evalphobia / minfraud-api-go

package main

import (

	"encoding/csv"

	"fmt"

	"os"

	"path/filepath"

)

// CSVHandler handles CSV file.

type CSVHandler struct {

	header    []string

	headerMap map[string]int

	reader    *csv.Reader

}

// NewCSVHandler returns initialized *CSVHandler

func NewCSVHandler(file string) (*CSVHandler, error) {

	info, err := os.Stat(file)

	if err == nil && info.IsDir() {

		return nil, fmt.Errorf("'%s' is dir, please set file path", file)

	}

	// load file

	fp, err := os.Open(file)

	if err != nil {

		return nil, err

	}

	// load csv

	reader := csv.NewReader(fp)

	reader.LazyQuotes = true

	switch filepath.Ext(file) {

	case ".tsv":

		reader.Comma = '\t'

	}

	header, err := reader.Read()

	if err != nil {

		return nil, err

	}

	headerMap := make(map[string]int)

	for i, col := range header {

		headerMap[col] = i

	}

	return &CSVHandler{

		header:    header,

		headerMap: headerMap,

		reader:    reader,

	}, nil

}

// ReadAll reads all lines from CSV file.

func (f *CSVHandler) ReadAll() ([]map[string]string, error) {

	if f.reader == nil {

		return nil, fmt.Errorf("f.reader is nil")

	}

	lines, err := f.reader.ReadAll()

	if err != nil {

		return nil, err

	}

	header := f.header

	result := make([]map[string]string, len(lines))

	for i, line := range lines {

		r := make(map[string]string)

		for j, col := range line {

			r[header[j]] = col

		}

		result[i] = r

	}

	return result, nil

}