import apiClient from './index.js'

/**
 * 通用的获取所有分页数据的函数
 * @param {Function} apiCall - API调用函数
 * @param {Object} params - 查询参数
 * @returns {Promise<Array>} 所有页面的数据数组
 */
const fetchAllPages = async (apiCall, params = {}) => {
  let allData = []
  let page = 1
  let hasNext = true

  console.log('Starting to fetch all pages for API call...')

  while (hasNext) {
    try {
      const currentParams = { ...params, page, page_size: 100 }
      console.log(`Fetching page ${page} with params:`, currentParams)

      const response = await apiCall(currentParams)

      if (response && response.results) {
        allData = [...allData, ...response.results]
        hasNext = !!response.next
        console.log(`Page ${page}: Got ${response.results.length} items, total so far: ${allData.length}, hasNext: ${hasNext}`)
      } else if (Array.isArray(response)) {
        allData = response
        hasNext = false
        console.log('Non-paginated response detected, got all data at once:', allData.length, 'items')
      } else {
        console.log('Unexpected response format, stopping pagination')
        hasNext = false
      }

      page++

      if (page > 100) {
        console.warn('Reached maximum page limit (100), stopping pagination')
        break
      }
    } catch (error) {
      console.error(`Error fetching page ${page}:`, error)
      throw error
    }
  }

  console.log(`Finished fetching all pages. Total items: ${allData.length}`)
  return allData
}

/**
 * 列出某 task 的所有图片元数据（spec 0004 子资源）。响应按 DRF 标准分页
 * { count, next, previous, results }，这里把结果数组拉平返回。
 * @param {number} taskId
 * @param {Object} [params]
 * @returns {Promise<Array>} 图片元数据数组（每项含 id / mime_type / file_name / key / etag / size_bytes / 审计字段）
 */
export const listTaskImages = async (taskId, params = {}) => {
  const listPage = async (p) => {
    const response = await apiClient.get(`/api/tasks/${taskId}/images/`, { params: p })
    return response.data
  }
  return fetchAllPages(listPage, params)
}

/**
 * 创建 task 图片（spec 0004 子资源）。body 走 StdtTaskImagesWrite schema：
 * 必填 image_base64，可选 mime_type/file_name。后端在 POST 时校验 ≤ 20 张软上限。
 * @param {number} taskId
 * @param {{mime_type?: string, file_name?: string, image_base64: string}} payload
 * @returns {Promise<Object>} StdtTaskImagesWrite 响应（含新分配的 id）
 */
export const createTaskImage = async (taskId, payload) => {
  const response = await apiClient.post(`/api/tasks/${taskId}/images/`, payload)
  console.log(`Task image created for task ${taskId}:`, response.data)
  return response.data
}

/**
 * 删除 task 图片（spec 0004 子资源）。DELETE 是软删——后端只翻 deleted_flag，
 * 不会真删 row；行还在表里、COS 上对象也不动，前端通过 refetch 自然看不到。
 * @param {number} taskId
 * @param {number} imageId
 */
export const deleteTaskImage = async (taskId, imageId) => {
  const response = await apiClient.delete(`/api/tasks/${taskId}/images/${imageId}/`)
  console.log(`Task image ${imageId} for task ${taskId} deleted`)
  return response.data
}

/**
 * 获取 task 图片的二进制内容（spec 0004 子资源 /content/）。
 * 必须 responseType: 'blob' + Accept 通配，否则 DRF 默认 JSON renderer 返 406。
 * @param {number} taskId
 * @param {number} imageId
 * @returns {Promise} 解析为 Blob
 */
export const getTaskImageContent = async (taskId, imageId) => {
  const response = await apiClient.get(
    `/api/tasks/${taskId}/images/${imageId}/content/`,
    {
      responseType: 'blob',
      headers: { Accept: '*/*' },
    }
  )
  console.log(`Task image ${imageId} content for task ${taskId} fetched`)
  return response.data
}

/**
 * 单页API调用函数（内部使用）
 */
const getTasksPage = async (params = {}) => {
  const response = await apiClient.get('/api/tasks/', { params })
  return response.data
}

/**
 * 获取所有作业任务
 * @param {Object} params - 查询参数（student_id / subject_id / term_id / story_id）
 * @returns {Promise<Array>} 全部任务的扁平数组（已处理分页）
 */
export const getTasks = async (params = {}) => {
  try {
    const queryParams = {}
    if (params.student_id) queryParams.student_id = params.student_id
    if (params.subject_id) queryParams.subject_id = params.subject_id
    if (params.term_id) queryParams.term_id = params.term_id
    if (params.story_id) queryParams.story_id = params.story_id

    console.log('Tasks API request params:', queryParams)

    const allTasks = await fetchAllPages(getTasksPage, queryParams)

    console.log('Tasks API final result:', {
      totalCount: allTasks.length,
      sampleData: allTasks.slice(0, 3)
    })

    return allTasks
  } catch (error) {
    console.error('Failed to fetch tasks:', error)
    throw error
  }
}

/**
 * 根据ID获取作业任务
 */
export const getTaskById = async (taskId) => {
  try {
    const response = await apiClient.get(`/api/tasks/${taskId}/`)
    console.log('Task detail API response:', response.data)
    return response.data
  } catch (error) {
    console.error('Failed to fetch task detail:', error)
    throw error
  }
}

/**
 * 创建新的作业任务
 * @param {Object} taskData 任务字段。spec 0004 后不再含 image_XX，新图片走
 *   /api/tasks/{id}/images/ 子资源。
 */
export const createTask = async (taskData) => {
  try {
    const response = await apiClient.post('/api/tasks/', taskData)
    console.log('Create task API response:', response.data)
    return response.data
  } catch (error) {
    console.error('Failed to create task:', error)
    throw error
  }
}

/**
 * 更新作业任务
 * @param {number} taskId
 * @param {Object} taskData 任务字段。spec 0004 后不再含 image_XX / delete_image_XX；
 *   改图、删图走 image 子资源。
 */
export const updateTask = async (taskId, taskData) => {
  try {
    const response = await apiClient.patch(`/api/tasks/${taskId}/`, taskData)
    console.log('Update task API response:', response.data)
    return response.data
  } catch (error) {
    console.error('Failed to update task:', error)
    throw error
  }
}

/**
 * 删除作业任务。spec 0004 / ADR-0004：软删，图片 row 不会被级联软删。
 */
export const deleteTask = async (taskId) => {
  try {
    const response = await apiClient.delete(`/api/tasks/${taskId}/`)
    console.log('Delete task API response:', response.data)
    return response.data
  } catch (error) {
    console.error('Failed to delete task:', error)
    throw error
  }
}