusCode: 0,
    setHeader: vi.fn((name: string, value: string) => headers.set(name.toLowerCase(), value)),
    end: vi.fn((chunk?: string) => { if (chunk) chunks.push(chunk); }),
  });
  return {
    res: res as unknown as ServerResponse,
    get status() { return (res as { statusCode: number }).statusCode; },
    header: (name: string) => headers.get(name.toLowerCase()),
    json: () => JSON.parse(chunks.join('')) as Record<string, unknown>,
  };
}

function success<T>(data: T): { success: true; status: 200; code: null; error: null; retryable: false; data: T } {
  return { success: true, status: 200, code: null, error: null, retryable: false, data };
}

function setup(overrides: Partial<Record<keyof DataServiceOperations, ReturnType<typeof vi.fn>>> = {}) {
  const operations = {
    configure: vi.fn().mockResolvedValue(success({})),
    inspect: vi.fn().mockResolvedValue(success({})),
    listProjects: vi.fn().mockResolvedValue(success({ items: [], total: 0, instance_limit: 20 })),
    getDocument: vi.fn().mockResolvedValue(success({})),
    listDocuments: vi.fn().mockResolvedValue(success({ items: [], next_cursor: null, limit: 50 })),
    putDocument: vi.fn().mockResolvedValue(success({})),
    deleteDocument: vi.fn().mockResolvedValue(success(null)),
    removeCollection: vi.fn().mockResolvedValue(success({ removed: true, usage: { document_count: 0, total_bytes: 0 } })),
    reset: vi.fn().mockResolvedValue(success({})),
    removeProject: vi.fn().mockResolvedValue(success({ removed: true })),
    ...overrides,
  } as unknown as DataServiceOperations;
  const ctx = { codingProducts: { dataService: operations } } as unknown as HostApiContext;
  return { operations, ctx };
}

async function invoke(
  ctx: HostApiContext,
  method: string,
  path: string,
  body?: unknown,
  headers: Record<string, string> = {},
) {
  const target = response();
  const handled = await handleDataServiceRoutes(
    request(method, body, headers),
    target.res,
    new URL(`http://localhost${path}`),
    ctx,
  );
  return { handled, ...target, payload: target.json() };
}

describe('Data Service Host routes', () => {
  it('uses the owner-wide listing without an active-project argument', async () => {
    const { operations, ctx } = setup();

    const result = await invoke(ctx, 'GET', '/api/works/data-service/projects');

    expect(result.handled).toBe(true);
    expect(result.status).toBe(200);
    expect(result.header('cache-control')).toBe('private, no-store');
    expect(operations.listProjects).toHaveBeenCalledOnce();
    expect(result.payload).toMatchObject({ success: true, data: { total: 0 } });
  });

  it('passes only strict collection input to active-project configure', async () => {
    const { operations, ctx } = setup();

    await invoke(ctx, 'PUT', '/api/works/data-service/project', { collections: ['todos', 'settings'] }, {
      'content-type': 'application/json',
    });

    expect(operations.configure).toHaveBeenCalledWith({ collections: ['todos', 'settings'] });
  });

  it('requires the literal confirmation before removing the active project', async () => {
    const { operations, ctx } = setup();

    const rejected = await invoke(ctx, 'DELETE', '/api/works/data-service/project');
    const accepted = await invoke(ctx, 'DELETE', '/api/works/data-service/project?confirmed=true');

    expect(rejected.payload).toMatchObject({ success: false, status: 400, code: 'confirmation_required', data: null });
    expect(operations.removeProject).toHaveBeenCalledOnce();
    expect(operations.removeProject).toHaveBeenCalledWith({ confirmed: true });
    expect(accepted.payload).toMatchObject({ success: true, status: 200 });
  });

  it('projects a document precondition and rejects extra request fields locally', async () => {
    const { operations, ctx } = setup();

    await invoke(
      ctx,
      'PUT',
      '/api/works/data-service/project/collections/todos/documents/todo-1',
      { data: { done: false } },
      { 'content-type': 'application/json', 'if-match': '"7"' },
    );
    const rejected = await invoke(
      ctx,
      'PUT',
      '/api/works/data-service/project/collections/todos/documents/todo-2',
      { data: {}, extra: true },
      { 'content-type': 'application/json' },
    );

    expect(operations.putDocument).toHaveBeenCalledWith({
      collection: 'todos',
      document_id: 'todo-1',
      data: { done: false },
      if_revision: 7,
    });
    expect(rejected.payload).toMatchObject({ success: false, status: 422, code: 'invalid_request', data: null });
    expect(operations.putDocument).toHaveBeenCalledOnce();
  });

  it('keeps malformed paths and unsupported query keys out of the operations adapter', async () => {
    const { operations, ctx } = setup();

    const result = await invoke(
      ctx,
      'GET',
      '/api/works/data-service/project/collections/todos/documents?limit=101&unexpected=x',
    );

    expect(result.payload).toMatchObject({ success: false, status: 422, code: 'invalid_request', data: null });
    expect(operations.listDocuments).not.toHaveBeenCalled();
  });
});