import type { Task, GraphData, CreateTaskInput, UpdateTaskInput } from './types';

const BASE = '/api';

async function request<T>(path: string, init?: RequestInit): Promise<T> {
  const res = await fetch(`${BASE}${path}`, {
    headers: { 'Content-Type': 'application/json', ...init?.headers },
    ...init,
  });
  if (!res.ok) {
    const text = await res.text().catch(() => res.statusText);
    throw new Error(`API error ${res.status}: ${text}`);
  }
  return res.json() as Promise<T>;
}

export async function getTasks(): Promise<Task[]> {
  return request<Task[]>('/tasks');
}

export async function createTask(input: CreateTaskInput): Promise<Task> {
  return request<Task>('/tasks', {
    method: 'POST',
    body: JSON.stringify(input),
  });
}

export async function updateTask(id: number, input: UpdateTaskInput): Promise<Task> {
  return request<Task>(`/tasks/${id}`, {
    method: 'PATCH',
    body: JSON.stringify(input),
  });
}

export async function deleteTask(id: number): Promise<void> {
  await fetch(`${BASE}/tasks/${id}`, { method: 'DELETE' });
}

export async function getGraph(): Promise<GraphData> {
  return request<GraphData>('/graph');
}