package zoopb

import (
	"bufio"
	"os"
	"strings"
)

// sent via -ldflags
var VERSION string
var BUILDTIME string

func (m *Machine) IsInstalled(name string) bool {
	loop := m.Packages.SortByName()
	for loop.Scan() {
		p := loop.Package()
		if name == p.Name {
			// log.Info("package installed:", p.Name, p.Version, p.PkgName)
			return true
		}
	}

	// log.Info("package not-installed:", name)
	return false
}

func (m *Machine) FindInstalledByName(name string) *Package {
	loop := m.Packages.SortByName()
	for loop.Scan() {
		p := loop.Package()
		if name == p.Name {
			// log.Info("package installed:", p.Name, p.Version, p.PkgName)
			return p
		}
	}

	// log.Info("package not-installed:", name)
	return nil
}

// looks to see if any package matches a name and version
// if version == "", return the first name found
func (m *Machine) FindVersion(name string, version string) *Package {
	// first check all installed versions
	loop := m.Packages.SortByName()
	for loop.Scan() {
		p := loop.Package()
		if name == p.Name {
			if version == "" {
				return p
			} else {
				if version == p.Version {
					return p
				}
			}
		}
	}

	// check all wit packages
	loop = m.Wit.SortByName()
	for loop.Scan() {
		p := loop.Package()
		if name == p.Name {
			if version == "" {
				return p
			} else {
				if version == p.Version {
					return p
				}
			}
		}
	}

	// log.Info("package not-installed:", name)
	return nil
}

// read the package list file from mirrors.wit.com
func (m *Machine) InitWit() error {
	if m.Wit == nil {
		m.Wit = new(Packages)
	}
	err := m.scanPackageListFile("/var/lib/apt/lists/mirrors.wit.com_wit_dists_sid_main_binary-amd64_Packages")
	return err
	/*
		for _, p := range allpackages {
			var all []string
			for _, ver := range p.versions {
				all = append(all, ver.v)
			}
			// log.Info(name, strings.Join(all, ", "))
		}
	*/
}

// breaks up the apt list file into sections
// then sends each section to be processed
// and added to zoopb.Machine.Wit
func (m *Machine) scanPackageListFile(filename string) error {
	file, err := os.Open(filename)
	if err != nil {
		return err
	}
	defer file.Close()
	scanner := bufio.NewScanner(file)
	var debInfo string
	for scanner.Scan() {
		line := scanner.Text()
		if line == "" {
			p := parsePackageInfo(debInfo)
			m.Wit.Append(p)
			debInfo = ""
		}
		debInfo += line + "\n"
	}
	p := parsePackageInfo(debInfo)
	m.Wit.Append(p)
	return nil
}

/*
func (m *Machine) addPackage(name string, version string, filename string) {
	if name == "" {
		return
	}
	// log.Info("addPackage:", name, version, filename)
	var deb *DebPackage
	var ok bool
	deb, ok = allp[name]
	if !ok {
		deb = NewPackage()
		deb.name.SetLabel(name)
		allp[name] = deb
	}
	newversion := new(Version)
	newversion.v = version
	newversion.file = filename
	deb.versions = append(deb.versions, newversion)
}
*/

// parses dpkg -s foo.deb
func parsePackageInfo(lines string) *Package {
	var name string
	var version string
	var filename string
	var gopath string

	for _, line := range strings.Split(lines, "\n") {
		if line == "" {
			continue
		}
		if strings.HasPrefix(line, " ") {
			// these are usually Description: lines
			continue
		}
		if strings.HasPrefix(line, "#") {
			// skip comment lines. (probably doesn't happen in debian list files
			continue
		}
		line = strings.TrimSpace(line)
		parts := strings.Split(line, " ")
		if len(parts) < 2 {
			continue
		}
		if parts[0] == "Package:" {
			name = parts[1]
		}
		if parts[0] == "Version:" {
			version = parts[1]
		}
		if parts[0] == "Filename:" {
			filename = parts[1]
		}
		if parts[0] == "GoPath:" {
			gopath = parts[1]
		}
	}

	p := Package{
		Name:    name,
		Version: version,
		PkgName: filename,
		SrcPath: gopath,
	}

	return &p
}