import { useEffect, useMemo, useState } from "react";
import { ArrowRight, CheckCircle2, Clock3, FileText, Info, RefreshCw, TriangleAlert } from "lucide-react";
import { useNavigate, useParams } from "react-router";
import { toast } from "sonner";

import { Button } from "~/components/ui/button";
import { Card, CardAction, CardContent, CardDescription, CardHeader, CardTitle } from "~/components/ui/card";
import { Input } from "~/components/ui/input";
import { Skeleton } from "~/components/ui/skeleton";
import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "~/components/ui/table";
import { Textarea } from "~/components/ui/textarea";
import {
  AbnormalBadge,
  FilterSelect,
  GradeBadge,
  MetricLineChart,
  OperationsPageHeader,
  SortingComboChart,
  StatusBadge,
} from "./OperationsUi";
import {
  FEATURE_METRICS,
  SORTING_DISTRIBUTION,
  abnormalLevelOf,
  abnormalReasonOf,
  gradeOf,
  modelTrend,
  monthsBetween,
} from "./modelData";
import { useOperationsData, useOperationsModelDetail } from "./OperationsDataContext";
import { useCanOperationsAction } from "./operationsRole";

function recentMonths(count: number): string[] {
  const end = 2026 * 12 + 6;
  return Array.from({ length: count }, (_, index) => {
    const value = end - count + 1 + index;
    return `${Math.floor(value / 12)}-${String(value % 12 + 1).padStart(2, "0")}`;
  });
}

export default function MonitoringDetailPage() {
  const navigate = useNavigate();
  const params = useParams();
  const { models } = useOperationsData();
  const modelId = params.modelId ?? models[0]?.modelId ?? "";
  const detail = useOperationsModelDetail(modelId, "2026-07");
  const baseModel = detail.model ?? models.find((item) => item.modelId === modelId) ?? models[0];
  const model = detail.monitoringResult ?? baseModel ?? models[0]!;
  const [range, setRange] = useState("6");
  const [fromMonth, setFromMonth] = useState("2026-02");
  const [toMonth, setToMonth] = useState("2026-07");
  const [compareId, setCompareId] = useState("");
  const [selectedFeature, setSelectedFeature] = useState<string | null>(null);
  const [reviewStage, setReviewStage] = useState<0 | 1 | 2>(0);
  const [reviewDecision, setReviewDecision] = useState("暂不处理");
  const [reviewNote, setReviewNote] = useState("");
  const months = range === "custom" ? monthsBetween(fromMonth, toMonth) : recentMonths(Number(range));
  const monitorMonth = detail.monitoringResult?.monitorMonth ?? "";
  const ksTrend = modelTrend(model, "ks", months);
  const psiTrend = modelTrend(model, "psi", months);
  const compareModel = models.find((item) => item.modelId === compareId && item.modelId !== model.modelId) ?? null;
  const compareKsTrend = compareModel ? modelTrend(compareModel, "ks", months) : null;
  const comparePsiTrend = compareModel ? modelTrend(compareModel, "psi", months) : null;
  const grade = gradeOf(model);
  const abnormal = abnormalLevelOf(model);
  const chosenFeature = FEATURE_METRICS.find((item) => item.key === selectedFeature) ?? null;
  const ivTop = useMemo(() => [...FEATURE_METRICS].sort((left, right) => right.ivDrop - left.ivDrop), []);
  const csiTop = useMemo(() => [...FEATURE_METRICS].sort((left, right) => right.csiRise - left.csiRise), []);
  const canInitialReview = useCanOperationsAction("monitor:initial-review");
  const canFinalReview = useCanOperationsAction("monitor:final-review");
  const effectiveReviewStage = grade === "A" ? 2 : reviewStage;
  const canReview = grade !== "A" && ((reviewStage === 0 && canInitialReview) || (reviewStage === 1 && canFinalReview));

  const submitReview = () => {
    if (!reviewNote.trim()) {
      toast.error("请填写处理说明");
      return;
    }
    if (reviewStage === 0) {
      setReviewStage(1);
      toast.success(`模型团队初审已提交：${reviewDecision}`);
    } else {
      setReviewStage(2);
      toast.success(`业务团队终审已提交：${reviewDecision}`);
    }
    setReviewNote("");
  };

  useEffect(() => {
    setReviewStage(0);
    setReviewDecision("暂不处理");
    setReviewNote("");
    setSelectedFeature(null);
    setCompareId("");
  }, [modelId]);

  if (detail.loading) {
    return <section className="h-full overflow-auto bg-bg p-6"><div className="w-full space-y-6"><Skeleton className="h-20 w-full rounded-4xl" /><Skeleton className="h-96 w-full rounded-4xl" /><div className="grid grid-cols-2 gap-6"><Skeleton className="h-72 rounded-4xl" /><Skeleton className="h-72 rounded-4xl" /></div></div></section>;
  }

  if (detail.error) {
    return <section className="grid h-full place-items-center bg-bg p-6"><Card className="w-full max-w-xl"><CardContent className="flex flex-col items-center py-12 text-center"><TriangleAlert className="size-10 text-danger" /><h2 className="mt-4 text-xl font-bold text-foreground">模型监控详情加载失败</h2><p className="mt-2 text-sm text-muted-foreground">{detail.error ?? "模型不存在"}</p><Button className="mt-5" onClick={detail.reload}><RefreshCw />重新加载</Button></CardContent></Card></section>;
  }

  return (
    <section className="h-full overflow-auto bg-bg p-6">
      <div className="flex w-full flex-col gap-6 pb-8">
        <OperationsPageHeader
          title="模型监控详情"
          description={`${model.bank} · ${model.name} ${model.version} · ${model.modelId}`}
          onBack={() => navigate("/operations/monitoring")}
          actions={(
            <div className="flex items-end gap-2">
              <FilterSelect
                className="w-72"
                label="监控模型"
                value={model.modelId}
                allLabel="请选择模型"
                options={models.filter((item) => item.status !== "下线").map((item) => ({
                  label: `${item.bank} · ${item.name} ${item.version}`,
                  value: item.modelId,
                }))}
                onChange={(modelId) => {
                  if (modelId) navigate(`/operations/monitoring/${modelId}`);
                }}
              />
              <FilterSelect
                className="w-40"
                label="时间范围"
                value={range}
                allLabel="请选择"
                options={[{ label: "近 3 个月", value: "3" }, { label: "近 6 个月", value: "6" }, { label: "近 12 个月", value: "12" }, { label: "自定义", value: "custom" }]}
                onChange={setRange}
              />
              <FilterSelect
                className="w-64"
                label="对比模型"
                value={compareId}
                allLabel="不对比"
                options={models.filter((item) => item.status !== "下线" && item.modelId !== model.modelId).map((item) => ({ label: `${item.bank} · ${item.modelId}`, value: item.modelId }))}
                onChange={setCompareId}
              />
              {range === "custom" && (
                <>
                  <label className="flex flex-col gap-1.5"><span className="text-xs font-medium text-ink-caption">起始月份</span><Input type="month" value={fromMonth} onChange={(event) => setFromMonth(event.target.value)} /></label>
                  <label className="flex flex-col gap-1.5"><span className="text-xs font-medium text-ink-caption">结束月份</span><Input type="month" value={toMonth} onChange={(event) => setToMonth(event.target.value)} /></label>
                </>
              )}
            </div>
          )}
        />

        <Card>
          <CardHeader className="border-b border-border">
            <CardTitle>① 监控结论</CardTitle>
            <CardDescription>{monitorMonth ? `${monitorMonth} 监控周期 · 结果优先展示` : "暂无监控结果"}</CardDescription>
            <CardAction className="flex items-center gap-2">
              <StatusBadge status={model.status} />
              <GradeBadge grade={grade} suffix="等级" />
            </CardAction>
          </CardHeader>
          <CardContent className="space-y-5">
            <div className="grid grid-cols-6 gap-4">
              {[
                ["监控结果等级", grade],
                ["排序性", model.ranking],
                ["KS", `${model.ks.toFixed(2)}%`],
                ["PSI", `${model.psi.toFixed(2)}%`],
                ["KS 环比降幅", `${model.ksDrop.toFixed(2)}%`],
                ["异常等级", abnormal],
              ].map(([label, value]) => (
                <div className="rounded-xl bg-muted/50 p-4" key={label}>
                  <span className="text-xs text-muted-foreground">{label}</span>
                  <strong className="mt-2 block whitespace-nowrap text-xl font-bold tabular-nums text-foreground">{value}</strong>
                </div>
              ))}
            </div>

            {grade === "A" ? (
              <div className="flex items-start gap-3 rounded-xl bg-success-soft p-4 text-sm text-success-strong">
                <CheckCircle2 className="mt-0.5 size-5 shrink-0" />
                <div><b>本期无异常</b><p className="mt-1">各项指标均在阈值内，生成模型监控报告并继续按月监控。</p></div>
              </div>
            ) : (
              <div className="flex items-start gap-3 rounded-xl bg-warning-soft p-4 text-sm text-foreground">
                <TriangleAlert className="mt-0.5 size-5 shrink-0 text-warning" />
                <div>
                  <b>异常原因（{abnormal}）</b>
                  <p className="mt-1 text-muted-foreground">{abnormalReasonOf(model)}</p>
                  {(model.ks < 30 || model.psi > 50) && <p className="mt-2 font-medium text-danger">已达到主动干预条件，请建模团队优先处理。</p>}
                </div>
              </div>
            )}

            <div className="grid grid-cols-2 gap-4">
              <div className="flex items-start gap-3 rounded-xl border border-border p-4">
                <Clock3 className="mt-0.5 size-5 shrink-0 text-primary" />
                <div className="flex-1">
                  <b className="text-sm text-foreground">处理进度</b>
                  <p className="mt-1 text-sm text-muted-foreground">{grade === "A" ? "本期无异常，无需进入处理流程。" : effectiveReviewStage === 0 ? "待模型团队初审，初审完成后流转至业务团队终审。" : effectiveReviewStage === 1 ? "模型团队已完成初审，待业务团队终审。" : "本期处理已结案。"}</p>
                  <div className="mt-3 flex items-center gap-2 text-xs text-muted-foreground">
                    <span className={`rounded-full px-2.5 py-1 ${effectiveReviewStage >= 1 ? "bg-success text-white" : "bg-primary text-white"}`}>1 模型团队初审</span>
                    <ArrowRight className="size-3.5" />
                    <span className={`rounded-full px-2.5 py-1 ${effectiveReviewStage >= 2 ? "bg-success text-white" : effectiveReviewStage === 1 ? "bg-primary text-white" : "bg-muted"}`}>2 业务团队终审</span>
                  </div>
                  {canReview && <div className="mt-4 space-y-3 border-t border-border pt-4"><FilterSelect label={reviewStage === 0 ? "模型团队处理建议" : "业务团队终审结论"} value={reviewDecision} allLabel="请选择" options={["暂不处理", "模型微调或重构"]} onChange={setReviewDecision} /><Textarea placeholder="必填：请输入本次处理依据或结论" value={reviewNote} onChange={(event) => setReviewNote(event.target.value)} /><Button size="sm" onClick={submitReview}>提交{reviewStage === 0 ? "初审" : "终审"}</Button></div>}
                  {!canReview && grade !== "A" && effectiveReviewStage < 2 && <p className="mt-3 text-xs text-muted-foreground">{effectiveReviewStage === 0 ? "当前角色需等待模型团队完成初审。" : "当前角色需等待业务团队完成终审。"}</p>}
                </div>
              </div>
              <div className="flex items-start gap-3 rounded-xl border border-border p-4">
                <FileText className="mt-0.5 size-5 shrink-0 text-primary" />
                <div className="flex-1">
                  <b className="text-sm text-foreground">关联报告</b>
                  <p className="mt-1 text-sm text-muted-foreground">{monitorMonth ? `${grade === "A" ? "模型监控报告" : "模型诊断报告"} · ${monitorMonth}` : "暂无关联报告"}</p>
                  <Button className="mt-2 px-0" variant="link" size="sm" onClick={() => navigate("/operations/reports")}>打开报告 <ArrowRight /></Button>
                </div>
              </div>
            </div>
          </CardContent>
        </Card>

        <Card>
          <CardHeader className="border-b border-border">
            <CardTitle>② 监控指标趋势</CardTitle>
            <CardDescription>{months[0]} 至 {months[months.length - 1]} · PSI 使用滚动基准期{compareModel ? ` · 对比 ${compareModel.modelId}` : ""}</CardDescription>
          </CardHeader>
          <CardContent className="space-y-6">
            <div className="grid grid-cols-2 gap-6">
              <Card size="sm">
                <CardHeader><CardTitle>KS 趋势</CardTitle><CardDescription>分档线 40%，干预线 30%</CardDescription></CardHeader>
                <CardContent><MetricLineChart months={months} values={ksTrend} name={`${model.bank} ${model.modelId} · KS`} comparison={compareModel && compareKsTrend ? { name: `${compareModel.bank} ${compareModel.modelId}`, values: compareKsTrend } : undefined} thresholds={[{ value: 40, label: "40% 分档线", tone: "danger" }, { value: 30, label: "30% 干预线", tone: "warning" }]} /></CardContent>
              </Card>
              <Card size="sm">
                <CardHeader><CardTitle>PSI 趋势（滚动基准期）</CardTitle><CardDescription>10% 关注线，25% 偏移线</CardDescription></CardHeader>
                <CardContent><MetricLineChart months={months} values={psiTrend} name={`${model.bank} ${model.modelId} · PSI`} comparison={compareModel && comparePsiTrend ? { name: `${compareModel.bank} ${compareModel.modelId}`, values: comparePsiTrend } : undefined} thresholds={[{ value: 10, label: "10% 关注线", tone: "warning" }, { value: 25, label: "25% 偏移线", tone: "danger" }]} /></CardContent>
              </Card>
            </div>

            <Card size="sm">
              <CardHeader><CardTitle>排序性趋势（当月）</CardTitle><CardDescription>{monitorMonth || "当期"} · 蓝色柱为客户数，橙色折线为坏客户占比</CardDescription></CardHeader>
              <CardContent><SortingComboChart {...SORTING_DISTRIBUTION} /></CardContent>
            </Card>

            <div className="grid grid-cols-2 gap-6">
              <Card size="sm">
                <CardHeader><CardTitle>IV · 降幅前 5 特征</CardTitle><CardDescription>只展示降幅最大的五项</CardDescription></CardHeader>
                <CardContent className="space-y-3">
                  {ivTop.map((feature) => (
                    <div className="grid grid-cols-[minmax(0,1fr)_auto] items-center gap-3" key={feature.key}>
                      <span><b className="block text-sm text-foreground">{feature.name}</b><small className="font-mono text-xs text-muted-foreground">{feature.key}</small></span>
                      <span className="text-right"><b className="block tabular-nums text-danger">-{feature.ivDrop}%</b><small className="text-xs text-muted-foreground">IV {feature.iv.toFixed(3)}</small></span>
                    </div>
                  ))}
                </CardContent>
              </Card>
              <Card size="sm">
                <CardHeader><CardTitle>CSI · 升幅前 5 特征</CardTitle><CardDescription>只展示升幅最大的五项</CardDescription></CardHeader>
                <CardContent className="space-y-3">
                  {csiTop.map((feature) => (
                    <div className="grid grid-cols-[minmax(0,1fr)_auto] items-center gap-3" key={feature.key}>
                      <span><b className="block text-sm text-foreground">{feature.name}</b><small className="font-mono text-xs text-muted-foreground">{feature.key}</small></span>
                      <span className="text-right"><b className="block tabular-nums text-warning">+{feature.csiRise}pp</b><small className="text-xs text-muted-foreground">CSI {feature.csi.toFixed(3)}</small></span>
                    </div>
                  ))}
                </CardContent>
              </Card>
            </div>
          </CardContent>
        </Card>

        <Card>
          <CardHeader className="border-b border-border">
            <CardTitle>③ 特征分析</CardTitle>
            <CardDescription>先查看全量指标概览，再进入单个特征查看分布变化</CardDescription>
          </CardHeader>
          <CardContent className="px-0">
            <Table>
              <TableHeader>
                <TableRow>
                  <TableHead>入模特征</TableHead>
                  <TableHead>特征释义</TableHead>
                  <TableHead>IV（当期）</TableHead>
                  <TableHead>IV 降幅</TableHead>
                  <TableHead>CSI（当期）</TableHead>
                  <TableHead>CSI 升幅</TableHead>
                  <TableHead>KS 贡献变动</TableHead>
                  <TableHead>PSI 贡献变动</TableHead>
                  <TableHead className="text-right">操作</TableHead>
                </TableRow>
              </TableHeader>
              <TableBody>
                {FEATURE_METRICS.map((feature) => (
                  <TableRow data-state={selectedFeature === feature.key ? "selected" : undefined} key={feature.key}>
                    <TableCell className="font-mono text-xs">{feature.key}</TableCell>
                    <TableCell className="font-medium text-foreground">{feature.name}</TableCell>
                    <TableCell className="tabular-nums">{feature.iv.toFixed(3)}</TableCell>
                    <TableCell className="tabular-nums text-danger">-{feature.ivDrop}%</TableCell>
                    <TableCell className="tabular-nums">{feature.csi.toFixed(3)}</TableCell>
                    <TableCell className="tabular-nums text-warning">+{feature.csiRise}pp</TableCell>
                    <TableCell className="tabular-nums">{feature.ksContribution > 0 ? "+" : ""}{feature.ksContribution}pp</TableCell>
                    <TableCell className="tabular-nums">{feature.psiContribution > 0 ? "+" : ""}{feature.psiContribution}pp</TableCell>
                    <TableCell className="text-right"><Button variant="link" size="sm" onClick={() => setSelectedFeature(feature.key)}>查看分布</Button></TableCell>
                  </TableRow>
                ))}
              </TableBody>
            </Table>
          </CardContent>

          {chosenFeature && (
            <CardContent className="border-t border-border">
              <div className="mb-4 flex items-start gap-3 rounded-xl bg-brand-soft p-4 text-sm text-primary">
                <Info className="mt-0.5 size-5 shrink-0" />
                <div><b>{chosenFeature.name}（{chosenFeature.key}）分布变化</b><p className="mt-1 text-primary/80">对比基准期与当期各分箱占比，正式数据由后端接口读取。</p></div>
              </div>
              <div className="rounded-xl border border-dashed border-border p-8 text-center text-sm text-muted-foreground">暂无特征分布数据</div>
            </CardContent>
          )}
        </Card>
      </div>
    </section>
  );
}