3 files changed, 200 insertions, 0 deletions
diff --git a/models/repo/collaboration.go b/models/repo/collaboration.go
new file mode 100644
index 0000000000..3ebb688143
--- /dev/null
+++ b/models/repo/collaboration.go
@@ -0,0 +1,150 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package repo
+
+import (
+	"context"
+	"fmt"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/perm"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/timeutil"
+)
+
+// Collaboration represent the relation between an individual and a repository.
+type Collaboration struct {
+	ID          int64              `xorm:"pk autoincr"`
+	RepoID      int64              `xorm:"UNIQUE(s) INDEX NOT NULL"`
+	UserID      int64              `xorm:"UNIQUE(s) INDEX NOT NULL"`
+	Mode        perm.AccessMode    `xorm:"DEFAULT 2 NOT NULL"`
+	CreatedUnix timeutil.TimeStamp `xorm:"INDEX created"`
+	UpdatedUnix timeutil.TimeStamp `xorm:"INDEX updated"`
+}
+
+func init() {
+	db.RegisterModel(new(Collaboration))
+}
+
+// Collaborator represents a user with collaboration details.
+type Collaborator struct {
+	*user_model.User
+	Collaboration *Collaboration
+}
+
+// GetCollaborators returns the collaborators for a repository
+func GetCollaborators(ctx context.Context, repoID int64, listOptions db.ListOptions) ([]*Collaborator, error) {
+	e := db.GetEngine(ctx)
+	collaborations, err := getCollaborations(e, repoID, listOptions)
+	if err != nil {
+		return nil, fmt.Errorf("getCollaborations: %v", err)
+	}
+
+	collaborators := make([]*Collaborator, 0, len(collaborations))
+	for _, c := range collaborations {
+		user, err := user_model.GetUserByIDEngine(e, c.UserID)
+		if err != nil {
+			if user_model.IsErrUserNotExist(err) {
+				log.Warn("Inconsistent DB: User: %d is listed as collaborator of %-v but does not exist", c.UserID, repoID)
+				user = user_model.NewGhostUser()
+			} else {
+				return nil, err
+			}
+		}
+		collaborators = append(collaborators, &Collaborator{
+			User:          user,
+			Collaboration: c,
+		})
+	}
+	return collaborators, nil
+}
+
+// CountCollaborators returns total number of collaborators for a repository
+func CountCollaborators(repoID int64) (int64, error) {
+	return db.GetEngine(db.DefaultContext).Where("repo_id = ? ", repoID).Count(&Collaboration{})
+}
+
+// GetCollaboration get collaboration for a repository id with a user id
+func GetCollaboration(ctx context.Context, repoID, uid int64) (*Collaboration, error) {
+	collaboration := &Collaboration{
+		RepoID: repoID,
+		UserID: uid,
+	}
+	has, err := db.GetEngine(ctx).Get(collaboration)
+	if !has {
+		collaboration = nil
+	}
+	return collaboration, err
+}
+
+// IsCollaborator check if a user is a collaborator of a repository
+func IsCollaborator(ctx context.Context, repoID, userID int64) (bool, error) {
+	return db.GetEngine(ctx).Get(&Collaboration{RepoID: repoID, UserID: userID})
+}
+
+func getCollaborations(e db.Engine, repoID int64, listOptions db.ListOptions) ([]*Collaboration, error) {
+	if listOptions.Page == 0 {
+		collaborations := make([]*Collaboration, 0, 8)
+		return collaborations, e.Find(&collaborations, &Collaboration{RepoID: repoID})
+	}
+
+	e = db.SetEnginePagination(e, &listOptions)
+
+	collaborations := make([]*Collaboration, 0, listOptions.PageSize)
+	return collaborations, e.Find(&collaborations, &Collaboration{RepoID: repoID})
+}
+
+// ChangeCollaborationAccessMode sets new access mode for the collaboration.
+func ChangeCollaborationAccessModeCtx(ctx context.Context, repo *Repository, uid int64, mode perm.AccessMode) error {
+	// Discard invalid input
+	if mode <= perm.AccessModeNone || mode > perm.AccessModeOwner {
+		return nil
+	}
+
+	e := db.GetEngine(ctx)
+
+	collaboration := &Collaboration{
+		RepoID: repo.ID,
+		UserID: uid,
+	}
+	has, err := e.Get(collaboration)
+	if err != nil {
+		return fmt.Errorf("get collaboration: %v", err)
+	} else if !has {
+		return nil
+	}
+
+	if collaboration.Mode == mode {
+		return nil
+	}
+	collaboration.Mode = mode
+
+	if _, err = e.
+		ID(collaboration.ID).
+		Cols("mode").
+		Update(collaboration); err != nil {
+		return fmt.Errorf("update collaboration: %v", err)
+	} else if _, err = e.Exec("UPDATE access SET mode = ? WHERE user_id = ? AND repo_id = ?", mode, uid, repo.ID); err != nil {
+		return fmt.Errorf("update access table: %v", err)
+	}
+
+	return nil
+}
+
+// ChangeCollaborationAccessMode sets new access mode for the collaboration.
+func ChangeCollaborationAccessMode(repo *Repository, uid int64, mode perm.AccessMode) error {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
+		return err
+	}
+	defer committer.Close()
+
+	if err := ChangeCollaborationAccessModeCtx(ctx, repo, uid, mode); err != nil {
+		return err
+	}
+
+	return committer.Commit()
+}
diff --git a/models/repo/collaboration_test.go b/models/repo/collaboration_test.go
new file mode 100644
index 0000000000..a7d04498e9
--- /dev/null
+++ b/models/repo/collaboration_test.go
@@ -0,0 +1,49 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package repo
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/unittest"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRepository_GetCollaborators(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+	test := func(repoID int64) {
+		repo := unittest.AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
+		collaborators, err := GetCollaborators(db.DefaultContext, repo.ID, db.ListOptions{})
+		assert.NoError(t, err)
+		expectedLen, err := db.GetEngine(db.DefaultContext).Count(&Collaboration{RepoID: repoID})
+		assert.NoError(t, err)
+		assert.Len(t, collaborators, int(expectedLen))
+		for _, collaborator := range collaborators {
+			assert.EqualValues(t, collaborator.User.ID, collaborator.Collaboration.UserID)
+			assert.EqualValues(t, repoID, collaborator.Collaboration.RepoID)
+		}
+	}
+	test(1)
+	test(2)
+	test(3)
+	test(4)
+}
+
+func TestRepository_IsCollaborator(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+
+	test := func(repoID, userID int64, expected bool) {
+		repo := unittest.AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
+		actual, err := IsCollaborator(db.DefaultContext, repo.ID, userID)
+		assert.NoError(t, err)
+		assert.Equal(t, expected, actual)
+	}
+	test(3, 2, true)
+	test(3, unittest.NonexistentID, false)
+	test(4, 2, false)
+	test(4, 4, true)
+}
diff --git a/models/repo/main_test.go b/models/repo/main_test.go
index e375e8a9f3..375d0e0df1 100644
--- a/models/repo/main_test.go
+++ b/models/repo/main_test.go
@@ -26,6 +26,7 @@ func TestMain(m *testing.M) {
 			"topic.yml",
 			"repo_topic.yml",
 			"user.yml",
+			"collaboration.yml",
 		},
 	})
 }