package services

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

	"github.com/mchus/quoteforge/internal/config"
	"github.com/mchus/quoteforge/internal/models"
	"github.com/xuri/excelize/v2"
)

type ExportService struct {
	config config.ExportConfig
}

func NewExportService(cfg config.ExportConfig) *ExportService {
	return &ExportService{config: cfg}
}

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
	}

	// Items
	for _, item := range data.Items {
		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) ToXLSX(data *ExportData) ([]byte, error) {
	f := excelize.NewFile()
	sheet := "Конфигурация"
	f.SetSheetName("Sheet1", sheet)

	// Styles
	headerStyle, _ := f.NewStyle(&excelize.Style{
		Font:      &excelize.Font{Bold: true, Size: 12, Color: "#FFFFFF"},
		Fill:      excelize.Fill{Type: "pattern", Color: []string{"#4472C4"}, Pattern: 1},
		Alignment: &excelize.Alignment{Horizontal: "center", Vertical: "center"},
		Border: []excelize.Border{
			{Type: "left", Color: "#000000", Style: 1},
			{Type: "top", Color: "#000000", Style: 1},
			{Type: "bottom", Color: "#000000", Style: 1},
			{Type: "right", Color: "#000000", Style: 1},
		},
	})

	totalStyle, _ := f.NewStyle(&excelize.Style{
		Font: &excelize.Font{Bold: true, Size: 12},
		Fill: excelize.Fill{Type: "pattern", Color: []string{"#E2EFDA"}, Pattern: 1},
	})

	priceStyle, _ := f.NewStyle(&excelize.Style{
		NumFmt: 4, // #,##0.00
	})

	// Title
	f.SetCellValue(sheet, "A1", s.config.CompanyName)
	f.SetCellValue(sheet, "A2", "Коммерческое предложение: "+data.Name)
	f.SetCellValue(sheet, "A3", "Дата: "+data.CreatedAt.Format("02.01.2006"))

	// Headers
	headers := []string{"Артикул", "Описание", "Категория", "Кол-во", "Цена", "Сумма"}
	for i, h := range headers {
		cell := fmt.Sprintf("%c5", 'A'+i)
		f.SetCellValue(sheet, cell, h)
		f.SetCellStyle(sheet, cell, cell, headerStyle)
	}

	// Data rows
	row := 6
	for _, item := range data.Items {
		f.SetCellValue(sheet, fmt.Sprintf("A%d", row), item.LotName)
		f.SetCellValue(sheet, fmt.Sprintf("B%d", row), item.Description)
		f.SetCellValue(sheet, fmt.Sprintf("C%d", row), item.Category)
		f.SetCellValue(sheet, fmt.Sprintf("D%d", row), item.Quantity)
		f.SetCellValue(sheet, fmt.Sprintf("E%d", row), item.UnitPrice)
		f.SetCellValue(sheet, fmt.Sprintf("F%d", row), item.TotalPrice)
		f.SetCellStyle(sheet, fmt.Sprintf("E%d", row), fmt.Sprintf("F%d", row), priceStyle)
		row++
	}

	// Total row
	f.SetCellValue(sheet, fmt.Sprintf("E%d", row), "ИТОГО:")
	f.SetCellValue(sheet, fmt.Sprintf("F%d", row), data.Total)
	f.SetCellStyle(sheet, fmt.Sprintf("E%d", row), fmt.Sprintf("F%d", row), totalStyle)

	// Notes
	if data.Notes != "" {
		row += 2
		f.SetCellValue(sheet, fmt.Sprintf("A%d", row), "Примечания: "+data.Notes)
	}

	// Column widths
	f.SetColWidth(sheet, "A", "A", 25)
	f.SetColWidth(sheet, "B", "B", 50)
	f.SetColWidth(sheet, "C", "C", 15)
	f.SetColWidth(sheet, "D", "D", 10)
	f.SetColWidth(sheet, "E", "E", 15)
	f.SetColWidth(sheet, "F", "F", 15)

	var buf bytes.Buffer
	if err := f.Write(&buf); err != nil {
		return nil, err
	}

	return buf.Bytes(), nil
}

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

	for i, item := range config.Items {
		itemTotal := item.UnitPrice * float64(item.Quantity)
		items[i] = ExportItem{
			LotName:    item.LotName,
			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,
	}
}