import type { JSX } from "react"
import Link from "next/link"
import { BarChart3, ArrowLeft } from "lucide-react"
import { getTranslations } from "next-intl/server"

import { Button } from "@/shared/components/ui/button"
import { EmptyState } from "@/shared/components/ui/empty-state"
import { requirePermission } from "@/shared/lib/auth-guard"
import { Permissions } from "@/shared/types/permissions"
import { getParam, type SearchParams } from "@/shared/lib/search-params"
import { getTeacherClasses } from "@/modules/classes/data-access"
import { getGrades } from "@/modules/school/data-access"
import { getSubjectOptions } from "@/modules/school/data-access"

import {
  getClassComparisonWithSignificance,
  getExamOptionsForGrades,
  getGradeDistribution,
  getGradeTrend,
  getSubjectComparison,
} from "@/modules/grades/data-access-analytics"
import { GradeTrendChart } from "@/modules/grades/components/grade-trend-chart"
import { ClassComparisonChart } from "@/modules/grades/components/class-comparison-chart"
import { SubjectComparisonChart } from "@/modules/grades/components/subject-comparison-chart"
import { GradeDistributionChart } from "@/modules/grades/components/grade-distribution-chart"
import { AnalyticsFilters } from "@/modules/grades/components/analytics-filters"
import { KnowledgePointMasteryChart } from "@/modules/grades/components/knowledge-point-mastery-chart"
import { getClassMasterySummary } from "@/modules/diagnostic/data-access"
import { WidgetBoundary } from "@/shared/components/widget-boundary"

export const dynamic = "force-dynamic"

export default async function GradeAnalyticsPage({
  searchParams,
}: {
  searchParams: Promise<SearchParams>
}): Promise<JSX.Element> {
  const sp = await searchParams
  const ctx = await requirePermission(Permissions.GRADE_RECORD_READ)
  const t = await getTranslations("grades")

  const classId = getParam(sp, "classId")
  const subjectId = getParam(sp, "subjectId")
  const gradeId = getParam(sp, "gradeId")
  // v3-P2-7: 学期和考试筛选
  const examId = getParam(sp, "examId")
  const semester = getParam(sp, "semester")

  const [classes, allGrades, allSubjects] = await Promise.all([
    getTeacherClasses(),
    getGrades(),
    getSubjectOptions(),
  ])

  if (classes.length === 0) {
    return (
      <div className="h-full flex-1 flex-col space-y-8 p-8 md:flex">
        <div>
          <h1 className="text-2xl font-bold tracking-tight">{t("title.analytics")}</h1>
          <p className="text-muted-foreground">{t("page.analytics.description")}</p>
        </div>
        <EmptyState
          title={t("page.analytics.noClassesTitle")}
          description={t("page.analytics.noClassesDescription")}
          icon={BarChart3}
          className="border-none shadow-none"
        />
      </div>
    )
  }

  const targetClassId = classId ?? classes[0].id
  const targetSubjectId =
    subjectId && subjectId !== "all" ? subjectId : undefined
  const targetGradeId = gradeId ?? allGrades[0]?.id
  // v3-P2-7: 解析 semester 和 examId
  const targetSemester: "1" | "2" | undefined =
    semester === "1" || semester === "2" ? semester : undefined
  const targetExamId = examId && examId !== "all" ? examId : undefined

  // Run analytics queries in parallel
  // P3-3: 集成 diagnostic 模块的知识点掌握度视图（classId 已由 getTeacherClasses 校验在 scope 内）
  const [
    trend,
    distribution,
    subjectComparison,
    classComparisonResult,
    examOptions,
    classMasterySummary,
  ] = await Promise.all([
    getGradeTrend({
      classId: targetClassId,
      subjectId: targetSubjectId,
      semester: targetSemester,
      examId: targetExamId,
      scope: ctx.dataScope,
      currentUserId: ctx.userId,
    }),
    getGradeDistribution({
      classId: targetClassId,
      subjectId: targetSubjectId,
      examId: targetExamId,
      semester: targetSemester,
      scope: ctx.dataScope,
      currentUserId: ctx.userId,
    }),
    getSubjectComparison({
      classId: targetClassId,
      examId: targetExamId,
      semester: targetSemester,
      scope: ctx.dataScope,
    }),
    targetGradeId
      ? getClassComparisonWithSignificance({
          gradeId: targetGradeId,
          subjectId: targetSubjectId ?? allSubjects[0]?.id ?? "",
          examId: targetExamId,
          semester: targetSemester,
          scope: ctx.dataScope,
        })
      : Promise.resolve({ items: [], significance: null }),
    getExamOptionsForGrades({
      classId: targetClassId,
      subjectId: targetSubjectId,
      scope: ctx.dataScope,
    }),
    getClassMasterySummary(targetClassId),
  ])

  return (
    <div className="h-full flex-1 flex-col space-y-6 p-8 md:flex">
      <div className="flex flex-col justify-between gap-4 md:flex-row md:items-center">
        <div>
          <h1 className="text-2xl font-bold tracking-tight">{t("title.analytics")}</h1>
          <p className="text-muted-foreground">{t("page.analytics.description")}</p>
        </div>
        <Button asChild variant="ghost" size="sm">
          <Link href="/teacher/grades">
            <ArrowLeft className="mr-2 h-4 w-4" aria-hidden="true" />
            {t("page.analytics.backToGrades")}
          </Link>
        </Button>
      </div>

      <AnalyticsFilters
        classes={classes.map((c) => ({ id: c.id, name: c.name }))}
        grades={allGrades.map((g) => ({ id: g.id, name: g.name }))}
        subjects={allSubjects.map((s) => ({ id: s.id, name: s.name ?? "Unknown" }))}
        exams={examOptions}
        currentClassId={targetClassId}
        currentSubjectId={subjectId ?? "all"}
        currentGradeId={targetGradeId ?? ""}
        currentExamId={examId ?? "all"}
        currentSemester={semester ?? "all"}
      />

      <div className="grid grid-cols-1 gap-6 lg:grid-cols-2">
        <WidgetBoundary title={t("page.analytics.trendTitle")}>
          {trend ? (
            <GradeTrendChart data={trend} />
          ) : (
            <EmptyState
              title={t("page.analytics.trendEmptyTitle")}
              description={t("page.analytics.trendEmptyDescription")}
              icon={BarChart3}
              className="border-none shadow-none"
            />
          )}
        </WidgetBoundary>
        <WidgetBoundary title={t("page.analytics.distributionTitle")}>
          {distribution.totalCount > 0 ? (
            <GradeDistributionChart data={distribution} />
          ) : (
            <EmptyState
              title={t("page.analytics.distributionEmptyTitle")}
              description={t("page.analytics.distributionEmptyDescription")}
              icon={BarChart3}
              className="border-none shadow-none"
            />
          )}
        </WidgetBoundary>
        <WidgetBoundary title={t("page.analytics.subjectComparisonTitle")}>
          {subjectComparison.length > 0 ? (
            <SubjectComparisonChart data={subjectComparison} />
          ) : (
            <EmptyState
              title={t("page.analytics.subjectComparisonEmptyTitle")}
              description={t("page.analytics.subjectComparisonEmptyDescription")}
              icon={BarChart3}
              className="border-none shadow-none"
            />
          )}
        </WidgetBoundary>
        <WidgetBoundary title={t("page.analytics.classComparisonTitle")}>
          {classComparisonResult.items.length > 0 ? (
            <ClassComparisonChart
              data={classComparisonResult.items}
              significance={classComparisonResult.significance}
            />
          ) : (
            <EmptyState
              title={t("page.analytics.classComparisonEmptyTitle")}
              description={t("page.analytics.classComparisonEmptyDescription")}
              icon={BarChart3}
              className="border-none shadow-none"
            />
          )}
        </WidgetBoundary>
        <WidgetBoundary title={t("knowledgePointMastery.title")}>
          <KnowledgePointMasteryChart
            data={classMasterySummary?.knowledgePointStats ?? []}
            detailHref="/teacher/diagnostic"
          />
        </WidgetBoundary>
      </div>
    </div>
  )
}
