bargain-hardware/internal/exporter/exporter.go

package exporter

import (
	"encoding/csv"
	"encoding/json"
	"fmt"
	"os"
	"strings"
	"time"

	"bargain-scraper/internal/models"
)

type Exporter struct{}

func New() *Exporter {
	return &Exporter{}
}

func (e *Exporter) ExportToJSON(products []models.StorageProduct, filename string) error {
	if filename == "" {
		filename = fmt.Sprintf("storage_products_%s.json", time.Now().Format("2006-01-02_150405"))
	}

	data, err := json.MarshalIndent(products, "", "  ")
	if err != nil {
		return fmt.Errorf("failed to marshal JSON: %w", err)
	}

	err = os.WriteFile(filename, data, 0644)
	if err != nil {
		return fmt.Errorf("failed to write JSON file: %w", err)
	}

	return nil
}

func (e *Exporter) ExportToCSV(products []models.StorageProduct, filename string) error {
	if filename == "" {
		filename = fmt.Sprintf("storage_products_%s.csv", time.Now().Format("2006-01-02_150405"))
	}

	file, err := os.Create(filename)
	if err != nil {
		return fmt.Errorf("failed to create CSV file: %w", err)
	}
	defer file.Close()

	writer := csv.NewWriter(file)
	defer writer.Flush()

	headers := []string{"ID", "Name", "Price", "Capacity", "Interface", "FormFactor", "Brand", "PartNumber", "StockStatus", "URL", "ScrapedAt"}
	if err := writer.Write(headers); err != nil {
		return fmt.Errorf("failed to write CSV headers: %w", err)
	}

	for _, p := range products {
		row := []string{
			p.ID,
			p.Name,
			p.Price,
			p.Capacity,
			p.Interface,
			p.FormFactor,
			p.Brand,
			p.PartNumber,
			p.StockStatus,
			p.URL,
			p.ScrapedAt.Format(time.RFC3339),
		}
		if err := writer.Write(row); err != nil {
			return fmt.Errorf("failed to write CSV row: %w", err)
		}
	}

	return nil
}

func (e *Exporter) PrintToConsole(products []models.StorageProduct) string {
	var b strings.Builder

	b.WriteString("\n")
	b.WriteString("═══════════════════════════════════════════════════════════════════════════════\n")
	b.WriteString(fmt.Sprintf("                    STORAGE PRODUCTS (%d items)                         \n", len(products)))
	b.WriteString("═══════════════════════════════════════════════════════════════════════════════\n")
	b.WriteString("\n")

	headerFmt := " %-4s | %-40s | %-10s | %-8s | %-6s | %-10s | %-12s\n"
	separator := "──────┼──────────────────────────────────────────┬────────────┬──────────┼────────┼────────────┼──────────────\n"

	b.WriteString(fmt.Sprintf(headerFmt, "#", "Name", "Capacity", "Interface", "Factor", "Stock", "Price"))
	b.WriteString(separator)

	for i, p := range products {
		name := p.Name
		if len(name) > 40 {
			name = name[:37] + "..."
		}

		capacity := p.Capacity
		if capacity == "" {
			capacity = "-"
		}

		interface_ := p.Interface
		if interface_ == "" {
			interface_ = "-"
		}

		formFactor := p.FormFactor
		if formFactor == "" {
			formFactor = "-"
		}

		stock := p.StockStatus
		if stock == "" {
			stock = "-"
		}

		price := p.Price
		if price == "" {
			price = "-"
		}

		b.WriteString(fmt.Sprintf(headerFmt,
			fmt.Sprintf("%d", i+1),
			name,
			capacity,
			interface_,
			formFactor,
			stock,
			price,
		))
	}

	b.WriteString("\n")
	b.WriteString(fmt.Sprintf("Total: %d products\n", len(products)))

	return b.String()
}

func (e *Exporter) Export(products []models.StorageProduct, format string, filename string) error {
	switch strings.ToLower(format) {
	case "json":
		return e.ExportToJSON(products, filename)
	case "csv":
		return e.ExportToCSV(products, filename)
	default:
		return fmt.Errorf("unsupported format: %s (use 'json' or 'csv')", format)
	}
}