import React, { useEffect, useState } from 'react';
import { useFarm } from '../context/FarmContext.tsx';
import {
  formatDateId,
  formatDateRange,
  resolveCycleBoundDate,
  resolveCycleStatus,
  cycleLastDayIndex,
} from '../utils/format.ts';
import type { Cycle } from '../types/api.ts';

type Phase = { name: string; startDay: number; endDay: number; color: string };

function phasesFor(totalDays: number): Phase[] {
  const safeDays = Math.max(totalDays, 1);
  const starterEnd = Math.min(10, safeDays);
  const growerEnd = Math.min(24, safeDays);
  const phases: Phase[] = [
    { name: 'Starter', startDay: 1, endDay: starterEnd, color: 'bg-red-400' },
  ];
  if (growerEnd > starterEnd) {
    phases.push({
      name: 'Grower',
      startDay: starterEnd + 1,
      endDay: growerEnd,
      color: 'bg-orange-400',
    });
  }
  if (safeDays > growerEnd) {
    phases.push({
      name: 'Finisher',
      startDay: growerEnd + 1,
      endDay: safeDays,
      color: 'bg-yellow-500',
    });
  }
  return phases;
}

const statusConfig = {
  active: { label: 'Active', bg: 'bg-red-100', text: 'text-red-800', icon: 'fa-running' },
  pending_close: {
    label: 'Menunggu GM',
    bg: 'bg-amber-100',
    text: 'text-amber-800',
    icon: 'fa-hourglass-half',
  },
  closed: {
    label: 'Completed',
    bg: 'bg-green-100',
    text: 'text-green-800',
    icon: 'fa-check-circle',
  },
};

const SingleCycleView: React.FC<{ cycle: Cycle }> = ({ cycle }) => {
  const boundDate = resolveCycleBoundDate(cycle);
  const displayTotalDays = Math.max(cycle.total_days || 1, cycleLastDayIndex(cycle) + 1);
  const phases = phasesFor(displayTotalDays);
  const currentDay = Math.min(Math.max(cycle.current_day, 0), displayTotalDays);
  const cycleStatus = resolveCycleStatus(cycle);
  const progress = displayTotalDays > 0 ? (currentDay / displayTotalDays) * 100 : 0;
  const showMarker = cycleStatus === 'active' || cycleStatus === 'pending_close';

  return (
    <div className="pt-4">
      <div className="flex flex-col sm:flex-row justify-between sm:items-center mb-4 gap-4">
        <p className="text-sm text-gray-500">
          Siklus:{' '}
          <span className="font-semibold">{formatDateRange(cycle.start_date, cycle.end_date)}</span>
        </p>
        <div className="text-sm sm:text-right">
          <p className="font-semibold text-gray-700">
            {cycle.end_date ? 'Estimasi Panen' : 'Batas data'}
          </p>
          <p className="text-red-600 font-bold">{formatDateId(cycle.end_date ?? boundDate)}</p>
        </div>
      </div>
      <div className="relative pt-8">
        <div className="relative h-8 bg-gray-200 rounded-lg flex items-center shadow-inner overflow-hidden">
          {phases.map((phase) => {
            const width = ((phase.endDay - phase.startDay + 1) / displayTotalDays) * 100;
            return (
              <div
                key={phase.name}
                className={`h-full ${phase.color} flex items-center justify-center text-white text-sm font-bold`}
                style={{ width: `${width}%` }}
                title={`${phase.name} (Hari ${phase.startDay}-${phase.endDay})`}
              >
                <span className="hidden sm:inline opacity-90">{phase.name}</span>
              </div>
            );
          })}
        </div>
        {showMarker && (
          <div
            className="absolute top-0 transition-all duration-500 ease-out"
            style={{ left: `calc(${progress}% - 2.5rem)` }}
          >
            <div className="relative w-24 text-center">
              <div className="font-bold text-red-600 bg-red-100 px-3 py-1.5 rounded-md shadow-sm border border-red-200 text-base">
                Hari ke-{currentDay}
              </div>
              <div className="absolute left-1/2 -translate-x-1/2 w-0 h-0 border-l-8 border-l-transparent border-r-8 border-r-transparent border-t-8 border-t-red-100" />
            </div>
          </div>
        )}
        <div className="flex justify-between items-center text-sm font-semibold text-gray-500 mt-2 px-1">
          <div className="flex flex-col items-start">
            <span>Hari 1</span>
            <span className="text-xs font-normal text-gray-400">
              {formatDateId(cycle.start_date)}
            </span>
            <span className="text-xs font-normal text-gray-400">
              Berat DOC: {cycle.chick_in_weight} gram
            </span>
            <span className="text-xs font-normal text-gray-400">
              DOC In: {cycle.doc_in_count.toLocaleString('id-ID')} ekor
            </span>
          </div>
          <div className="flex flex-col items-end">
            <span>Hari {displayTotalDays}</span>
            <span className="text-xs font-normal text-gray-400">
              {formatDateId(cycle.end_date ?? boundDate)}
            </span>
          </div>
        </div>
      </div>
    </div>
  );
};

const CycleTimeline: React.FC = () => {
  const { cycles, selectedCycleId, setSelectedCycleId } = useFarm();
  const [localId, setLocalId] = useState<number | null>(selectedCycleId);

  useEffect(() => {
    setLocalId(selectedCycleId);
  }, [selectedCycleId]);

  const selected = cycles.find((c) => c.id === localId) ?? null;

  return (
    <div className="bg-white p-6 sm:p-8 rounded-xl shadow-sm mb-8">
      <h2 className="text-2xl font-bold text-gray-800 mb-4">Linimasa Siklus Produksi</h2>
      {cycles.length === 0 ? (
        <p className="text-sm text-gray-500">
          Belum ada siklus untuk kandang ini. Buat di Pengaturan.
        </p>
      ) : (
        <>
          <div className="border-b border-gray-200 overflow-x-auto">
            <nav className="-mb-px flex space-x-6 min-w-max" aria-label="Tabs">
              {cycles.map((cycle) => {
                const config = statusConfig[resolveCycleStatus(cycle)];
                const isActive = cycle.id === selected?.id;
                return (
                  <button
                    key={cycle.id}
                    onClick={() => {
                      setLocalId(cycle.id);
                      setSelectedCycleId(cycle.id);
                    }}
                    className={`flex items-center gap-2 px-3 py-2 text-sm font-semibold rounded-t-lg transition-colors border-b-2 whitespace-nowrap ${
                      isActive
                        ? 'border-red-500 text-red-600'
                        : 'border-transparent text-gray-500 hover:text-gray-700 hover:border-gray-300'
                    }`}
                  >
                    <i className={`fa-solid ${config.icon}`} />
                    <span>
                      {formatDateId(cycle.start_date)} ({config.label})
                    </span>
                  </button>
                );
              })}
            </nav>
          </div>
          {selected ? (
            <SingleCycleView cycle={selected} />
          ) : (
            <p className="text-sm text-gray-500 mt-4">
              Pilih tab siklus di atas, atau buat di Pengaturan.
            </p>
          )}
        </>
      )}
    </div>
  );
};

export default CycleTimeline;