import { useEffect } from "react";
import { useMutation } from "@tanstack/react-query";
import { Button } from "@/components/ui/button";
import { Sparkles, Loader2 } from "lucide-react";
import { analyticsService } from "@/services/analytics.service";
import { useToast } from "@/hooks/use-toast";

interface Props {
  onAccept: (marks: number, feedback: string) => void;
  submissionId?: number;
  submissionText?: string;
  rubricId?: number;
}

const DEFAULT_TEXT =
  "Sample submission for AI grading suggestion. Replace by passing submissionText when integrating with real submissions.";

export default function AiGradingAssistant({
  onAccept,
  submissionId = 1,
  submissionText = DEFAULT_TEXT,
  rubricId,
}: Props) {
  const { toast } = useToast();

  const gradeMutation = useMutation({
    mutationFn: () =>
      analyticsService.getGradingSuggestion({
        submission_id: submissionId,
        text: submissionText,
        ...(rubricId !== undefined ? { rubric_id: rubricId } : {}),
      }),
    onError: (err: Error) => {
      toast({
        variant: "destructive",
        title: "Could not load AI grade",
        description: err.message || "Try again later.",
      });
    },
  });

  useEffect(() => {
    gradeMutation.mutate();
    // eslint-disable-next-line react-hooks/exhaustive-deps -- refetch when inputs change
  }, [submissionId, submissionText, rubricId]);

  const data = gradeMutation.data;
  const marks = data ? Math.round(data.overall_score) : 0;
  const feedbackBlock = data
    ? [
        data.feedback,
        data.suggestions?.length
          ? `Suggestions:\n${data.suggestions.map((s) => `• ${s}`).join("\n")}`
          : "",
      ]
        .filter(Boolean)
        .join("\n\n")
    : "";

  return (
    <div className="rounded-lg border bg-muted/30 p-4 space-y-3">
      <p className="text-xs font-semibold text-primary flex items-center gap-1">
        <Sparkles className="h-3 w-3" /> AI Suggested Grade
      </p>
      {gradeMutation.isPending ? (
        <div className="flex items-center gap-2 text-sm text-muted-foreground py-2">
          <Loader2 className="h-4 w-4 animate-spin text-primary" /> Analyzing submission...
        </div>
      ) : gradeMutation.isError ? (
        <p className="text-sm text-destructive">Could not load a suggestion. Check the console or try again.</p>
      ) : data ? (
        <>
          <div>
            <p className="text-sm text-muted-foreground">Suggested marks</p>
            <p className="text-2xl font-bold">{marks}/100</p>
          </div>
          <div>
            <p className="text-sm text-muted-foreground mb-1">Suggested feedback</p>
            <p className="text-sm whitespace-pre-wrap">{feedbackBlock}</p>
          </div>
          {data.scores && Object.keys(data.scores).length > 0 && (
            <div className="space-y-1">
              <p className="text-sm text-muted-foreground">Rubric scores</p>
              <ul className="text-xs text-muted-foreground space-y-0.5">
                {Object.entries(data.scores).map(([k, v]) => (
                  <li key={k}>
                    {k}: {v}
                  </li>
                ))}
              </ul>
            </div>
          )}
          <Button size="sm" onClick={() => onAccept(marks, feedbackBlock)}>
            <Sparkles className="h-3.5 w-3.5 mr-1" /> Accept AI Grade
          </Button>
        </>
      ) : null}
    </div>
  );
}