import {useState, useEffect} from 'react';
import {Dialog, DialogContent, DialogDescription, DialogFooter, DialogHeader, DialogTitle} from '@/components/ui/dialog';
import {Select, SelectContent, SelectItem, SelectTrigger, SelectValue} from '@/components/ui/select';
import {Button} from '@/components/ui/button';
import {Input} from '@/components/ui/input';
import {Label} from '@/components/ui/label';
import {useAppDispatch, updateLiability, deleteLiability, type Liability} from '@/store';
import {validatePositiveNumber, validateRequired} from '@/lib/validation';

interface Props {
  open: boolean;
  onOpenChange: (open: boolean) => void;
  liability: Liability | null;
}

const liabilityTypes = ['credit_card', 'loan', 'mortgage', 'other'] as const;

export default function EditLiabilityDialog({open, onOpenChange, liability}: Props) {
  const dispatch = useAppDispatch();
  const [form, setForm] = useState({name: '', type: '', balance: ''});
  const [errors, setErrors] = useState({name: '', balance: ''});

  useEffect(() => {
    if (liability) {
      setForm({
        name: liability.name,
        type: liability.type,
        balance: liability.balance.toString()
      });
      setErrors({name: '', balance: ''});
    }
  }, [liability]);

  const validate = (): boolean => {
    const newErrors = {name: '', balance: ''};
    let isValid = true;

    if (!validateRequired(form.name)) {
      newErrors.name = 'Name is required';
      isValid = false;
    }

    const balanceNum = validatePositiveNumber(form.balance);
    if (balanceNum === null) {
      newErrors.balance = 'Please enter a valid positive number';
      isValid = false;
    }

    setErrors(newErrors);
    return isValid;
  };

  const handleSubmit = (e: React.FormEvent) => {
    e.preventDefault();
    if (!liability || !validate()) return;

    const balanceNum = validatePositiveNumber(form.balance);
    if (balanceNum === null) return;

    dispatch(
      updateLiability({
        id: liability.id,
        data: {
          name: form.name.trim(),
          type: form.type.toUpperCase() as 'CREDIT_CARD' | 'LOAN' | 'MORTGAGE' | 'OTHER',
          currentBalance: balanceNum,
        }
      })
    );
    onOpenChange(false);
  };

  const handleDelete = () => {
    if (!liability) return;
    if (confirm(`Are you sure you want to delete "${liability.name}"?`)) {
      dispatch(deleteLiability(liability.id));
      onOpenChange(false);
    }
  };

  if (!liability) return null;

  return (
    <Dialog open={open} onOpenChange={onOpenChange}>
      <DialogContent className="card-elevated sm:max-w-md">
        <DialogHeader>
          <DialogTitle>Edit Liability</DialogTitle>
          <DialogDescription>Update liability details or delete this liability</DialogDescription>
        </DialogHeader>
        <form onSubmit={handleSubmit}>
          <div className="grid gap-4 py-4">
            <div className="grid gap-2">
              <Label htmlFor="edit-name">Name</Label>
              <Input
                id="edit-name"
                placeholder="e.g., Credit Card"
                value={form.name}
                onChange={e => setForm({...form, name: e.target.value})}
                className="input-depth"
                required
              />
              {errors.name && <p className="text-xs text-red-400">{errors.name}</p>}
            </div>
            <div className="grid gap-2">
              <Label>Type</Label>
              <Select value={form.type} onValueChange={v => setForm({...form, type: v})} required>
                <SelectTrigger className="input-depth">
                  <SelectValue placeholder="Select type" />
                </SelectTrigger>
                <SelectContent>
                  {liabilityTypes.map(t => (
                    <SelectItem key={t} value={t} className="capitalize">
                      {t.replace('_', ' ')}
                    </SelectItem>
                  ))}
                </SelectContent>
              </Select>
            </div>
            <div className="grid gap-2">
              <Label htmlFor="edit-balance">Balance</Label>
              <Input
                id="edit-balance"
                type="number"
                step="0.01"
                min="0"
                placeholder="0.00"
                value={form.balance}
                onChange={e => setForm({...form, balance: e.target.value})}
                className="input-depth"
                required
              />
              {errors.balance && <p className="text-xs text-red-400">{errors.balance}</p>}
            </div>
          </div>
          <DialogFooter className="flex justify-between sm:justify-between">
            <Button type="button" variant="destructive" onClick={handleDelete} size="sm">
              Delete
            </Button>
            <div className="flex gap-2">
              <Button type="button" variant="secondary" onClick={() => onOpenChange(false)}>
                Cancel
              </Button>
              <Button type="submit">Save Changes</Button>
            </div>
          </DialogFooter>
        </form>
      </DialogContent>
    </Dialog>
  );
}