/**
 * Mail list component with pagination.
 * Shows list of mails in selected folder with seen/flagged indicators.
 */

import React from 'react';
import clsx from 'clsx';
import { useTranslation } from 'react-i18next';
import type { Mail } from '@/api/mail';
import { decodeMimeHeader } from '@/api/mail';
import { EmptyState } from '@/components/ui/EmptyState';
import { Pagination } from '@/components/ui/Pagination';

export interface MailListProps {
  mails: Mail[];
  selectedMailId: string | null;
  onSelectMail: (mail: Mail) => void;
  loading: boolean;
  currentPage: number;
  total: number;
  pageSize: number;
  onPageChange: (page: number) => void;
  selectedMailIds: Set<string>;
  onToggleSelect: (mailId: string) => void;
  onSelectAll: () => void;
  sortBy?: 'date' | 'from' | 'subject';
  sortOrder?: 'asc' | 'desc';
  onSortChange?: (sortBy: 'date' | 'from' | 'subject', sortOrder: 'asc' | 'desc') => void;
}

function formatDate(dateStr: string): string {
  const date = new Date(dateStr);
 const now = new Date();
  if (date.toDateString() === now.toDateString()) {
    return date.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
  }
  return date.toLocaleDateString([], { month: 'short', day: 'numeric' });
}

export function MailList({
  mails,
  selectedMailId,
  onSelectMail,
  loading,
  currentPage,
  total,
  pageSize,
  onPageChange,
  selectedMailIds,
  onToggleSelect,
  onSelectAll,
  sortBy = 'date',
  sortOrder = 'desc',
  onSortChange,
}: MailListProps) {
  const { t } = useTranslation();
  const totalPages = Math.ceil(total / pageSize);
  const allSelected = mails.length > 0 && mails.every((m) => selectedMailIds.has(m.id));

  const handleSortFieldChange = (e: React.ChangeEvent<HTMLSelectElement>) => {
    const newSortBy = e.target.value as 'date' | 'from' | 'subject';
    onSortChange?.(newSortBy, sortOrder);
  };

  const handleSortOrderToggle = () => {
    const newOrder = sortOrder === 'asc' ? 'desc' : 'asc';
    onSortChange?.(sortBy, newOrder);
  };

  if (loading) {
    return (
      <div className="flex items-center justify-center py-12" data-testid="mail-list-loading">
        <svg className="animate-spin h-5 w-5 text-secondary-400" fill="none" viewBox="0 0 24 24" aria-hidden="true">
          <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
          <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z" />
        </svg>
        <span className="ml-2 text-sm text-secondary-500">{t('common.loading')}</span>
      </div>
    );
  }

  if (mails.length === 0) {
    return (
      <EmptyState
        title={t('mail.noMails')}
        description={t('mail.noMailsDesc')}
        data-testid="mail-list-empty"
      />
    );
  }

  return (
    <div className="flex flex-col h-full" data-testid="mail-list" role="listbox" aria-label={t('mail.selectMail')}>
      {/* Select-all + Sort header in one row */}
      <div className="flex items-center justify-between gap-2 px-3 py-2 md:px-4 md:py-2 border-b border-secondary-200 bg-secondary-50 flex-shrink-0">
        <div className="flex items-center gap-2">
          <input
            type="checkbox"
            checked={allSelected}
            onChange={onSelectAll}
            className="w-4 h-4 rounded border-secondary-300 text-primary-600 focus:ring-primary-500"
            aria-label={t('mail.selectAll')}
            data-testid="mail-select-all"
          />
          {selectedMailIds.size > 0 && (
            <span className="text-xs text-secondary-600">
              {t('mail.selectedCount', { count: selectedMailIds.size })}
            </span>
          )}
        </div>
        {onSortChange && (
          <div className="flex items-center gap-2" data-testid="mail-sort-bar">
            <label htmlFor="mail-sort-by" className="text-xs text-secondary-600">
              {t('mail.sortBy')}:
            </label>
            <select
              id="mail-sort-by"
              value={sortBy}
              onChange={handleSortFieldChange}
              className="text-xs rounded border border-secondary-300 bg-white px-1.5 py-0.5 text-secondary-700 focus:outline-none focus:ring-1 focus:ring-primary-500"
              aria-label={t('mail.sortBy')}
              data-testid="mail-sort-by"
            >
              <option value="date">{t('mail.sortDate')}</option>
              <option value="from">{t('mail.sortFrom')}</option>
              <option value="subject">{t('mail.sortSubject')}</option>
            </select>
            <button
              onClick={handleSortOrderToggle}
              className="inline-flex items-center gap-1 text-xs rounded border border-secondary-300 bg-white px-1.5 py-0.5 text-secondary-700 hover:bg-secondary-100 focus:outline-none focus:ring-1 focus:ring-primary-500"
              aria-label={sortOrder === 'asc' ? t('mail.sortAsc') : t('mail.sortDesc')}
              title={sortOrder === 'asc' ? t('mail.sortAsc') : t('mail.sortDesc')}
              data-testid="mail-sort-order"
            >
              <svg className="w-3 h-3" fill="none" viewBox="0 0 24 24" stroke="currentColor" aria-hidden="true">
                {sortOrder === 'asc'
                  ? <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M5 15l7-7 7 7" />
                  : <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />}
              </svg>
              <span>{sortOrder === 'asc' ? t('mail.sortAsc') : t('mail.sortDesc')}</span>
            </button>
          </div>
        )}
      </div>
      {/* Mail list — scrolls, pagination stays fixed */}
      <ul className="divide-y divide-secondary-100 flex-1 overflow-y-auto" role="list">
        {mails.map((mail) => (
          <li key={mail.id} role="listitem" className={clsx(selectedMailIds.has(mail.id) && 'bg-primary-50')}>
            <div className="flex items-start gap-2">
              <div className="flex items-center pt-3 pl-3 md:pl-4">
                <input
                  type="checkbox"
                  checked={selectedMailIds.has(mail.id)}
                  onChange={() => onToggleSelect(mail.id)}
                  className="w-4 h-4 rounded border-secondary-300 text-primary-600 focus:ring-primary-500"
                  aria-label={t('mail.selectMail')}
                  data-testid={`mail-checkbox-${mail.id}`}
                />
              </div>
              <button
                onClick={() => onSelectMail(mail)}
                className={clsx(
                  'w-full text-left px-1 py-2 md:px-2 md:py-3 hover:bg-secondary-50 min-h-touch motion-safe:transition-colors',
                  'focus:outline-none focus-visible:ring-2 focus-visible:ring-primary-500',
                  mail.id === selectedMailId && 'bg-primary-50',
                  !mail.is_seen && 'font-semibold',
                )}
                aria-selected={mail.id === selectedMailId}
                data-testid={`mail-item-${mail.id}`}
              >
                <div className="flex items-center gap-2">
                  {!mail.is_seen && (
                    <span className="w-2 h-2 rounded-full bg-primary-500 flex-shrink-0" aria-label={t('mail.unread')} />
                  )}
                  {mail.is_flagged && (
                    <span className="flex-shrink-0" aria-label={t('mail.flagged')}>
                      {mail.flag_type === 'star' && <span className="text-sm">⭐</span>}
                      {mail.flag_type === 'flag' && <span className="text-sm">🚩</span>}
                      {mail.flag_type === 'bookmark' && <span className="text-sm">🔖</span>}
                      {mail.flag_type === 'important' && <span className="text-sm">❗</span>}
                      {mail.flag_type === 'question' && <span className="text-sm">❓</span>}
                      {(!mail.flag_type || mail.flag_type === '') && (
                        <svg className="w-4 h-4 text-warning-500" fill="currentColor" viewBox="0 0 24 24">
                          <path d="M12 2l3.09 6.26L22 9.27l-5 4.87 1.18 6.88L12 17.77l-6.18 3.25L7 14.14 2 9.27l6.91-1.01L12 2z" />
                        </svg>
                      )}
                    </span>
                  )}
                  {mail.has_attachments && (
                    <svg className="w-4 h-4 text-secondary-400 flex-shrink-0" fill="none" viewBox="0 0 24 24" stroke="currentColor" aria-hidden="true">
                      <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M15.172 13l-3.586 3.586a2 2 0 01-2.828 0L5 12.828a2 2 0 010-2.828l5.657-5.657a2 2 0 012.828 0L17 6.343M14.828 8.172a2 2 0 00-2.828 0l-3.586 3.586a2 2 0 000 2.828l1.414 1.414a2 2 0 002.828 0" />
                    </svg>
                  )}
                  <div className="flex-1 min-w-0">
                    <div className="flex items-center justify-between gap-2">
                      <span className={clsx('text-sm truncate', !mail.is_seen ? 'text-secondary-900 font-semibold' : 'text-secondary-700')}>
                        {decodeMimeHeader(mail.from_name) || mail.from_address}
                      </span>
                      <span className="text-xs text-secondary-400 flex-shrink-0">{formatDate(mail.date)}</span>
                    </div>
                    <p className={clsx('text-sm truncate mt-0.5', !mail.is_seen ? 'text-secondary-800' : 'text-secondary-600')}>
                      {decodeMimeHeader(mail.subject) || t('mail.noSubject')}
                    </p>
                    {mail.labels && mail.labels.length > 0 && (
                      <div className="flex gap-1 mt-1">
                        {mail.labels.map((label) => (
                          <span key={label.id} className="inline-flex items-center px-2 py-0.5 rounded-full text-xs text-white" style={{ backgroundColor: label.color }}>
                            {label.name}
                          </span>
                        ))}
                      </div>
                    )}
                  </div>
                </div>
              </button>
            </div>
          </li>
        ))}
      </ul>
      {totalPages > 1 && (
        <div className="flex-shrink-0">
          <Pagination
            currentPage={currentPage}
            totalPages={totalPages}
            total={total}
            pageSize={pageSize}
            onPageChange={onPageChange}
          />
        </div>
      )}
    </div>
  );
}