Mail assignee when issue/pull request is assigned (#8546)

* Send email to assigned user

* Only send mail if enabled

* Mail also when assigned through API

* Need to refactor functions from models to issue service

* Refer to issue index rather than ID

* Disable email notifications completly at initalization if global disable

* Check of user enbled mail shall be in mail notification function only

* Initialize notifications from routers init function.

* Use the assigned comment when sending assigned mail

* Refactor so that assignees always added as separate step when new issue/pr.

* Check error from AddAssignees

* Check if user can be assiged to issue or pull request

* Missing return

* Refactor of CanBeAssigned check.

CanBeAssigned shall have same check as UI.

* Clarify function names (toggle rather than update/change), and clean up.

* Fix review comments.

* Flash error if assignees was not added when creating issue/pr

* Generate error if assignee users doesn't exist

2 files changed, 41 insertions, 11 deletions

diff --git a/routers/repo/issue.go b/routers/repo/issue.go
index dee2c6e698..94c39ae224 100644
--- a/routers/repo/issue.go
+++ b/routers/repo/issue.go
@@ -503,21 +503,21 @@ func ValidateRepoMetas(ctx *context.Context, form auth.CreateIssueForm, isPull b
 			return nil, nil, 0
 		}
 
-		// Check if the passed assignees actually exists and has write access to the repo
+		// Check if the passed assignees actually exists and is assignable
 		for _, aID := range assigneeIDs {
-			user, err := models.GetUserByID(aID)
+			assignee, err := models.GetUserByID(aID)
 			if err != nil {
 				ctx.ServerError("GetUserByID", err)
 				return nil, nil, 0
 			}
 
-			perm, err := models.GetUserRepoPermission(repo, user)
+			valid, err := models.CanBeAssigned(assignee, repo, isPull)
 			if err != nil {
-				ctx.ServerError("GetUserRepoPermission", err)
+				ctx.ServerError("canBeAssigned", err)
 				return nil, nil, 0
 			}
-			if !perm.CanWriteIssuesOrPulls(isPull) {
-				ctx.ServerError("CanWriteIssuesOrPulls", fmt.Errorf("No permission for %s", user.Name))
+			if !valid {
+				ctx.ServerError("canBeAssigned", models.ErrUserDoesNotHaveAccessToRepo{UserID: aID, RepoName: repo.Name})
 				return nil, nil, 0
 			}
 		}
@@ -574,7 +574,7 @@ func NewIssuePost(ctx *context.Context, form auth.CreateIssueForm) {
 		Content:     form.Content,
 		Ref:         form.Ref,
 	}
-	if err := issue_service.NewIssue(repo, issue, labelIDs, assigneeIDs, attachments); err != nil {
+	if err := issue_service.NewIssue(repo, issue, labelIDs, attachments); err != nil {
 		if models.IsErrUserDoesNotHaveAccessToRepo(err) {
 			ctx.Error(400, "UserDoesNotHaveAccessToRepo", err.Error())
 			return
@@ -583,6 +583,11 @@ func NewIssuePost(ctx *context.Context, form auth.CreateIssueForm) {
 		return
 	}
 
+	if err := issue_service.AddAssignees(issue, ctx.User, assigneeIDs); err != nil {
+		log.Error("AddAssignees: %v", err)
+		ctx.Flash.Error(ctx.Tr("issues.assignee.error"))
+	}
+
 	notification.NotifyNewIssue(issue)
 
 	log.Trace("Issue created: %d/%d", repo.ID, issue.ID)
@@ -1112,7 +1117,7 @@ func UpdateIssueMilestone(ctx *context.Context) {
 	})
 }
 
-// UpdateIssueAssignee change issue's assignee
+// UpdateIssueAssignee change issue's or pull's assignee
 func UpdateIssueAssignee(ctx *context.Context) {
 	issues := getActionIssues(ctx)
 	if ctx.Written() {
@@ -1130,10 +1135,29 @@ func UpdateIssueAssignee(ctx *context.Context) {
 				return
 			}
 		default:
-			if err := issue.ChangeAssignee(ctx.User, assigneeID); err != nil {
-				ctx.ServerError("ChangeAssignee", err)
+			assignee, err := models.GetUserByID(assigneeID)
+			if err != nil {
+				ctx.ServerError("GetUserByID", err)
+				return
+			}
+
+			valid, err := models.CanBeAssigned(assignee, issue.Repo, issue.IsPull)
+			if err != nil {
+				ctx.ServerError("canBeAssigned", err)
 				return
 			}
+			if !valid {
+				ctx.ServerError("canBeAssigned", models.ErrUserDoesNotHaveAccessToRepo{UserID: assigneeID, RepoName: issue.Repo.Name})
+				return
+			}
+
+			removed, comment, err := issue.ToggleAssignee(ctx.User, assigneeID)
+			if err != nil {
+				ctx.ServerError("ToggleAssignee", err)
+				return
+			}
+
+			notification.NotifyIssueChangeAssignee(ctx.User, issue, assignee, removed, comment)
 		}
 	}
 	ctx.JSON(200, map[string]interface{}{
diff --git a/routers/repo/pull.go b/routers/repo/pull.go
index 4b73571e66..23d97e7b7e 100644
--- a/routers/repo/pull.go
+++ b/routers/repo/pull.go
@@ -24,6 +24,7 @@ import (
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/services/gitdiff"
+	issue_service "code.gitea.io/gitea/services/issue"
 	pull_service "code.gitea.io/gitea/services/pull"
 
 	"github.com/unknwon/com"
@@ -770,7 +771,7 @@ func CompareAndPullRequestPost(ctx *context.Context, form auth.CreateIssueForm)
 	// FIXME: check error in the case two people send pull request at almost same time, give nice error prompt
 	// instead of 500.
 
-	if err := pull_service.NewPullRequest(repo, pullIssue, labelIDs, attachments, pullRequest, patch, assigneeIDs); err != nil {
+	if err := pull_service.NewPullRequest(repo, pullIssue, labelIDs, attachments, pullRequest, patch); err != nil {
 		if models.IsErrUserDoesNotHaveAccessToRepo(err) {
 			ctx.Error(400, "UserDoesNotHaveAccessToRepo", err.Error())
 			return
@@ -782,6 +783,11 @@ func CompareAndPullRequestPost(ctx *context.Context, form auth.CreateIssueForm)
 		return
 	}
 
+	if err := issue_service.AddAssignees(pullIssue, ctx.User, assigneeIDs); err != nil {
+		log.Error("AddAssignees: %v", err)
+		ctx.Flash.Error(ctx.Tr("issues.assignee.error"))
+	}
+
 	notification.NotifyNewPullRequest(pullRequest)
 
 	log.Trace("Pull request created: %d/%d", repo.ID, pullIssue.ID)