import type {
  Project,
  AvailableProject,
  Session,
  Chat,
  Message,
  ModelInfo,
  SidebarResponse,
  ListDirResult,
  ViewFileResult,
} from './types';

export class ApiError extends Error {
  constructor(
    public status: number,
    public body: unknown
  ) {
    super(typeof body === 'object' && body && 'error' in body ? String((body as { error: unknown }).error) : `HTTP ${status}`);
  }
}

async function request<T>(
  path: string,
  init: RequestInit = {}
): Promise<T> {
  const res = await fetch(path, {
    ...init,
    headers: {
      'Content-Type': 'application/json',
      ...(init.headers ?? {}),
    },
  });
  if (res.status === 204) return undefined as T;
  const text = await res.text();
  const data = text ? JSON.parse(text) : undefined;
  if (!res.ok) throw new ApiError(res.status, data);
  return data as T;
}

export const api = {
  health: () => request<{ status: string; db: boolean }>('/api/health'),

  projects: {
    list: (params?: { status?: 'open' | 'archived' }) =>
      request<Project[]>(`/api/projects${params?.status ? `?status=${params.status}` : ''}`),
    available: () => request<AvailableProject[]>('/api/projects/available'),
    add: (body: { path: string; name?: string }) =>
      request<Project>('/api/projects', {
        method: 'POST',
        body: JSON.stringify(body),
      }),
    update: (id: string, body: { name: string }) =>
      request<Project>(`/api/projects/${id}`, {
        method: 'PATCH',
        body: JSON.stringify(body),
      }),
    archive: (id: string) =>
      request<void>(`/api/projects/${id}/archive`, { method: 'POST' }),
    unarchive: (id: string) =>
      request<Project>(`/api/projects/${id}/unarchive`, { method: 'POST' }),
    create: (body: {
      name: string;
      commit_message?: string;
      visibility?: 'private' | 'public';
      create_gitea_remote?: boolean;
    }) =>
      request<{
        project: Project;
        bootstrap: {
          folder_created: boolean;
          git_initialized: boolean;
          first_commit: boolean;
          gitea_remote_created: boolean;
          gitea_pushed: boolean;
          warnings: string[];
        };
      }>(`/api/projects/create`, {
        method: 'POST',
        body: JSON.stringify(body),
      }),
    remove: (id: string) =>
      request<void>(`/api/projects/${id}`, { method: 'DELETE' }),
    listDir: (id: string, path: string) =>
      request<ListDirResult>(`/api/projects/${id}/list_dir?path=${encodeURIComponent(path)}`),
    viewFile: (id: string, path: string) =>
      request<ViewFileResult>(`/api/projects/${id}/view_file?path=${encodeURIComponent(path)}`),
    files: (id: string) =>
      request<{ files: string[] }>(`/api/projects/${id}/files`),
  },

  sessions: {
    listForProject: (projectId: string, status?: 'open' | 'archived') =>
      request<Session[]>(`/api/projects/${projectId}/sessions${status ? `?status=${status}` : ''}`),
    create: (
      projectId: string,
      body: { name?: string; model?: string; system_prompt?: string }
    ) =>
      request<Session>(`/api/projects/${projectId}/sessions`, {
        method: 'POST',
        body: JSON.stringify(body),
      }),
    get: (id: string) => request<Session>(`/api/sessions/${id}`),
    update: (
      id: string,
      body: Partial<Pick<Session, 'name' | 'model' | 'system_prompt'>>
    ) =>
      request<Session>(`/api/sessions/${id}`, {
        method: 'PATCH',
        body: JSON.stringify(body),
      }),
    remove: (id: string) =>
      request<void>(`/api/sessions/${id}`, { method: 'DELETE' }),
    archive: (id: string) =>
      request<void>(`/api/sessions/${id}/archive`, { method: 'POST' }),
    unarchive: (id: string) =>
      request<Session>(`/api/sessions/${id}/unarchive`, { method: 'POST' }),
  },

  chats: {
    listForSession: (sessionId: string, params?: { status?: 'open' | 'archived' }) =>
      request<Chat[]>(
        `/api/sessions/${sessionId}/chats${params?.status ? `?status=${params.status}` : ''}`
      ),
    create: (sessionId: string, body?: { name?: string }) =>
      request<Chat>(`/api/sessions/${sessionId}/chats`, {
        method: 'POST',
        body: JSON.stringify(body ?? {}),
      }),
    update: (chatId: string, body: { name: string }) =>
      request<Chat>(`/api/chats/${chatId}`, {
        method: 'PATCH',
        body: JSON.stringify(body),
      }),
    archive: (chatId: string) =>
      request<void>(`/api/chats/${chatId}/archive`, { method: 'POST' }),
    unarchive: (chatId: string) =>
      request<Chat>(`/api/chats/${chatId}/unarchive`, { method: 'POST' }),
    remove: (chatId: string) =>
      request<void>(`/api/chats/${chatId}`, { method: 'DELETE' }),
    messages: (chatId: string) =>
      request<Message[]>(`/api/chats/${chatId}/messages`),
    compact: (chatId: string) =>
      request<{ compact_message_id: string }>(`/api/chats/${chatId}/compact`, { method: 'POST' }),
    stop: (chatId: string) =>
      request<{ stopped: boolean }>(`/api/chats/${chatId}/stop`, { method: 'POST' }),
    forceSend: (chatId: string, content: string) =>
      request<{ user_message_id: string; assistant_message_id: string }>(
        `/api/chats/${chatId}/force_send`,
        { method: 'POST', body: JSON.stringify({ content }) }
      ),
    fork: (chatId: string, body: { messageId: string; name?: string }) =>
      request<Chat>(`/api/chats/${chatId}/fork`, {
        method: 'POST',
        body: JSON.stringify({ message_id: body.messageId, name: body.name }),
      }),
  },

  messages: {
    list: (sessionId: string) =>
      request<Message[]>(`/api/sessions/${sessionId}/messages`),
    send: (chatId: string, content: string) =>
      request<{ user_message_id: string; assistant_message_id: string }>(
        `/api/chats/${chatId}/messages`,
        {
          method: 'POST',
          body: JSON.stringify({ content }),
        }
      ),
    regenerate: (chatId: string, messageId: string) =>
      request<{ assistant_message_id: string }>(
        `/api/chats/${chatId}/messages/${messageId}/regenerate`,
        { method: 'POST' }
      ),
    remove: (chatId: string, messageId: string) =>
      request<void>(`/api/chats/${chatId}/messages/${messageId}`, {
        method: 'DELETE',
      }),
  },

  models: () => request<ModelInfo[]>('/api/models'),

  settings: {
    get: () => request<Record<string, unknown>>('/api/settings'),
    patch: (body: Record<string, unknown>) =>
      request<Record<string, unknown>>('/api/settings', {
        method: 'PATCH',
        body: JSON.stringify(body),
      }),
  },

  sidebar: {
    get: () => request<SidebarResponse>('/api/sidebar'),
  },
};