import type {
  PlazaCategoriesResponse,
  PlazaCommentsResponse,
  PlazaCreatePostResponse,
  PlazaFeedResponse,
  PlazaPostResponse,
  PlazaSitemapData,
  PlazaUserProfileResponse,
} from '@/types/plaza';
import { apiBase } from '@/lib/site';

type FetchOptions = {
  revalidate?: number | false;
  cache?: RequestCache;
  cookie?: string;
};

export type PlazaAuthStatus = {
  authenticated: boolean;
  user?: { id: string; username: string; slug?: string; displayName: string } | null;
};

class PlazaApiError extends Error {
  code: string;

  constructor(message: string, code: string) {
    super(message);
    this.code = code;
  }
}

async function plazaFetch<T>(path: string, init?: RequestInit, options?: FetchOptions): Promise<T> {
  const base = apiBase();
  const url = `${base}${path.startsWith('/') ? path : `/${path}`}`;
  const headers = new Headers(init?.headers);
  if (options?.cookie) headers.set('cookie', options.cookie);
  if (!headers.has('Accept')) headers.set('Accept', 'application/json');

  const next =
    options?.revalidate === false
      ? { revalidate: 0 }
      : options?.revalidate != null
        ? { revalidate: options.revalidate }
        : undefined;

  const response = await fetch(url, {
    ...init,
    headers,
    credentials: typeof window !== 'undefined' ? 'include' : init?.credentials,
    cache: options?.cache ?? (options?.revalidate === false ? 'no-store' : undefined),
    next,
  });

  const payload = await response.json().catch(() => ({}));
  if (!response.ok) {
    const code = payload?.error?.code ?? 'request_failed';
    const message = payload?.error?.message ?? `请求失败 (${response.status})`;
    throw new PlazaApiError(message, code);
  }
  return payload.data as T;
}

export async function fetchAuthStatus(cookie?: string): Promise<PlazaAuthStatus> {
  try {
    const base = apiBase();
    const url = `${base}/auth/status`;
    const headers = new Headers({ Accept: 'application/json' });
    if (cookie) headers.set('cookie', cookie);
    const response = await fetch(url, {
      headers,
      credentials: typeof window !== 'undefined' ? 'include' : undefined,
      cache: 'no-store',
    });
    if (!response.ok) return { authenticated: false };
    const status = (await response.json()) as PlazaAuthStatus;
    return status;
  } catch {
    return { authenticated: false };
  }
}

export async function fetchCategories(options?: FetchOptions) {
  return plazaFetch<PlazaCategoriesResponse>('/api/plaza/v1/categories', undefined, {
    revalidate: 300,
    ...options,
  });
}

export async function fetchFeed(
  params: {
    sort?: 'hot' | 'new';
    category?: string;
    cursor?: string;
    limit?: number;
  } = {},
  options?: FetchOptions,
) {
  const query = new URLSearchParams();
  if (params.sort) query.set('sort', params.sort);
  if (params.category) query.set('category', params.category);
  if (params.cursor) query.set('cursor', params.cursor);
  if (params.limit) query.set('limit', String(params.limit));
  const suffix = query.size ? `?${query.toString()}` : '';
  return plazaFetch<PlazaFeedResponse>(`/api/plaza/v1/feed${suffix}`, undefined, {
    revalidate: 60,
    ...options,
  });
}

export async function fetchPost(id: string, options?: FetchOptions) {
  return plazaFetch<PlazaPostResponse>(`/api/plaza/v1/posts/${encodeURIComponent(id)}`, undefined, {
    revalidate: false,
    cache: 'no-store',
    ...options,
  });
}

export async function createPlazaPost(
  body: {
    publication_id: string;
    category_id: string;
    tags?: string[];
    cover_url?: string;
    allow_comment?: boolean;
  },
  cookie: string,
) {
  return plazaFetch<PlazaCreatePostResponse>(
    '/api/plaza/v1/posts',
    {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(body),
    },
    { revalidate: false, cookie },
  );
}

export async function togglePostReaction(
  postId: string,
  type: 'like' | 'collect' | 'share',
  active: boolean,
) {
  if (type === 'share') {
    return plazaFetch<{ post_id: string; type: string; active: boolean }>(
      `/api/plaza/v1/posts/${encodeURIComponent(postId)}/reactions`,
      {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ type: 'share' }),
      },
      { revalidate: false },
    );
  }
  if (active) {
    return plazaFetch<{ post_id: string; type: string; active: boolean }>(
      `/api/plaza/v1/posts/${encodeURIComponent(postId)}/reactions/${type}`,
      { method: 'DELETE' },
      { revalidate: false },
    );
  }
  return plazaFetch<{ post_id: string; type: string; active: boolean }>(
    `/api/plaza/v1/posts/${encodeURIComponent(postId)}/reactions`,
    {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ type }),
    },
    { revalidate: false },
  );
}

export async function fetchComments(
  postId: string,
  params: { parent_id?: string; cursor?: string } = {},
) {
  const query = new URLSearchParams();
  if (params.parent_id) query.set('parent_id', params.parent_id);
  if (params.cursor) query.set('cursor', params.cursor);
  const suffix = query.size ? `?${query.toString()}` : '';
  return plazaFetch<PlazaCommentsResponse>(
    `/api/plaza/v1/posts/${encodeURIComponent(postId)}/comments${suffix}`,
    undefined,
    { revalidate: false, cache: 'no-store' },
  );
}

export async function createComment(postId: string, content: string, parentId?: string | null) {
  return plazaFetch<{ comment: { id: string } }>(
    `/api/plaza/v1/posts/${encodeURIComponent(postId)}/comments`,
    {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ content, parent_id: parentId ?? null }),
    },
    { revalidate: false },
  );
}

export async function toggleCommentLike(commentId: string, liked: boolean) {
  return plazaFetch<{ id: string; liked: boolean }>(
    `/api/plaza/v1/comments/${encodeURIComponent(commentId)}/reactions`,
    {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ liked }),
    },
    { revalidate: false },
  );
}

export async function fetchUserProfile(slug: string, options?: FetchOptions) {
  return plazaFetch<PlazaUserProfileResponse>(
    `/api/plaza/v1/users/${encodeURIComponent(slug)}`,
    undefined,
    { revalidate: 300, ...options },
  );
}

export async function fetchUserPosts(
  slug: string,
  params: { cursor?: string; limit?: number } = {},
  options?: FetchOptions,
) {
  const query = new URLSearchParams();
  if (params.cursor) query.set('cursor', params.cursor);
  if (params.limit) query.set('limit', String(params.limit));
  const suffix = query.size ? `?${query.toString()}` : '';
  return plazaFetch<Pick<PlazaFeedResponse, 'posts' | 'next_cursor' | 'has_more'>>(
    `/api/plaza/v1/users/${encodeURIComponent(slug)}/posts${suffix}`,
    undefined,
    { revalidate: false, cache: 'no-store', ...options },
  );
}

export async function toggleFollow(slug: string, following: boolean) {
  if (following) {
    return plazaFetch<{ following: boolean }>(
      `/api/plaza/v1/users/${encodeURIComponent(slug)}/follow`,
      { method: 'DELETE' },
      { revalidate: false },
    );
  }
  return plazaFetch<{ following: boolean }>(
    `/api/plaza/v1/users/${encodeURIComponent(slug)}/follow`,
      { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: '{}' },
    { revalidate: false },
  );
}

export async function fetchSitemapData(options?: FetchOptions) {
  return plazaFetch<PlazaSitemapData>('/api/plaza/v1/seo/sitemap', undefined, {
    revalidate: 3600,
    ...options,
  });
}

export async function recordAttributionEvent(body: {
  event_type: 'landing' | 'signup';
  utm_source: string;
  utm_medium?: string;
  utm_campaign?: string;
  ref_id?: string;
}) {
  return plazaFetch<{ id: string; event_type: string }>(
    '/api/plaza/v1/attribution/events',
    {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(body),
    },
    { revalidate: false },
  );
}

export async function submitPostReport(postId: string, reason: string, detail?: string) {
  return plazaFetch<{ report: { id: string; status: string } }>(
    `/api/plaza/v1/posts/${encodeURIComponent(postId)}/reports`,
    {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ reason, detail: detail ?? '' }),
    },
    { revalidate: false },
  );
}

export async function submitCommentReport(commentId: string, reason: string, detail?: string) {
  return plazaFetch<{ report: { id: string; status: string } }>(
    `/api/plaza/v1/comments/${encodeURIComponent(commentId)}/reports`,
    {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ reason, detail: detail ?? '' }),
    },
    { revalidate: false },
  );
}

export { PlazaApiError };