1 files changed, 143 insertions, 0 deletions

diff --git a/models/pull/automerge.go b/models/pull/automerge.go
new file mode 100644
index 0000000000..fd73f2b0fb
--- /dev/null
+++ b/models/pull/automerge.go
@@ -0,0 +1,143 @@
+// Copyright 2022 Gitea. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package pull
+
+import (
+	"context"
+	"fmt"
+
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
+	repo_model "code.gitea.io/gitea/models/repo"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/timeutil"
+)
+
+// AutoMerge represents a pull request scheduled for merging when checks succeed
+type AutoMerge struct {
+	ID          int64                 `xorm:"pk autoincr"`
+	PullID      int64                 `xorm:"UNIQUE"`
+	DoerID      int64                 `xorm:"NOT NULL"`
+	Doer        *user_model.User      `xorm:"-"`
+	MergeStyle  repo_model.MergeStyle `xorm:"varchar(30)"`
+	Message     string                `xorm:"LONGTEXT"`
+	CreatedUnix timeutil.TimeStamp    `xorm:"created"`
+}
+
+// TableName return database table name for xorm
+func (AutoMerge) TableName() string {
+	return "pull_auto_merge"
+}
+
+func init() {
+	db.RegisterModel(new(AutoMerge))
+}
+
+// ErrAlreadyScheduledToAutoMerge represents a "PullRequestHasMerged"-error
+type ErrAlreadyScheduledToAutoMerge struct {
+	PullID int64
+}
+
+func (err ErrAlreadyScheduledToAutoMerge) Error() string {
+	return fmt.Sprintf("pull request is already scheduled to auto merge when checks succeed [pull_id: %d]", err.PullID)
+}
+
+// IsErrAlreadyScheduledToAutoMerge checks if an error is a ErrAlreadyScheduledToAutoMerge.
+func IsErrAlreadyScheduledToAutoMerge(err error) bool {
+	_, ok := err.(ErrAlreadyScheduledToAutoMerge)
+	return ok
+}
+
+// ScheduleAutoMerge schedules a pull request to be merged when all checks succeed
+func ScheduleAutoMerge(ctx context.Context, doer *user_model.User, pullID int64, style repo_model.MergeStyle, message string) error {
+	// Check if we already have a merge scheduled for that pull request
+	if exists, _, err := GetScheduledMergeByPullID(ctx, pullID); err != nil {
+		return err
+	} else if exists {
+		return ErrAlreadyScheduledToAutoMerge{PullID: pullID}
+	}
+
+	if _, err := db.GetEngine(ctx).Insert(&AutoMerge{
+		DoerID:     doer.ID,
+		PullID:     pullID,
+		MergeStyle: style,
+		Message:    message,
+	}); err != nil {
+		return err
+	}
+
+	pr, err := models.GetPullRequestByID(ctx, pullID)
+	if err != nil {
+		return err
+	}
+
+	_, err = createAutoMergeComment(ctx, models.CommentTypePRScheduledToAutoMerge, pr, doer)
+	return err
+}
+
+// GetScheduledMergeByPullID gets a scheduled pull request merge by pull request id
+func GetScheduledMergeByPullID(ctx context.Context, pullID int64) (bool, *AutoMerge, error) {
+	scheduledPRM := &AutoMerge{}
+	exists, err := db.GetEngine(ctx).Where("pull_id = ?", pullID).Get(scheduledPRM)
+	if err != nil || !exists {
+		return false, nil, err
+	}
+
+	doer, err := user_model.GetUserByIDCtx(ctx, scheduledPRM.DoerID)
+	if err != nil {
+		return false, nil, err
+	}
+
+	scheduledPRM.Doer = doer
+	return true, scheduledPRM, nil
+}
+
+// RemoveScheduledAutoMerge cancels a previously scheduled pull request
+func RemoveScheduledAutoMerge(ctx context.Context, doer *user_model.User, pullID int64, comment bool) error {
+	return db.WithTx(func(ctx context.Context) error {
+		exist, scheduledPRM, err := GetScheduledMergeByPullID(ctx, pullID)
+		if err != nil {
+			return err
+		} else if !exist {
+			return models.ErrNotExist{ID: pullID}
+		}
+
+		if _, err := db.GetEngine(ctx).ID(scheduledPRM.ID).Delete(&AutoMerge{}); err != nil {
+			return err
+		}
+
+		// if pull got merged we don't need to add "auto-merge canceled comment"
+		if !comment || doer == nil {
+			return nil
+		}
+
+		pr, err := models.GetPullRequestByID(ctx, pullID)
+		if err != nil {
+			return err
+		}
+
+		_, err = createAutoMergeComment(ctx, models.CommentTypePRUnScheduledToAutoMerge, pr, doer)
+		return err
+	}, ctx)
+}
+
+// createAutoMergeComment is a internal function, only use it for CommentTypePRScheduledToAutoMerge and CommentTypePRUnScheduledToAutoMerge CommentTypes
+func createAutoMergeComment(ctx context.Context, typ models.CommentType, pr *models.PullRequest, doer *user_model.User) (comment *models.Comment, err error) {
+	if err = pr.LoadIssueCtx(ctx); err != nil {
+		return
+	}
+
+	if err = pr.LoadBaseRepoCtx(ctx); err != nil {
+		return
+	}
+
+	comment, err = models.CreateCommentCtx(ctx, &models.CreateCommentOptions{
+		Type:  typ,
+		Doer:  doer,
+		Repo:  pr.BaseRepo,
+		Issue: pr.Issue,
+	})
+	return
+}