go-dpkg/deb822/deb822.go

package deb822

import (
	"fmt"
	"io"
	"slices"
	"strconv"
	"strings"

	"sirherobrine23.com.br/sirherobrine23/go-dpkg/internal/scanner"
)

type Source interface {
	IsMultiline() bool
	IsBool() bool
	IsInt() bool

	Len() int
	Line(int) string

	String() string
	ToSlice() []string
	ToBool() bool
	ToInt() int
}

var (
	_ Source = SingleLine("")
	_ Source = NumberLine(0)
	_ Source = Multiline{}
)

type SingleLine string

func (SingleLine) IsInt() bool         { return false }
func (SingleLine) ToInt() int          { return 0 }
func (s SingleLine) IsMultiline() bool { return false }
func (s SingleLine) IsBool() bool      { return slices.Contains([]string{"yes", "no"}, string(s)) }
func (s SingleLine) ToBool() bool      { return s.IsBool() && s.String() == "yes" }
func (s SingleLine) String() string    { return string(s) }
func (s SingleLine) Line(int) string   { return string(s) }
func (s SingleLine) Len() int          { return len(s) }
func (s SingleLine) ToSlice() []string {
	if s == "" {
		return nil
	}
	return []string{string(s)}
}

type NumberLine int

func (s NumberLine) IsMultiline() bool { return false }
func (s NumberLine) IsBool() bool      { return false }
func (s NumberLine) IsInt() bool       { return true }
func (s NumberLine) String() string    { return strconv.Itoa(int(s)) }
func (s NumberLine) Line(int) string   { return s.String() }
func (s NumberLine) Len() int          { return len(s.String()) }
func (s NumberLine) ToSlice() []string { return []string{s.String()} }
func (s NumberLine) ToInt() int        { return int(s) }
func (s NumberLine) ToBool() bool      { return s == 1 }

type Multiline []string

func (m Multiline) IsMultiline() bool { return len(m) > 1 }
func (m Multiline) IsBool() bool      { return slices.Contains([]string{"yes", "no"}, m.String()) }
func (m Multiline) ToBool() bool      { return m.IsBool() && m.String() == "yes" }
func (m Multiline) String() string    { return strings.Join(m, "\n") }
func (m Multiline) Len() int          { return len(m) }
func (m Multiline) ToSlice() []string { return m }
func (Multiline) IsInt() bool         { return true }
func (Multiline) ToInt() int          { return 0 }
func (m Multiline) Line(i int) string {
	if i < 0 || i >= len(m) {
		return ""
	}
	return m[i]
}

// Debian control file
type Deb822 map[string]Source

// Parse control file
func Parse(body []byte) (Deb822, error) {
	deb822Map := Deb822{}
	if err := deb822Map.UnmarshalBinary(body); err != nil {
		return nil, err
	}
	return deb822Map, nil
}

// Get key, if not exists return SingleLine
func (deb822Map Deb822) Get(key string) Source {
	if value, ok := deb822Map[key]; ok {
		return value
	}
	return SingleLine("")
}

// Unmarshall Debian822
func (deb822Map *Deb822) UnmarshalBinary(body []byte) error {
	if err := newParse(deb822Map, strings.NewReader(strings.TrimSpace(string(body)))); err != nil {
		return err
	}
	return nil
}

// Parse Debian822 with stream file
func NewParse(r io.Reader) (Deb822, error) {
	deb822Map := Deb822{}
	if err := newParse(&deb822Map, r); err != nil {
		return nil, err
	}
	return deb822Map, nil
}

// parse Debian822 file
func newParse(deb822Map *Deb822, r io.Reader) error {
	multilineKey, scann := "", scanner.NewScanner(r)
	for scann.Scan() {
		line := scann.Text()
		if line == "" {
			break // New deb822 ignore
		} else if strings.HasPrefix(line, "#") || strings.HasPrefix(line, "-") {
			continue // Ignore line
		} else if line[0] == ' ' || line[0] == '\t' {
			if multilineKey == "" {
				return fmt.Errorf("invalid control file, line: %s", line)
			} else if line = strings.TrimLeft(line, " \t"); line == "." {
				line = "" // Replace . with empty line
			}

			(*deb822Map)[multilineKey] = append(Multiline((*deb822Map)[multilineKey].ToSlice()), line)
			continue
		}

		keys := strings.SplitN(line, ":", 2)
		if len(keys) != 2 {
			return fmt.Errorf("invalid line: %s", line)
		}

		multilineKey, line = keys[0], keys[1]
		if line == "" {
			(*deb822Map)[multilineKey] = Multiline{}
			continue
		} else if line[0] == ' ' || line[0] == '\t' {
			line = line[1:]
		}

		if _, ok := (*deb822Map)[multilineKey]; !ok {
			(*deb822Map)[multilineKey] = SingleLine(line)
			if nu, err := strconv.Atoi(line); err == nil {
				(*deb822Map)[multilineKey] = NumberLine(nu)
			}
			continue
		}
		(*deb822Map)[multilineKey] = append(Multiline((*deb822Map)[multilineKey].ToSlice()), line)
	}
	return scann.Err()
}