Move `convert` package to services (#22264)

Addition to #22256

The `convert` package relies heavily on different models which is
[disallowed by our definition of
modules](https://github.com/go-gitea/gitea/blob/main/CONTRIBUTING.md#design-guideline).
This helps to prevent possible import cycles.

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

1 files changed, 202 insertions, 0 deletions

diff --git a/services/convert/git_commit.go b/services/convert/git_commit.go
new file mode 100644
index 0000000000..59842e4020
--- /dev/null
+++ b/services/convert/git_commit.go
@@ -0,0 +1,202 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package convert
+
+import (
+	"net/url"
+	"time"
+
+	repo_model "code.gitea.io/gitea/models/repo"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/log"
+	api "code.gitea.io/gitea/modules/structs"
+	"code.gitea.io/gitea/modules/util"
+	"code.gitea.io/gitea/services/gitdiff"
+)
+
+// ToCommitUser convert a git.Signature to an api.CommitUser
+func ToCommitUser(sig *git.Signature) *api.CommitUser {
+	return &api.CommitUser{
+		Identity: api.Identity{
+			Name:  sig.Name,
+			Email: sig.Email,
+		},
+		Date: sig.When.UTC().Format(time.RFC3339),
+	}
+}
+
+// ToCommitMeta convert a git.Tag to an api.CommitMeta
+func ToCommitMeta(repo *repo_model.Repository, tag *git.Tag) *api.CommitMeta {
+	return &api.CommitMeta{
+		SHA:     tag.Object.String(),
+		URL:     util.URLJoin(repo.APIURL(), "git/commits", tag.ID.String()),
+		Created: tag.Tagger.When,
+	}
+}
+
+// ToPayloadCommit convert a git.Commit to api.PayloadCommit
+func ToPayloadCommit(repo *repo_model.Repository, c *git.Commit) *api.PayloadCommit {
+	authorUsername := ""
+	if author, err := user_model.GetUserByEmail(c.Author.Email); err == nil {
+		authorUsername = author.Name
+	} else if !user_model.IsErrUserNotExist(err) {
+		log.Error("GetUserByEmail: %v", err)
+	}
+
+	committerUsername := ""
+	if committer, err := user_model.GetUserByEmail(c.Committer.Email); err == nil {
+		committerUsername = committer.Name
+	} else if !user_model.IsErrUserNotExist(err) {
+		log.Error("GetUserByEmail: %v", err)
+	}
+
+	return &api.PayloadCommit{
+		ID:      c.ID.String(),
+		Message: c.Message(),
+		URL:     util.URLJoin(repo.HTMLURL(), "commit", c.ID.String()),
+		Author: &api.PayloadUser{
+			Name:     c.Author.Name,
+			Email:    c.Author.Email,
+			UserName: authorUsername,
+		},
+		Committer: &api.PayloadUser{
+			Name:     c.Committer.Name,
+			Email:    c.Committer.Email,
+			UserName: committerUsername,
+		},
+		Timestamp:    c.Author.When,
+		Verification: ToVerification(c),
+	}
+}
+
+// ToCommit convert a git.Commit to api.Commit
+func ToCommit(repo *repo_model.Repository, gitRepo *git.Repository, commit *git.Commit, userCache map[string]*user_model.User, stat bool) (*api.Commit, error) {
+	var apiAuthor, apiCommitter *api.User
+
+	// Retrieve author and committer information
+
+	var cacheAuthor *user_model.User
+	var ok bool
+	if userCache == nil {
+		cacheAuthor = (*user_model.User)(nil)
+		ok = false
+	} else {
+		cacheAuthor, ok = userCache[commit.Author.Email]
+	}
+
+	if ok {
+		apiAuthor = ToUser(cacheAuthor, nil)
+	} else {
+		author, err := user_model.GetUserByEmail(commit.Author.Email)
+		if err != nil && !user_model.IsErrUserNotExist(err) {
+			return nil, err
+		} else if err == nil {
+			apiAuthor = ToUser(author, nil)
+			if userCache != nil {
+				userCache[commit.Author.Email] = author
+			}
+		}
+	}
+
+	var cacheCommitter *user_model.User
+	if userCache == nil {
+		cacheCommitter = (*user_model.User)(nil)
+		ok = false
+	} else {
+		cacheCommitter, ok = userCache[commit.Committer.Email]
+	}
+
+	if ok {
+		apiCommitter = ToUser(cacheCommitter, nil)
+	} else {
+		committer, err := user_model.GetUserByEmail(commit.Committer.Email)
+		if err != nil && !user_model.IsErrUserNotExist(err) {
+			return nil, err
+		} else if err == nil {
+			apiCommitter = ToUser(committer, nil)
+			if userCache != nil {
+				userCache[commit.Committer.Email] = committer
+			}
+		}
+	}
+
+	// Retrieve parent(s) of the commit
+	apiParents := make([]*api.CommitMeta, commit.ParentCount())
+	for i := 0; i < commit.ParentCount(); i++ {
+		sha, _ := commit.ParentID(i)
+		apiParents[i] = &api.CommitMeta{
+			URL: repo.APIURL() + "/git/commits/" + url.PathEscape(sha.String()),
+			SHA: sha.String(),
+		}
+	}
+
+	res := &api.Commit{
+		CommitMeta: &api.CommitMeta{
+			URL:     repo.APIURL() + "/git/commits/" + url.PathEscape(commit.ID.String()),
+			SHA:     commit.ID.String(),
+			Created: commit.Committer.When,
+		},
+		HTMLURL: repo.HTMLURL() + "/commit/" + url.PathEscape(commit.ID.String()),
+		RepoCommit: &api.RepoCommit{
+			URL: repo.APIURL() + "/git/commits/" + url.PathEscape(commit.ID.String()),
+			Author: &api.CommitUser{
+				Identity: api.Identity{
+					Name:  commit.Author.Name,
+					Email: commit.Author.Email,
+				},
+				Date: commit.Author.When.Format(time.RFC3339),
+			},
+			Committer: &api.CommitUser{
+				Identity: api.Identity{
+					Name:  commit.Committer.Name,
+					Email: commit.Committer.Email,
+				},
+				Date: commit.Committer.When.Format(time.RFC3339),
+			},
+			Message: commit.Message(),
+			Tree: &api.CommitMeta{
+				URL:     repo.APIURL() + "/git/trees/" + url.PathEscape(commit.ID.String()),
+				SHA:     commit.ID.String(),
+				Created: commit.Committer.When,
+			},
+			Verification: ToVerification(commit),
+		},
+		Author:    apiAuthor,
+		Committer: apiCommitter,
+		Parents:   apiParents,
+	}
+
+	// Retrieve files affected by the commit
+	if stat {
+		fileStatus, err := git.GetCommitFileStatus(gitRepo.Ctx, repo.RepoPath(), commit.ID.String())
+		if err != nil {
+			return nil, err
+		}
+		affectedFileList := make([]*api.CommitAffectedFiles, 0, len(fileStatus.Added)+len(fileStatus.Removed)+len(fileStatus.Modified))
+		for _, files := range [][]string{fileStatus.Added, fileStatus.Removed, fileStatus.Modified} {
+			for _, filename := range files {
+				affectedFileList = append(affectedFileList, &api.CommitAffectedFiles{
+					Filename: filename,
+				})
+			}
+		}
+
+		diff, err := gitdiff.GetDiff(gitRepo, &gitdiff.DiffOptions{
+			AfterCommitID: commit.ID.String(),
+		})
+		if err != nil {
+			return nil, err
+		}
+
+		res.Files = affectedFileList
+		res.Stats = &api.CommitStats{
+			Total:     diff.TotalAddition + diff.TotalDeletion,
+			Additions: diff.TotalAddition,
+			Deletions: diff.TotalDeletion,
+		}
+	}
+
+	return res, nil
+}