package services

import (
	"bytes"
	"encoding/csv"
	"fmt"
	"time"

	"git.mchus.pro/mchus/quoteforge/internal/config"
	"git.mchus.pro/mchus/quoteforge/internal/models"
	"git.mchus.pro/mchus/quoteforge/internal/repository"
)

type ExportService struct {
	config     config.ExportConfig
	categoryRepo *repository.CategoryRepository
}

func NewExportService(cfg config.ExportConfig, categoryRepo *repository.CategoryRepository) *ExportService {
	return &ExportService{
		config:       cfg,
		categoryRepo: categoryRepo,
	}
}

type ExportData struct {
	Name      string
	Items     []ExportItem
	Total     float64
	Notes     string
	CreatedAt time.Time
}

type ExportItem struct {
	LotName     string
	Description string
	Category    string
	Quantity    int
	UnitPrice   float64
	TotalPrice  float64
}

func (s *ExportService) ToCSV(data *ExportData) ([]byte, error) {
	var buf bytes.Buffer
	w := csv.NewWriter(&buf)

	// Header
	headers := []string{"Артикул", "Описание", "Категория", "Количество", "Цена за единицу", "Сумма"}
	if err := w.Write(headers); err != nil {
		return nil, err
	}

	// Get category hierarchy for sorting
	categoryOrder := make(map[string]int)
	if s.categoryRepo != nil {
		categories, err := s.categoryRepo.GetAll()
		if err == nil {
			for _, cat := range categories {
				categoryOrder[cat.Code] = cat.DisplayOrder
			}
		}
	}

	// Sort items by category display order
	sortedItems := make([]ExportItem, len(data.Items))
	copy(sortedItems, data.Items)

	// Sort using category display order (items without category go to the end)
	for i := 0; i < len(sortedItems)-1; i++ {
		for j := i + 1; j < len(sortedItems); j++ {
			orderI, hasI := categoryOrder[sortedItems[i].Category]
			orderJ, hasJ := categoryOrder[sortedItems[j].Category]

			// Items without category go to the end
			if !hasI && hasJ {
				sortedItems[i], sortedItems[j] = sortedItems[j], sortedItems[i]
			} else if hasI && hasJ {
				// Both have categories, sort by display order
				if orderI > orderJ {
					sortedItems[i], sortedItems[j] = sortedItems[j], sortedItems[i]
				}
			}
		}
	}

	// Items
	for _, item := range sortedItems {
		row := []string{
			item.LotName,
			item.Description,
			item.Category,
			fmt.Sprintf("%d", item.Quantity),
			fmt.Sprintf("%.2f", item.UnitPrice),
			fmt.Sprintf("%.2f", item.TotalPrice),
		}
		if err := w.Write(row); err != nil {
			return nil, err
		}
	}

	// Total row
	if err := w.Write([]string{"", "", "", "", "ИТОГО:", fmt.Sprintf("%.2f", data.Total)}); err != nil {
		return nil, err
	}

	w.Flush()
	return buf.Bytes(), w.Error()
}

func (s *ExportService) ConfigToExportData(config *models.Configuration, componentService *ComponentService) *ExportData {
	items := make([]ExportItem, len(config.Items))
	var total float64

	for i, item := range config.Items {
		itemTotal := item.UnitPrice * float64(item.Quantity)

		// Получаем информацию о компоненте для заполнения категории
		componentView, err := componentService.GetByLotName(item.LotName)
		if err != nil {
			// Если не удалось получить информацию о компоненте, используем только основные данные
			items[i] = ExportItem{
				LotName:    item.LotName,
				Quantity:   item.Quantity,
				UnitPrice:  item.UnitPrice,
				TotalPrice: itemTotal,
			}
		} else {
			items[i] = ExportItem{
				LotName:     item.LotName,
				Description: componentView.Description,
				Category:    componentView.Category,
				Quantity:    item.Quantity,
				UnitPrice:   item.UnitPrice,
				TotalPrice:  itemTotal,
			}
		}
		total += itemTotal
	}

	return &ExportData{
		Name:      config.Name,
		Items:     items,
		Total:     total,
		Notes:     config.Notes,
		CreatedAt: config.CreatedAt,
	}
}