import React, { useState, useEffect, useCallback } from 'react'
import { useAuth } from './auth/AuthContext'
import TaskDetail from './TaskDetail'
import LoadingError from './LoadingError'
import Toast from './Toast'
import './WishlistDetail.css'
import './TaskList.css'

const API_URL = '/api/wishlist'

function WishlistDetail({ wishlistId, onNavigate, onRefresh }) {
  const { authFetch } = useAuth()
  const [wishlistItem, setWishlistItem] = useState(null)
  const [loading, setLoading] = useState(true)
  const [loadingWishlist, setLoadingWishlist] = useState(true)
  const [error, setError] = useState(null)
  const [isCompleting, setIsCompleting] = useState(false)
  const [isDeleting, setIsDeleting] = useState(false)
  const [toastMessage, setToastMessage] = useState(null)
  const [selectedTaskForDetail, setSelectedTaskForDetail] = useState(null)

  const fetchWishlistDetail = useCallback(async () => {
    try {
      setLoadingWishlist(true)
      setLoading(true)
      setError(null)
      const response = await authFetch(`${API_URL}/${wishlistId}`)
      if (!response.ok) {
        throw new Error('Ошибка загрузки желания')
      }
      const data = await response.json()
      setWishlistItem(data)
    } catch (err) {
      setError(err.message)
      console.error('Error fetching wishlist detail:', err)
    } finally {
      setLoading(false)
      setLoadingWishlist(false)
    }
  }, [wishlistId, authFetch])

  useEffect(() => {
    if (wishlistId) {
      fetchWishlistDetail()
    } else {
      setWishlistItem(null)
      setLoading(true)
      setLoadingWishlist(true)
      setError(null)
    }
  }, [wishlistId, fetchWishlistDetail])

  const handleEdit = () => {
    onNavigate?.('wishlist-form', { wishlistId: wishlistId })
  }

  const handleComplete = async () => {
    if (!wishlistItem || !wishlistItem.unlocked) return

    setIsCompleting(true)
    try {
      const response = await authFetch(`${API_URL}/${wishlistId}/complete`, {
        method: 'POST',
      })

      if (!response.ok) {
        throw new Error('Ошибка при завершении')
      }

      if (onRefresh) {
        onRefresh()
      }
      if (onNavigate) {
        onNavigate('wishlist')
      }
    } catch (err) {
      console.error('Error completing wishlist:', err)
      setToastMessage({ text: err.message || 'Ошибка при завершении', type: 'error' })
    } finally {
      setIsCompleting(false)
    }
  }

  const handleUncomplete = async () => {
    if (!wishlistItem || !wishlistItem.completed) return

    setIsCompleting(true)
    try {
      const response = await authFetch(`${API_URL}/${wishlistId}/uncomplete`, {
        method: 'POST',
      })

      if (!response.ok) {
        throw new Error('Ошибка при отмене завершения')
      }

      if (onRefresh) {
        onRefresh()
      }
      fetchWishlistDetail()
    } catch (err) {
      console.error('Error uncompleting wishlist:', err)
      setToastMessage({ text: err.message || 'Ошибка при отмене завершения', type: 'error' })
    } finally {
      setIsCompleting(false)
    }
  }

  const handleDelete = async () => {
    if (!wishlistItem) return

    if (!window.confirm('Вы уверены, что хотите удалить это желание?')) {
      return
    }

    setIsDeleting(true)
    try {
      const response = await authFetch(`${API_URL}/${wishlistId}`, {
        method: 'DELETE',
      })

      if (!response.ok) {
        throw new Error('Ошибка при удалении')
      }

      if (onRefresh) {
        onRefresh()
      }
      if (onNavigate) {
        onNavigate('wishlist')
      }
    } catch (err) {
      console.error('Error deleting wishlist:', err)
      setToastMessage({ text: err.message || 'Ошибка при удалении', type: 'error' })
    } finally {
      setIsDeleting(false)
    }
  }

  const handleCreateTask = () => {
    if (!wishlistItem || !wishlistItem.unlocked || wishlistItem.completed) return
    onNavigate?.('task-form', { wishlistId: wishlistId })
  }

  const handleTaskCheckmarkClick = (e) => {
    e.stopPropagation()
    if (wishlistItem?.linked_task) {
      setSelectedTaskForDetail(wishlistItem.linked_task.id)
    }
  }

  const handleTaskItemClick = () => {
    if (wishlistItem?.linked_task) {
      onNavigate?.('task-form', { taskId: wishlistItem.linked_task.id })
    }
  }

  const handleCloseDetail = () => {
    setSelectedTaskForDetail(null)
  }

  const handleTaskCompleted = () => {
    setToastMessage({ text: 'Задача выполнена', type: 'success' })
    // После выполнения задачи желание тоже завершается, перенаправляем на список
    if (onRefresh) {
      onRefresh()
    }
    if (onNavigate) {
      onNavigate('wishlist')
    }
  }

  const handleUnlinkTask = async (e) => {
    e.stopPropagation()
    if (!wishlistItem?.linked_task) return

    try {
      // Загружаем текущую задачу
      const taskResponse = await authFetch(`/api/tasks/${wishlistItem.linked_task.id}`)
      if (!taskResponse.ok) {
        throw new Error('Ошибка при загрузке задачи')
      }
      const taskData = await taskResponse.json()
      const task = taskData.task

      // Формируем payload для обновления задачи
      const payload = {
        name: task.name,
        reward_message: task.reward_message || null,
        progression_base: task.progression_base || null,
        repetition_period: task.repetition_period || null,
        repetition_date: task.repetition_date || null,
        wishlist_id: null, // Отвязываем от желания
        rewards: (task.rewards || []).map(r => ({
          position: r.position,
          project_name: r.project_name,
          value: r.value,
          use_progression: r.use_progression || false
        })),
        subtasks: (task.subtasks || []).map(st => ({
          id: st.id,
          name: st.name || null,
          reward_message: st.reward_message || null,
          rewards: (st.rewards || []).map(r => ({
            position: r.position,
            project_name: r.project_name,
            value: r.value,
            use_progression: r.use_progression || false
          }))
        }))
      }

      // Обновляем задачу, отвязывая от желания
      const updateResponse = await authFetch(`/api/tasks/${wishlistItem.linked_task.id}`, {
        method: 'PUT',
        headers: {
          'Content-Type': 'application/json',
        },
        body: JSON.stringify(payload),
      })

      if (!updateResponse.ok) {
        const errorData = await updateResponse.json().catch(() => ({}))
        throw new Error(errorData.message || errorData.error || 'Ошибка при отвязке задачи')
      }

      setToastMessage({ text: 'Задача отвязана от желания', type: 'success' })
      // Обновляем данные желания
      fetchWishlistDetail()
      if (onRefresh) {
        onRefresh()
      }
    } catch (err) {
      console.error('Error unlinking task:', err)
      setToastMessage({ text: err.message || 'Ошибка при отвязке задачи', type: 'error' })
    }
  }


  const formatPrice = (price) => {
    return new Intl.NumberFormat('ru-RU', {
      style: 'currency',
      currency: 'RUB',
      minimumFractionDigits: 0,
      maximumFractionDigits: 0,
    }).format(price)
  }

  const renderUnlockConditions = () => {
    if (!wishlistItem || !wishlistItem.unlock_conditions || wishlistItem.unlock_conditions.length === 0) {
      return null
    }

    return (
      <div className="wishlist-detail-conditions">
        <h3 className="wishlist-detail-section-title">Цели:</h3>
        {wishlistItem.unlock_conditions.map((condition, index) => {
          let conditionText = ''
          let progress = null
          
          if (condition.type === 'task_completion') {
            conditionText = condition.task_name || 'Задача'
            const isCompleted = condition.task_completed === true
            progress = {
              type: 'task',
              completed: isCompleted
            }
          } else {
            const requiredPoints = condition.required_points || 0
            const currentPoints = condition.current_points || 0
            const project = condition.project_name || 'Проект'
            let dateText = ''
            if (condition.start_date) {
              const date = new Date(condition.start_date + 'T00:00:00')
              dateText = ` с ${date.toLocaleDateString('ru-RU')}`
            } else {
              dateText = ' за всё время'
            }
            conditionText = `${requiredPoints} в ${project}${dateText}`
            const remaining = Math.max(0, requiredPoints - currentPoints)
            progress = {
              type: 'points',
              current: currentPoints,
              required: requiredPoints,
              remaining: remaining,
              percentage: requiredPoints > 0 ? Math.min(100, (currentPoints / requiredPoints) * 100) : 0
            }
          }

          // Проверяем каждое условие индивидуально
          let isMet = false
          if (progress?.type === 'task') {
            isMet = progress.completed === true
          } else if (progress?.type === 'points') {
            isMet = progress.current >= progress.required
          }

          return (
            <div 
              key={index} 
              className={`wishlist-detail-condition ${isMet ? 'met' : 'not-met'}`}
            >
              <div className="condition-header">
                <svg className="condition-icon" width="16" height="16" viewBox="0 0 24 24" fill="currentColor">
                  {isMet ? (
                    <path d="M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z"/>
                  ) : (
                    <path d="M18 8h-1V6c0-2.76-2.24-5-5-5S7 3.24 7 6v2H6c-1.1 0-2 .9-2 2v10c0 1.1.9 2 2 2h12c1.1 0 2-.9 2-2V10c0-1.1-.9-2-2-2zM9 6c0-1.66 1.34-3 3-3s3 1.34 3 3v2H9V6zm9 14H6V10h12v10zm-6-3c1.1 0 2-.9 2-2s-.9-2-2-2-2 .9-2 2 .9 2 2 2z"/>
                  )}
                </svg>
                <span className="condition-text">{conditionText}</span>
              </div>
              {progress && progress.type === 'points' && !isMet && (
                <div className="condition-progress">
                  <div className="progress-bar">
                    <div 
                      className="progress-fill" 
                      style={{ width: `${progress.percentage}%` }}
                    ></div>
                  </div>
                  <div className="progress-text">
                    <span>{Math.round(progress.current)} / {Math.round(progress.required)}</span>
                    {progress.remaining > 0 && (
                      <span className="progress-remaining">Осталось: {Math.round(progress.remaining)}</span>
                    )}
                  </div>
                </div>
              )}
            </div>
          )
        })}
      </div>
    )
  }

  if (loadingWishlist) {
    return (
      <div className="wishlist-detail">
        <div className="fixed inset-0 bottom-20 flex justify-center items-center">
          <div className="flex flex-col items-center">
            <div className="w-12 h-12 border-4 border-indigo-200 border-t-indigo-600 rounded-full animate-spin mb-4"></div>
            <div className="text-gray-600 font-medium">Загрузка...</div>
          </div>
        </div>
      </div>
    )
  }

  return (
    <div className="wishlist-detail">
      <button className="close-x-button" onClick={() => onNavigate?.('wishlist')}>
        ✕
      </button>
      <h2>{wishlistItem ? wishlistItem.name : 'Желание'}</h2>

      <div className="wishlist-detail-content">
        {error && (
          <LoadingError onRetry={fetchWishlistDetail} />
        )}

        {!error && wishlistItem && (
            <>
              {/* Изображение */}
              {wishlistItem.image_url && (
                <div className="wishlist-detail-image">
                  <img src={wishlistItem.image_url} alt={wishlistItem.name} />
                </div>
              )}

              {/* Цена */}
              {wishlistItem.price && (
                <div className="wishlist-detail-price">
                  {formatPrice(wishlistItem.price)}
                </div>
              )}

              {/* Ссылка */}
              {wishlistItem.link && (() => {
                try {
                  const url = new URL(wishlistItem.link)
                  const host = url.host.replace(/^www\./, '') // Убираем www. если есть
                  return (
                    <div className="wishlist-detail-link">
                      <a href={wishlistItem.link} target="_blank" rel="noopener noreferrer">
                        {host}
                      </a>
                    </div>
                  )
                } catch {
                  // Если URL некорректный, показываем оригинальный текст
                  return (
                    <div className="wishlist-detail-link">
                      <a href={wishlistItem.link} target="_blank" rel="noopener noreferrer">
                        Открыть ссылку
                      </a>
                    </div>
                  )
                }
              })()}

              {/* Условия разблокировки */}
              {renderUnlockConditions()}

              {/* Связанная задача или кнопки действий */}
              {wishlistItem.unlocked && !wishlistItem.completed && (
                <>
                  {wishlistItem.linked_task ? (
                    <div className="wishlist-detail-linked-task">
                      <div className="linked-task-label-header">Связанная задача:</div>
                      <div
                        className="task-item"
                        onClick={handleTaskItemClick}
                      >
                        <div className="task-item-content">
                          <div
                            className="task-checkmark"
                            onClick={handleTaskCheckmarkClick}
                            title="Выполнить задачу"
                          >
                            <svg width="20" height="20" viewBox="0 0 20 20" fill="none" xmlns="http://www.w3.org/2000/svg">
                              <circle cx="10" cy="10" r="9" stroke="currentColor" strokeWidth="2" fill="none" className="checkmark-circle" />
                              <path d="M6 10 L9 13 L14 7" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round" className="checkmark-check" />
                            </svg>
                          </div>
                          <div className="task-name-container">
                            <div className="task-name-wrapper">
                              <div className="task-name">
                                {wishlistItem.linked_task.name}
                              </div>
                              {/* Показываем дату только для выполненных задач (next_show_at > сегодня) */}
                              {wishlistItem.linked_task.next_show_at && (() => {
                                const showDate = new Date(wishlistItem.linked_task.next_show_at)
                                // Нормализуем дату: устанавливаем время в 00:00:00 в локальном времени
                                const showDateNormalized = new Date(showDate.getFullYear(), showDate.getMonth(), showDate.getDate())
                                
                                const today = new Date()
                                const todayNormalized = new Date(today.getFullYear(), today.getMonth(), today.getDate())
                                
                                // Показываем только если дата > сегодня
                                if (showDateNormalized.getTime() <= todayNormalized.getTime()) {
                                  return null
                                }
                                
                                const tomorrowNormalized = new Date(todayNormalized)
                                tomorrowNormalized.setDate(tomorrowNormalized.getDate() + 1)
                                
                                let dateText
                                if (showDateNormalized.getTime() === tomorrowNormalized.getTime()) {
                                  dateText = 'Завтра'
                                } else {
                                  dateText = showDate.toLocaleDateString('ru-RU', { day: 'numeric', month: 'long', year: 'numeric' })
                                }
                                
                                return (
                                  <div className="task-next-show-date">
                                    {dateText}
                                  </div>
                                )
                              })()}
                            </div>
                          </div>
                          <div className="task-actions">
                            <button
                              className="task-unlink-button"
                              onClick={handleUnlinkTask}
                              title="Отвязать от желания"
                            >
                              ✕
                            </button>
                          </div>
                        </div>
                      </div>
                    </div>
                  ) : (
                    <div className="wishlist-detail-actions">
                      <button
                        onClick={handleComplete}
                        disabled={isCompleting}
                        className="wishlist-detail-complete-button"
                      >
                        {isCompleting ? 'Завершение...' : 'Завершить'}
                      </button>
                      <button
                        onClick={handleCreateTask}
                        className="wishlist-detail-create-task-button"
                        title="Создать задачу"
                      >
                        <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
                          <path d="M9 11l3 3L22 4"></path>
                          <path d="M21 12v7a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h11"></path>
                        </svg>
                      </button>
                    </div>
                  )}
                </>
              )}
          </>
        )}
      </div>
      {toastMessage && (
        <Toast
          message={toastMessage.text}
          type={toastMessage.type}
          onClose={() => setToastMessage(null)}
        />
      )}

      {/* Модальное окно для деталей задачи */}
      {selectedTaskForDetail && (
        <TaskDetail
          taskId={selectedTaskForDetail}
          onClose={handleCloseDetail}
          onRefresh={() => {
            fetchWishlistDetail()
            if (onRefresh) onRefresh()
          }}
          onTaskCompleted={handleTaskCompleted}
          onNavigate={onNavigate}
        />
      )}
    </div>
  )
}

export default WishlistDetail