package utils

import (
	"encoding/csv"
	"os"
	"strings"
)

// ReadCSV reads a CSV file and returns its contents as a slice of string slices
func ReadCSV(filename string) ([][]string, error) {
	file, err := os.Open(filename)
	if err != nil {
		return nil, err
	}
	defer file.Close()

	reader := csv.NewReader(file)
	return reader.ReadAll()
}

// WriteCSV writes a slice of string slices to a CSV file
func WriteCSV(filename string, data [][]string) error {
	file, err := os.Create(filename)
	if err != nil {
		return err
	}
	defer file.Close()

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

	return writer.WriteAll(data)
}

// ReadCSVFromBytes reads CSV data from a byte slice
func ReadCSVFromBytes(data []byte) ([][]string, error) {
	reader := csv.NewReader(strings.NewReader(string(data)))
	return reader.ReadAll()
}

// CSVToMap converts CSV data to a map of maps for easier access
// The first row is assumed to be headers
func CSVToMap(data [][]string) ([]map[string]string, error) {
	if len(data) < 2 {
		return nil, nil // No data or just headers
	}

	headers := data[0]
	result := make([]map[string]string, 0, len(data)-1)

	for i := 1; i < len(data); i++ {
		row := data[i]
		if len(row) == 0 {
			continue // Skip empty rows
		}

		rowMap := make(map[string]string)
		for j, value := range row {
			if j < len(headers) {
				rowMap[headers[j]] = value
			}
		}
		result = append(result, rowMap)
	}

	return result, nil
}