import { useEffect, useMemo, useState } from "react";
import type {
  FeedbackCenterRecord,
  FeedbackCenterReviewStatus,
  FeedbackReasonCandidate,
} from "@/api/feedbackCenter";
import { Badge } from "@/components/ui/badge";
import { Button } from "@/components/ui/button";
import { Textarea } from "@/components/ui/textarea";

interface ReasonPickerProps {
  record: FeedbackCenterRecord | null;
  catalog: FeedbackReasonCandidate[];
  isPending: boolean;
  onSubmit: (payload: {
    review_status: Exclude<FeedbackCenterReviewStatus, "pending">;
    reason_code?: string;
    reason_text?: string;
  }) => Promise<void> | void;
}

export function ReasonPicker({ record, catalog, isPending, onSubmit }: ReasonPickerProps) {
  const [selectedReason, setSelectedReason] = useState<string>("");
  const [reasonText, setReasonText] = useState("");
  const [targetStatus, setTargetStatus] = useState<Exclude<FeedbackCenterReviewStatus, "pending">>("accepted");

  const candidates = useMemo(() => {
    if (!record) return [];
    const base = Array.isArray(record.reason_candidates) ? record.reason_candidates : [];
    const merged = [...base];
    catalog.forEach((item) => {
      if (merged.some((candidate) => candidate.code === item.code)) return;
      merged.push(item);
    });
    return merged;
  }, [catalog, record]);

  useEffect(() => {
    setSelectedReason(record?.reason_code || "");
    setReasonText(record?.reason_text || "");
    if (record?.review_status === "reviewed" || record?.review_status === "rejected") {
      setTargetStatus(record.review_status);
      return;
    }
    setTargetStatus("accepted");
  }, [record?.id, record?.reason_code, record?.reason_text, record?.review_status]);

  if (!record) {
    return (
      <div className="rounded-2xl border border-dashed border-slate-200 bg-slate-50/80 p-5 text-sm text-slate-500">
        选择左侧记录后，这里会显示候选原因与学习确认操作。
      </div>
    );
  }

  return (
    <div className="rounded-2xl border border-slate-200 bg-white p-5 shadow-sm">
      <div className="space-y-1">
        <p className="text-xs font-semibold uppercase tracking-[0.18em] text-slate-400">Review Action</p>
        <h3 className="text-lg font-semibold text-slate-900">确认学习原因</h3>
        <p className="text-sm text-slate-500">AI 已经先给出候选原因，人只需要确认、修正，或拒绝纳入学习。</p>
      </div>

      <div className="mt-5 space-y-3">
        <div className="flex flex-wrap gap-2">
          {(["reviewed", "accepted", "rejected"] as const).map((status) => (
            <Button
              key={status}
              type="button"
              size="sm"
              variant={targetStatus === status ? "default" : "outline"}
              className={targetStatus === status ? "bg-slate-900 text-white hover:bg-slate-800" : ""}
              onClick={() => setTargetStatus(status)}
            >
              {status === "reviewed" ? "仅复核" : status === "accepted" ? "确认学习" : "拒绝样本"}
            </Button>
          ))}
        </div>

        <div className="space-y-2">
          <p className="text-sm font-medium text-slate-700">候选原因</p>
          <div className="flex flex-wrap gap-2">
            {candidates.map((candidate) => {
              const active = selectedReason === candidate.code;
              return (
                <button
                  key={candidate.code}
                  type="button"
                  className={`rounded-full border px-3 py-1 text-xs transition ${
                    active
                      ? "border-slate-900 bg-slate-900 text-white"
                      : "border-slate-200 bg-slate-50 text-slate-600 hover:border-slate-300 hover:bg-slate-100"
                  }`}
                  onClick={() => setSelectedReason(candidate.code)}
                >
                  {candidate.label}
                  {candidate.confidence !== undefined && candidate.confidence !== null && (
                    <span className={`ml-1 ${active ? "text-slate-200" : "text-slate-400"}`}>
                      {Math.round(Number(candidate.confidence) * 100)}%
                    </span>
                  )}
                </button>
              );
            })}
          </div>
          {!candidates.length && (
            <Badge variant="outline" className="border-amber-200 bg-amber-50 text-amber-700">
              当前没有自动候选，请手工补充原因
            </Badge>
          )}
        </div>

        <div className="space-y-2">
          <p className="text-sm font-medium text-slate-700">补充备注</p>
          <Textarea
            value={reasonText}
            onChange={(event) => setReasonText(event.target.value)}
            placeholder="例如：依赖链路还没锁定，所以负责人不该提前自动落库。"
            className="min-h-[110px] resize-none border-slate-200"
          />
        </div>

        <Button
          type="button"
          className="w-full bg-blue-600 text-white hover:bg-blue-700"
          disabled={isPending}
          onClick={() =>
            Promise.resolve(
              onSubmit({
                review_status: targetStatus,
                reason_code: selectedReason || undefined,
                reason_text: reasonText.trim() || undefined,
              })
            )
          }
        >
          {isPending ? "提交中..." : targetStatus === "accepted" ? "确认进入学习池" : targetStatus === "rejected" ? "拒绝该样本" : "保存复核结果"}
        </Button>
      </div>
    </div>
  );
}