import type { HostApiResult } from '@src/types/runtime';
import type { IncomingMessage, ServerResponse } from 'node:http';

export interface HostApiRequest {
  path: string;
  method?: string;
  headers?: Record<string, string>;
  body?: unknown;
}

export interface NormalizedHostApiRequest {
  path: string;
  pathname: string;
  method: string;
  headers: Record<string, string>;
  body: unknown;
  url: URL;
}

export async function parseRawJsonBody<T>(req: IncomingMessage): Promise<T> {
  const chunks: Buffer[] = [];
  for await (const chunk of req) {
    chunks.push(Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk));
  }

  const raw = Buffer.concat(chunks).toString('utf8').trim();
  if (!raw) {
    return {} as T;
  }

  return JSON.parse(raw) as T;
}

export function normalizeRequest(request: HostApiRequest): NormalizedHostApiRequest {
  const path = String(request.path || '/').trim() || '/';

  return {
    path,
    pathname: new URL(path, 'http://127.0.0.1').pathname,
    method: String(request.method || 'GET').trim().toUpperCase(),
    headers: request.headers || {},
    body: request.body ?? null,
    url: new URL(path, 'http://127.0.0.1'),
  };
}

export function parseJsonBody<T>(body: unknown): T {
  if (body == null || body === '') {
    return {} as T;
  }

  if (typeof body === 'string') {
    return JSON.parse(body) as T;
  }

  return body as T;
}

export function ok<T>(data: T, status = 200): HostApiResult<T> {
  return {
    success: true,
    ok: true,
    status,
    json: data,
    data,
  };
}

export function fail<T = unknown>(status: number, error: string, data?: T): HostApiResult<T> {
  return {
    success: false,
    ok: false,
    status,
    error,
    text: error,
    data,
  };
}

export function setCorsHeaders(res: ServerResponse, origin?: string): void {
  if (origin) {
    res.setHeader('Access-Control-Allow-Origin', origin);
    res.setHeader('Vary', 'Origin');
  } else {
    res.setHeader('Access-Control-Allow-Origin', '*');
  }
  res.setHeader('Access-Control-Allow-Methods', 'GET,POST,PUT,DELETE,OPTIONS');
  res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization, X-Host-Api-Token');
}

export function requireJsonContentType(req: IncomingMessage): boolean {
  if (req.method === 'GET' || req.method === 'OPTIONS' || req.method === 'HEAD') {
    return true;
  }

  const contentLength = req.headers['content-length'];
  if (contentLength === '0' || contentLength === undefined) {
    return true;
  }

  const contentType = req.headers['content-type'] || '';
  return contentType.includes('application/json');
}

export function sendJsonResponse(res: ServerResponse, statusCode: number, payload: unknown): void {
  res.statusCode = statusCode;
  res.setHeader('Content-Type', 'application/json; charset=utf-8');
  res.end(JSON.stringify(payload));
}