// Install installs the dependencies from a Lockfile.
func (i *Installer) Install(lock *cfg.Lockfile, conf *cfg.Config) (*cfg.Config, error) {

	cwd, err := gpath.Vendor()
	if err != nil {
		return conf, err
	}

	// Create a config setup based on the Lockfile data to process with
	// existing commands.
	newConf := &cfg.Config{}
	newConf.Name = conf.Name

	newConf.Imports = make(cfg.Dependencies, len(lock.Imports))
	for k, v := range lock.Imports {
		newConf.Imports[k] = cfg.DependencyFromLock(v)
	}

	newConf.DevImports = make(cfg.Dependencies, len(lock.DevImports))
	for k, v := range lock.DevImports {
		newConf.DevImports[k] = cfg.DependencyFromLock(v)
	}

	newConf.DeDupe()

	if len(newConf.Imports) == 0 {
		msg.Info("No dependencies found. Nothing installed.\n")
		return newConf, nil
	}

	msg.Info("Downloading dependencies. Please wait...")

	LazyConcurrentUpdate(newConf.Imports, cwd, i, newConf)
	LazyConcurrentUpdate(newConf.DevImports, cwd, i, newConf)
	return newConf, nil
}

// VendoredCleanup cleans up vendored codebases after an update.
//
// This should _only_ be run for installations that do not want VCS repos inside
// of the vendor/ directory.
func VendoredCleanup(conf *cfg.Config) error {
	vend, err := gpath.Vendor()
	if err != nil {
		return err
	}

	for _, dep := range conf.Imports {
		if dep.UpdateAsVendored == true {
			msg.Info("Cleaning up vendored package %s\n", dep.Name)

			// Remove the VCS directory
			cwd := filepath.Join(vend, dep.Name)
			repo, err := dep.GetRepo(cwd)
			if err != nil {
				msg.Err("Error cleaning up %s:%s", dep.Name, err)
				continue
			}
			t := repo.Vcs()
			err = os.RemoveAll(cwd + string(os.PathSeparator) + "." + string(t))
			if err != nil {
				msg.Err("Error cleaning up VCS dir for %s:%s", dep.Name, err)
			}
		}

	}

	return nil
}

// SetReference is a command to set the VCS reference (commit id, tag, etc) for
// a project.
func SetReference(conf *cfg.Config, resolveTest bool) error {

	cwd, err := gpath.Vendor()
	if err != nil {
		return err
	}

	if len(conf.Imports) == 0 && len(conf.DevImports) == 0 {
		msg.Info("No references set.\n")
		return nil
	}

	done := make(chan struct{}, concurrentWorkers)
	in := make(chan *cfg.Dependency, concurrentWorkers)
	var wg sync.WaitGroup

	for i := 0; i < concurrentWorkers; i++ {
		go func(ch <-chan *cfg.Dependency) {
			for {
				select {
				case dep := <-ch:
					if err := VcsVersion(dep, cwd); err != nil {
						msg.Err("Failed to set version on %s to %s: %s\n", dep.Name, dep.Reference, err)
					}
					wg.Done()
				case <-done:
					return
				}
			}
		}(in)
	}

	for _, dep := range conf.Imports {
		if !conf.HasIgnore(dep.Name) {
			wg.Add(1)
			in <- dep
		}
	}

	if resolveTest {
		for _, dep := range conf.DevImports {
			if !conf.HasIgnore(dep.Name) {
				wg.Add(1)
				in <- dep
			}
		}
	}

	wg.Wait()
	// Close goroutines setting the version
	for i := 0; i < concurrentWorkers; i++ {
		done <- struct{}{}
	}
	// close(done)
	// close(in)

	return nil
}

// VendorPath returns the path to the location to put vendor packages
func (i *Installer) VendorPath() string {
	if i.Vendor != "" {
		return i.Vendor
	}

	vp, err := gpath.Vendor()
	if err != nil {
		return filepath.FromSlash("./vendor")
	}

	return vp
}

// Install installs the dependencies from a Lockfile.
func (i *Installer) Install(lock *cfg.Lockfile, conf *cfg.Config) (*cfg.Config, error) {

	cwd, err := gpath.Vendor()
	if err != nil {
		return conf, err
	}

	// Create a config setup based on the Lockfile data to process with
	// existing commands.
	newConf := &cfg.Config{}
	newConf.Name = conf.Name

	newConf.Imports = make(cfg.Dependencies, len(lock.Imports))
	for k, v := range lock.Imports {
		newConf.Imports[k] = &cfg.Dependency{
			Name:        v.Name,
			Reference:   v.Version,
			Repository:  v.Repository,
			VcsType:     v.VcsType,
			Subpackages: v.Subpackages,
			Arch:        v.Arch,
			Os:          v.Os,
		}
	}

	newConf.DevImports = make(cfg.Dependencies, len(lock.DevImports))
	for k, v := range lock.DevImports {
		newConf.DevImports[k] = &cfg.Dependency{
			Name:        v.Name,
			Reference:   v.Version,
			Repository:  v.Repository,
			VcsType:     v.VcsType,
			Subpackages: v.Subpackages,
			Arch:        v.Arch,
			Os:          v.Os,
		}
	}

	newConf.DeDupe()

	if len(newConf.Imports) == 0 {
		msg.Info("No dependencies found. Nothing installed.\n")
		return newConf, nil
	}

	msg.Info("Downloading dependencies. Please wait...")

	ConcurrentUpdate(newConf.Imports, cwd, i, newConf)
	ConcurrentUpdate(newConf.DevImports, cwd, i, newConf)
	return newConf, nil
}

// allPackages gets a list of all packages required to satisfy the given deps.
func allPackages(deps []*cfg.Dependency, res *dependency.Resolver) ([]string, error) {
	if len(deps) == 0 {
		return []string{}, nil
	}

	vdir, err := gpath.Vendor()
	if err != nil {
		return []string{}, err
	}
	vdir += string(os.PathSeparator)
	ll, err := res.ResolveAll(deps)
	if err != nil {
		return []string{}, err
	}

	for i := 0; i < len(ll); i++ {
		ll[i] = strings.TrimPrefix(ll[i], vdir)
	}
	return ll, nil
}

// Rebuild rebuilds '.a' files for a project.
//
// Prior to Go 1.4, this could substantially reduce time on incremental compiles.
// It remains to be seen whether this is tremendously beneficial to modern Go
// programs.
func Rebuild() {
	conf := EnsureConfig()
	vpath, err := gpath.Vendor()
	if err != nil {
		msg.Die("Could not get vendor path: %s", err)
	}

	msg.Info("Building dependencies.\n")

	if len(conf.Imports) == 0 {
		msg.Info("No dependencies found. Nothing built.\n")
		return
	}

	for _, dep := range conf.Imports {
		if err := buildDep(dep, vpath); err != nil {
			msg.Warn("Failed to build %s: %s\n", dep.Name, err)
		}
	}
}

// Rebuild rebuilds '.a' files for a project.
//
// Prior to Go 1.4, this could substantially reduce time on incremental compiles.
// It remains to be seen whether this is tremendously beneficial to modern Go
// programs.
func Rebuild() {
	msg.Warn("The rebuild command is deprecated and will be removed in a future version")
	msg.Warn("Use the go install command instead")
	conf := EnsureConfig()
	vpath, err := gpath.Vendor()
	if err != nil {
		msg.Die("Could not get vendor path: %s", err)
	}

	msg.Info("Building dependencies.\n")

	if len(conf.Imports) == 0 {
		msg.Info("No dependencies found. Nothing built.\n")
		return
	}

	for _, dep := range conf.Imports {
		if err := buildDep(dep, vpath); err != nil {
			msg.Warn("Failed to build %s: %s\n", dep.Name, err)
		}
	}
}

// DeleteUnused removes packages from vendor/ that are no longer used.
//
// TODO: This should work off of a Lock file, not glide.yaml.
func DeleteUnused(conf *cfg.Config) error {
	vpath, err := gpath.Vendor()
	if err != nil {
		return err
	}
	if vpath == "" {
		return errors.New("Vendor not set")
	}

	// Build directory tree of what to keep.
	var pkgList []string
	for _, dep := range conf.Imports {
		pkgList = append(pkgList, dep.Name)
	}

	var searchPath string
	var markForDelete []string
	// Callback function for filepath.Walk to delete packages not in yaml file.
	fn := func(path string, info os.FileInfo, err error) error {
		// Bubble up the error
		if err != nil {
			return err
		}

		if info.IsDir() == false || path == searchPath || path == vpath {
			return nil
		}

		localPath := strings.TrimPrefix(path, searchPath)
		keep := false

		// First check if the path has a prefix that's a specific package. If
		// so we keep it to keep the package.
		for _, name := range pkgList {
			if strings.HasPrefix(localPath, name) {
				keep = true
			}
		}

		// If a package is, for example, github.com/Masterminds/glide the
		// previous look will not mark the directories github.com or
		// github.com/Masterminds to keep. Here we see if these names prefix
		// and packages we know about to mark as keepers.
		if keep == false {
			for _, name := range pkgList {
				if strings.HasPrefix(name, localPath) {
					keep = true
				}
			}
		}

		// If the parent directory has already been marked for delete this
		// directory doesn't need to be marked.
		for _, markedDirectory := range markForDelete {
			if strings.HasPrefix(path, markedDirectory) {
				return nil
			}
		}

		// Remove the directory if we are not keeping it.
		if keep == false {
			// Mark for deletion
			markForDelete = append(markForDelete, path)
		}

		return nil
	}

	// Walk vendor directory
	searchPath = vpath + string(os.PathSeparator)
	err = filepath.Walk(searchPath, fn)
	if err != nil {
		return err
	}

	// Perform the actual delete.
	for _, path := range markForDelete {
		localPath := strings.TrimPrefix(path, searchPath)
		msg.Info("Removing unused package: %s\n", localPath)
		rerr := os.RemoveAll(path)
		if rerr != nil {
			return rerr
		}
	}

	return nil
}