source: frontend/src/app/students/applications/page.tsx

"use client"

import { FontAwesomeIcon } from '@fortawesome/react-fontawesome';
import { 
  faPenToSquare, 
  faChevronDown,
  faCalendarAlt,
  faFileText,
  faMoneyBillWave,
  faUser,
  faInfoCircle,
  faCheckCircle,
  faTimesCircle
} from '@fortawesome/free-solid-svg-icons';
import { useState } from 'react';
import { useTranslation } from 'react-i18next';
import applicationsData from '@/data/applications.json';

interface TableCellProps {
  children: React.ReactNode;
  className?: string;
}

const TableCell = ({ children, className = "" }: TableCellProps) => (
  <td className={`px-4 py-3 text-sm border-b border-border ${className}`}>
    {children}
  </td>
);

const CompletedBadge = ({ completed }: { completed: string }) => {
  const { t } = useTranslation();
  if (completed === 'Да') {
    return (
      <span className="inline-flex items-center justify-center w-6 h-6 bg-green-100 text-green-600 rounded-full" title={t('completed')}> 
        <FontAwesomeIcon icon={faCheckCircle} className="w-4 h-4" />
      </span>
    );
  } else {
    return (
      <span className="inline-flex items-center justify-center w-6 h-6 bg-red-100 text-red-600 rounded-full" title={t('not_completed')}>
        <FontAwesomeIcon icon={faTimesCircle} className="w-4 h-4" />
      </span>
    );
  }
};

const FeeBadge = ({ fee }: { fee: string }) => {
  const feeValue = parseFloat(fee.replace(',', '.'));
  
  if (feeValue === 0) {
    return (
      <span className="inline-flex items-center gap-1 px-2 py-1 bg-green-100 text-green-800 rounded-md text-xs font-medium">
        <FontAwesomeIcon icon={faMoneyBillWave} className="w-3 h-3" />
        {fee}
      </span>
    );
  } else {
    return (
      <span className="inline-flex items-center gap-1 px-2 py-1 bg-yellow-100 text-yellow-800 rounded-md text-xs font-medium">
        <FontAwesomeIcon icon={faMoneyBillWave} className="w-3 h-3" />
        {fee}
      </span>
    );
  }
};

export default function ApplicationsPage() {
  const { t } = useTranslation();
  const [selectedSession, setSelectedSession] = useState(applicationsData.currentSession.id);
  const [isDropdownOpen, setIsDropdownOpen] = useState(false);

  const currentSessionData = applicationsData.examSessions.find(s => s.id === selectedSession) || applicationsData.currentSession;
  const { applications } = applicationsData;

  return (
    <div className="min-h-screen pb-8">
      {/* Header */}
      <div className="bg-primary text-white rounded-xl p-8 mb-8">
        <div className="flex items-center gap-4">
          <div className="bg-white rounded-full p-4">
            <FontAwesomeIcon icon={faPenToSquare} className="text-3xl text-[#0272D1]" />
          </div>
          <div>
            <h1 className="text-3xl font-bold mb-2">{t('applications_header', 'Пријави')}</h1>
            <p className="text-lg opacity-90">
              {t('applications_subheader', 'Електронски пријави за испити')}
            </p>
          </div>
        </div>
      </div>

      {/* Session Selection */}
      <div className="bg-card rounded-xl p-6 shadow-sm border border-border mb-8">
        <div className="flex items-center justify-between">
          <h2 className="text-lg font-semibold text-card-foreground flex items-center gap-2">
            <FontAwesomeIcon icon={faCalendarAlt} className="text-primary" />
            {t('select_exam_session', 'Избери испитна сесија:')}
          </h2>

          <div className="relative">
            <button
              onClick={() => setIsDropdownOpen(!isDropdownOpen)}
              className="bg-card border border-border rounded-lg px-4 py-2 text-left focus:outline-none focus:ring-2 focus:ring-primary focus:border-primary min-w-80"
            >
              <div className="flex items-center justify-between">
                <span className="text-sm font-medium text-primary">
                  {t(currentSessionData.id, currentSessionData.name)}
                </span>
                <FontAwesomeIcon
                  icon={faChevronDown}
                  className={`w-4 h-4 text-muted-foreground transition-transform ml-4 ${isDropdownOpen ? 'rotate-180' : ''}`}
                />
              </div>
            </button>

            {isDropdownOpen && (
              <div className="absolute z-10 right-0 mt-1 w-80 bg-card border border-border rounded-lg shadow-lg">
                {applicationsData.examSessions.map((session) => (
                  <button
                    key={session.id}
                    onClick={() => {
                      setSelectedSession(session.id);
                      setIsDropdownOpen(false);
                    }}
                    className="w-full px-4 py-3 text-left text-sm hover:bg-accent focus:outline-none focus:bg-accent first:rounded-t-lg last:rounded-b-lg"
                  >
                    <div className="font-medium text-card-foreground">{t(session.id, session.name)}</div>
                    <div className="text-xs text-muted-foreground">{session.year} - {t(session.semester, session.semester)} - {t(session.session, session.session)}</div>
                  </button>
                ))}
              </div>
            )}
          </div>
        </div>
      </div>

      {/* Applications Section */}
      <div className="bg-card rounded-xl shadow-sm border border-border overflow-hidden">
        <div className="bg-primary text-white px-6 py-4">
          <h2 className="text-xl font-bold">{t('registered_exams', 'Пријавени испити')}</h2>
        </div>

        <div className="overflow-x-auto">
          <table className="w-full">
            <thead className="bg-accent">
              <tr>
                <th className="px-4 py-4 text-left text-xs font-medium text-muted-foreground uppercase tracking-wider">#</th>
                <th className="px-4 py-4 text-left text-xs font-medium text-muted-foreground uppercase tracking-wider">{t('serial_number', 'Сериски број')}</th>
                <th className="px-4 py-4 text-left text-xs font-medium text-muted-foreground uppercase tracking-wider">{t('code', 'Код')}</th>
                <th className="px-4 py-4 text-left text-xs font-medium text-muted-foreground uppercase tracking-wider">{t('subject', 'Предмет')}</th>
                <th className="px-4 py-4 text-center text-xs font-medium text-muted-foreground uppercase tracking-wider">{t('completed', 'Завршена')}</th>
                <th className="px-4 py-4 text-center text-xs font-medium text-muted-foreground uppercase tracking-wider">{t('fee', 'Таксени')}</th>
                <th className="px-4 py-4 text-left text-xs font-medium text-muted-foreground uppercase tracking-wider">{t('date', 'Датум')}</th>
                <th className="px-4 py-4 text-left text-xs font-medium text-muted-foreground uppercase tracking-wider">{t('instructor', 'Наставник')}</th>
                <th className="px-4 py-4 text-center text-xs font-medium text-muted-foreground uppercase tracking-wider">{t('decade', 'Декада')}</th>
              </tr>
            </thead>
            <tbody className="divide-y divide-border">
              {applications.map((application) => (
                <tr key={application.id} className="hover:bg-accent transition-colors">
                  <TableCell className="font-medium text-card-foreground">{application.id}</TableCell>
                  <TableCell>
                    <span className="font-mono text-sm text-primary font-medium hover:underline cursor-pointer">
                      {application.serviceNumber}
                    </span>
                  </TableCell>
                  <TableCell className="font-mono text-sm font-medium">{application.code}</TableCell>
                  <TableCell className="font-medium text-card-foreground max-w-xs">
                    <div className="flex items-center gap-2">
                      <FontAwesomeIcon icon={faFileText} className="w-4 h-4 text-primary" />
                      {t(application.subject, application.subject)}
                    </div>
                  </TableCell>
                  <TableCell className="text-center">
                    <CompletedBadge completed={application.completed} />
                  </TableCell>
                  <TableCell className="text-center">
                    <FeeBadge fee={application.fee} />
                  </TableCell>
                  <TableCell className="text-muted-foreground font-medium">{application.date}</TableCell>
                  <TableCell>
                    <div className="flex items-center gap-2">
                      <FontAwesomeIcon icon={faUser} className="w-4 h-4 text-muted-foreground" />
                      <span className="font-medium text-card-foreground">{t(application.instructor, application.instructor)}</span>
                    </div>
                  </TableCell>
                  <TableCell className="text-center font-medium text-primary">{application.decade}</TableCell>
                </tr>
              ))}
            </tbody>
          </table>
        </div>

        {/* Important Note */}
        <div className="bg-blue-50 border-t border-blue-100 p-6">
          <div className="flex items-start gap-3">
            <FontAwesomeIcon icon={faInfoCircle} className="w-5 h-5 text-blue-600 mt-0.5 flex-shrink-0" />
            <div>
              <h3 className="font-medium text-blue-900 mb-1">{t('important_note', 'Важна забелешка')}</h3>
              <p className="text-sm text-blue-800 leading-relaxed">
                {t('applications_important_note_text')}
              </p>
            </div>
          </div>
        </div>
      </div>

      {/* Statistics Cards */}
      <div className="grid grid-cols-1 md:grid-cols-3 gap-6 mt-8">
        <div className="bg-card rounded-xl p-6 shadow-sm border border-border">
          <div className="flex items-center gap-4">
            <div className="bg-blue-100 text-blue-600 rounded-full p-3">
              <FontAwesomeIcon icon={faFileText} className="text-xl" />
            </div>
            <div>
              <h3 className="text-lg font-bold text-card-foreground">{t('registered_exams', 'Пријавени испити')}</h3>
              <p className="text-2xl font-bold text-blue-600">
                {applications.length}
              </p>
            </div>
          </div>
        </div>

        <div className="bg-card rounded-xl p-6 shadow-sm border border-border">
          <div className="flex items-center gap-4">
            <div className="bg-green-100 text-green-600 rounded-full p-3">
              <FontAwesomeIcon icon={faCheckCircle} className="text-xl" />
            </div>
            <div>
              <h3 className="text-lg font-bold text-card-foreground">{t('completed', 'Завршени')}</h3>
              <p className="text-2xl font-bold text-green-600">
                {applications.filter(app => app.completed === 'Да').length}
              </p>
            </div>
          </div>
        </div>

        <div className="bg-card rounded-xl p-6 shadow-sm border border-border">
          <div className="flex items-center gap-4">
            <div className="bg-yellow-100 text-yellow-600 rounded-full p-3">
              <FontAwesomeIcon icon={faMoneyBillWave} className="text-xl" />
            </div>
            <div>
              <h3 className="text-lg font-bold text-card-foreground">{t('total_fee', 'Вкупна такса')}</h3>
              <p className="text-2xl font-bold text-yellow-600">
                {applications.reduce((sum, app) => sum + parseFloat(app.fee.replace(',', '.')), 0).toFixed(2)}
              </p>
            </div>
          </div>
        </div>
      </div>
    </div>
  );
}