import { z } from "zod"

/**
 * 公告类型与目标受众的联合校验：
 * - type=school：targetGradeId / targetClassId 必须为空
 * - type=grade：targetGradeId 必填，targetClassId 必须为空
 * - type=class：targetClassId 必填
 *
 * 避免"创建无受众公告"的数据完整性问题。
 */
const refineAudience = (
  data: {
    type?: "school" | "grade" | "class"
    targetGradeId?: string | null
    targetClassId?: string | null
  },
  ctx: z.RefinementCtx
): void => {
  const type = data.type ?? "school"
  const hasGrade = (data.targetGradeId ?? "").trim().length > 0
  const hasClass = (data.targetClassId ?? "").trim().length > 0

  if (type === "school" && (hasGrade || hasClass)) {
    ctx.addIssue({
      code: z.ZodIssueCode.custom,
      path: ["targetGradeId"],
      message: "全校公告不应指定目标年级或班级",
    })
    return
  }

  if (type === "grade" && !hasGrade) {
    ctx.addIssue({
      code: z.ZodIssueCode.custom,
      path: ["targetGradeId"],
      message: "年级公告必须指定目标年级",
    })
    return
  }

  if (type === "class" && !hasClass) {
    ctx.addIssue({
      code: z.ZodIssueCode.custom,
      path: ["targetClassId"],
      message: "班级公告必须指定目标班级",
    })
    return
  }
}

export const CreateAnnouncementSchema = z
  .object({
    title: z.string().trim().min(1).max(255),
    content: z.string().trim().min(1),
    type: z.enum(["school", "grade", "class"]).optional(),
    status: z.enum(["draft", "published", "archived"]).optional(),
    targetGradeId: z.string().trim().optional().nullable(),
    targetClassId: z.string().trim().optional().nullable(),
    publishedAt: z.string().optional().nullable(),
  })
  .superRefine(refineAudience)
  .transform((v) => ({
    title: v.title,
    content: v.content,
    type: v.type ?? "school",
    status: v.status ?? "draft",
    targetGradeId: v.targetGradeId && v.targetGradeId.length > 0 ? v.targetGradeId : null,
    targetClassId: v.targetClassId && v.targetClassId.length > 0 ? v.targetClassId : null,
    publishedAt: v.publishedAt && v.publishedAt.length > 0 ? v.publishedAt : null,
  }))

export type CreateAnnouncementInput = z.infer<typeof CreateAnnouncementSchema>

export const UpdateAnnouncementSchema = z
  .object({
    title: z.string().trim().min(1).max(255),
    content: z.string().trim().min(1),
    type: z.enum(["school", "grade", "class"]).optional(),
    status: z.enum(["draft", "published", "archived"]).optional(),
    targetGradeId: z.string().trim().optional().nullable(),
    targetClassId: z.string().trim().optional().nullable(),
    publishedAt: z.string().optional().nullable(),
  })
  .superRefine(refineAudience)
  .transform((v) => ({
    title: v.title,
    content: v.content,
    type: v.type ?? "school",
    status: v.status ?? "draft",
    targetGradeId: v.targetGradeId && v.targetGradeId.length > 0 ? v.targetGradeId : null,
    targetClassId: v.targetClassId && v.targetClassId.length > 0 ? v.targetClassId : null,
    publishedAt: v.publishedAt && v.publishedAt.length > 0 ? v.publishedAt : null,
  }))

export type UpdateAnnouncementInput = z.infer<typeof UpdateAnnouncementSchema>