import { use } from "react"
import type { TeacherDashboardData } from "@/modules/dashboard/types"
import type { TeacherDashboardMetrics } from "@/modules/dashboard/lib/dashboard-utils"
import type { ActionState } from "@/shared/types/action-state"
import { getTranslations } from "next-intl/server"
import type { TeacherTodoItem } from "./teacher-todo-card"

import { DashboardSection } from "../dashboard-section"
import { TeacherClassesCard } from "./teacher-classes-card"
import { TeacherDashboardHeader } from "./teacher-dashboard-header"
import { TeacherHomeworkCard } from "./teacher-homework-card"
import { RecentSubmissions } from "./recent-submissions"
import { TeacherSchedule } from "./teacher-schedule"
import { TeacherStats } from "./teacher-stats"
import { TeacherGradeTrends } from "./teacher-grade-trends"
import { TeacherTodoCard } from "./teacher-todo-card"

type TeacherDashboardResult = ActionState<TeacherDashboardData & { metrics: TeacherDashboardMetrics }>

/**
 * 教师仪表盘视图（P2-1 流式架构）
 *
 * 接收未解析的 Promise，用 React `use()` 消费。
 * 页面外壳立即渲染，数据到达后在 DashboardSection 的 Suspense 边界内填充。
 */
export function TeacherDashboardView({ dataPromise }: { dataPromise: Promise<TeacherDashboardResult> }) {
  const result = use(dataPromise)
  if (!result.success || !result.data) {
    throw new Error(result.message ?? "Failed to load teacher dashboard")
  }

  return <TeacherDashboardContent data={result.data} />
}

async function TeacherDashboardContent({ data }: { data: TeacherDashboardData & { metrics: TeacherDashboardMetrics } }) {
  const t = await getTranslations("dashboard")
  const { metrics } = data

  // 待办聚合（使用预计算指标）
  const todoItems: TeacherTodoItem[] = [
    {
      label: t("todo.toGrade"),
      count: metrics.toGradeCount,
      href: "/teacher/homework/submissions",
      variant: metrics.toGradeCount > 0 ? "urgent" : "normal",
    },
    {
      label: t("todo.todayAttendance"),
      count: metrics.todayScheduleItems.length,
      href: "/teacher/attendance/sheet",
      variant: "info",
    },
    {
      label: t("todo.activeAssignments"),
      count: metrics.activeAssignmentsCount,
      href: "/teacher/homework/assignments",
      variant: "normal",
    },
  ]

  return (
    <div className="flex h-full flex-col space-y-6 p-8">
      <header>
        <TeacherDashboardHeader teacherName={data.teacherName} />
      </header>

      <DashboardSection variant="stats" ariaLabel={t("sections.quickStats")}>
        <TeacherStats
          toGradeCount={metrics.toGradeCount}
          activeAssignmentsCount={metrics.activeAssignmentsCount}
          averageScore={metrics.averageScore}
          submissionRate={metrics.submissionRate}
        />
      </DashboardSection>

      <div className="flex flex-col gap-6 lg:grid lg:grid-cols-12">
        {/* 课表：移动端首位，桌面端右上 — 仅渲染一次（P2-9 修复，原为双实例） */}
        <div className="order-1 lg:col-start-9 lg:col-span-4 lg:row-start-1">
          <DashboardSection variant="card" ariaLabel={t("sections.todaySchedule")}>
            <TeacherSchedule items={metrics.todayScheduleItems} />
          </DashboardSection>
        </div>

        <section aria-label={t("sections.pendingGrading")} className="flex flex-col gap-6 order-2 lg:col-start-1 lg:col-span-8 lg:row-start-1 lg:row-span-2">
          <DashboardSection variant="card" ariaLabel={t("todo.title")}>
            <TeacherTodoCard items={todoItems} />
          </DashboardSection>
          <DashboardSection variant="chart" ariaLabel={t("sections.gradeTrends")}>
            <TeacherGradeTrends trends={data.gradeTrends} />
          </DashboardSection>
          <DashboardSection variant="list" ariaLabel={t("sections.recentSubmissions")}>
            <RecentSubmissions
              submissions={metrics.submissionsToGrade}
              title={t("sections.pendingGrading")}
              emptyTitle={t("empty.allGraded")}
              emptyDescription={t("empty.allGradedDesc")}
            />
          </DashboardSection>
        </section>

        <aside aria-label={t("sections.myClasses")} className="flex flex-col gap-6 order-3 lg:col-start-9 lg:col-span-4 lg:row-start-2">
          <DashboardSection variant="list" ariaLabel={t("sections.homework")}>
            <TeacherHomeworkCard assignments={data.assignments} />
          </DashboardSection>
          <DashboardSection variant="list" ariaLabel={t("sections.myClasses")}>
            <TeacherClassesCard classes={data.classes} />
          </DashboardSection>
        </aside>
      </div>
    </div>
  )
}
