import type {
  Board,
  BoardListData,
  TaskSummary,
  TaskDetail,
  TaskListData,
  CreateTaskPayload,
  CommentPayload,
  ApiResponse,
  HealthData,
} from '@kanban/contracts'
import { getInitData } from '../telegram'

const BRIDGE_URL = import.meta.env.VITE_BRIDGE_URL || '/bridge'
const AUTH_TOKEN: string = import.meta.env.VITE_AUTH_TOKEN || ''

async function request<T>(path: string, init: RequestInit = {}): Promise<T> {
  const headers = new Headers(init.headers)
  headers.set('Content-Type', 'application/json')

  // Auth: prefer X-Bridge-Token, fall back to Telegram initData
  if (AUTH_TOKEN) {
    headers.set('X-Bridge-Token', AUTH_TOKEN)
  } else {
    const initData = getInitData()
    if (initData) {
      headers.set('X-Bridge-Token', initData)
    }
  }

  const url = `${BRIDGE_URL}${path}`
  const response = await fetch(url, { ...init, headers })

  const data = await response.json().catch(() => null)

  if (!response.ok || !data) {
    const message =
      (data as { error?: { message?: string } })?.error?.message ||
      response.statusText ||
      `HTTP ${response.status}`
    throw new Error(message)
  }

  const envelope = data as ApiResponse<T>
  if (!envelope.ok) {
    throw new Error(envelope.error?.message || 'API error')
  }

  return envelope.data
}

// ─── API methods ────────────────────────────────────────────

export async function fetchHealth(): Promise<HealthData> {
  return request<HealthData>('/v1/health')
}

export async function fetchBoards(): Promise<Board[]> {
  return request<BoardListData>('/v1/boards')
}

export async function fetchTasks(board: string): Promise<TaskListData> {
  return request<TaskListData>(`/v1/boards/${encodeURIComponent(board)}/tasks`)
}

export async function fetchTask(board: string, taskId: string): Promise<TaskDetail> {
  return request<TaskDetail>(
    `/v1/boards/${encodeURIComponent(board)}/tasks/${encodeURIComponent(taskId)}`
  )
}

export async function createTask(
  board: string,
  payload: CreateTaskPayload
): Promise<TaskDetail> {
  return request<TaskDetail>(
    `/v1/boards/${encodeURIComponent(board)}/tasks`,
    {
      method: 'POST',
      body: JSON.stringify(payload),
    }
  )
}

export async function addComment(
  board: string,
  taskId: string,
  payload: CommentPayload
): Promise<void> {
  await request<void>(
    `/v1/boards/${encodeURIComponent(board)}/tasks/${encodeURIComponent(taskId)}/comments`,
    {
      method: 'POST',
      body: JSON.stringify(payload),
    }
  )
}