package parser

import (
	"fmt"
	"strings"

	"github.com/xuri/excelize/v2"
)

// ExcelParser extracts all sheets from Excel files as Markdown tables.
type ExcelParser struct{}

func (p *ExcelParser) SupportedExtensions() []string {
	return []string{".xlsx", ".xls"}
}

func (p *ExcelParser) ParseToMarkdown(path string) (string, error) {
	f, err := excelize.OpenFile(path)
	if err != nil {
		return "", fmt.Errorf("open excel: %w", err)
	}
	defer f.Close()

	var sb strings.Builder
	for _, sheet := range f.GetSheetList() {
		rows, err := f.GetRows(sheet)
		if err != nil {
			continue
		}
		if len(rows) == 0 {
			continue
		}

		sb.WriteString(fmt.Sprintf("## Sheet: %s\n\n", sheet))

		// Header row
		sb.WriteString("| ")
		for _, cell := range rows[0] {
			sb.WriteString(cell + " | ")
		}
		sb.WriteString("\n|")
		for range rows[0] {
			sb.WriteString(" --- |")
		}
		sb.WriteString("\n")

		// Data rows
		for _, row := range rows[1:] {
			sb.WriteString("| ")
			for i := 0; i < len(rows[0]); i++ {
				if i < len(row) {
					sb.WriteString(row[i])
				}
				sb.WriteString(" | ")
			}
			sb.WriteString("\n")
		}
		sb.WriteString("\n")
	}

	return sb.String(), nil
}