import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
import { ApiError, useApi } from '../app/composables/useApi'

/**
 * useApi — fetch wrapper ของ web portal: ไฟล์ร่าง (FR-16) ใช้ downloadFile แบบ
 * POST + JSON body ที่คืนไฟล์ (ชื่อไทยอ่านจาก Content-Disposition filename* ที่ CORS expose ไว้)
 */

const getAccessToken = vi.fn()
const fetchMock = vi.fn()

/** Response ปลอม — ไม่พึ่ง global Response ของ environment (happy-dom) */
function fakeResponse(options: {
  ok?: boolean
  status?: number
  headers?: Record<string, string>
  body?: string
}): Response {
  const lower = Object.fromEntries(
    Object.entries(options.headers ?? {}).map(([k, v]) => [k.toLowerCase(), v]),
  )
  return {
    ok: options.ok ?? true,
    status: options.status ?? 200,
    headers: { get: (name: string) => lower[name.toLowerCase()] ?? null },
    blob: async () => new Blob([options.body ?? 'docx-bytes']),
    text: async () => options.body ?? '',
  } as unknown as Response
}

let clicked: HTMLAnchorElement | null = null
const originalCreateObjectURL = URL.createObjectURL
const originalRevokeObjectURL = URL.revokeObjectURL

beforeEach(() => {
  vi.stubGlobal('useRuntimeConfig', () => ({ public: { apiBaseUrl: 'https://api.test/' } }))
  vi.stubGlobal('useAuth', () => ({ getAccessToken }))
  vi.stubGlobal('fetch', fetchMock)
  getAccessToken.mockReset().mockResolvedValue('token-1')
  fetchMock.mockReset()
  clicked = null
  vi.spyOn(HTMLAnchorElement.prototype, 'click').mockImplementation(function click(this: HTMLAnchorElement) {
    clicked = this
  })
  URL.createObjectURL = vi.fn(() => 'blob:mock')
  URL.revokeObjectURL = vi.fn()
})

afterEach(() => {
  vi.unstubAllGlobals()
  vi.restoreAllMocks()
  URL.createObjectURL = originalCreateObjectURL
  URL.revokeObjectURL = originalRevokeObjectURL
})

describe('downloadFile (FR-16 ไฟล์ร่าง — POST + JSON body คืนไฟล์)', () => {
  it('forwards method/body to fetch with Bearer and saves the Thai filename from Content-Disposition', async () => {
    fetchMock.mockResolvedValue(
      fakeResponse({
        headers: {
          // .NET ใส่ทั้ง filename และ filename* (RFC 5987) สำหรับชื่อไทย
          'Content-Disposition':
            "attachment; filename=\"draft.docx\"; filename*=UTF-8''%E0%B9%84%E0%B8%9F%E0%B8%A5%E0%B9%8C%E0%B8%A3%E0%B9%88%E0%B8%B2%E0%B8%87.docx",
        },
      }),
    )

    await useApi().downloadFile('/api/templates/abc/generate-draft', 'fallback.docx', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ values: { employee_name: 'สมหญิง' } }),
    })

    expect(fetchMock).toHaveBeenCalledWith('https://api.test/api/templates/abc/generate-draft', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', Authorization: 'Bearer token-1' },
      body: JSON.stringify({ values: { employee_name: 'สมหญิง' } }),
    })
    expect(clicked?.download).toBe('ไฟล์ร่าง.docx')
  })

  it('falls back to the given name when Content-Disposition is missing (CORS ไม่ expose)', async () => {
    fetchMock.mockResolvedValue(fakeResponse({}))

    await useApi().downloadFile('/api/templates/abc/generate-draft', 'fallback.docx', { method: 'POST' })

    expect(clicked?.download).toBe('fallback.docx')
  })

  it('retries once with a refreshed token on 401 before saving', async () => {
    getAccessToken.mockImplementation(async (forceRefresh?: boolean) => (forceRefresh ? 'token-2' : 'token-1'))
    fetchMock
      .mockResolvedValueOnce(fakeResponse({ ok: false, status: 401 }))
      .mockResolvedValueOnce(fakeResponse({ headers: { 'Content-Disposition': 'attachment; filename="draft.docx"' } }))

    await useApi().downloadFile('/api/templates/abc/generate-draft', 'fallback.docx', { method: 'POST' })

    expect(fetchMock).toHaveBeenCalledTimes(2)
    expect(fetchMock.mock.calls[1][1].headers.Authorization).toBe('Bearer token-2')
    expect(clicked?.download).toBe('draft.docx')
  })

  it('throws ApiError with the backend message when the response is not ok', async () => {
    fetchMock.mockResolvedValue(
      fakeResponse({ ok: false, status: 400, body: 'กรอก required fields ให้ครบ: employee_name' }),
    )

    await expect(
      useApi().downloadFile('/api/templates/abc/generate-draft', 'fallback.docx', { method: 'POST' }),
    ).rejects.toMatchObject({
      constructor: ApiError,
      status: 400,
      message: 'กรอก required fields ให้ครบ: employee_name',
    })
    expect(clicked).toBeNull() // ไม่มีการดาวน์โหลดเกิดขึ้น
  })
})