package buildfile

import (
	"bufio"
	"io"
	"strings"
)

// Reader is the buildfile reader
type Reader struct {
	// linux distribution to run on
	distribution string
	Content      []*instruction
}

// NewReader creates a new reader for the specified build file and linux distribution
func NewReader(distro string, buildfile io.Reader) (*Reader, error) {

	r := &Reader{
		distribution: distro,
		Content:      make([]*instruction, 0),
	}

	// read each line
	l, reader := 0, bufio.NewReader(buildfile)
	for {
		l++

		line, err := reader.ReadString('\n')
		if err == io.EOF {
			break
		} else if err != nil {
			return nil, LineError{l, err}
		}
		line = strings.Trim(line, " \t\n")

		// get and add instruction to list
		inst, err := createInstruction(line)
		if err != nil {
			return nil, LineError{l, err}
		}
		r.Content = append(r.Content, inst)

	}

	return r, nil
}