Improve Gitea's web context, decouple "issue template" code into service package (#24590)

1. Remove unused fields/methods in web context.
2. Make callers call target function directly instead of the light
wrapper like "IsUserRepoReaderSpecific"
3. The "issue template" code shouldn't be put in the "modules/context"
package, so move them to the service package.

---------

Co-authored-by: Giteabot <teabot@gitea.io>

1 files changed, 189 insertions, 0 deletions

diff --git a/services/issue/template.go b/services/issue/template.go
new file mode 100644
index 0000000000..4f1e3d93a0
--- /dev/null
+++ b/services/issue/template.go
@@ -0,0 +1,189 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package issue
+
+import (
+	"fmt"
+	"io"
+	"net/url"
+	"path"
+	"strings"
+
+	"code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/issue/template"
+	"code.gitea.io/gitea/modules/log"
+	api "code.gitea.io/gitea/modules/structs"
+
+	"gopkg.in/yaml.v3"
+)
+
+// templateDirCandidates issue templates directory
+var templateDirCandidates = []string{
+	"ISSUE_TEMPLATE",
+	"issue_template",
+	".gitea/ISSUE_TEMPLATE",
+	".gitea/issue_template",
+	".github/ISSUE_TEMPLATE",
+	".github/issue_template",
+	".gitlab/ISSUE_TEMPLATE",
+	".gitlab/issue_template",
+}
+
+var templateConfigCandidates = []string{
+	".gitea/ISSUE_TEMPLATE/config",
+	".gitea/issue_template/config",
+	".github/ISSUE_TEMPLATE/config",
+	".github/issue_template/config",
+}
+
+func GetDefaultTemplateConfig() api.IssueConfig {
+	return api.IssueConfig{
+		BlankIssuesEnabled: true,
+		ContactLinks:       make([]api.IssueConfigContactLink, 0),
+	}
+}
+
+// GetTemplateConfig loads the given issue config file.
+// It never returns a nil config.
+func GetTemplateConfig(gitRepo *git.Repository, path string, commit *git.Commit) (api.IssueConfig, error) {
+	if gitRepo == nil {
+		return GetDefaultTemplateConfig(), nil
+	}
+
+	var err error
+
+	treeEntry, err := commit.GetTreeEntryByPath(path)
+	if err != nil {
+		return GetDefaultTemplateConfig(), err
+	}
+
+	reader, err := treeEntry.Blob().DataAsync()
+	if err != nil {
+		log.Debug("DataAsync: %v", err)
+		return GetDefaultTemplateConfig(), nil
+	}
+
+	defer reader.Close()
+
+	configContent, err := io.ReadAll(reader)
+	if err != nil {
+		return GetDefaultTemplateConfig(), err
+	}
+
+	issueConfig := api.IssueConfig{}
+	if err := yaml.Unmarshal(configContent, &issueConfig); err != nil {
+		return GetDefaultTemplateConfig(), err
+	}
+
+	for pos, link := range issueConfig.ContactLinks {
+		if link.Name == "" {
+			return GetDefaultTemplateConfig(), fmt.Errorf("contact_link at position %d is missing name key", pos+1)
+		}
+
+		if link.URL == "" {
+			return GetDefaultTemplateConfig(), fmt.Errorf("contact_link at position %d is missing url key", pos+1)
+		}
+
+		if link.About == "" {
+			return GetDefaultTemplateConfig(), fmt.Errorf("contact_link at position %d is missing about key", pos+1)
+		}
+
+		_, err = url.ParseRequestURI(link.URL)
+		if err != nil {
+			return GetDefaultTemplateConfig(), fmt.Errorf("%s is not a valid URL", link.URL)
+		}
+	}
+
+	return issueConfig, nil
+}
+
+// IsTemplateConfig returns if the given path is a issue config file.
+func IsTemplateConfig(path string) bool {
+	for _, configName := range templateConfigCandidates {
+		if path == configName+".yaml" || path == configName+".yml" {
+			return true
+		}
+	}
+	return false
+}
+
+// GetTemplatesFromDefaultBranch checks for issue templates in the repo's default branch,
+// returns valid templates and the errors of invalid template files.
+func GetTemplatesFromDefaultBranch(repo *repo.Repository, gitRepo *git.Repository) ([]*api.IssueTemplate, map[string]error) {
+	var issueTemplates []*api.IssueTemplate
+
+	if repo.IsEmpty {
+		return issueTemplates, nil
+	}
+
+	commit, err := gitRepo.GetBranchCommit(repo.DefaultBranch)
+	if err != nil {
+		return issueTemplates, nil
+	}
+
+	invalidFiles := map[string]error{}
+	for _, dirName := range templateDirCandidates {
+		tree, err := commit.SubTree(dirName)
+		if err != nil {
+			log.Debug("get sub tree of %s: %v", dirName, err)
+			continue
+		}
+		entries, err := tree.ListEntries()
+		if err != nil {
+			log.Debug("list entries in %s: %v", dirName, err)
+			return issueTemplates, nil
+		}
+		for _, entry := range entries {
+			if !template.CouldBe(entry.Name()) {
+				continue
+			}
+			fullName := path.Join(dirName, entry.Name())
+			if it, err := template.UnmarshalFromEntry(entry, dirName); err != nil {
+				invalidFiles[fullName] = err
+			} else {
+				if !strings.HasPrefix(it.Ref, "refs/") { // Assume that the ref intended is always a branch - for tags users should use refs/tags/<ref>
+					it.Ref = git.BranchPrefix + it.Ref
+				}
+				issueTemplates = append(issueTemplates, it)
+			}
+		}
+	}
+	return issueTemplates, invalidFiles
+}
+
+// GetTemplateConfigFromDefaultBranch returns the issue config for this repo.
+// It never returns a nil config.
+func GetTemplateConfigFromDefaultBranch(repo *repo.Repository, gitRepo *git.Repository) (api.IssueConfig, error) {
+	if repo.IsEmpty {
+		return GetDefaultTemplateConfig(), nil
+	}
+
+	commit, err := gitRepo.GetBranchCommit(repo.DefaultBranch)
+	if err != nil {
+		return GetDefaultTemplateConfig(), err
+	}
+
+	for _, configName := range templateConfigCandidates {
+		if _, err := commit.GetTreeEntryByPath(configName + ".yaml"); err == nil {
+			return GetTemplateConfig(gitRepo, configName+".yaml", commit)
+		}
+
+		if _, err := commit.GetTreeEntryByPath(configName + ".yml"); err == nil {
+			return GetTemplateConfig(gitRepo, configName+".yml", commit)
+		}
+	}
+
+	return GetDefaultTemplateConfig(), nil
+}
+
+func HasTemplatesOrContactLinks(repo *repo.Repository, gitRepo *git.Repository) bool {
+	ret, _ := GetTemplatesFromDefaultBranch(repo, gitRepo)
+	if len(ret) > 0 {
+		return true
+	}
+
+	issueConfig, _ := GetTemplateConfigFromDefaultBranch(repo, gitRepo)
+	return len(issueConfig.ContactLinks) > 0
+}