building.go

package csvutil

import (
	"io"

	"github.com/pkg/errors"
)

// BuildingOption is option holder for Building.
type BuildingOption struct {
	// Source file does not have header line. (default false)
	NoHeader bool
	// Encoding of source file. (default utf8)
	Encoding string
	// Encoding for output
	OutputEncoding string
	// Target column symbol
	Column string
	// Rate of office output
	OfficeRate int
	// BlockNumber width(1 or 2)
	NumberWidth int
	// Append to source value
	Append bool
}

func (o BuildingOption) validate() error {
	if o.Column == "" {
		return errors.New("no column")
	}
	if o.NoHeader {
		if !isDigit(o.Column) {
			return errors.New("not number column symbol")
		}
	}
	if o.OfficeRate < 0 || 100 < o.OfficeRate {
		return errors.New("invalid office rate (0 <= rate <= 100)")
	}
	if o.NumberWidth != 1 && o.NumberWidth != 2 {
		return errors.New("invalid number width (1 or 2)")
	}

	return nil
}

func (o BuildingOption) isFullWidth() bool {
	return o.NumberWidth == 2
}

func (o BuildingOption) outputEncoding() string {
	if o.OutputEncoding != "" {
		return o.OutputEncoding
	}
	return o.Encoding
}

// Building overwrite value of given column by dummy office or apartment.
func Building(r io.Reader, w io.Writer, o BuildingOption) error {
	if err := o.validate(); err != nil {
		return errors.Wrap(err, "invalid option")
	}

	cr, bom := reader(r, o.Encoding)
	cw := writer(w, bom, o.outputEncoding())
	defer cw.Flush()

	var col *column
	csvp := NewCSVProcessor(cr, cw)
	if o.NoHeader {
		csvp.SetPreBodyRead(func() error {
			col = newColumnWithIndex(o.Column, nil)
			return col.err
		})
	} else {
		csvp.SetHeaderHanlder(func(hdr []string) ([]string, error) {
			col = newColumnWithIndex(o.Column, hdr)
			return hdr, col.err
		})
	}
	csvp.SetRecordHandler(func(rec []string) ([]string, error) {
		if !o.Append {
			rec[col.index] = ""
		}
		if lot(o.OfficeRate) {
			rec[col.index] += fakeOffice(o.isFullWidth())
		} else {
			rec[col.index] += fakeApartment(o.isFullWidth())
		}
		return rec, nil
	})

	return csvp.Process()
}