feat: add graph subcommand to print dependency graph

Signed-off-by: Akash Kumar <meakash7902@gmail.com>

go.mod

@@ -35,6 +35,7 @@ require (
 	github.com/docker/go-connections v0.4.0 // indirect
 	github.com/docker/go-metrics v0.0.1 // indirect
 	github.com/docker/go-units v0.5.0 // indirect
+	github.com/dominikbraun/graph v0.23.0 // indirect
 	github.com/emirpasic/gods v1.18.1 // indirect
 	github.com/fatih/color v1.10.0 // indirect
 	github.com/go-git/gcfg v1.5.1-0.20230307220236-3a3c6141e376 // indirect

go.sum

@@ -113,6 +113,8 @@ github.com/docker/go-metrics v0.0.1/go.mod h1:cG1hvH2utMXtqgqqYE9plW6lDxS3/5ayHz
 github.com/docker/go-units v0.5.0 h1:69rxXcBk27SvSaaxTtLh/8llcHD8vYHT7WSdRZ/jvr4=
 github.com/docker/go-units v0.5.0/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
 github.com/docker/libtrust v0.0.0-20150114040149-fa567046d9b1 h1:ZClxb8laGDf5arXfYcAtECDFgAgHklGI8CxgjHnXKJ4=
+github.com/dominikbraun/graph v0.23.0 h1:TdZB4pPqCLFxYhdyMFb1TBdFxp8XLcJfTTBQucVPgCo=
+github.com/dominikbraun/graph v0.23.0/go.mod h1:yOjYyogZLY1LSG9E33JWZJiq5k83Qy2C6POAuiViluc=
 github.com/elazarl/goproxy v0.0.0-20230808193330-2592e75ae04a h1:mATvB/9r/3gvcejNsXKSkQ6lcIaNec2nyfOdlTBR2lU=
 github.com/emirpasic/gods v1.18.1 h1:FXtiHYKDGKCW2KzwZKx0iC0PQmdlorYgdFG9jPXJ1Bc=
 github.com/emirpasic/gods v1.18.1/go.mod h1:8tpGGwCnJ5H4r6BWwaV6OrWmMoPhUl5jm/FMNAnJvWQ=

kpm.go

@@ -25,6 +25,7 @@ func main() {
 	app.UsageText = "kpm  <command> [arguments]..."
 	app.Commands = []*cli.Command{
 		cmd.NewInitCmd(kpmcli),
+		// cmd.NewGraphCmd(kpmcli),
 		cmd.NewAddCmd(kpmcli),
 		cmd.NewPkgCmd(kpmcli),
 		cmd.NewMetadataCmd(kpmcli),

pkg/client/client.go

@@ -9,6 +9,7 @@ import (
 	"reflect"
 	"strings"
 
+	"github.com/dominikbraun/graph"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/otiai10/copy"
 	"kcl-lang.io/kcl-go/pkg/kcl"
@@ -567,7 +568,7 @@ func (c *KpmClient) AddDepToPkg(kclPkg *pkg.KclPkg, d *pkg.Dependency) error {
 	}
 
 	// download all the dependencies.
-	changedDeps, err := c.downloadDeps(kclPkg.ModFile.Dependencies, kclPkg.Dependencies)
+	changedDeps, _, err := c.downloadDeps(kclPkg.ModFile.Dependencies, kclPkg.Dependencies)
 
 	if err != nil {
 		return err
@@ -1068,6 +1069,40 @@ func (c *KpmClient) ParseOciOptionFromString(oci string, tag string) (*opt.OciOp
 	return ociOpt, nil
 }
 
+// PrintDependencyGraph will print the dependency graph of kcl package dependencies
+func (c *KpmClient) PrintDependencyGraph(kclPkg *pkg.KclPkg) error {
+	// create the main graph with a single root vertex.
+	root := fmt.Sprint(kclPkg.GetPkgName())
+	mainGraph := graph.New(graph.StringHash, graph.Directed())
+	err := mainGraph.AddVertex(root)
+	if err != nil {
+		return err
+	}
+
+	// get the dependency graphs and merge them into the main graph at root vertex.
+	_, depGraphs, err := c.downloadDeps(kclPkg.Dependencies, kclPkg.ModFile.Dependencies)
+	if err != nil {
+		return err
+	}
+
+	for _, g := range depGraphs {
+		mainGraph, err = graph.Union(mainGraph, g)
+		if err != nil {
+			return err
+		}
+		src, err := FindSource(g)
+		if err != nil {
+			return err
+		}
+		err = mainGraph.AddEdge(root, src)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 // dependencyExists will check whether the dependency exists in the local filesystem.
 func (c *KpmClient) dependencyExists(dep *pkg.Dependency, lockDeps *pkg.Dependencies) *pkg.Dependency {
 
@@ -1092,15 +1127,24 @@ func (c *KpmClient) dependencyExists(dep *pkg.Dependency, lockDeps *pkg.Dependen
 }
 
 // downloadDeps will download all the dependencies of the current kcl package.
-func (c *KpmClient) downloadDeps(deps pkg.Dependencies, lockDeps pkg.Dependencies) (*pkg.Dependencies, error) {
+func (c *KpmClient) downloadDeps(deps pkg.Dependencies, lockDeps pkg.Dependencies) (*pkg.Dependencies, []graph.Graph[string, string], error) {
 	newDeps := pkg.Dependencies{
 		Deps: make(map[string]pkg.Dependency),
 	}
 
+	depGraphs := make([]graph.Graph[string, string], len(deps.Deps))
+	i := 0
+
 	// Traverse all dependencies in kcl.mod
 	for _, d := range deps.Deps {
+		depGraphs[i] = graph.New(graph.StringHash, graph.Directed())
+		err := depGraphs[i].AddVertex(fmt.Sprintf("%s@%s", d.Name, d.Version))
+		if err != nil {
+			return nil, nil, err
+		}
+		i++
 		if len(d.Name) == 0 {
-			return nil, errors.InvalidDependency
+			return nil, nil, errors.InvalidDependency
 		}
 
 		existDep := c.dependencyExists(&d, &lockDeps)
@@ -1112,7 +1156,7 @@ func (c *KpmClient) downloadDeps(deps pkg.Dependencies, lockDeps pkg.Dependencie
 		expectedSum := lockDeps.Deps[d.Name].Sum
 		// Clean the cache
 		if len(c.homePath) == 0 || len(d.FullName) == 0 {
-			return nil, errors.InternalBug
+			return nil, nil, errors.InternalBug
 		}
 		dir := filepath.Join(c.homePath, d.FullName)
 		os.RemoveAll(dir)
@@ -1121,15 +1165,15 @@ func (c *KpmClient) downloadDeps(deps pkg.Dependencies, lockDeps pkg.Dependencie
 
 		lockedDep, err := c.Download(&d, dir)
 		if err != nil {
-			return nil, err
+			return nil, nil, err
 		}
 
 		if !lockedDep.IsFromLocal() {
 			if !c.noSumCheck && expectedSum != "" &&
 				lockedDep.Sum != expectedSum &&
 				existDep != nil &&
 				existDep.FullName == d.FullName {
-				return nil, reporter.NewErrorEvent(
+				return nil, nil, reporter.NewErrorEvent(
 					reporter.CheckSumMismatch,
 					errors.CheckSumMismatchError,
 					fmt.Sprintf("checksum for '%s' changed in lock file", lockedDep.Name),
@@ -1142,6 +1186,7 @@ func (c *KpmClient) downloadDeps(deps pkg.Dependencies, lockDeps pkg.Dependencie
 		lockDeps.Deps[d.Name] = *lockedDep
 	}
 
+	i = 0
 	// Recursively download the dependencies of the new dependencies.
 	for _, d := range newDeps.Deps {
 		// Load kcl.mod file of the new downloaded dependencies.
@@ -1154,13 +1199,34 @@ func (c *KpmClient) downloadDeps(deps pkg.Dependencies, lockDeps pkg.Dependencie
 			if os.IsNotExist(err) {
 				continue
 			}
-			return nil, err
+			return nil, nil, err
 		}
 
 		// Download the dependencies.
-		nested, err := c.downloadDeps(deppkg.ModFile.Dependencies, lockDeps)
+		nested, nestedDepGraphs, err := c.downloadDeps(deppkg.ModFile.Dependencies, lockDeps)
 		if err != nil {
-			return nil, err
+			return nil, nil, err
+		}
+
+		// merge the depGraph with the nestedDepGraphs.
+		src, err := FindSource(depGraphs[i])
+		if err != nil {
+			return nil, nil, err
+		}
+
+		for _, g := range nestedDepGraphs {
+			depGraphs[i], err = graph.Union(g, depGraphs[i])
+			if err != nil {
+				return nil, nil, err
+			}
+			srcOfNestedg, err := FindSource(g)
+			if err != nil {
+				return nil, nil, err
+			}
+			err = depGraphs[i].AddEdge(src, srcOfNestedg)
+			if err != nil {
+				return nil, nil, err
+			}
 		}
 
 		// Update kcl.mod.
@@ -1169,9 +1235,10 @@ func (c *KpmClient) downloadDeps(deps pkg.Dependencies, lockDeps pkg.Dependencie
 				newDeps.Deps[d.Name] = d
 			}
 		}
+		i++
 	}
 
-	return &newDeps, nil
+	return &newDeps, depGraphs, nil
 }
 
 // pullTarFromOci will pull a kcl package tar file from oci registry.
@@ -1244,3 +1311,23 @@ func check(dep pkg.Dependency, newDepPath string) bool {
 
 	return dep.Sum == sum
 }
+
+func FindSource[K comparable, T any](g graph.Graph[K, T]) (K, error) {
+	var src K
+	if !g.Traits().IsDirected {
+		return src, fmt.Errorf("cannot find source of a non-DAG graph ")
+	}
+
+	predecessorMap, err := g.PredecessorMap()
+	if err != nil {
+		return src, fmt.Errorf("failed to get predecessor map: %w", err)
+	}
+
+	for vertex, predecessors := range predecessorMap {
+		if len(predecessors) == 0 {
+			src = vertex
+			break
+		}
+	}
+	return src, nil
+}

pkg/cmd/cmd_graph.go

@@ -0,0 +1,68 @@
+// Copyright 2024 The KCL Authors. All rights reserved.
+
+package cmd
+
+import (
+	"os"
+
+	"github.com/urfave/cli/v2"
+	"kcl-lang.io/kpm/pkg/client"
+	"kcl-lang.io/kpm/pkg/env"
+	pkg "kcl-lang.io/kpm/pkg/package"
+	"kcl-lang.io/kpm/pkg/reporter"
+)
+
+// NewGraphCmd new a Command for `kpm graph`.
+func NewGraphCmd(kpmcli *client.KpmClient) *cli.Command {
+	return &cli.Command{
+		Hidden: false,
+		Name:   "graph",
+		Usage:  "prints the module dependency graph",
+		Action: func(c *cli.Context) error {
+			return KpmGraph(c, kpmcli)
+		},
+	}
+}
+
+func KpmGraph(c *cli.Context, kpmcli *client.KpmClient) error {
+	// acquire the lock of the package cache.
+	err := kpmcli.AcquirePackageCacheLock()
+	if err != nil {
+		return err
+	}
+
+	defer func() {
+		// release the lock of the package cache after the function returns.
+		releaseErr := kpmcli.ReleasePackageCacheLock()
+		if releaseErr != nil && err == nil {
+			err = releaseErr
+		}
+	}()
+
+	pwd, err := os.Getwd()
+
+	if err != nil {
+		return reporter.NewErrorEvent(reporter.Bug, err, "internal bugs, please contact us to fix it.")
+	}
+
+	globalPkgPath, err := env.GetAbsPkgPath()
+	if err != nil {
+		return err
+	}
+
+	kclPkg, err := pkg.LoadKclPkg(pwd)
+	if err != nil {
+		return err
+	}
+
+	err = kclPkg.ValidateKpmHome(globalPkgPath)
+	if err != (*reporter.KpmEvent)(nil) {
+		return err
+	}
+
+	err = kpmcli.PrintDependencyGraph(kclPkg)
+	if err != nil {
+		return err
+	}
+	return nil
+}