import { useState, useEffect, useCallback } from 'react'
import { motion } from 'framer-motion'
import { useAuth } from '../context/AuthContext'
import { useAlert } from '../context/AlertContext'
import Forbidden from '../components/Forbidden'
import Pagination from '../components/Pagination'
import FormField from '../components/FormField'
import AdminDatePicker from '../components/AdminDatePicker'
import { czechPlural } from '../utils/formatters'
import apiFetch from '../utils/api'

const API_BASE = '/api/admin'

const ACTION_LABELS: Record<string, string> = {
  create: 'Vytvoření',
  update: 'Úprava',
  delete: 'Smazání',
  login: 'Přihlášení',
  login_failed: 'Neúspěšné přihlášení',
  logout: 'Odhlášení',
  view: 'Zobrazení',
  activate: 'Aktivace',
  deactivate: 'Deaktivace',
  password_change: 'Změna hesla',
  permission_change: 'Změna oprávnění',
  access_denied: 'Přístup odepřen',
}

const ACTION_BADGE_CLASS: Record<string, string> = {
  create: 'admin-badge-success',
  update: 'admin-badge-info',
  delete: 'admin-badge-danger',
  login: 'admin-badge-secondary',
  login_failed: 'admin-badge-danger',
  logout: 'admin-badge-secondary',
  view: 'admin-badge-info',
  activate: 'admin-badge-success',
  deactivate: 'admin-badge-warning',
  password_change: 'admin-badge-info',
  permission_change: 'admin-badge-warning',
  access_denied: 'admin-badge-danger',
}

const ENTITY_TYPE_LABELS: Record<string, string> = {
  user: 'Uživatel',
  attendance: 'Docházka',
  leave_request: 'Žádost o nepřítomnost',
  offers_quotation: 'Nabídka',
  offers_customer: 'Zákazník',
  offers_item_template: 'Šablona položky',
  offers_scope_template: 'Šablona rozsahu',
  offers_settings: 'Nastavení nabídek',
  orders_order: 'Objednávka',
  invoices_invoice: 'Faktura',
  projects_project: 'Projekt',
  role: 'Role',
  trips: 'Jízda',
  vehicles: 'Vozidlo',
  bank_account: 'Bankovní účet',
}

const ACTION_OPTIONS = Object.entries(ACTION_LABELS).map(([value, label]) => ({ value, label }))
const ENTITY_OPTIONS = Object.entries(ENTITY_TYPE_LABELS).map(([value, label]) => ({ value, label }))

interface AuditLogEntry {
  id: number
  created_at: string
  username: string | null
  action: string
  entity_type: string | null
  description: string | null
  user_ip: string | null
}

interface PaginationData {
  total: number
  page: number
  per_page: number
  total_pages: number
}

interface Filters {
  search: string
  action: string
  entity_type: string
  date_from: string
  date_to: string
}

export default function AuditLog() {
  const { hasPermission } = useAuth()
  const alert = useAlert()
  const [logs, setLogs] = useState<AuditLogEntry[]>([])
  const [loading, setLoading] = useState(true)
  const [pagination, setPagination] = useState<PaginationData | null>(null)
  const [filters, setFilters] = useState<Filters>({
    search: '',
    action: '',
    entity_type: '',
    date_from: '',
    date_to: '',
  })
  const [showCleanup, setShowCleanup] = useState(false)
  const [cleanupDays, setCleanupDays] = useState(90)
  const [cleaning, setCleaning] = useState(false)

  const fetchLogs = useCallback(async (page = 1, perPage = 50) => {
    setLoading(true)
    try {
      const params = new URLSearchParams({ page: String(page), per_page: String(perPage) })

      if (filters.search) params.set('search', filters.search)
      if (filters.action) params.set('action', filters.action)
      if (filters.entity_type) params.set('entity_type', filters.entity_type)
      if (filters.date_from) params.set('date_from', filters.date_from)
      if (filters.date_to) params.set('date_to', filters.date_to)

      const response = await apiFetch(`${API_BASE}/audit-log?${params.toString()}`)
      const data = await response.json()

      if (data.success) {
        setLogs(Array.isArray(data.data) ? data.data : [])
        setPagination({
          total: data.pagination?.total ?? 0,
          page: data.pagination?.page ?? 1,
          per_page: data.pagination?.limit ?? 50,
          total_pages: data.pagination?.total_pages ?? 1,
        })
      } else {
        alert.error(data.error || 'Nepodařilo se načíst audit log')
      }
    } catch {
      alert.error('Chyba připojení')
    } finally {
      setLoading(false)
    }
  }, [filters, alert])

  useEffect(() => {
    fetchLogs()
  }, [fetchLogs])

  if (!hasPermission('settings.audit')) {
    return <Forbidden />
  }

  const handleFilterChange = (key: keyof Filters, value: string) => {
    setFilters(prev => ({ ...prev, [key]: value }))
  }

  const handlePageChange = (newPage: number) => {
    fetchLogs(newPage, pagination?.per_page || 50)
  }

  const handlePerPageChange = (newPerPage: number) => {
    fetchLogs(1, newPerPage)
  }

  const handleCleanup = async () => {
    setCleaning(true)
    try {
      const response = await apiFetch(`${API_BASE}/audit-log/cleanup`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ days: cleanupDays }),
      })
      const data = await response.json()
      if (data.success) {
        alert.success(data.message)
        setShowCleanup(false)
        fetchLogs()
      } else {
        alert.error(data.error)
      }
    } catch {
      alert.error('Chyba připojení')
    } finally {
      setCleaning(false)
    }
  }

  const formatDatetime = (dateString: string | null): string => {
    if (!dateString) return '-'
    return new Date(dateString).toLocaleString('cs-CZ')
  }

  if (loading && logs.length === 0) {
    return (
      <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: '160px', marginBottom: '0.5rem' }} />
            <div className="admin-skeleton-line" style={{ width: '100px' }} />
          </div>
        </div>
        <div className="admin-card">
          <div className="admin-skeleton" style={{ gap: '0.75rem', padding: '1rem' }}>
            <div className="admin-skeleton-line h-10" style={{ width: '100%', borderRadius: '8px' }} />
          </div>
        </div>
        <div className="admin-card">
          <div className="admin-skeleton" style={{ gap: '1rem' }}>
            <div className="admin-skeleton-line h-10" style={{ width: '100%', borderRadius: '4px' }} />
            {Array.from({ length: 8 }, (_, i) => (
              <div key={i} className="admin-skeleton-row">
                <div className="admin-skeleton-line" style={{ width: '120px' }} />
                <div className="admin-skeleton-line" style={{ width: '80px' }} />
                <div className="admin-skeleton-line" style={{ width: '70px', borderRadius: '10px' }} />
                <div className="admin-skeleton-line" style={{ width: '80px' }} />
                <div className="admin-skeleton-line flex-1" />
                <div className="admin-skeleton-line" style={{ width: '90px' }} />
              </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">Audit log</h1>
          {pagination && (
            <p className="admin-page-subtitle">
              {pagination.total} {czechPlural(pagination.total, 'záznam', 'záznamy', 'záznamů')}
            </p>
          )}
        </div>
        <button
          className="admin-btn admin-btn-secondary admin-btn-sm"
          onClick={() => setShowCleanup(true)}
        >
          <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
            <polyline points="3 6 5 6 21 6" />
            <path d="M19 6v14a2 2 0 0 1-2 2H7a2 2 0 0 1-2-2V6m3 0V4a2 2 0 0 1 2-2h4a2 2 0 0 1 2 2v2" />
          </svg>
          Vyčistit
        </button>
      </motion.div>

      {showCleanup && (
        <div className="admin-modal-overlay" style={{ opacity: 1 }}>
          <div className="admin-modal-backdrop" onClick={() => !cleaning && setShowCleanup(false)} />
          <motion.div
            className="admin-modal admin-confirm-modal"
            initial={{ opacity: 0, scale: 0.95, y: 20 }}
            animate={{ opacity: 1, scale: 1, y: 0 }}
            transition={{ duration: 0.2 }}
          >
            <div className="admin-modal-body admin-confirm-content">
              <div className="admin-confirm-icon admin-confirm-icon-danger">
                <svg width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
                  <polyline points="3 6 5 6 21 6" />
                  <path d="M19 6v14a2 2 0 0 1-2 2H7a2 2 0 0 1-2-2V6m3 0V4a2 2 0 0 1 2-2h4a2 2 0 0 1 2 2v2" />
                </svg>
              </div>
              <h2 className="admin-confirm-title">Vyčistit audit log</h2>
              <p className="admin-confirm-message">Smazat záznamy starší než:</p>
              <div style={{ margin: '0.75rem auto', maxWidth: '200px' }}>
                <select
                  className="admin-form-select"
                  value={cleanupDays}
                  onChange={(e) => setCleanupDays(parseInt(e.target.value))}
                >
                  <option value={30}>30 dní</option>
                  <option value={60}>60 dní</option>
                  <option value={90}>90 dní</option>
                  <option value={180}>180 dní</option>
                  <option value={365}>1 rok</option>
                  <option value={0}>Vše</option>
                </select>
              </div>
              <p className="admin-confirm-message" style={{ fontSize: '12px', opacity: 0.6 }}>Tato akce je nevratná.</p>
            </div>
            <div className="admin-modal-footer">
              <button
                type="button"
                onClick={() => setShowCleanup(false)}
                className="admin-btn admin-btn-secondary"
                disabled={cleaning}
              >
                Zrušit
              </button>
              <button
                type="button"
                onClick={handleCleanup}
                className="admin-btn admin-btn-primary"
                disabled={cleaning}
              >
                {cleaning ? 'Mažu...' : 'Smazat'}
              </button>
            </div>
          </motion.div>
        </div>
      )}

      <motion.div
        className="admin-card mb-4"
        initial={{ opacity: 0, y: 12 }}
        animate={{ opacity: 1, y: 0 }}
        transition={{ duration: 0.25, delay: 0.06 }}
      >
        <div className="admin-card-body">
          <div className="admin-form-row admin-form-row-5">
            <FormField label="Hledat">
              <input
                type="text"
                className="admin-form-input"
                placeholder="Popis, uživatel..."
                value={filters.search}
                onChange={(e) => handleFilterChange('search', e.target.value)}
              />
            </FormField>
            <FormField label="Akce">
              <select
                className="admin-form-select"
                value={filters.action}
                onChange={(e) => handleFilterChange('action', e.target.value)}
              >
                <option value="">Všechny</option>
                {ACTION_OPTIONS.map(opt => (
                  <option key={opt.value} value={opt.value}>{opt.label}</option>
                ))}
              </select>
            </FormField>
            <FormField label="Typ entity">
              <select
                className="admin-form-select"
                value={filters.entity_type}
                onChange={(e) => handleFilterChange('entity_type', e.target.value)}
              >
                <option value="">Všechny</option>
                {ENTITY_OPTIONS.map(opt => (
                  <option key={opt.value} value={opt.value}>{opt.label}</option>
                ))}
              </select>
            </FormField>
            <FormField label="Od">
              <AdminDatePicker
                mode="date"
                value={filters.date_from}
                onChange={(val: string) => handleFilterChange('date_from', val)}
              />
            </FormField>
            <FormField label="Do">
              <AdminDatePicker
                mode="date"
                value={filters.date_to}
                onChange={(val: string) => handleFilterChange('date_to', val)}
              />
            </FormField>
          </div>
        </div>
      </motion.div>

      <motion.div
        className="admin-card"
        initial={{ opacity: 0, y: 12 }}
        animate={{ opacity: 1, y: 0 }}
        transition={{ duration: 0.25, delay: 0.08 }}
      >
        <div className="admin-card-body">
          <div className="admin-table-responsive">
            <table className="admin-table">
              <thead>
                <tr>
                  <th>Čas</th>
                  <th>Uživatel</th>
                  <th>Akce</th>
                  <th>Typ entity</th>
                  <th>Popis</th>
                  <th>IP</th>
                </tr>
              </thead>
              <tbody>
                {loading && Array.from({ length: 10 }, (_, i) => (
                  <tr key={`skeleton-${i}`}>
                    <td><div className="admin-skeleton-line" style={{ width: '110px', height: '14px' }} /></td>
                    <td><div className="admin-skeleton-line" style={{ width: '80px', height: '14px' }} /></td>
                    <td><div className="admin-skeleton-line" style={{ width: '70px', height: '22px', borderRadius: '10px' }} /></td>
                    <td><div className="admin-skeleton-line" style={{ width: '80px', height: '14px' }} /></td>
                    <td><div className="admin-skeleton-line" style={{ width: '60%', height: '14px' }} /></td>
                    <td><div className="admin-skeleton-line" style={{ width: '90px', height: '14px' }} /></td>
                  </tr>
                ))}
                {!loading && logs.length === 0 && (
                  <tr>
                    <td colSpan={6}>
                      <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">
                            <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z" />
                            <polyline points="14 2 14 8 20 8" />
                            <line x1="16" y1="13" x2="8" y2="13" />
                            <line x1="16" y1="17" x2="8" y2="17" />
                          </svg>
                        </div>
                        <p>Žádné záznamy k zobrazení</p>
                      </div>
                    </td>
                  </tr>
                )}
                {!loading && logs.map((log) => (
                  <tr key={log.id}>
                    <td className="admin-mono">{formatDatetime(log.created_at)}</td>
                    <td className="fw-500">{log.username || '-'}</td>
                    <td>
                      <span className={`admin-badge ${ACTION_BADGE_CLASS[log.action] || 'admin-badge-secondary'}`}>
                        {ACTION_LABELS[log.action] || log.action}
                      </span>
                    </td>
                    <td>{ENTITY_TYPE_LABELS[log.entity_type || ''] || log.entity_type || '-'}</td>
                    <td>{log.description || '-'}</td>
                    <td className="admin-mono">{log.user_ip || '-'}</td>
                  </tr>
                ))}
              </tbody>
            </table>
          </div>

          <Pagination
            pagination={pagination}
            onPageChange={handlePageChange}
            onPerPageChange={handlePerPageChange}
          />
        </div>
      </motion.div>
    </div>
  )
}