Add support for workflow_dispatch (#3334)

Closes #2797

I'm aware of https://github.com/go-gitea/gitea/pull/28163 exists, but since I had it laying around on my drive and collecting dust, I might as well open a PR for it if anyone wants the feature a bit sooner than waiting for upstream to release it or to be a forgejo "native" implementation.

This PR Contains:
- Support for the `workflow_dispatch` trigger
- Inputs: boolean, string, number, choice

Things still to be done:
- [x] API Endpoint `/api/v1/<org>/<repo>/actions/workflows/<workflow id>/dispatches`
- ~~Fixing some UI bugs I had no time figuring out, like why dropdown/choice inputs's menu's behave weirdly~~ Unrelated visual bug with dropdowns inside dropdowns
- [x] Fix bug where opening the branch selection submits the form
- [x] Limit on inputs to render/process

Things not in this PR:
- Inputs: environment (First need support for environments in forgejo)

Things needed to test this:
- A patch for https://code.forgejo.org/forgejo/runner to actually consider the inputs inside the workflow.
  ~~One possible patch can be seen here: https://code.forgejo.org/Mai-Lapyst/runner/src/branch/support-workflow-inputs~~
  [PR](https://code.forgejo.org/forgejo/runner/pulls/199)

![image](/attachments/2db50c9e-898f-41cb-b698-43edeefd2573)

## Testing

- Checkout PR
- Setup new development runner with [this PR](https://code.forgejo.org/forgejo/runner/pulls/199)
- Create a repo with a workflow (see below)
- Go to the actions tab, select the workflow and see the notice as in the screenshot above
- Use the button + dropdown to run the workflow
  - Try also running it via the api using the `` endpoint
- ...
- Profit!

<details>
<summary>Example workflow</summary>

```yaml
on:
  workflow_dispatch:
    inputs:
      logLevel:
        description: 'Log Level'
        required: true
        default: 'warning'
        type: choice
        options:
        - info
        - warning
        - debug
      tags:
        description: 'Test scenario tags'
        required: false
        type: boolean
      boolean_default_true:
        description: 'Test scenario tags'
        required: true
        type: boolean
        default: true
      boolean_default_false:
        description: 'Test scenario tags'
        required: false
        type: boolean
        default: false
      number1_default:
        description: 'Number w. default'
        default: '100'
        type: number
      number2:
        description: 'Number w/o. default'
        type: number
      string1_default:
        description: 'String w. default'
        default: 'Hello world'
        type: string
      string2:
        description: 'String w/o. default'
        required: true
        type: string

jobs:
  test:
    runs-on: docker
    steps:
      - uses: actions/checkout@v3
      - run: whoami
      - run: cat /etc/issue
      - run: uname -a
      - run: date
      - run: echo ${{ inputs.logLevel }}
      - run: echo ${{ inputs.tags }}
      - env:
          GITHUB_CONTEXT: ${{ toJson(github) }}
        run: echo "$GITHUB_CONTEXT"
      - run: echo "abc"
```
</details>

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/3334
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Co-authored-by: Mai-Lapyst <mai-lapyst@noreply.codeberg.org>
Co-committed-by: Mai-Lapyst <mai-lapyst@noreply.codeberg.org>

1 files changed, 171 insertions, 0 deletions

diff --git a/services/actions/workflows.go b/services/actions/workflows.go
new file mode 100644
index 0000000000..deff7e7dd6
--- /dev/null
+++ b/services/actions/workflows.go
@@ -0,0 +1,171 @@
+// Copyright The Forgejo Authors.
+// SPDX-License-Identifier: MIT
+
+package actions
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"strconv"
+
+	actions_model "code.gitea.io/gitea/models/actions"
+	"code.gitea.io/gitea/models/perm"
+	"code.gitea.io/gitea/models/perm/access"
+	repo_model "code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/actions"
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/json"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/structs"
+	"code.gitea.io/gitea/modules/webhook"
+	"code.gitea.io/gitea/services/convert"
+
+	"github.com/nektos/act/pkg/jobparser"
+	act_model "github.com/nektos/act/pkg/model"
+)
+
+type InputRequiredErr struct {
+	Name string
+}
+
+func (err InputRequiredErr) Error() string {
+	return fmt.Sprintf("input required for '%s'", err.Name)
+}
+
+func IsInputRequiredErr(err error) bool {
+	_, ok := err.(InputRequiredErr)
+	return ok
+}
+
+type Workflow struct {
+	WorkflowID string
+	Ref        string
+	Commit     *git.Commit
+	GitEntry   *git.TreeEntry
+}
+
+type InputValueGetter func(key string) string
+
+func (entry *Workflow) Dispatch(ctx context.Context, inputGetter InputValueGetter, repo *repo_model.Repository, doer *user.User) error {
+	content, err := actions.GetContentFromEntry(entry.GitEntry)
+	if err != nil {
+		return err
+	}
+
+	wf, err := act_model.ReadWorkflow(bytes.NewReader(content))
+	if err != nil {
+		return err
+	}
+
+	fullWorkflowID := ".forgejo/workflows/" + entry.WorkflowID
+
+	title := wf.Name
+	if len(title) < 1 {
+		title = fullWorkflowID
+	}
+
+	inputs := make(map[string]string)
+	if workflowDispatch := wf.WorkflowDispatchConfig(); workflowDispatch != nil {
+		for key, input := range workflowDispatch.Inputs {
+			val := inputGetter(key)
+			if len(val) == 0 {
+				val = input.Default
+				if len(val) == 0 {
+					if input.Required {
+						name := input.Description
+						if len(name) == 0 {
+							name = key
+						}
+						return InputRequiredErr{Name: name}
+					}
+					continue
+				}
+			} else {
+				switch input.Type {
+				case "boolean":
+					// Since "boolean" inputs are rendered as a checkbox in html, the value inside the form is "on"
+					val = strconv.FormatBool(val == "on")
+				}
+			}
+			inputs[key] = val
+		}
+	}
+
+	if int64(len(inputs)) > setting.Actions.LimitDispatchInputs {
+		return errors.New("to many inputs")
+	}
+
+	payload := &structs.WorkflowDispatchPayload{
+		Inputs:     inputs,
+		Ref:        entry.Ref,
+		Repository: convert.ToRepo(ctx, repo, access.Permission{AccessMode: perm.AccessModeNone}),
+		Sender:     convert.ToUser(ctx, doer, nil),
+		Workflow:   fullWorkflowID,
+	}
+
+	p, err := json.Marshal(payload)
+	if err != nil {
+		return err
+	}
+
+	run := &actions_model.ActionRun{
+		Title:         title,
+		RepoID:        repo.ID,
+		Repo:          repo,
+		OwnerID:       repo.OwnerID,
+		WorkflowID:    entry.WorkflowID,
+		TriggerUserID: doer.ID,
+		TriggerUser:   doer,
+		Ref:           entry.Ref,
+		CommitSHA:     entry.Commit.ID.String(),
+		Event:         webhook.HookEventWorkflowDispatch,
+		EventPayload:  string(p),
+		TriggerEvent:  string(webhook.HookEventWorkflowDispatch),
+		Status:        actions_model.StatusWaiting,
+	}
+
+	vars, err := actions_model.GetVariablesOfRun(ctx, run)
+	if err != nil {
+		return err
+	}
+
+	jobs, err := jobparser.Parse(content, jobparser.WithVars(vars))
+	if err != nil {
+		return err
+	}
+
+	return actions_model.InsertRun(ctx, run, jobs)
+}
+
+func GetWorkflowFromCommit(gitRepo *git.Repository, ref, workflowID string) (*Workflow, error) {
+	commit, err := gitRepo.GetCommit(ref)
+	if err != nil {
+		return nil, err
+	}
+
+	entries, err := actions.ListWorkflows(commit)
+	if err != nil {
+		return nil, err
+	}
+
+	var workflowEntry *git.TreeEntry
+	for _, entry := range entries {
+		if entry.Name() == workflowID {
+			workflowEntry = entry
+			break
+		}
+	}
+	if workflowEntry == nil {
+		return nil, errors.New("workflow not found")
+	}
+
+	return &Workflow{
+		WorkflowID: workflowID,
+		Ref:        ref,
+		Commit:     commit,
+		GitEntry:   workflowEntry,
+	}, nil
+}