import { appendClientIdHeader } from '../../app/main/clientIdentity';
import { normalizeAutomationTypeId } from '../../app/main/automationTypeAccess';
import { getRegisteredAccessToken } from '../../app/main/tokenAccess';
import type { BoardAutomationType, BoardDraft, BoardPost } from './types';

class BoardApiError extends Error {
  status: number;

  constructor(message: string, status: number) {
    super(message);
    this.name = 'BoardApiError';
    this.status = status;
  }
}

function normalizeBoardAutomationType(value: unknown): BoardAutomationType {
  return normalizeAutomationTypeId(value);
}

function resolveBoardApiBaseUrl() {
  if (import.meta.env.VITE_WORK_SERVER_URL) {
    return import.meta.env.VITE_WORK_SERVER_URL;
  }

  return '/api';
}

function resolveBoardFallbackBaseUrl() {
  if (typeof window === 'undefined') {
    return null;
  }

  const hostname = window.location.hostname;
  const isLocalWorkServerHost =
    hostname === 'localhost' || hostname === '127.0.0.1' || hostname === '0.0.0.0';

  if (!isLocalWorkServerHost) {
    return null;
  }

  const fallbackUrl = new URL(window.location.origin);
  fallbackUrl.port = '3100';
  fallbackUrl.pathname = '/api';
  fallbackUrl.search = '';
  fallbackUrl.hash = '';
  return fallbackUrl.toString().replace(/\/+$/, '');
}

const BOARD_API_BASE_URL = resolveBoardApiBaseUrl();
const BOARD_API_FALLBACK_BASE_URL =
  !import.meta.env.VITE_WORK_SERVER_URL && BOARD_API_BASE_URL === '/api'
    ? resolveBoardFallbackBaseUrl()
    : null;

async function requestOnce<T>(baseUrl: string, path: string, init?: RequestInit) {
  const headers = appendClientIdHeader(init?.headers);
  const hasBody = init?.body !== undefined && init.body !== null;
  const method = init?.method?.toUpperCase() ?? 'GET';
  const controller = new AbortController();
  const timeoutId = globalThis.setTimeout(() => controller.abort(), 8000);

  if (hasBody && !headers.has('Content-Type')) {
    headers.set('Content-Type', 'application/json');
  }

  const token = getRegisteredAccessToken();
  if (token && !headers.has('X-Access-Token')) {
    headers.set('X-Access-Token', token);
  }

  let response: Response;

  try {
    response = await fetch(`${baseUrl}${path}`, {
      ...init,
      headers,
      signal: controller.signal,
      cache: init?.cache ?? (method === 'GET' ? 'no-store' : undefined),
    });
  } catch (error) {
    globalThis.clearTimeout(timeoutId);

    if (error instanceof DOMException && error.name === 'AbortError') {
      throw new BoardApiError('게시판 서버 응답이 지연됩니다.', 408);
    }

    throw error;
  }

  globalThis.clearTimeout(timeoutId);

  if (!response.ok) {
    const text = await response.text();
    let message = text || '게시판 요청에 실패했습니다.';

    try {
      const payload = JSON.parse(text) as { message?: string };
      message = payload.message || message;
    } catch {
      // Keep the plain text fallback when the response body is not JSON.
    }

    throw new BoardApiError(message, response.status);
  }

  return response.json() as Promise<T>;
}

async function request<T>(path: string, init?: RequestInit): Promise<T> {
  try {
    return await requestOnce<T>(BOARD_API_BASE_URL, path, init);
  } catch (error) {
    const shouldRetryWithFallback =
      BOARD_API_FALLBACK_BASE_URL &&
      BOARD_API_FALLBACK_BASE_URL !== BOARD_API_BASE_URL &&
      (error instanceof BoardApiError
        ? error.status === 404 || error.status === 408 || error.status === 502
        : error instanceof Error && /404|Failed to fetch|NetworkError/i.test(error.message));

    if (!shouldRetryWithFallback) {
      throw error;
    }

    return requestOnce<T>(BOARD_API_FALLBACK_BASE_URL, path, init);
  }
}

export async function setupBoard() {
  return request<{ ok: boolean; table: string }>('/board/setup', {
    method: 'POST',
    body: JSON.stringify({}),
  });
}

export async function fetchBoardPosts() {
  const response = await request<{ ok: boolean; items: BoardPost[] }>('/board/posts');
  return response.items.map((item) => ({
    ...item,
    automationType: normalizeBoardAutomationType(item.automationType),
  }));
}

export async function createBoardPost(draft: BoardDraft) {
  const response = await request<{ ok: boolean; item: BoardPost }>('/board/posts', {
    method: 'POST',
    body: JSON.stringify({
      title: draft.title,
      content: draft.content,
      automationType: draft.automationType,
    }),
  });

  return {
    ...response.item,
    automationType: normalizeBoardAutomationType(response.item.automationType),
  };
}

export async function updateBoardPost(draft: BoardDraft) {
  if (!draft.id) {
    throw new Error('수정할 게시글 ID가 없습니다.');
  }

  const response = await request<{ ok: boolean; item: BoardPost }>(`/board/posts/${draft.id}`, {
    method: 'PATCH',
    body: JSON.stringify({
      title: draft.title,
      content: draft.content,
      automationType: draft.automationType,
    }),
  });

  return {
    ...response.item,
    automationType: normalizeBoardAutomationType(response.item.automationType),
  };
}

export async function receiveBoardPostAutomation(id: number) {
  const response = await request<{
    ok: boolean;
    item: BoardPost;
    planItemId: number | null;
    alreadyReceived: boolean;
  }>(`/board/posts/${id}/actions/automation-receive`, {
    method: 'POST',
    body: JSON.stringify({}),
  });

  return {
    item: {
      ...response.item,
      automationType: normalizeBoardAutomationType(response.item.automationType),
    },
    planItemId: response.planItemId,
    alreadyReceived: response.alreadyReceived,
  };
}

export async function deleteBoardPost(id: number) {
  const response = await request<{ ok: boolean; id: number }>(`/board/posts/${id}`, {
    method: 'DELETE',
  });

  return response.id;
}