package debian

import (
	"bytes"
	"fmt"
	"github.com/smira/aptly/utils"
	debc "github.com/smira/godebiancontrol"
	"github.com/ugorji/go/codec"
	"os"
	"strconv"
	"strings"
)

// Package is single instance of Debian package
//
// TODO: support source & binary
type Package struct {
	Name         string
	Version      string
	Filename     string
	Filesize     int64
	Architecture string
	Depends      []string
	PreDepends   []string
	Suggests     []string
	Recommends   []string
	Extra        debc.Paragraph
}

func parseDependencies(input debc.Paragraph, key string) []string {
	value, ok := input[key]
	if !ok {
		return nil
	}

	delete(input, key)

	return strings.Split(value, ", ")
}

// NewPackageFromControlFile creates Package from parsed Debian control file
func NewPackageFromControlFile(input debc.Paragraph) *Package {
	result := &Package{
		Name:         input["Package"],
		Version:      input["Version"],
		Filename:     input["Filename"],
		Architecture: input["Architecture"],
	}

	delete(input, "Package")
	delete(input, "Version")
	delete(input, "Filename")
	delete(input, "Architecture")

	result.Filesize, _ = strconv.ParseInt(input["Size"], 10, 64)
	delete(input, "Size")

	result.Depends = parseDependencies(input, "Depends")
	result.PreDepends = parseDependencies(input, "Pre-Depends")
	result.Suggests = parseDependencies(input, "Suggests")
	result.Recommends = parseDependencies(input, "Recommends")

	result.Extra = input

	return result
}

// Key returns unique key identifying package
func (p *Package) Key() []byte {
	return []byte("P" + p.Name + " " + p.Version + " " + p.Architecture)
}

// Encode does msgpack encoding of Package
func (p *Package) Encode() []byte {
	var buf bytes.Buffer

	encoder := codec.NewEncoder(&buf, &codec.MsgpackHandle{})
	encoder.Encode(p)

	return buf.Bytes()
}

// Decode decodes msgpack representation into Package
func (p *Package) Decode(input []byte) error {
	decoder := codec.NewDecoderBytes(input, &codec.MsgpackHandle{})
	return decoder.Decode(p)
}

// String creates readable representation
func (p *Package) String() string {
	return fmt.Sprintf("%s-%s_%s", p.Name, p.Version, p.Architecture)
}

// Equals compares two packages to be identical
func (p *Package) Equals(p2 *Package) bool {
	return p.Name == p2.Name && p.Version == p2.Version && p.Filename == p2.Filename &&
		p.Architecture == p2.Architecture && utils.StrSlicesEqual(p.Depends, p2.Depends) &&
		utils.StrSlicesEqual(p.PreDepends, p2.PreDepends) && utils.StrSlicesEqual(p.Suggests, p2.Suggests) &&
		utils.StrSlicesEqual(p.Recommends, p2.Recommends) && utils.StrMapsEqual(p.Extra, p2.Extra) &&
		p.Filesize == p2.Filesize
}

// VerifyFile verifies integrity and existence of local files for the package
func (p *Package) VerifyFile(filepath string) bool {
	st, err := os.Stat(filepath)
	if err != nil {
		return false
	}
	return st.Size() == p.Filesize
}