/**
 * Form 16 Quick Actions – RE actions for the Quick Actions sidebar.
 * Shown only for Form 16 requests when RE user and no credit note yet.
 * Location: custom (Form 16 only); does not modify shared workflow components.
 */

import { useState, useEffect } from 'react';
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from '@/components/ui/dialog';
import { Loader2, Receipt, X, RotateCcw } from 'lucide-react';
import {
  getCreditNoteByRequestId,
  cancelForm16Submission,
  setForm16ResubmissionNeeded,
  generateForm16CreditNoteManually,
} from '@/services/form16Api';
import { toast } from 'sonner';

interface Form16QuickActionsProps {
  requestId: string;
  request: any;
  onRefresh?: () => void;
}

export function Form16QuickActions({ requestId, request, onRefresh }: Form16QuickActionsProps) {
  const [creditNote, setCreditNote] = useState<{ id: number; status: string } | null>(null);
  const [loading, setLoading] = useState(true);
  const [actionLoading, setActionLoading] = useState<'cancel' | 'resubmit' | 'credit' | null>(null);
  const [generateCnOpen, setGenerateCnOpen] = useState(false);
  const [generateCnAmount, setGenerateCnAmount] = useState('');

  const form16 = request?.form16Submission;
  const hasSubmission = !!form16;
  const hasCreditNote = !!creditNote && creditNote.status !== 'withdrawn';
  const suggestedAmount = form16?.tdsAmount != null ? Number(form16.tdsAmount) : undefined;

  useEffect(() => {
    if (!requestId) {
      setLoading(false);
      return;
    }
    let cancelled = false;
    (async () => {
      try {
        const note = await getCreditNoteByRequestId(requestId);
        if (!cancelled) setCreditNote(note ? { id: typeof note.id === 'number' ? note.id : Number(note.id), status: note.status || '' } : null);
      } catch {
        if (!cancelled) setCreditNote(null);
      } finally {
        if (!cancelled) setLoading(false);
      }
    })();
    return () => { cancelled = true; };
  }, [requestId]);

  const handleCancelSubmission = async () => {
    if (!requestId || !window.confirm('Cancel this Form 16 submission? The request will be marked as rejected.')) return;
    setActionLoading('cancel');
    try {
      await cancelForm16Submission(requestId);
      toast.success('Submission cancelled');
      onRefresh?.();
    } catch (e) {
      toast.error(e instanceof Error ? e.message : 'Failed to cancel submission');
    } finally {
      setActionLoading(null);
    }
  };

  const handleResubmissionNeeded = async () => {
    if (!requestId || !window.confirm('Mark this submission as resubmission needed? The dealer will need to resubmit Form 16.')) return;
    setActionLoading('resubmit');
    try {
      await setForm16ResubmissionNeeded(requestId);
      toast.success('Marked as resubmission needed');
      onRefresh?.();
    } catch (e) {
      toast.error(e instanceof Error ? e.message : 'Failed to update');
    } finally {
      setActionLoading(null);
    }
  };

  const handleGenerateCreditNote = async () => {
    const amount = parseFloat(generateCnAmount);
    if (!requestId || Number.isNaN(amount) || amount <= 0) {
      toast.error('Enter a valid amount to generate credit note');
      return;
    }
    setActionLoading('credit');
    try {
      await generateForm16CreditNoteManually(requestId, amount);
      setGenerateCnOpen(false);
      setGenerateCnAmount('');
      toast.success('Credit note generated (manually approved)');
      const note = await getCreditNoteByRequestId(requestId);
      setCreditNote(note ? { id: typeof note.id === 'number' ? note.id : Number(note.id), status: note.status || '' } : null);
      onRefresh?.();
    } catch (e) {
      toast.error(e instanceof Error ? e.message : 'Failed to generate credit note');
    } finally {
      setActionLoading(null);
    }
  };

  if (loading || !hasSubmission || hasCreditNote) return null;

  return (
    <>
      <Card className="border-blue-200 bg-blue-50/30" data-testid="form16-quick-actions-card">
        <CardHeader className="pb-2">
          <CardTitle className="text-sm flex items-center gap-2 text-blue-800">
            <Receipt className="w-4 h-4" />
            Form 16 actions
          </CardTitle>
          <CardDescription className="text-xs text-gray-600">
            View the document in the Documents tab. Cancel submission, mark resubmission needed, or generate credit note (e.g. when OCR was partial).
          </CardDescription>
        </CardHeader>
        <CardContent className="space-y-2">
          <Button
            variant="outline"
            size="sm"
            className="w-full justify-start border-red-300 text-red-700 hover:bg-red-50"
            onClick={handleCancelSubmission}
            disabled={!!actionLoading}
          >
            {actionLoading === 'cancel' ? <Loader2 className="w-3 h-3 animate-spin mr-1" /> : <X className="w-3 h-3 mr-1" />}
            Cancel submission
          </Button>
          <Button
            variant="outline"
            size="sm"
            className="w-full justify-start border-amber-300 text-amber-700 hover:bg-amber-50"
            onClick={handleResubmissionNeeded}
            disabled={!!actionLoading}
          >
            {actionLoading === 'resubmit' ? <Loader2 className="w-3 h-3 animate-spin mr-1" /> : <RotateCcw className="w-3 h-3 mr-1" />}
            Resubmission needed
          </Button>
          <Button
            variant="outline"
            size="sm"
            className="w-full justify-start border-emerald-300 text-emerald-700 hover:bg-emerald-50"
            onClick={() => {
              setGenerateCnAmount(suggestedAmount != null ? String(suggestedAmount) : '');
              setGenerateCnOpen(true);
            }}
            disabled={!!actionLoading}
          >
            {actionLoading === 'credit' ? <Loader2 className="w-3 h-3 animate-spin mr-1" /> : <Receipt className="w-3 h-3 mr-1" />}
            Generate credit note
          </Button>
        </CardContent>
      </Card>

      <Dialog open={generateCnOpen} onOpenChange={setGenerateCnOpen}>
        <DialogContent className="sm:max-w-md">
          <DialogHeader>
            <DialogTitle>Generate credit note (manual)</DialogTitle>
            <DialogDescription>
              Enter the amount for the credit note. This will mark the Form 16 as manually approved.
            </DialogDescription>
          </DialogHeader>
          <div className="grid gap-4 py-4">
            <div className="grid gap-2">
              <Label htmlFor="form16-cn-amount">Amount (₹)</Label>
              <Input
                id="form16-cn-amount"
                type="number"
                min="0"
                step="0.01"
                placeholder={suggestedAmount != null ? String(suggestedAmount) : '0'}
                value={generateCnAmount}
                onChange={(e) => setGenerateCnAmount(e.target.value)}
              />
              {suggestedAmount != null && (
                <p className="text-xs text-gray-500">Suggested from submission TDS amount: ₹{suggestedAmount.toLocaleString('en-IN')}</p>
              )}
            </div>
          </div>
          <DialogFooter>
            <Button variant="outline" onClick={() => setGenerateCnOpen(false)} disabled={!!actionLoading}>
              Cancel
            </Button>
            <Button onClick={handleGenerateCreditNote} disabled={!!actionLoading || !generateCnAmount.trim()}>
              {actionLoading === 'credit' ? <Loader2 className="w-4 h-4 animate-spin mr-2" /> : null}
              Generate credit note
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>
    </>
  );
}