import { useState } from 'react'
import { useAlert } from '../context/AlertContext'
import { useAuth } from '../context/AuthContext'
import { Link } from 'react-router-dom'
import Forbidden from '../components/Forbidden'
import { motion } from 'framer-motion'
import ConfirmModal from '../components/ConfirmModal'

import apiFetch from '../utils/api'
import { formatDate, czechPlural } from '../utils/formatters'
import SortIcon from '../components/SortIcon'
import useTableSort from '../hooks/useTableSort'
import useListData from '../hooks/useListData'
import Pagination from '../components/Pagination'

const API_BASE = '/api/admin'

const STATUS_LABELS: Record<string, string> = {
  aktivni: 'Aktivní',
  dokonceny: 'Dokončený',
  zruseny: 'Zrušený'
}

const STATUS_CLASSES: Record<string, string> = {
  aktivni: 'admin-badge-project-aktivni',
  dokonceny: 'admin-badge-project-dokonceny',
  zruseny: 'admin-badge-project-zruseny'
}

interface Project {
  id: number
  project_number: string
  name: string
  customer_name: string
  responsible_user_name: string
  status: string
  start_date: string
  end_date: string
  order_id?: number
  order_number?: string
}

export default function Projects() {
  const alert = useAlert()
  const { hasPermission } = useAuth()

  const { sort, order, handleSort, activeSort } = useTableSort('project_number')
  const [search, setSearch] = useState('')
  const [page, setPage] = useState(1)
  const [deletingId, setDeletingId] = useState<number | null>(null)
  const [deleteTarget, setDeleteTarget] = useState<Project | null>(null)
  const [deleteFiles, setDeleteFiles] = useState(false)

  const { items: projects, setItems: setProjects, loading, initialLoad, pagination } = useListData<Project>('projects', {
    search, sort, order, page,
    errorMsg: 'Nepodařilo se načíst projekty'
  })

  if (!hasPermission('projects.view')) return <Forbidden />

  const handleDelete = async () => {
    if (!deleteTarget) return
    setDeletingId(deleteTarget.id)
    try {
      const res = await apiFetch(`${API_BASE}/projects/${deleteTarget.id}`, {
        method: 'DELETE',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ delete_files: deleteFiles }),
      })
      const data = await res.json()
      if (data.success) {
        alert.success(data.message || 'Projekt byl smazán')
        setProjects((prev: Project[]) => prev.filter(p => p.id !== deleteTarget.id))
      } else {
        alert.error(data.error || 'Nepodařilo se smazat projekt')
      }
    } catch {
      alert.error('Chyba připojení')
    } finally {
      setDeletingId(null)
      setDeleteTarget(null)
      setDeleteFiles(false)
    }
  }

  if (initialLoad) {
    return (
      <div>
        <div className="admin-skeleton" style={{ padding: 0, gap: '1.5rem' }}>
          <div className="admin-skeleton-row" style={{ justifyContent: 'space-between' }}>
            <div>
              <div className="admin-skeleton-line h-8" style={{ width: '200px', marginBottom: '0.5rem' }} />
              <div className="admin-skeleton-line" style={{ width: '140px' }} />
            </div>
            <div className="admin-skeleton-line h-10" style={{ width: '140px', borderRadius: '8px' }} />
          </div>
          <div className="admin-card">
            <div className="admin-skeleton" style={{ gap: '1.25rem' }}>
              {[0, 1, 2, 3, 4].map(i => (
                <div key={i} className="admin-skeleton-row">
                  <div className="admin-skeleton-line circle" />
                  <div className="flex-1">
                    <div className="admin-skeleton-line w-1/3" style={{ marginBottom: '0.5rem' }} />
                    <div className="admin-skeleton-line w-1/4" style={{ height: '10px' }} />
                  </div>
                  <div className="admin-skeleton-line w-1/4" />
                </div>
              ))}
            </div>
          </div>
        </div>
      </div>
    )
  }

  return (
    <div>
      <motion.div
        className="admin-page-header"
        initial={{ opacity: 0, y: 12 }}
        animate={{ opacity: 1, y: 0 }}
        transition={{ duration: 0.25 }}
      >
        <div>
          <h1 className="admin-page-title">Projekty</h1>
          <p className="admin-page-subtitle">
            {pagination?.total ?? projects.length} {czechPlural(pagination?.total ?? projects.length, 'projekt', 'projekty', 'projektů')}
          </p>
        </div>
        {hasPermission('projects.create') && (
          <Link to="/projects/new" className="admin-btn admin-btn-primary">
            <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
              <line x1="12" y1="5" x2="12" y2="19" />
              <line x1="5" y1="12" x2="19" y2="12" />
            </svg>
            Nový projekt
          </Link>
        )}
      </motion.div>

      <motion.div
        className="admin-card"
        initial={{ opacity: 0, y: 12 }}
        animate={{ opacity: 1, y: 0 }}
        transition={{ duration: 0.25, delay: 0.06 }}
        style={{ opacity: loading ? 0.6 : 1, transition: 'opacity 0.2s' }}
      >
        <div className="admin-card-body">
          <div className="admin-search-bar mb-4">
            <input
              type="text"
              value={search}
              onChange={(e) => { setSearch(e.target.value); setPage(1) }}
              className="admin-form-input"
              placeholder="Hledat podle čísla, názvu nebo zákazníka..."
            />
          </div>

          {projects.length === 0 ? (
            <div className="admin-empty-state">
              <div className="admin-empty-icon">
                <svg width="28" height="28" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round" strokeLinejoin="round">
                  <path d="M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2z" />
                </svg>
              </div>
              <p>Zatím nejsou žádné projekty.</p>
              <p style={{ color: 'var(--text-tertiary)', fontSize: '0.875rem' }}>
                Vytvořte první projekt tlačítkem výše nebo automaticky při vytvoření objednávky.
              </p>
            </div>
          ) : (
            <div className="admin-table-responsive">
              <table className="admin-table">
                <thead>
                  <tr>
                    <th style={{ cursor: 'pointer' }} onClick={() => handleSort('project_number')}>
                      Číslo <SortIcon column="project_number" sort={activeSort} order={order} />
                    </th>
                    <th style={{ cursor: 'pointer' }} onClick={() => handleSort('name')}>
                      Název <SortIcon column="name" sort={activeSort} order={order} />
                    </th>
                    <th>Zákazník</th>
                    <th>Zodpovědná osoba</th>
                    <th style={{ cursor: 'pointer' }} onClick={() => handleSort('status')}>
                      Stav <SortIcon column="status" sort={activeSort} order={order} />
                    </th>
                    <th style={{ cursor: 'pointer' }} onClick={() => handleSort('start_date')}>
                      Začátek <SortIcon column="start_date" sort={activeSort} order={order} />
                    </th>
                    <th style={{ cursor: 'pointer' }} onClick={() => handleSort('end_date')}>
                      Konec <SortIcon column="end_date" sort={activeSort} order={order} />
                    </th>
                    <th>Objednávka</th>
                    <th>Akce</th>
                  </tr>
                </thead>
                <tbody>
                  {(projects as Project[]).map((p) => (
                    <tr key={p.id}>
                      <td className="admin-mono">
                        <Link to={`/projects/${p.id}`} className="link-accent">
                          {p.project_number}
                        </Link>
                      </td>
                      <td className="fw-500">{p.name || '—'}</td>
                      <td>{p.customer_name || '—'}</td>
                      <td>{p.responsible_user_name || '—'}</td>
                      <td>
                        <span className={`admin-badge ${STATUS_CLASSES[p.status] || ''}`}>
                          {STATUS_LABELS[p.status] || p.status}
                        </span>
                      </td>
                      <td className="admin-mono">{formatDate(p.start_date)}</td>
                      <td className="admin-mono">{formatDate(p.end_date)}</td>
                      <td>
                        {p.order_id ? (
                          <Link to={`/orders/${p.order_id}`} className="text-secondary" style={{ textDecoration: 'none' }}>
                            {p.order_number}
                          </Link>
                        ) : '—'}
                      </td>
                      <td>
                        <div className="admin-table-actions">
                          <Link to={`/projects/${p.id}`} className="admin-btn-icon" title="Upravit" aria-label="Upravit">
                            <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
                              <path d="M11 4H4a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2v-7" />
                              <path d="M18.5 2.5a2.121 2.121 0 0 1 3 3L12 15l-4 1 1-4 9.5-9.5z" />
                            </svg>
                          </Link>
                          {!p.order_id && hasPermission('projects.create') && (
                            <button
                              onClick={() => setDeleteTarget(p)}
                              className="admin-btn-icon danger"
                              title="Smazat projekt"
                              disabled={deletingId === p.id}
                            >
                              {deletingId === p.id ? (
                                <div className="admin-spinner admin-spinner-sm" />
                              ) : (
                                <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
                                  <polyline points="3 6 5 6 21 6" />
                                  <path d="M19 6l-1 14a2 2 0 0 1-2 2H8a2 2 0 0 1-2-2L5 6" />
                                  <path d="M10 11v6M14 11v6" />
                                </svg>
                              )}
                            </button>
                          )}
                        </div>
                      </td>
                    </tr>
                  ))}
                </tbody>
              </table>
            </div>
          )}
          <Pagination pagination={pagination} onPageChange={setPage} />
        </div>
      </motion.div>

      <ConfirmModal
        isOpen={!!deleteTarget}
        onClose={() => {
          setDeleteTarget(null)
          setDeleteFiles(false)
        }}
        onConfirm={handleDelete}
        title="Smazat projekt"
        message={
          <>
            Opravdu chcete smazat projekt {deleteTarget?.project_number}?
            <label className="admin-form-checkbox" style={{ marginTop: '1rem', display: 'flex' }}>
              <input
                type="checkbox"
                checked={deleteFiles}
                onChange={(e) => setDeleteFiles(e.target.checked)}
              />
              <span>Smazat i soubory na disku</span>
            </label>
          </>
        }
        confirmText="Smazat"
        type="danger"
        loading={!!deletingId}
      />
    </div>
  )
}