Move team related functions to service layer (#32537)

There are still some functions under `models` after last big refactor
about `models`. This change will move all team related functions to
service layer with no code change.

services/org/user.go

@@ -0,0 +1,102 @@
+// Copyright 2014 The Gogs Authors. All rights reserved.
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package org
+
+import (
+	"context"
+	"fmt"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/organization"
+	access_model "code.gitea.io/gitea/models/perm/access"
+	repo_model "code.gitea.io/gitea/models/repo"
+	user_model "code.gitea.io/gitea/models/user"
+)
+
+// RemoveOrgUser removes user from given organization.
+func RemoveOrgUser(ctx context.Context, org *organization.Organization, user *user_model.User) error {
+	ou := new(organization.OrgUser)
+
+	has, err := db.GetEngine(ctx).
+		Where("uid=?", user.ID).
+		And("org_id=?", org.ID).
+		Get(ou)
+	if err != nil {
+		return fmt.Errorf("get org-user: %w", err)
+	} else if !has {
+		return nil
+	}
+
+	// Check if the user to delete is the last member in owner team.
+	if isOwner, err := organization.IsOrganizationOwner(ctx, org.ID, user.ID); err != nil {
+		return err
+	} else if isOwner {
+		t, err := organization.GetOwnerTeam(ctx, org.ID)
+		if err != nil {
+			return err
+		}
+		if t.NumMembers == 1 {
+			if err := t.LoadMembers(ctx); err != nil {
+				return err
+			}
+			if t.Members[0].ID == user.ID {
+				return organization.ErrLastOrgOwner{UID: user.ID}
+			}
+		}
+	}
+
+	ctx, committer, err := db.TxContext(ctx)
+	if err != nil {
+		return err
+	}
+	defer committer.Close()
+
+	if _, err := db.DeleteByID[organization.OrgUser](ctx, ou.ID); err != nil {
+		return err
+	} else if _, err = db.Exec(ctx, "UPDATE `user` SET num_members=num_members-1 WHERE id=?", org.ID); err != nil {
+		return err
+	}
+
+	// Delete all repository accesses and unwatch them.
+	env, err := organization.AccessibleReposEnv(ctx, org, user.ID)
+	if err != nil {
+		return fmt.Errorf("AccessibleReposEnv: %w", err)
+	}
+	repoIDs, err := env.RepoIDs(1, org.NumRepos)
+	if err != nil {
+		return fmt.Errorf("GetUserRepositories [%d]: %w", user.ID, err)
+	}
+	for _, repoID := range repoIDs {
+		repo, err := repo_model.GetRepositoryByID(ctx, repoID)
+		if err != nil {
+			return err
+		}
+		if err = repo_model.WatchRepo(ctx, user, repo, false); err != nil {
+			return err
+		}
+	}
+
+	if len(repoIDs) > 0 {
+		if _, err = db.GetEngine(ctx).
+			Where("user_id = ?", user.ID).
+			In("repo_id", repoIDs).
+			Delete(new(access_model.Access)); err != nil {
+			return err
+		}
+	}
+
+	// Delete member in their teams.
+	teams, err := organization.GetUserOrgTeams(ctx, org.ID, user.ID)
+	if err != nil {
+		return err
+	}
+	for _, t := range teams {
+		if err = removeTeamMember(ctx, t, user); err != nil {
+			return err
+		}
+	}
+
+	return committer.Commit()
+}