import React, { useCallback, useEffect, useMemo, useState } from 'react';
import { api, errorMessage } from '../../services/apiClient.ts';
import type { Cycle, InitialBalanceResult } from '../../types/api.ts';
import { formatNumber } from '../../utils/format.ts';
import InitialBalanceComparison from './InitialBalanceComparison.tsx';

interface InitialBalanceCardProps {
  cycle: Cycle;
  onSaved: (result: InitialBalanceResult) => void;
}

const InitialBalanceCard: React.FC<InitialBalanceCardProps> = ({ cycle, onSaved }) => {
  const savedBalanceDate = cycle.feed_initial_balance_date ?? cycle.start_date;
  const [balanceDate, setBalanceDate] = useState(savedBalanceDate);
  const [manualEntry, setManualEntry] = useState<string>(
    cycle.feed_initial_balance > 0 ? String(cycle.feed_initial_balance) : ''
  );
  const [saving, setSaving] = useState(false);
  const [comparing, setComparing] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [comparison, setComparison] = useState<InitialBalanceResult | null>(null);

  useEffect(() => {
    setBalanceDate(cycle.feed_initial_balance_date ?? cycle.start_date);
    setManualEntry(cycle.feed_initial_balance > 0 ? String(cycle.feed_initial_balance) : '');
    setComparison(null);
    setError(null);
  }, [cycle.id, cycle.feed_initial_balance, cycle.feed_initial_balance_date, cycle.start_date]);

  const manualValue = manualEntry === '' ? null : Number(manualEntry);

  const canSave = useMemo(
    () => balanceDate !== '' && manualEntry !== '' && Number(manualEntry) >= 0 && !saving,
    [balanceDate, manualEntry, saving]
  );

  const loadComparison = useCallback(async () => {
    if (balanceDate === '' || manualValue == null || Number.isNaN(manualValue) || manualValue < 0) {
      setComparison(null);
      return;
    }

    setComparing(true);
    try {
      const compared = await api.cycles.initialBalanceCompare(cycle.id, {
        date: balanceDate,
        manual: manualValue,
      });
      setComparison(compared);
    } catch (err) {
      setComparison(null);
      setError(errorMessage(err));
    } finally {
      setComparing(false);
    }
  }, [balanceDate, cycle.id, manualValue]);

  useEffect(() => {
    if (manualValue == null || manualValue < 0) {
      setComparison(null);
      return;
    }
    void loadComparison();
  }, [loadComparison, manualValue]);

  const handleSave = async () => {
    if (!canSave) return;
    setSaving(true);
    setError(null);
    try {
      const saved = await api.cycles.initialBalance(cycle.id, {
        date: balanceDate,
        feed_in_manual: Number(manualEntry),
      });
      setComparison(saved);
      onSaved(saved);
    } catch (err) {
      setError(errorMessage(err));
    } finally {
      setSaving(false);
    }
  };

  return (
    <div className="bg-gradient-to-br from-blue-50 to-indigo-50 p-6 rounded-xl shadow-sm border-2 border-blue-200">
      <div className="flex items-center gap-3 mb-4">
        <div className="bg-blue-500 text-white p-3 rounded-lg">
          <i className="fa-solid fa-boxes-packing text-2xl"></i>
        </div>
        <div>
          <h2 className="text-xl font-bold text-gray-800">Saldo Awal</h2>
          <p className="text-sm text-gray-600">
            Masukkan saldo awal karung pakan pada tanggal tertentu, lalu bandingkan dengan deteksi
            IoT.
          </p>
        </div>
      </div>

      <div className="bg-white rounded-lg p-6 border border-blue-200">
        <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
          <div>
            <label
              htmlFor="initial-balance-date"
              className="text-sm font-semibold text-gray-700 block mb-1"
            >
              Tanggal
            </label>
            <input
              id="initial-balance-date"
              type="date"
              value={balanceDate}
              onChange={(event) => setBalanceDate(event.target.value)}
              className="w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:ring-blue-500 focus:border-blue-500 text-sm"
            />
          </div>
          <div>
            <label
              htmlFor="initial-balance-manual"
              className="text-sm font-semibold text-gray-700 block mb-1"
            >
              Feed In Manual (karung)
            </label>
            <input
              id="initial-balance-manual"
              type="number"
              min={0}
              value={manualEntry}
              onChange={(event) => setManualEntry(event.target.value)}
              placeholder="Contoh: 120"
              className="w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:ring-blue-500 focus:border-blue-500 text-sm"
            />
          </div>
        </div>

        {error && (
          <p className="mt-3 text-sm font-semibold text-red-700 bg-red-50 border border-red-200 rounded-lg p-3">
            {error}
          </p>
        )}

        <div className="mt-4 flex flex-col sm:flex-row sm:items-center sm:justify-between gap-3">
          <div className="flex flex-wrap items-center gap-2">
            <button
              type="button"
              onClick={handleSave}
              disabled={!canSave}
              className="inline-flex items-center gap-2 rounded-lg bg-blue-600 px-4 py-2 text-sm font-semibold text-white transition-colors hover:bg-blue-700 disabled:cursor-not-allowed disabled:bg-gray-400"
            >
              <i className={`fa-solid fa-floppy-disk ${saving ? 'fa-spin' : ''}`} />
              <span>{saving ? 'Menyimpan...' : 'Simpan Saldo Awal'}</span>
            </button>
            <button
              type="button"
              onClick={() => void loadComparison()}
              disabled={manualValue == null || manualValue < 0 || comparing}
              className="inline-flex items-center gap-2 rounded-lg border border-blue-300 bg-white px-4 py-2 text-sm font-semibold text-blue-700 transition-colors hover:bg-blue-50 disabled:cursor-not-allowed disabled:text-gray-400"
            >
              <i className={`fa-solid fa-satellite-dish ${comparing ? 'fa-spin' : ''}`} />
              <span>{comparing ? 'Memuat IoT...' : 'Refresh IoT'}</span>
            </button>
          </div>
          {cycle.feed_initial_balance > 0 && comparison == null && (
            <p className="text-sm text-gray-600">
              Saldo awal tersimpan:{' '}
              <strong className="text-blue-700">
                {formatNumber(cycle.feed_initial_balance)} karung
              </strong>
            </p>
          )}
        </div>

        {comparison && <InitialBalanceComparison result={comparison} loading={comparing} />}
      </div>
    </div>
  );
};

export default InitialBalanceCard;