import { useState } from 'react';
import { Plus } from 'lucide-react';
import { toast } from 'sonner';
import { api } from '@/api.js';
import { fmt, fmtDate } from '@/lib/utils';
import { METHOD_NONE, paymentSummary } from '@/lib/trackerUtils';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import {
  Dialog, DialogContent, DialogHeader, DialogTitle,
} from '@/components/ui/dialog';
import {
  Select, SelectTrigger, SelectValue, SelectContent, SelectItem,
} from '@/components/ui/select';
import PaymentModal from '@/components/tracker/PaymentModal';
import { PaymentProgress } from '@/components/tracker/PaymentProgress';
import { LowerThisMonthButton } from '@/components/tracker/LowerThisMonthButton';

export function PaymentLedgerDialog({ row, year, month, threshold, defaultPaymentDate, onClose, onSaved }) {
  const summary = paymentSummary(row, threshold);
  const [amount, setAmount] = useState(String(summary.remaining || summary.target || ''));
  const [date, setDate] = useState(defaultPaymentDate);
  const [method, setMethod] = useState(METHOD_NONE);
  const [notes, setNotes] = useState('');
  const [busy, setBusy] = useState(false);
  const [editPayment, setEditPayment] = useState(null);
  const payments = [...(row.payments || [])].sort((a, b) => String(b.paid_date).localeCompare(String(a.paid_date)));

  async function handleAdd(e) {
    e.preventDefault();
    const parsedAmount = parseFloat(amount);
    if (!Number.isFinite(parsedAmount) || parsedAmount <= 0) {
      toast.error('Enter a positive payment amount');
      return;
    }
    if (!date) {
      toast.error('Choose a payment date');
      return;
    }

    setBusy(true);
    try {
      await api.createPayment({
        bill_id: row.id,
        amount: parsedAmount,
        paid_date: date,
        method: method === METHOD_NONE ? null : method,
        notes: notes || null,
      });
      toast.success('Partial payment added');
      onSaved?.();
      onClose?.();
    } catch (err) {
      toast.error(err.message || 'Failed to add payment');
    } finally {
      setBusy(false);
    }
  }

  return (
    <>
      <Dialog open onOpenChange={value => { if (!value) onClose(); }}>
        <DialogContent className="max-h-[92svh] overflow-y-auto border-border/60 bg-card/95 backdrop-blur-xl sm:max-w-2xl">
          <DialogHeader>
            <DialogTitle className="text-base font-semibold tracking-tight">{row.name} Payments</DialogTitle>
          </DialogHeader>

          <div className="space-y-4">
            <div className="rounded-lg border border-border/60 bg-muted/25 p-3">
              <PaymentProgress row={row} threshold={threshold} onOpen={() => {}} />
              <div className="mt-2 flex justify-end">
                <LowerThisMonthButton
                  row={row}
                  year={year}
                  month={month}
                  refresh={onSaved}
                />
              </div>
            </div>

            <div className="grid gap-3 md:grid-cols-[1fr_1fr]">
              <div className="rounded-lg border border-border/60 bg-background/45 p-3">
                <p className="mb-2 text-xs font-semibold uppercase tracking-wider text-muted-foreground">Payment History</p>
                {payments.length > 0 ? (
                  <div className="space-y-2">
                    {payments.map(payment => (
                      <div key={payment.id} className="flex items-center justify-between gap-3 rounded-md border border-border/50 bg-card/60 px-3 py-2">
                        <div className="min-w-0">
                          <p className="font-mono text-sm font-semibold text-foreground">{fmt(payment.amount)}</p>
                          <p className="truncate text-xs text-muted-foreground">
                            {fmtDate(payment.paid_date)}
                            {payment.method ? ` · ${payment.method}` : ''}
                          </p>
                          {payment.notes && (
                            <p className="mt-0.5 truncate text-xs text-muted-foreground/80">{payment.notes}</p>
                          )}
                        </div>
                        <Button type="button" size="sm" variant="ghost" className="h-8 px-2.5 text-xs" onClick={() => setEditPayment(payment)}>
                          Edit
                        </Button>
                      </div>
                    ))}
                  </div>
                ) : (
                  <p className="rounded-md border border-dashed border-border/70 px-3 py-8 text-center text-sm text-muted-foreground">
                    No payments recorded for this month.
                  </p>
                )}
              </div>

              <form onSubmit={handleAdd} className="rounded-lg border border-border/60 bg-background/45 p-3">
                <p className="mb-2 text-xs font-semibold uppercase tracking-wider text-muted-foreground">Add Partial Payment</p>
                <div className="space-y-3">
                  <div className="space-y-1.5">
                    <Label htmlFor={`partial-amount-${row.id}`} className="text-xs uppercase tracking-wider text-muted-foreground">Amount</Label>
                    <Input
                      id={`partial-amount-${row.id}`}
                      type="number"
                      min="0"
                      step="0.01"
                      value={amount}
                      onChange={e => setAmount(e.target.value)}
                      className="font-mono bg-background/70 border-border/60"
                    />
                  </div>
                  <div className="space-y-1.5">
                    <Label htmlFor={`partial-date-${row.id}`} className="text-xs uppercase tracking-wider text-muted-foreground">Paid Date</Label>
                    <Input
                      id={`partial-date-${row.id}`}
                      type="date"
                      value={date}
                      onChange={e => setDate(e.target.value)}
                      className="font-mono bg-background/70 border-border/60"
                    />
                  </div>
                  <div className="space-y-1.5">
                    <Label className="text-xs uppercase tracking-wider text-muted-foreground">Method</Label>
                    <Select value={method} onValueChange={setMethod}>
                      <SelectTrigger className="bg-background/70 border-border/60">
                        <SelectValue placeholder="—" />
                      </SelectTrigger>
                      <SelectContent>
                        <SelectItem value={METHOD_NONE}>—</SelectItem>
                        <SelectItem value="bank">Bank Transfer</SelectItem>
                        <SelectItem value="card">Card</SelectItem>
                        <SelectItem value="autopay">Autopay</SelectItem>
                        <SelectItem value="check">Check</SelectItem>
                        <SelectItem value="cash">Cash</SelectItem>
                      </SelectContent>
                    </Select>
                  </div>
                  <div className="space-y-1.5">
                    <Label htmlFor={`partial-notes-${row.id}`} className="text-xs uppercase tracking-wider text-muted-foreground">Notes</Label>
                    <Input
                      id={`partial-notes-${row.id}`}
                      value={notes}
                      onChange={e => setNotes(e.target.value)}
                      className="bg-background/70 border-border/60"
                    />
                  </div>
                  <Button type="submit" disabled={busy} className="w-full gap-2">
                    <Plus className="h-4 w-4" />
                    {busy ? 'Adding...' : 'Add Payment'}
                  </Button>
                </div>
              </form>
            </div>
          </div>
        </DialogContent>
      </Dialog>

      {editPayment && (
        <PaymentModal
          payment={editPayment}
          onClose={() => setEditPayment(null)}
          onSave={() => {
            onSaved?.();
            setEditPayment(null);
          }}
        />
      )}
    </>
  );
}