"use client";

import { useState } from "react";
import { useRouter } from "next/navigation";
import { Sparkles, Plus, Loader2 } from "lucide-react";
import { Button } from "@/components/ui/button";
import { Textarea } from "@/components/ui/textarea";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { Badge } from "@/components/ui/badge";
import { Sheet, SheetContent, SheetHeader, SheetTitle, SheetTrigger } from "@/components/ui/sheet";
import { getRiskGrade } from "@/lib/constants";
import { addHazard } from "@/actions/risk-assessment";

interface SuggestedHazard {
  category: string;
  hazard: string;
  consequence: string;
  severity: number;
  likelihood: number;
  existingControls: string;
}

export function AiHazardPanel({ assessmentId }: { assessmentId: string }) {
  const router = useRouter();
  const [activity, setActivity] = useState("");
  const [loading, setLoading] = useState(false);
  const [suggestions, setSuggestions] = useState<SuggestedHazard[]>([]);
  const [error, setError] = useState("");

  async function handleSuggest() {
    if (!activity.trim()) return;
    setLoading(true);
    setError("");
    setSuggestions([]);

    try {
      const res = await fetch("/api/ai/suggest-hazards", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ activity }),
      });
      const data = await res.json();
      if (data.error) throw new Error(data.error);
      setSuggestions(data.hazards || []);
    } catch (err) {
      setError(err instanceof Error ? err.message : "AI 오류");
    }
    setLoading(false);
  }

  async function handleAdd(hazard: SuggestedHazard) {
    await addHazard(assessmentId, {
      category: hazard.category,
      activity: activity,
      hazard: hazard.hazard,
      consequence: hazard.consequence,
      severity: hazard.severity,
      likelihood: hazard.likelihood,
      existingControls: hazard.existingControls,
    });
    router.refresh();
  }

  return (
    <Sheet>
      <SheetTrigger asChild>
        <Button variant="outline" size="sm">
          <Sparkles className="h-4 w-4 mr-2" />
          AI 추천
        </Button>
      </SheetTrigger>
      <SheetContent className="w-[500px] sm:max-w-[500px] overflow-auto">
        <SheetHeader>
          <SheetTitle>AI 유해위험요인 추천</SheetTitle>
        </SheetHeader>
        <div className="space-y-4 mt-4">
          <div className="space-y-2">
            <Textarea
              value={activity}
              onChange={(e) => setActivity(e.target.value)}
              placeholder="작업/공정을 설명하세요. 예: 5층 건물 외벽 페인트 작업, 비계 사용"
              rows={3}
            />
            <Button onClick={handleSuggest} disabled={loading || !activity.trim()}>
              {loading ? (
                <Loader2 className="h-4 w-4 mr-2 animate-spin" />
              ) : (
                <Sparkles className="h-4 w-4 mr-2" />
              )}
              {loading ? "분석 중..." : "위험요인 분석"}
            </Button>
          </div>

          {error && <p className="text-sm text-destructive">{error}</p>}

          {suggestions.map((h, i) => {
            const risk = h.severity * h.likelihood;
            const grade = getRiskGrade(risk);
            return (
              <Card key={i}>
                <CardContent className="py-3 space-y-2">
                  <div className="flex items-center justify-between">
                    <Badge variant="outline">{h.category}</Badge>
                    <Badge className={`${grade.color} ${grade.textColor} border`} variant="outline">
                      {risk} ({grade.label})
                    </Badge>
                  </div>
                  <p className="text-sm font-medium">{h.hazard}</p>
                  {h.consequence && (
                    <p className="text-xs text-muted-foreground">
                      예상 재해: {h.consequence}
                    </p>
                  )}
                  {h.existingControls && (
                    <p className="text-xs text-muted-foreground">
                      기존 조치: {h.existingControls}
                    </p>
                  )}
                  <div className="flex justify-between items-center text-xs text-muted-foreground">
                    <span>S={h.severity} x L={h.likelihood}</span>
                    <Button size="sm" variant="outline" onClick={() => handleAdd(h)}>
                      <Plus className="h-3.5 w-3.5 mr-1" />
                      추가
                    </Button>
                  </div>
                </CardContent>
              </Card>
            );
          })}
        </div>
      </SheetContent>
    </Sheet>
  );
}