1 files changed, 245 insertions, 0 deletions
diff --git a/pkg/runner/reusable_workflow.go b/pkg/runner/reusable_workflow.go
new file mode 100644
index 0000000..717913f
--- /dev/null
+++ b/pkg/runner/reusable_workflow.go
@@ -0,0 +1,245 @@
+package runner
+
+import (
+	"archive/tar"
+	"context"
+	"errors"
+	"fmt"
+	"io/fs"
+	"os"
+	"path"
+	"regexp"
+	"strings"
+	"sync"
+
+	"github.com/nektos/act/pkg/common"
+	"github.com/nektos/act/pkg/common/git"
+	"github.com/nektos/act/pkg/model"
+)
+
+func newLocalReusableWorkflowExecutor(rc *RunContext) common.Executor {
+	if !rc.Config.NoSkipCheckout {
+		fullPath := rc.Run.Job().Uses
+
+		fileName := path.Base(fullPath)
+		workflowDir := strings.TrimSuffix(fullPath, path.Join("/", fileName))
+		workflowDir = strings.TrimPrefix(workflowDir, "./")
+
+		return common.NewPipelineExecutor(
+			newReusableWorkflowExecutor(rc, workflowDir, fileName),
+		)
+	}
+
+	// ./.gitea/workflows/wf.yml -> .gitea/workflows/wf.yml
+	trimmedUses := strings.TrimPrefix(rc.Run.Job().Uses, "./")
+	// uses string format is {owner}/{repo}/.{git_platform}/workflows/{filename}@{ref}
+	uses := fmt.Sprintf("%s/%s@%s", rc.Config.PresetGitHubContext.Repository, trimmedUses, rc.Config.PresetGitHubContext.Sha)
+
+	remoteReusableWorkflow := newRemoteReusableWorkflowWithPlat(rc.Config.GitHubInstance, uses)
+	if remoteReusableWorkflow == nil {
+		return common.NewErrorExecutor(fmt.Errorf("expected format {owner}/{repo}/.{git_platform}/workflows/{filename}@{ref}. Actual '%s' Input string was not in a correct format", uses))
+	}
+
+	workflowDir := fmt.Sprintf("%s/%s", rc.ActionCacheDir(), safeFilename(uses))
+
+	// If the repository is private, we need a token to clone it
+	token := rc.Config.GetToken()
+
+	return common.NewPipelineExecutor(
+		newMutexExecutor(cloneIfRequired(rc, *remoteReusableWorkflow, workflowDir, token)),
+		newReusableWorkflowExecutor(rc, workflowDir, remoteReusableWorkflow.FilePath()),
+	)
+}
+
+func newRemoteReusableWorkflowExecutor(rc *RunContext) common.Executor {
+	uses := rc.Run.Job().Uses
+
+	remoteReusableWorkflow := newRemoteReusableWorkflowWithPlat(rc.Config.GitHubInstance, uses)
+	if remoteReusableWorkflow == nil {
+		return common.NewErrorExecutor(fmt.Errorf("expected format {owner}/{repo}/.{git_platform}/workflows/{filename}@{ref}. Actual '%s' Input string was not in a correct format", uses))
+	}
+
+	// uses with safe filename makes the target directory look something like this {owner}-{repo}-.github-workflows-{filename}@{ref}
+	// instead we will just use {owner}-{repo}@{ref} as our target directory. This should also improve performance when we are using
+	// multiple reusable workflows from the same repository and ref since for each workflow we won't have to clone it again
+	filename := fmt.Sprintf("%s/%s@%s", remoteReusableWorkflow.Org, remoteReusableWorkflow.Repo, remoteReusableWorkflow.Ref)
+	workflowDir := fmt.Sprintf("%s/%s", rc.ActionCacheDir(), safeFilename(filename))
+
+	// FIXME: if the reusable workflow is from a private repository, we need to provide a token to access the repository.
+	token := ""
+
+	if rc.Config.ActionCache != nil {
+		return newActionCacheReusableWorkflowExecutor(rc, filename, remoteReusableWorkflow)
+	}
+
+	return common.NewPipelineExecutor(
+		newMutexExecutor(cloneIfRequired(rc, *remoteReusableWorkflow, workflowDir, token)),
+		newReusableWorkflowExecutor(rc, workflowDir, remoteReusableWorkflow.FilePath()),
+	)
+}
+
+func newActionCacheReusableWorkflowExecutor(rc *RunContext, filename string, remoteReusableWorkflow *remoteReusableWorkflow) common.Executor {
+	return func(ctx context.Context) error {
+		ghctx := rc.getGithubContext(ctx)
+		remoteReusableWorkflow.URL = ghctx.ServerURL
+		sha, err := rc.Config.ActionCache.Fetch(ctx, filename, remoteReusableWorkflow.CloneURL(), remoteReusableWorkflow.Ref, ghctx.Token)
+		if err != nil {
+			return err
+		}
+		archive, err := rc.Config.ActionCache.GetTarArchive(ctx, filename, sha, fmt.Sprintf(".github/workflows/%s", remoteReusableWorkflow.Filename))
+		if err != nil {
+			return err
+		}
+		defer archive.Close()
+		treader := tar.NewReader(archive)
+		if _, err = treader.Next(); err != nil {
+			return err
+		}
+		planner, err := model.NewSingleWorkflowPlanner(remoteReusableWorkflow.Filename, treader)
+		if err != nil {
+			return err
+		}
+		plan, err := planner.PlanEvent("workflow_call")
+		if err != nil {
+			return err
+		}
+
+		runner, err := NewReusableWorkflowRunner(rc)
+		if err != nil {
+			return err
+		}
+
+		return runner.NewPlanExecutor(plan)(ctx)
+	}
+}
+
+var (
+	executorLock sync.Mutex
+)
+
+func newMutexExecutor(executor common.Executor) common.Executor {
+	return func(ctx context.Context) error {
+		executorLock.Lock()
+		defer executorLock.Unlock()
+
+		return executor(ctx)
+	}
+}
+
+func cloneIfRequired(rc *RunContext, remoteReusableWorkflow remoteReusableWorkflow, targetDirectory, token string) common.Executor {
+	return common.NewConditionalExecutor(
+		func(ctx context.Context) bool {
+			_, err := os.Stat(targetDirectory)
+			notExists := errors.Is(err, fs.ErrNotExist)
+			return notExists
+		},
+		func(ctx context.Context) error {
+			// Do not change the remoteReusableWorkflow.URL, because:
+			// 	1. Gitea doesn't support specifying GithubContext.ServerURL by the GITHUB_SERVER_URL env
+			//	2. Gitea has already full URL with rc.Config.GitHubInstance when calling newRemoteReusableWorkflowWithPlat
+			// remoteReusableWorkflow.URL = rc.getGithubContext(ctx).ServerURL
+			return git.NewGitCloneExecutor(git.NewGitCloneExecutorInput{
+				URL:         remoteReusableWorkflow.CloneURL(),
+				Ref:         remoteReusableWorkflow.Ref,
+				Dir:         targetDirectory,
+				Token:       token,
+				OfflineMode: rc.Config.ActionOfflineMode,
+			})(ctx)
+		},
+		nil,
+	)
+}
+
+func newReusableWorkflowExecutor(rc *RunContext, directory string, workflow string) common.Executor {
+	return func(ctx context.Context) error {
+		planner, err := model.NewWorkflowPlanner(path.Join(directory, workflow), true)
+		if err != nil {
+			return err
+		}
+
+		plan, err := planner.PlanEvent("workflow_call")
+		if err != nil {
+			return err
+		}
+
+		runner, err := NewReusableWorkflowRunner(rc)
+		if err != nil {
+			return err
+		}
+
+		return runner.NewPlanExecutor(plan)(ctx)
+	}
+}
+
+func NewReusableWorkflowRunner(rc *RunContext) (Runner, error) {
+	runner := &runnerImpl{
+		config:    rc.Config,
+		eventJSON: rc.EventJSON,
+		caller: &caller{
+			runContext: rc,
+		},
+	}
+
+	return runner.configure()
+}
+
+type remoteReusableWorkflow struct {
+	URL      string
+	Org      string
+	Repo     string
+	Filename string
+	Ref      string
+
+	GitPlatform string
+}
+
+func (r *remoteReusableWorkflow) CloneURL() string {
+	// In Gitea, r.URL always has the protocol prefix, we don't need to add extra prefix in this case.
+	if strings.HasPrefix(r.URL, "http://") || strings.HasPrefix(r.URL, "https://") {
+		return fmt.Sprintf("%s/%s/%s", r.URL, r.Org, r.Repo)
+	}
+	return fmt.Sprintf("https://%s/%s/%s", r.URL, r.Org, r.Repo)
+}
+
+func (r *remoteReusableWorkflow) FilePath() string {
+	return fmt.Sprintf("./.%s/workflows/%s", r.GitPlatform, r.Filename)
+}
+
+// For Gitea
+// newRemoteReusableWorkflowWithPlat create a `remoteReusableWorkflow`
+// workflows from `.gitea/workflows` and `.github/workflows` are supported
+func newRemoteReusableWorkflowWithPlat(url, uses string) *remoteReusableWorkflow {
+	// GitHub docs:
+	// https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_iduses
+	r := regexp.MustCompile(`^([^/]+)/([^/]+)/\.([^/]+)/workflows/([^@]+)@(.*)$`)
+	matches := r.FindStringSubmatch(uses)
+	if len(matches) != 6 {
+		return nil
+	}
+	return &remoteReusableWorkflow{
+		Org:         matches[1],
+		Repo:        matches[2],
+		GitPlatform: matches[3],
+		Filename:    matches[4],
+		Ref:         matches[5],
+		URL:         url,
+	}
+}
+
+// deprecated: use newRemoteReusableWorkflowWithPlat
+func newRemoteReusableWorkflow(uses string) *remoteReusableWorkflow {
+	// GitHub docs:
+	// https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_iduses
+	r := regexp.MustCompile(`^([^/]+)/([^/]+)/.github/workflows/([^@]+)@(.*)$`)
+	matches := r.FindStringSubmatch(uses)
+	if len(matches) != 5 {
+		return nil
+	}
+	return &remoteReusableWorkflow{
+		Org:      matches[1],
+		Repo:     matches[2],
+		Filename: matches[3],
+		Ref:      matches[4],
+		URL:      "https://github.com",
+	}
+}