"use client"

import type { HomeworkAssignmentQuestionAnalytics } from "@/modules/homework/types"
import { ScrollArea } from "@/shared/components/ui/scroll-area"

const isRecord = (v: unknown): v is Record<string, unknown> => typeof v === "object" && v !== null

const getOptions = (content: unknown): Array<{ id: string; text: string }> => {
  if (!isRecord(content)) return []
  const raw = content.options
  if (!Array.isArray(raw)) return []
  const out: Array<{ id: string; text: string }> = []
  for (const item of raw) {
    if (!isRecord(item)) continue
    const id = typeof item.id === "string" ? item.id : ""
    const text = typeof item.text === "string" ? item.text : ""
    if (!id || !text) continue
    out.push({ id, text })
  }
  return out
}

const safeInlineJson = (v: unknown) => {
  try {
    const s = JSON.stringify(v)
    if (typeof s === "string" && s.length > 180) return `${s.slice(0, 180)}…`
    return s ?? String(v)
  } catch {
    return String(v)
  }
}

const formatAnswer = (answerContent: unknown, question: HomeworkAssignmentQuestionAnalytics | null) => {
  if (isRecord(answerContent) && "answer" in answerContent) answerContent = answerContent.answer
  if (answerContent === null || answerContent === undefined) return "未作答"
  const options = getOptions(question?.questionContent ?? null)
  const optionTextById = new Map(options.map((o) => [o.id, o.text] as const))

  if (typeof answerContent === "boolean") return answerContent ? "True" : "False"
  if (typeof answerContent === "string") return optionTextById.get(answerContent) ?? answerContent
  if (Array.isArray(answerContent)) {
    const parts = answerContent
      .map((x) => (typeof x === "string" ? optionTextById.get(x) ?? x : x))
      .map((x) => (typeof x === "string" ? x : safeInlineJson(x)))
    return parts.join(", ")
  }
  return safeInlineJson(answerContent)
}

const clamp01 = (v: number) => Math.max(0, Math.min(1, v))

function ErrorRatePieChart({ errorRate }: { errorRate: number }) {
  const pct = clamp01(errorRate) * 100
  const r = 15.91549430918954
  const dashA = pct
  const dashB = 100 - pct
  const showError = pct > 0

  return (
    <svg viewBox="0 0 36 36" className="size-12" role="img" aria-label={`错误率 ${pct.toFixed(1)}%`}>
      <circle cx="18" cy="18" r={r} fill="none" strokeWidth="3.5" className="stroke-border" />
      <circle cx="18" cy="18" r={r} fill="none" strokeWidth="3.5" className="stroke-chart-2" />
      {showError ? (
        <circle
          cx="18"
          cy="18"
          r={r}
          fill="none"
          strokeWidth="3.5"
          strokeLinecap="round"
          strokeDasharray={`${dashA} ${dashB}`}
          transform="rotate(-90 18 18)"
          className="stroke-destructive"
        />
      ) : null}
      <text x="18" y="19.2" textAnchor="middle" className="fill-foreground text-[8px] font-medium tabular-nums">
        {pct.toFixed(0)}%
      </text>
    </svg>
  )
}

export function HomeworkAssignmentQuestionErrorDetailPanel({
  selected,
  gradedSampleCount,
}: {
  selected: HomeworkAssignmentQuestionAnalytics | null
  gradedSampleCount: number
}) {
  const wrongAnswers = selected?.wrongAnswers ?? []
  const errorCount = selected?.errorCount ?? 0
  const errorRate = selected?.errorRate ?? 0

  return (
    <div className="flex h-full flex-col overflow-hidden rounded-md border bg-card">
      <div className="border-b px-4 py-3">
        <div className="text-sm font-medium">错题详情</div>
        {selected ? (
          <div className="mt-2 flex items-center gap-3">
            <div className="shrink-0">
              <ErrorRatePieChart errorRate={errorRate} />
            </div>
            <div className="min-w-0 flex-1 grid gap-1 text-xs text-muted-foreground">
              <div className="flex items-center justify-between">
                <span>错误人数</span>
                <span className="tabular-nums text-foreground">{errorCount}</span>
              </div>
              <div className="flex items-center justify-between">
                <span>错误率</span>
                <span className="tabular-nums text-foreground">{(errorRate * 100).toFixed(1)}%</span>
              </div>
              <div className="flex items-center justify-between">
                <span>统计样本</span>
                <span className="tabular-nums text-foreground">{gradedSampleCount}</span>
              </div>
            </div>
          </div>
        ) : (
          <div className="mt-2 text-xs text-muted-foreground">请选择左侧题目</div>
        )}
      </div>

      <div className="flex-1 overflow-hidden">
        <ScrollArea className="h-full p-4">
          {!selected ? (
            <div className="text-sm text-muted-foreground">暂无数据</div>
          ) : wrongAnswers.length === 0 ? (
            <div className="text-sm text-muted-foreground">暂无错误答案</div>
          ) : (
            <div className="space-y-2">
              <div className="text-xs text-muted-foreground">错误答案列表（可滚动）</div>
              <div className="space-y-2">
                {wrongAnswers.map((item, idx) => (
                  <div key={`${selected.questionId}-${idx}`} className="rounded-md border bg-muted/20 px-3 py-2">
                    <div className="flex items-start gap-3">
                      <div className="w-24 shrink-0 text-xs text-muted-foreground truncate">{item.studentName}</div>
                      <div className="min-w-0 flex-1 text-sm wrap-break-word whitespace-pre-wrap">
                        {formatAnswer(item.answerContent, selected)}
                      </div>
                    </div>
                  </div>
                ))}
              </div>
            </div>
          )}
        </ScrollArea>
      </div>
    </div>
  )
}