'use client';

import { useState } from 'react';
import { Sparkles, Loader2 } from 'lucide-react';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Alert, AlertDescription } from '@/components/ui/alert';
import { StatusBadge } from '@/components/ui/status-badge';
import { toast } from 'sonner';
import { useSession } from '@/lib/auth-client';
import { hasPermission } from '@/lib/permissions';

export interface ClassificationCardData {
  id: string;
  verdict: 'SPAM' | 'UNWANTED' | 'THREAT' | 'USER_AWARENESS';
  confidence: string | null;
  summary: string | null;
  reasons: string[];
  recommendedActions: string[];
  requiresApproval: boolean;
  createdAt: string;
}

interface ClassificationCardProps {
  campaignId: string;
  classification: ClassificationCardData | null;
  onReclassified: () => void;
}

const VERDICT_VARIANT_CLASS: Record<ClassificationCardData['verdict'], string> = {
  SPAM: 'bg-slate-500/15 text-slate-600',
  UNWANTED: 'bg-amber-500/15 text-amber-600',
  THREAT: 'bg-destructive/15 text-destructive',
  USER_AWARENESS: 'bg-emerald-500/15 text-emerald-600',
};

const ACTION_LABEL: Record<string, string> = {
  block_sender: 'Block sender',
  purge_message: 'Purge message',
  warn_user: 'Warn user',
  no_action: 'No action',
  reset_password: 'Reset password',
  isolate_endpoint: 'Isolate endpoint',
  disable_forwarding_rule: 'Disable forwarding rule',
  acknowledge_user: 'Acknowledge user',
};

function humanizeAction(actionType: string): string {
  return (
    ACTION_LABEL[actionType] ??
    actionType
      .split('_')
      .map((word) => word.charAt(0).toUpperCase() + word.slice(1))
      .join(' ')
  );
}

export function ClassificationCard({
  campaignId,
  classification,
  onReclassified,
}: ClassificationCardProps) {
  const { data: session } = useSession();
  const [isReclassifying, setIsReclassifying] = useState(false);
  const role = (session?.user as { role?: string } | undefined)?.role ?? 'user';
  const canReclassify = hasPermission(role, 'phishing', 'analyze');

  // Guard: this card renders nothing for a null classification. The review
  // page (not this card) chooses the replacement UI for both null-classification
  // paths — the default "grouped but not yet classified" empty state (plan 06)
  // and the D-08 ungrouped-report Alert (plan 06) — so we never dereference
  // classification.verdict/.reasons/etc. here.
  if (classification == null) return null;

  async function handleReclassify() {
    setIsReclassifying(true);
    try {
      const res = await fetch(`/api/phishing/campaigns/${campaignId}/classify`, {
        method: 'POST',
      });
      const data = await res.json();
      if (!res.ok) throw new Error(data.message ?? data.error ?? 'Reclassify failed');
      toast.success('Ticket reclassified');
      onReclassified();
    } catch (err) {
      toast.error(`Reclassify failed: ${err instanceof Error ? err.message : 'Unknown error'}`);
    } finally {
      setIsReclassifying(false);
    }
  }

  return (
    <Card>
      <CardHeader>
        <div className="flex items-start justify-between gap-4">
          <CardTitle className="font-bold">
            <Sparkles className="h-4 w-4 mr-2 inline" />
            Classification
          </CardTitle>
          {canReclassify && (
            <Button
              variant="outline"
              size="sm"
              disabled={isReclassifying}
              onClick={handleReclassify}
            >
              {isReclassifying ? (
                <Loader2 className="h-3.5 w-3.5 mr-1.5 animate-spin" />
              ) : null}
              Reclassify ticket
            </Button>
          )}
        </div>
      </CardHeader>
      <CardContent className="space-y-4">
        <div className="flex items-center gap-2">
          <StatusBadge variantClass={VERDICT_VARIANT_CLASS[classification.verdict]}>
            {classification.verdict}
          </StatusBadge>
          {classification.confidence != null && Number.isFinite(Number(classification.confidence)) && (
            <span className="text-sm text-muted-foreground">
              {Math.round(Number(classification.confidence) * 100)}% confidence
            </span>
          )}
        </div>

        {classification.summary && (
          <p className="text-sm">{classification.summary}</p>
        )}

        {classification.reasons.length > 0 && (
          <ul className="list-disc pl-5 text-sm text-muted-foreground space-y-1">
            {classification.reasons.map((reason, idx) => (
              <li key={idx}>{reason}</li>
            ))}
          </ul>
        )}

        {classification.recommendedActions.length > 0 && (
          <div className="flex flex-wrap gap-2">
            {classification.recommendedActions.map((actionType) => (
              <StatusBadge
                key={actionType}
                variantClass="bg-slate-500/15 text-slate-600"
              >
                {humanizeAction(actionType)}
              </StatusBadge>
            ))}
          </div>
        )}

        {classification.requiresApproval && (
          <Alert className="border-amber-500/50 text-amber-600 dark:border-amber-500 [&>svg]:text-amber-600">
            <AlertDescription>
              This classification recommends a destructive action and requires
              explicit approval before remediation can proceed.
            </AlertDescription>
          </Alert>
        )}
      </CardContent>
    </Card>
  );
}