package q5

import "io"
import "os"
import "bufio"
import "strings"

type CsvReader struct {
	columns map[string]int32
	values []string

	currLine int
	lines []string
}

func (this *CsvReader) Load(fileName string) bool {
	this.columns = map[string]int32{}
	this.values = []string{}
	this.currLine = 0
	this.lines = []string{}

	f, err := os.Open(fileName)
	if err == nil {
		defer f.Close()

		br := bufio.NewReader(f)
		for {
			line, _, c := br.ReadLine()
			if c == io.EOF {
				break
			}
			this.lines = append(this.lines, string(line))
		}
	}
	return err == nil
}

func (this *CsvReader) NextLine() bool {
	if this.currLine >= len(this.lines) {
		return false
	}
	this.values = strings.Split(this.lines[this.currLine], ",")
	this.currLine++
	return true
}

func (this *CsvReader) GetValue(fieldName string) *XValue {
	index, ok := this.columns[fieldName]
	if ok {
		if index >= 0 && index < int32(len(this.values)) {
			return (&XValue{}).SetString(this.values[index])
		} else {
			return &XValue{}
		}
	} else {
		return &XValue{}
	}
}

func (this *CsvReader) KeyExists(fieldName string) bool {
	_, ok := this.columns[fieldName]
	return ok
}