Move issues related files into models/issues (#19931)

* Move access and repo permission to models/perm/access

* fix test

* fix git test

* Move functions sequence

* Some improvements per @KN4CK3R and @delvh

* Move issues related code to models/issues

* Move some issues related sub package

* Merge

* Fix test

* Fix test

* Fix test

* Fix test

* Rename some files

models/issues/assignees.go

@@ -0,0 +1,171 @@
+// Copyright 2018 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 issues
+
+import (
+	"context"
+	"fmt"
+
+	"code.gitea.io/gitea/models/db"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/util"
+)
+
+// IssueAssignees saves all issue assignees
+type IssueAssignees struct {
+	ID         int64 `xorm:"pk autoincr"`
+	AssigneeID int64 `xorm:"INDEX"`
+	IssueID    int64 `xorm:"INDEX"`
+}
+
+func init() {
+	db.RegisterModel(new(IssueAssignees))
+}
+
+// LoadAssignees load assignees of this issue.
+func (issue *Issue) LoadAssignees(ctx context.Context) (err error) {
+	// Reset maybe preexisting assignees
+	issue.Assignees = []*user_model.User{}
+	issue.Assignee = nil
+
+	err = db.GetEngine(ctx).Table("`user`").
+		Join("INNER", "issue_assignees", "assignee_id = `user`.id").
+		Where("issue_assignees.issue_id = ?", issue.ID).
+		Find(&issue.Assignees)
+	if err != nil {
+		return err
+	}
+
+	// Check if we have at least one assignee and if yes put it in as `Assignee`
+	if len(issue.Assignees) > 0 {
+		issue.Assignee = issue.Assignees[0]
+	}
+	return
+}
+
+// GetAssigneeIDsByIssue returns the IDs of users assigned to an issue
+// but skips joining with `user` for performance reasons.
+// User permissions must be verified elsewhere if required.
+func GetAssigneeIDsByIssue(issueID int64) ([]int64, error) {
+	userIDs := make([]int64, 0, 5)
+	return userIDs, db.GetEngine(db.DefaultContext).Table("issue_assignees").
+		Cols("assignee_id").
+		Where("issue_id = ?", issueID).
+		Distinct("assignee_id").
+		Find(&userIDs)
+}
+
+// IsUserAssignedToIssue returns true when the user is assigned to the issue
+func IsUserAssignedToIssue(ctx context.Context, issue *Issue, user *user_model.User) (isAssigned bool, err error) {
+	return db.GetByBean(ctx, &IssueAssignees{IssueID: issue.ID, AssigneeID: user.ID})
+}
+
+// ToggleIssueAssignee changes a user between assigned and not assigned for this issue, and make issue comment for it.
+func ToggleIssueAssignee(issue *Issue, doer *user_model.User, assigneeID int64) (removed bool, comment *Comment, err error) {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
+		return false, nil, err
+	}
+	defer committer.Close()
+
+	removed, comment, err = toggleIssueAssignee(ctx, issue, doer, assigneeID, false)
+	if err != nil {
+		return false, nil, err
+	}
+
+	if err := committer.Commit(); err != nil {
+		return false, nil, err
+	}
+
+	return removed, comment, nil
+}
+
+func toggleIssueAssignee(ctx context.Context, issue *Issue, doer *user_model.User, assigneeID int64, isCreate bool) (removed bool, comment *Comment, err error) {
+	removed, err = toggleUserAssignee(ctx, issue, assigneeID)
+	if err != nil {
+		return false, nil, fmt.Errorf("UpdateIssueUserByAssignee: %v", err)
+	}
+
+	// Repo infos
+	if err = issue.LoadRepo(ctx); err != nil {
+		return false, nil, fmt.Errorf("loadRepo: %v", err)
+	}
+
+	opts := &CreateCommentOptions{
+		Type:            CommentTypeAssignees,
+		Doer:            doer,
+		Repo:            issue.Repo,
+		Issue:           issue,
+		RemovedAssignee: removed,
+		AssigneeID:      assigneeID,
+	}
+	// Comment
+	comment, err = CreateCommentCtx(ctx, opts)
+	if err != nil {
+		return false, nil, fmt.Errorf("createComment: %v", err)
+	}
+
+	// if pull request is in the middle of creation - don't call webhook
+	if isCreate {
+		return removed, comment, err
+	}
+
+	return removed, comment, nil
+}
+
+// toggles user assignee state in database
+func toggleUserAssignee(ctx context.Context, issue *Issue, assigneeID int64) (removed bool, err error) {
+	// Check if the user exists
+	assignee, err := user_model.GetUserByIDCtx(ctx, assigneeID)
+	if err != nil {
+		return false, err
+	}
+
+	// Check if the submitted user is already assigned, if yes delete him otherwise add him
+	found := false
+	i := 0
+	for ; i < len(issue.Assignees); i++ {
+		if issue.Assignees[i].ID == assigneeID {
+			found = true
+			break
+		}
+	}
+
+	assigneeIn := IssueAssignees{AssigneeID: assigneeID, IssueID: issue.ID}
+	if found {
+		issue.Assignees = append(issue.Assignees[:i], issue.Assignees[i+1:]...)
+		_, err = db.DeleteByBean(ctx, &assigneeIn)
+		if err != nil {
+			return found, err
+		}
+	} else {
+		issue.Assignees = append(issue.Assignees, assignee)
+		if err = db.Insert(ctx, &assigneeIn); err != nil {
+			return found, err
+		}
+	}
+
+	return found, nil
+}
+
+// MakeIDsFromAPIAssigneesToAdd returns an array with all assignee IDs
+func MakeIDsFromAPIAssigneesToAdd(oneAssignee string, multipleAssignees []string) (assigneeIDs []int64, err error) {
+	var requestAssignees []string
+
+	// Keeping the old assigning method for compatibility reasons
+	if oneAssignee != "" && !util.IsStringInSlice(oneAssignee, multipleAssignees) {
+		requestAssignees = append(requestAssignees, oneAssignee)
+	}
+
+	// Prevent empty assignees
+	if len(multipleAssignees) > 0 && multipleAssignees[0] != "" {
+		requestAssignees = append(requestAssignees, multipleAssignees...)
+	}
+
+	// Get the IDs of all assignees
+	assigneeIDs, err = user_model.GetUserIDsByNames(requestAssignees, false)
+
+	return
+}