import React, { useState } from 'react';
import { useSessions } from '../../hooks/useSleepSession';
import { Edit2, Check, X } from 'lucide-react';
import type { SleepSessionRead } from '../../types';
import { formatDateTime, toLocalDatetimeInputValue, getDurationMinutes } from '../../utils/time';

export function SessionList() {
  const { sessions, isLoading, updateSession } = useSessions();
  const [editingId, setEditingId] = useState<number | null>(null);
  const [editStart, setEditStart] = useState('');
  const [editEnd, setEditEnd] = useState('');

  if (isLoading) return <div className="text-center p-4">Loading sessions...</div>;
  if (!sessions.length) return <div className="text-center p-4 text-gray-500">No sessions recorded.</div>;

  const handleSave = async (id: number) => {
    try {
      await updateSession({
        sessionId: id,
        payload: {
          start_time: new Date(editStart).toISOString(),
          end_time: editEnd ? new Date(editEnd).toISOString() : null,
        }
      } as any);
      setEditingId(null);
    } catch (err) {
      console.error(err);
      alert('Failed to update session');
    }
  };

  const startEditing = (s: SleepSessionRead) => {
    setEditingId(s.id);
    setEditStart(toLocalDatetimeInputValue(new Date(s.start_time)));
    setEditEnd(s.end_time ? toLocalDatetimeInputValue(new Date(s.end_time)) : '');
  };

  const handleCancel = () => {
    setEditingId(null);
  };

  return (
    <div className="bg-white p-4 rounded-xl shadow-sm border border-gray-200">
      <h3 className="text-lg font-semibold mb-4 text-gray-800">Sleep Sessions</h3>
      <div className="space-y-2">
        {sessions.map((s) => (
          <div key={s.id} className="border-b border-gray-100 last:border-0 pb-2">
            {editingId === s.id ? (
              <div className="flex flex-col space-y-2 py-1">
                <div className="grid grid-cols-1 gap-2 text-xs text-gray-500">
                  <div className="flex flex-col gap-1">
                    <span>Start Time</span>
                    <input
                      type="datetime-local"
                      className="border rounded px-1 py-0.5 text-sm text-black w-full"
                      value={editStart}
                      onChange={(e) => setEditStart(e.target.value)}
                    />
                  </div>
                  <div className="flex flex-col gap-1">
                    <span>End Time</span>
                    <input
                      type="datetime-local"
                      className="border rounded px-1 py-0.5 text-sm text-black w-full"
                      value={editEnd}
                      onChange={(e) => setEditEnd(e.target.value)}
                    />
                  </div>
                </div>
                <div className="flex justify-end space-x-2">
                  <button 
                    onClick={handleCancel} 
                    className="p-1 text-gray-500 hover:text-gray-700 transition-colors"
                    title="Cancel"
                  >
                    <X size={18} />
                  </button>
                  <button 
                    onClick={() => handleSave(s.id)} 
                    className="p-1 text-green-600 hover:text-green-700 transition-colors"
                    title="Save"
                  >
                    <Check size={18} />
                  </button>
                </div>
              </div>
            ) : (
              <div 
                className="flex justify-between items-center text-sm cursor-pointer hover:bg-gray-50 p-1 rounded transition-colors"
                onClick={() => startEditing(s)}
              >
                <div className="flex flex-col">
                  <span className="text-gray-900 font-medium">
                    {formatDateTime(s.start_time)}
                  </span>
                  <span className="text-gray-500 text-xs">
                    {s.end_time
                      ? `${formatDateTime(s.start_time)} → ${formatDateTime(s.end_time)}`
                      : 'In progress'}
                  </span>
                </div>
                <div className="flex items-center space-x-2">
                  <span className="text-blue-600 font-mono text-sm">
                                    {s.end_time && s.start_time
                                      ? `${getDurationMinutes(s.start_time, s.end_time)} min`
                                      : '—'}
                                  </span>

                  <Edit2 size={14} className="text-gray-400" />
                </div>
              </div>
            )}
          </div>
        ))}
      </div>
    </div>
  );
}