1 files changed, 415 insertions, 0 deletions
diff --git a/pkg/model/planner.go b/pkg/model/planner.go
new file mode 100644
index 0000000..2d68145
--- /dev/null
+++ b/pkg/model/planner.go
@@ -0,0 +1,415 @@
+package model
+
+import (
+	"fmt"
+	"io"
+	"io/fs"
+	"math"
+	"os"
+	"path/filepath"
+	"regexp"
+	"sort"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// WorkflowPlanner contains methods for creating plans
+type WorkflowPlanner interface {
+	PlanEvent(eventName string) (*Plan, error)
+	PlanJob(jobName string) (*Plan, error)
+	PlanAll() (*Plan, error)
+	GetEvents() []string
+}
+
+// Plan contains a list of stages to run in series
+type Plan struct {
+	Stages []*Stage
+}
+
+// Stage contains a list of runs to execute in parallel
+type Stage struct {
+	Runs []*Run
+}
+
+// Run represents a job from a workflow that needs to be run
+type Run struct {
+	Workflow *Workflow
+	JobID    string
+}
+
+func (r *Run) String() string {
+	jobName := r.Job().Name
+	if jobName == "" {
+		jobName = r.JobID
+	}
+	return jobName
+}
+
+// Job returns the job for this Run
+func (r *Run) Job() *Job {
+	return r.Workflow.GetJob(r.JobID)
+}
+
+type WorkflowFiles struct {
+	workflowDirEntry os.DirEntry
+	dirPath          string
+}
+
+// NewWorkflowPlanner will load a specific workflow, all workflows from a directory or all workflows from a directory and its subdirectories
+//
+//nolint:gocyclo
+func NewWorkflowPlanner(path string, noWorkflowRecurse bool) (WorkflowPlanner, error) {
+	path, err := filepath.Abs(path)
+	if err != nil {
+		return nil, err
+	}
+
+	fi, err := os.Stat(path)
+	if err != nil {
+		return nil, err
+	}
+
+	var workflows []WorkflowFiles
+
+	if fi.IsDir() {
+		log.Debugf("Loading workflows from '%s'", path)
+		if noWorkflowRecurse {
+			files, err := os.ReadDir(path)
+			if err != nil {
+				return nil, err
+			}
+
+			for _, v := range files {
+				workflows = append(workflows, WorkflowFiles{
+					dirPath:          path,
+					workflowDirEntry: v,
+				})
+			}
+		} else {
+			log.Debug("Loading workflows recursively")
+			if err := filepath.Walk(path,
+				func(p string, f os.FileInfo, err error) error {
+					if err != nil {
+						return err
+					}
+
+					if !f.IsDir() {
+						log.Debugf("Found workflow '%s' in '%s'", f.Name(), p)
+						workflows = append(workflows, WorkflowFiles{
+							dirPath:          filepath.Dir(p),
+							workflowDirEntry: fs.FileInfoToDirEntry(f),
+						})
+					}
+
+					return nil
+				}); err != nil {
+				return nil, err
+			}
+		}
+	} else {
+		log.Debugf("Loading workflow '%s'", path)
+		dirname := filepath.Dir(path)
+
+		workflows = append(workflows, WorkflowFiles{
+			dirPath:          dirname,
+			workflowDirEntry: fs.FileInfoToDirEntry(fi),
+		})
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	wp := new(workflowPlanner)
+	for _, wf := range workflows {
+		ext := filepath.Ext(wf.workflowDirEntry.Name())
+		if ext == ".yml" || ext == ".yaml" {
+			f, err := os.Open(filepath.Join(wf.dirPath, wf.workflowDirEntry.Name()))
+			if err != nil {
+				return nil, err
+			}
+
+			log.Debugf("Reading workflow '%s'", f.Name())
+			workflow, err := ReadWorkflow(f)
+			if err != nil {
+				_ = f.Close()
+				if err == io.EOF {
+					return nil, fmt.Errorf("unable to read workflow '%s': file is empty: %w", wf.workflowDirEntry.Name(), err)
+				}
+				return nil, fmt.Errorf("workflow is not valid. '%s': %w", wf.workflowDirEntry.Name(), err)
+			}
+			_, err = f.Seek(0, 0)
+			if err != nil {
+				_ = f.Close()
+				return nil, fmt.Errorf("error occurring when resetting io pointer in '%s': %w", wf.workflowDirEntry.Name(), err)
+			}
+
+			workflow.File = wf.workflowDirEntry.Name()
+			if workflow.Name == "" {
+				workflow.Name = wf.workflowDirEntry.Name()
+			}
+
+			err = validateJobName(workflow)
+			if err != nil {
+				_ = f.Close()
+				return nil, err
+			}
+
+			wp.workflows = append(wp.workflows, workflow)
+			_ = f.Close()
+		}
+	}
+
+	return wp, nil
+}
+
+// CombineWorkflowPlanner combines workflows to a WorkflowPlanner
+func CombineWorkflowPlanner(workflows ...*Workflow) WorkflowPlanner {
+	return &workflowPlanner{
+		workflows: workflows,
+	}
+}
+
+func NewSingleWorkflowPlanner(name string, f io.Reader) (WorkflowPlanner, error) {
+	wp := new(workflowPlanner)
+
+	log.Debugf("Reading workflow %s", name)
+	workflow, err := ReadWorkflow(f)
+	if err != nil {
+		if err == io.EOF {
+			return nil, fmt.Errorf("unable to read workflow '%s': file is empty: %w", name, err)
+		}
+		return nil, fmt.Errorf("workflow is not valid. '%s': %w", name, err)
+	}
+	workflow.File = name
+	if workflow.Name == "" {
+		workflow.Name = name
+	}
+
+	err = validateJobName(workflow)
+	if err != nil {
+		return nil, err
+	}
+
+	wp.workflows = append(wp.workflows, workflow)
+
+	return wp, nil
+}
+
+func validateJobName(workflow *Workflow) error {
+	jobNameRegex := regexp.MustCompile(`^([[:alpha:]_][[:alnum:]_\-]*)$`)
+	for k := range workflow.Jobs {
+		if ok := jobNameRegex.MatchString(k); !ok {
+			return fmt.Errorf("workflow is not valid. '%s': Job name '%s' is invalid. Names must start with a letter or '_' and contain only alphanumeric characters, '-', or '_'", workflow.Name, k)
+		}
+	}
+	return nil
+}
+
+type workflowPlanner struct {
+	workflows []*Workflow
+}
+
+// PlanEvent builds a new list of runs to execute in parallel for an event name
+func (wp *workflowPlanner) PlanEvent(eventName string) (*Plan, error) {
+	plan := new(Plan)
+	if len(wp.workflows) == 0 {
+		log.Debug("no workflows found by planner")
+		return plan, nil
+	}
+	var lastErr error
+
+	for _, w := range wp.workflows {
+		events := w.On()
+		if len(events) == 0 {
+			log.Debugf("no events found for workflow: %s", w.File)
+			continue
+		}
+
+		for _, e := range events {
+			if e == eventName {
+				stages, err := createStages(w, w.GetJobIDs()...)
+				if err != nil {
+					log.Warn(err)
+					lastErr = err
+				} else {
+					plan.mergeStages(stages)
+				}
+			}
+		}
+	}
+	return plan, lastErr
+}
+
+// PlanJob builds a new run to execute in parallel for a job name
+func (wp *workflowPlanner) PlanJob(jobName string) (*Plan, error) {
+	plan := new(Plan)
+	if len(wp.workflows) == 0 {
+		log.Debugf("no jobs found for workflow: %s", jobName)
+	}
+	var lastErr error
+
+	for _, w := range wp.workflows {
+		stages, err := createStages(w, jobName)
+		if err != nil {
+			log.Warn(err)
+			lastErr = err
+		} else {
+			plan.mergeStages(stages)
+		}
+	}
+	return plan, lastErr
+}
+
+// PlanAll builds a new run to execute in parallel all
+func (wp *workflowPlanner) PlanAll() (*Plan, error) {
+	plan := new(Plan)
+	if len(wp.workflows) == 0 {
+		log.Debug("no workflows found by planner")
+		return plan, nil
+	}
+	var lastErr error
+
+	for _, w := range wp.workflows {
+		stages, err := createStages(w, w.GetJobIDs()...)
+		if err != nil {
+			log.Warn(err)
+			lastErr = err
+		} else {
+			plan.mergeStages(stages)
+		}
+	}
+
+	return plan, lastErr
+}
+
+// GetEvents gets all the events in the workflows file
+func (wp *workflowPlanner) GetEvents() []string {
+	events := make([]string, 0)
+	for _, w := range wp.workflows {
+		found := false
+		for _, e := range events {
+			for _, we := range w.On() {
+				if e == we {
+					found = true
+					break
+				}
+			}
+			if found {
+				break
+			}
+		}
+
+		if !found {
+			events = append(events, w.On()...)
+		}
+	}
+
+	// sort the list based on depth of dependencies
+	sort.Slice(events, func(i, j int) bool {
+		return events[i] < events[j]
+	})
+
+	return events
+}
+
+// MaxRunNameLen determines the max name length of all jobs
+func (p *Plan) MaxRunNameLen() int {
+	maxRunNameLen := 0
+	for _, stage := range p.Stages {
+		for _, run := range stage.Runs {
+			runNameLen := len(run.String())
+			if runNameLen > maxRunNameLen {
+				maxRunNameLen = runNameLen
+			}
+		}
+	}
+	return maxRunNameLen
+}
+
+// GetJobIDs will get all the job names in the stage
+func (s *Stage) GetJobIDs() []string {
+	names := make([]string, 0)
+	for _, r := range s.Runs {
+		names = append(names, r.JobID)
+	}
+	return names
+}
+
+// Merge stages with existing stages in plan
+func (p *Plan) mergeStages(stages []*Stage) {
+	newStages := make([]*Stage, int(math.Max(float64(len(p.Stages)), float64(len(stages)))))
+	for i := 0; i < len(newStages); i++ {
+		newStages[i] = new(Stage)
+		if i >= len(p.Stages) {
+			newStages[i].Runs = append(newStages[i].Runs, stages[i].Runs...)
+		} else if i >= len(stages) {
+			newStages[i].Runs = append(newStages[i].Runs, p.Stages[i].Runs...)
+		} else {
+			newStages[i].Runs = append(newStages[i].Runs, p.Stages[i].Runs...)
+			newStages[i].Runs = append(newStages[i].Runs, stages[i].Runs...)
+		}
+	}
+	p.Stages = newStages
+}
+
+func createStages(w *Workflow, jobIDs ...string) ([]*Stage, error) {
+	// first, build a list of all the necessary jobs to run, and their dependencies
+	jobDependencies := make(map[string][]string)
+	for len(jobIDs) > 0 {
+		newJobIDs := make([]string, 0)
+		for _, jID := range jobIDs {
+			// make sure we haven't visited this job yet
+			if _, ok := jobDependencies[jID]; !ok {
+				if job := w.GetJob(jID); job != nil {
+					jobDependencies[jID] = job.Needs()
+					newJobIDs = append(newJobIDs, job.Needs()...)
+				}
+			}
+		}
+		jobIDs = newJobIDs
+	}
+
+	// next, build an execution graph
+	stages := make([]*Stage, 0)
+	for len(jobDependencies) > 0 {
+		stage := new(Stage)
+		for jID, jDeps := range jobDependencies {
+			// make sure all deps are in the graph already
+			if listInStages(jDeps, stages...) {
+				stage.Runs = append(stage.Runs, &Run{
+					Workflow: w,
+					JobID:    jID,
+				})
+				delete(jobDependencies, jID)
+			}
+		}
+		if len(stage.Runs) == 0 {
+			return nil, fmt.Errorf("unable to build dependency graph for %s (%s)", w.Name, w.File)
+		}
+		stages = append(stages, stage)
+	}
+
+	if len(stages) == 0 {
+		return nil, fmt.Errorf("Could not find any stages to run. View the valid jobs with `act --list`. Use `act --help` to find how to filter by Job ID/Workflow/Event Name")
+	}
+
+	return stages, nil
+}
+
+// return true iff all strings in srcList exist in at least one of the stages
+func listInStages(srcList []string, stages ...*Stage) bool {
+	for _, src := range srcList {
+		found := false
+		for _, stage := range stages {
+			for _, search := range stage.GetJobIDs() {
+				if src == search {
+					found = true
+				}
+			}
+		}
+		if !found {
+			return false
+		}
+	}
+	return true
+}