/**
 * 标题相关 API
 * Phase 1 新增：全局标题库
 * 注意：后端 schema 使用 name + text 字段，前端 UI 用 content 展示
 */
import apiClient from "./client"

/** 标题条目（前端展示用） */
export interface TitleItem {
  id: string
  content: string
  category?: string
  source?: string
  word_count?: number
  is_favorite?: boolean
  created_at?: string
  updated_at?: string
}

/** 后端标题响应格式 */
interface BackendTitleResponse {
  id: string
  user_id: string
  name: string
  text: string
  category: string
  description: string
  tags: string[]
  usage_count: number
  is_active: boolean
  created_at: string
  updated_at: string
}

/** 后端创建标题请求格式 */
interface BackendCreateTitleRequest {
  name: string
  text: string
  category: string
  description?: string
  tags?: string[]
}

/** 后端更新标题请求格式 */
interface BackendUpdateTitleRequest {
  name?: string
  text?: string
  category?: string
  description?: string
  tags?: string[]
}

/** 将后端响应映射为前端 TitleItem */
const toTitleItem = (item: BackendTitleResponse): TitleItem => ({
  id: item.id,
  content: item.text,
  category: item.category,
  word_count: item.text?.length || 0,
  created_at: item.created_at,
  updated_at: item.updated_at,
})

/** 创建标题请求（前端接口，保持向后兼容） */
export interface CreateTitleRequest {
  content: string
  category?: string
}

/** 获取当前用户的所有标题 */
export const getTitles = async (): Promise<TitleItem[]> => {
  const response = await apiClient.get<{ items: BackendTitleResponse[] } | BackendTitleResponse[]>(
    "/titles",
  )
  // 兼容两种后端返回格式：{ items: [...] } 或直接 [...]
  const items = Array.isArray(response.data) ? response.data : response.data.items || []
  return items.map(toTitleItem)
}

/** 创建标题 */
export const createTitle = async (data: CreateTitleRequest): Promise<TitleItem> => {
  // 后端要求 name（≤255）和 text（≤500），name 从 content 截取
  const payload: BackendCreateTitleRequest = {
    name: data.content.slice(0, 255),
    text: data.content.slice(0, 500),
    category: data.category || "default",
  }
  const response = await apiClient.post<BackendTitleResponse>("/titles", payload)
  return toTitleItem(response.data)
}

/** 更新标题 */
export const updateTitle = async (
  titleId: string,
  data: Partial<CreateTitleRequest>,
): Promise<TitleItem> => {
  const payload: BackendUpdateTitleRequest = {}
  if (data.content !== undefined) {
    payload.name = data.content.slice(0, 255)
    payload.text = data.content.slice(0, 500)
  }
  if (data.category !== undefined) {
    payload.category = data.category
  }
  // 后端用 PUT，非 PATCH
  const response = await apiClient.put<BackendTitleResponse>(`/titles/${titleId}`, payload)
  return toTitleItem(response.data)
}

/** 删除标题 */
export const deleteTitle = async (titleId: string): Promise<void> => {
  await apiClient.delete(`/titles/${titleId}`)
}

/** 批量导入标题 */
export const batchImportTitles = async (titles: string[]): Promise<{ imported_count: number }> => {
  const response = await apiClient.post("/titles/batch-import", { titles })
  return response.data
}