"use client";

/**
 * 课程对练：输入课程标识 → 生成题目 → 查看可对练题目 → 发起对练逐题作答 → 结束生成报告。
 */

import { useState } from "react";
import { GraduationCap } from "lucide-react";

import {
  CredibilityBadge,
  RawDetails,
  ScoreBar,
  StatTile,
} from "@/components/display";
import { RadialProgress } from "@/components/charts";
import {
  EmptyState,
  ErrorBanner,
  Loading,
  PageHeading,
} from "@/components/feedback";
import { Badge } from "@/components/ui/badge";
import { Button } from "@/components/ui/button";
import {
  Card,
  CardContent,
  CardHeader,
  CardTitle,
} from "@/components/ui/card";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { Textarea } from "@/components/ui/textarea";
import { UsageGuide } from "@/components/usage-guide";
import { ApiError } from "@/lib/api";
import { practiceApi } from "@/lib/services";
import type { AnswerResult, PracticeReport } from "@/lib/types";

/* eslint-disable @typescript-eslint/no-explicit-any */

export default function PracticePage() {
  const [courseId, setCourseId] = useState("");
  const [busy, setBusy] = useState(false);
  const [error, setError] = useState<string | null>(null);

  const [questions, setQuestions] = useState<any[]>([]);
  const [session, setSession] = useState<any>(null);
  const [answer, setAnswer] = useState("");
  const [lastResult, setLastResult] = useState<AnswerResult | null>(null);
  const [report, setReport] = useState<PracticeReport | null>(null);

  async function run<T>(fn: () => Promise<T>, after?: (v: T) => void) {
    setError(null);
    setBusy(true);
    try {
      const v = await fn();
      after?.(v);
    } catch (err) {
      setError(err instanceof ApiError ? err.message : "操作失败");
    } finally {
      setBusy(false);
    }
  }

  const currentQuestion: any =
    session?.questions?.[session?.currentIndex ?? 0] ??
    session?.currentQuestion ??
    null;

  return (
    <div className="space-y-6">
      <PageHeading
        icon={<GraduationCap className="size-5" />}
        title="医学题库"
        description="基于教学大纲智能出题，在线作答并获得知识薄弱点分析与能力报告。"
      />

      <UsageGuide
        steps={[
          { title: "输入课程标识", detail: "如「内科学101」，定位要对练的课程。" },
          { title: "生成或查看题目", detail: "「生成题目」按课程内容出题，或「查看可对练题目」加载已有题。" },
          { title: "发起对练并作答", detail: "点击「发起对练」，逐题输入答案（选择题填选项字母）。" },
          { title: "结束生成报告", detail: "完成后「结束并生成报告」，查看正确率、薄弱环节与改进建议。" },
        ]}
        tip="作答有计时，超时将判错；报告中的薄弱环节会回流到你的胜任力画像。"
      />

      <Card>
        <CardHeader>
          <CardTitle>选择课程</CardTitle>
        </CardHeader>
        <CardContent>
          <div className="flex flex-wrap items-end gap-3">
            <div className="min-w-[220px] flex-1">
              <Label>课程标识</Label>
              <Input
                value={courseId}
                onChange={(e) => setCourseId(e.target.value)}
                placeholder="如：内科学101"
              />
            </div>
            <Button
              disabled={!courseId || busy}
              onClick={() =>
                run(
                  () => practiceApi.generateQuestions(courseId, {}),
                  (v: any) => setQuestions(v?.questions ?? v?.items ?? []),
                )
              }
            >
              生成题目
            </Button>
            <Button
              variant="outline"
              disabled={!courseId || busy}
              onClick={() =>
                run(
                  () => practiceApi.listAvailableQuestions(courseId),
                  (v: any) => setQuestions(Array.isArray(v) ? v : []),
                )
              }
            >
              查看可对练题目
            </Button>
            <Button
              variant="outline"
              disabled={!courseId || busy}
              onClick={() =>
                run(
                  () => practiceApi.startSession(courseId),
                  (v: any) => {
                    setSession(v);
                    setReport(null);
                    setLastResult(null);
                  },
                )
              }
            >
              发起对练
            </Button>
          </div>
          {error && (
            <div className="mt-4">
              <ErrorBanner message={error} />
            </div>
          )}
        </CardContent>
      </Card>

      {busy && <Loading />}

      {questions.length > 0 && (
        <Card>
          <CardHeader>
            <CardTitle>题目（{questions.length}）</CardTitle>
          </CardHeader>
          <CardContent>
            <ul className="space-y-3">
              {questions.map((q: any, i: number) => (
                <li key={q.id ?? i} className="rounded-lg border border-border p-3">
                  <div className="flex items-start justify-between gap-3">
                    <p className="text-sm text-foreground">
                      {i + 1}. {q.stem ?? q.title ?? q.content ?? "（题干）"}
                    </p>
                    {q.reviewStatus && (
                      <Badge variant="warning">
                        {q.reviewStatus === "pending" ? "待审核" :
                         q.reviewStatus === "approved" ? "已通过" :
                         q.reviewStatus === "returned" ? "已退回" :
                         q.reviewStatus}
                      </Badge>
                    )}
                  </div>
                  {Array.isArray(q.options) && (
                    <ul className="mt-2 space-y-1 text-xs text-muted-foreground">
                      {q.options.map((o: any, oi: number) => (
                        <li key={oi}>
                          {o.key ?? String.fromCharCode(65 + oi)}.{" "}
                          {o.text ?? o.label ?? String(o)}
                        </li>
                      ))}
                    </ul>
                  )}
                </li>
              ))}
            </ul>
          </CardContent>
        </Card>
      )}

      {session && !report && (
        <Card>
          <CardHeader>
            <CardTitle>进行对练</CardTitle>
          </CardHeader>
          <CardContent>
            {currentQuestion ? (
              <div className="space-y-3">
                <p className="text-sm font-medium text-foreground">
                  {currentQuestion.stem ??
                    currentQuestion.title ??
                    currentQuestion.content ??
                    "当前题目"}
                </p>
                {Array.isArray(currentQuestion.options) && (
                  <ul className="space-y-1 text-xs text-muted-foreground">
                    {currentQuestion.options.map((o: any, oi: number) => (
                      <li key={oi}>
                        {o.key ?? String.fromCharCode(65 + oi)}.{" "}
                        {o.text ?? o.label ?? String(o)}
                      </li>
                    ))}
                  </ul>
                )}
                <Textarea
                  rows={3}
                  value={answer}
                  onChange={(e) => setAnswer(e.target.value)}
                  placeholder="输入你的作答（选择题填选项字母，分析题填要点）"
                />
                <div className="flex gap-3">
                  <Button
                    disabled={busy || !answer}
                    onClick={() =>
                      run(
                        () =>
                          practiceApi.submitAnswer(session.id, {
                            questionId:
                              currentQuestion.id ?? currentQuestion.questionId,
                            answer,
                          }),
                        (v: any) => {
                          setLastResult(v);
                          setAnswer("");
                          if (v?.session) setSession(v.session);
                        },
                      )
                    }
                  >
                    提交作答
                  </Button>
                  <Button
                    variant="outline"
                    disabled={busy}
                    onClick={() =>
                      run(
                        () => practiceApi.finishSession(session.id),
                        (v: any) => setReport(v),
                      )
                    }
                  >
                    结束并生成报告
                  </Button>
                </div>
              </div>
            ) : (
              <EmptyState message="本次对练暂无可作答题目，可直接结束生成报告。" />
            )}

            {lastResult && (
              <div className="mt-4">
                <div
                  className={`flex items-center gap-2 rounded-lg px-4 py-3 text-sm ${
                    lastResult.correct
                      ? "bg-success/12 text-success"
                      : "bg-destructive/12 text-destructive"
                  }`}
                >
                  <span className="font-medium">
                    {lastResult.correct ? "✓ 回答正确" : "✗ 回答错误"}
                  </span>
                  {lastResult.timedOut && <Badge variant="warning">超时判错</Badge>}
                  <span className="ml-auto text-xs text-muted-foreground">
                    用时 {(lastResult.elapsedMs / 1000).toFixed(1)} 秒
                  </span>
                </div>
                {lastResult.next && (
                  <p className="mt-2 text-xs text-muted-foreground">
                    下一题：第 {lastResult.next.position} / {lastResult.next.total} 题
                  </p>
                )}
              </div>
            )}
          </CardContent>
        </Card>
      )}

      {report && <PracticeReportView report={report} />}
    </div>
  );
}

/** 对练报告：正确率、用时、能力标签统计、薄弱环节与改进建议。 */
function PracticeReportView({ report }: { report: PracticeReport }) {
  return (
    <Card>
      <CardHeader>
        <CardTitle>对练报告</CardTitle>
      </CardHeader>
      <CardContent>
        <div className="flex flex-col gap-5 sm:flex-row sm:items-center">
          <div className="flex shrink-0 items-center justify-center">
            <RadialProgress
              value={report.accuracy}
              size={120}
              label={`${report.accuracy.toFixed(0)}%`}
              sublabel="正确率"
              tone={report.accuracy >= 60 ? "success" : "destructive"}
            />
          </div>
          <div className="grid flex-1 grid-cols-3 gap-3">
            <StatTile label="题目总数" value={report.totalQuestions} />
            <StatTile
              label="正确 / 错误"
              value={`${report.correctCount}/${report.incorrectCount}`}
            />
            <StatTile
              label="总用时"
              value={`${report.totalTimeSeconds}s`}
              tone="primary"
            />
          </div>
        </div>

        {report.tagBreakdown?.length > 0 && (
          <div className="mt-5">
            <h3 className="mb-2 text-sm font-semibold text-foreground">
              能力标签正确率
            </h3>
            <div className="space-y-2">
              {report.tagBreakdown.map((t) => (
                <ScoreBar
                  key={t.tagId}
                  label={`${t.tagId}（${t.correctCount}/${t.totalQuestions}）`}
                  score={t.correctnessRate}
                  tone={t.correctnessRate >= 60 ? "success" : "destructive"}
                />
              ))}
            </div>
          </div>
        )}

        {report.weakAreas?.length > 0 && (
          <div className="mt-5">
            <h3 className="mb-2 text-sm font-semibold text-foreground">
              薄弱环节（正确率 &lt; 60%）
            </h3>
            <div className="flex flex-wrap gap-2">
              {report.weakAreas.map((w) => (
                <Badge key={w.tagId} variant="destructive">
                  {w.tagName ?? w.tagId}（{w.correctnessRate.toFixed(0)}%）
                </Badge>
              ))}
            </div>
          </div>
        )}

        {report.suggestions?.length > 0 && (
          <div className="mt-5">
            <h3 className="mb-2 text-sm font-semibold text-foreground">改进建议</h3>
            <ul className="space-y-3">
              {report.suggestions.map((s, i) => (
                <li key={i} className="rounded-lg border border-border p-3">
                  <p className="text-sm text-foreground">{s.content}</p>
                  <div className="mt-2">
                    <CredibilityBadge annotation={s.annotation} />
                  </div>
                </li>
              ))}
            </ul>
          </div>
        )}

        <RawDetails data={report} />
      </CardContent>
    </Card>
  );
}