// Copyright 2018 The Gitea Authors.
// Copyright 2016 The Gogs Authors.
// All rights reserved.
// SPDX-License-Identifier: MIT

package issues

import (
	"context"
	"fmt"
	"html/template"
	"slices"
	"strconv"
	"unicode/utf8"

	"code.gitea.io/gitea/models/db"
	git_model "code.gitea.io/gitea/models/git"
	"code.gitea.io/gitea/models/organization"
	project_model "code.gitea.io/gitea/models/project"
	repo_model "code.gitea.io/gitea/models/repo"
	user_model "code.gitea.io/gitea/models/user"
	"code.gitea.io/gitea/modules/container"
	"code.gitea.io/gitea/modules/log"
	"code.gitea.io/gitea/modules/optional"
	"code.gitea.io/gitea/modules/references"
	"code.gitea.io/gitea/modules/structs"
	"code.gitea.io/gitea/modules/timeutil"
	"code.gitea.io/gitea/modules/translation"
	"code.gitea.io/gitea/modules/util"

	"xorm.io/builder"
)

// ErrCommentNotExist represents a "CommentNotExist" kind of error.
type ErrCommentNotExist struct {
	ID      int64
	IssueID int64
}

// IsErrCommentNotExist checks if an error is a ErrCommentNotExist.
func IsErrCommentNotExist(err error) bool {
	_, ok := err.(ErrCommentNotExist)
	return ok
}

func (err ErrCommentNotExist) Error() string {
	return fmt.Sprintf("comment does not exist [id: %d, issue_id: %d]", err.ID, err.IssueID)
}

func (err ErrCommentNotExist) Unwrap() error {
	return util.ErrNotExist
}

var ErrCommentAlreadyChanged = util.NewInvalidArgumentErrorf("the comment is already changed")

// CommentType defines whether a comment is just a simple comment, an action (like close) or a reference.
type CommentType int

// CommentTypeUndefined is used to search for comments of any type
const CommentTypeUndefined CommentType = -1

const (
	CommentTypeComment CommentType = iota // 0 Plain comment, can be associated with a commit (CommitID > 0) and a line (LineNum > 0)

	CommentTypeReopen // 1
	CommentTypeClose  // 2

	CommentTypeIssueRef   // 3 References.
	CommentTypeCommitRef  // 4 Reference from a commit (not part of a pull request)
	CommentTypeCommentRef // 5 Reference from a comment
	CommentTypePullRef    // 6 Reference from a pull request

	CommentTypeLabel        // 7 Labels changed
	CommentTypeMilestone    // 8 Milestone changed
	CommentTypeAssignees    // 9 Assignees changed
	CommentTypeChangeTitle  // 10 Change Title
	CommentTypeDeleteBranch // 11 Delete Branch

	CommentTypeStartTracking    // 12 Start a stopwatch for time tracking
	CommentTypeStopTracking     // 13 Stop a stopwatch for time tracking
	CommentTypeAddTimeManual    // 14 Add time manual for time tracking
	CommentTypeCancelTracking   // 15 Cancel a stopwatch for time tracking
	CommentTypeAddedDeadline    // 16 Added a due date
	CommentTypeModifiedDeadline // 17 Modified the due date
	CommentTypeRemovedDeadline  // 18 Removed a due date

	CommentTypeAddDependency    // 19 Dependency added
	CommentTypeRemoveDependency // 20 Dependency removed

	CommentTypeCode   // 21 Comment a line of code
	CommentTypeReview // 22 Reviews a pull request by giving general feedback

	CommentTypeLock   // 23 Lock an issue, giving only collaborators access
	CommentTypeUnlock // 24 Unlocks a previously locked issue

	CommentTypeChangeTargetBranch // 25 Change pull request's target branch

	CommentTypeDeleteTimeManual // 26 Delete time manual for time tracking

	CommentTypeReviewRequest   // 27 add or remove Request from one
	CommentTypeMergePull       // 28 merge pull request
	CommentTypePullRequestPush // 29 push to PR head branch

	CommentTypeProject       // 30 Project changed
	CommentTypeProjectColumn // 31 Project column changed

	CommentTypeDismissReview // 32 Dismiss Review

	CommentTypeChangeIssueRef // 33 Change issue ref

	CommentTypePRScheduledToAutoMerge   // 34 pr was scheduled to auto merge when checks succeed
	CommentTypePRUnScheduledToAutoMerge // 35 pr was un scheduled to auto merge when checks succeed

	CommentTypePin   // 36 pin Issue/PullRequest
	CommentTypeUnpin // 37 unpin Issue/PullRequest

	CommentTypeChangeTimeEstimate // 38 Change time estimate
)

var commentStrings = []string{
	"comment",
	"reopen",
	"close",
	"issue_ref",
	"commit_ref",
	"comment_ref",
	"pull_ref",
	"label",
	"milestone",
	"assignees",
	"change_title",
	"delete_branch",
	"start_tracking",
	"stop_tracking",
	"add_time_manual",
	"cancel_tracking",
	"added_deadline",
	"modified_deadline",
	"removed_deadline",
	"add_dependency",
	"remove_dependency",
	"code",
	"review",
	"lock",
	"unlock",
	"change_target_branch",
	"delete_time_manual",
	"review_request",
	"merge_pull",
	"pull_push",
	"project",
	"project_board", // FIXME: the name should be project_column
	"dismiss_review",
	"change_issue_ref",
	"pull_scheduled_merge",
	"pull_cancel_scheduled_merge",
	"pin",
	"unpin",
	"change_time_estimate",
}

func (t CommentType) String() string {
	return commentStrings[t]
}

func AsCommentType(typeName string) CommentType {
	for index, name := range commentStrings {
		if typeName == name {
			return CommentType(index)
		}
	}
	return CommentTypeUndefined
}

func (t CommentType) HasContentSupport() bool {
	switch t {
	case CommentTypeComment, CommentTypeCode, CommentTypeReview, CommentTypeDismissReview:
		return true
	}
	return false
}

func (t CommentType) HasAttachmentSupport() bool {
	switch t {
	case CommentTypeComment, CommentTypeCode, CommentTypeReview:
		return true
	}
	return false
}

func (t CommentType) HasMailReplySupport() bool {
	switch t {
	case CommentTypeComment, CommentTypeCode, CommentTypeReview, CommentTypeDismissReview, CommentTypeReopen, CommentTypeClose, CommentTypeMergePull, CommentTypeAssignees:
		return true
	}
	return false
}

func (t CommentType) CountedAsConversation() bool {
	return slices.Contains(ConversationCountedCommentType(), t)
}

// ConversationCountedCommentType returns the comment types that are counted as a conversation
func ConversationCountedCommentType() []CommentType {
	return []CommentType{CommentTypeComment, CommentTypeReview}
}

// RoleInRepo presents the user's participation in the repo
type RoleInRepo string

// RoleDescriptor defines comment "role" tags
type RoleDescriptor struct {
	IsPoster   bool
	RoleInRepo RoleInRepo
}

// Enumerate all the role tags.
const (
	RoleRepoOwner                RoleInRepo = "owner"
	RoleRepoMember               RoleInRepo = "member"
	RoleRepoCollaborator         RoleInRepo = "collaborator"
	RoleRepoFirstTimeContributor RoleInRepo = "first_time_contributor"
	RoleRepoContributor          RoleInRepo = "contributor"
)

// LocaleString returns the locale string name of the role
func (r RoleInRepo) LocaleString(lang translation.Locale) string {
	return lang.TrString("repo.issues.role." + string(r))
}

// LocaleHelper returns the locale tooltip of the role
func (r RoleInRepo) LocaleHelper(lang translation.Locale) string {
	return lang.TrString("repo.issues.role." + string(r) + "_helper")
}

// CommentMetaData stores metadata for a comment, these data will not be changed once inserted into database
type CommentMetaData struct {
	ProjectColumnID    int64  `json:"project_column_id,omitempty"`
	ProjectColumnTitle string `json:"project_column_title,omitempty"`
	ProjectTitle       string `json:"project_title,omitempty"`
}

// Comment represents a comment in commit and issue page.
type Comment struct {
	ID               int64            `xorm:"pk autoincr"`
	Type             CommentType      `xorm:"INDEX"`
	PosterID         int64            `xorm:"INDEX"`
	Poster           *user_model.User `xorm:"-"`
	OriginalAuthor   string
	OriginalAuthorID int64
	IssueID          int64  `xorm:"INDEX"`
	Issue            *Issue `xorm:"-"`
	LabelID          int64
	Label            *Label   `xorm:"-"`
	AddedLabels      []*Label `xorm:"-"`
	RemovedLabels    []*Label `xorm:"-"`
	OldProjectID     int64
	ProjectID        int64
	OldProject       *project_model.Project `xorm:"-"`
	Project          *project_model.Project `xorm:"-"`
	OldMilestoneID   int64
	MilestoneID      int64
	OldMilestone     *Milestone `xorm:"-"`
	Milestone        *Milestone `xorm:"-"`
	TimeID           int64
	Time             *TrackedTime `xorm:"-"`
	AssigneeID       int64
	RemovedAssignee  bool
	Assignee         *user_model.User   `xorm:"-"`
	AssigneeTeamID   int64              `xorm:"NOT NULL DEFAULT 0"`
	AssigneeTeam     *organization.Team `xorm:"-"`
	ResolveDoerID    int64
	ResolveDoer      *user_model.User `xorm:"-"`
	OldTitle         string
	NewTitle         string
	OldRef           string
	NewRef           string
	DependentIssueID int64  `xorm:"index"` // This is used by issue_service.deleteIssue
	DependentIssue   *Issue `xorm:"-"`

	CommitID        int64
	Line            int64         // - previous line / + proposed line
	TreePath        string        `xorm:"VARCHAR(4000)"` // SQLServer only supports up to 4000
	Content         string        `xorm:"LONGTEXT"`
	ContentVersion  int           `xorm:"NOT NULL DEFAULT 0"`
	RenderedContent template.HTML `xorm:"-"`

	// Path represents the 4 lines of code cemented by this comment
	Patch       string `xorm:"-"`
	PatchQuoted string `xorm:"LONGTEXT patch"`

	CreatedUnix timeutil.TimeStamp `xorm:"INDEX created"`
	UpdatedUnix timeutil.TimeStamp `xorm:"INDEX updated"`

	// Reference issue in commit message
	CommitSHA string `xorm:"VARCHAR(64)"`

	Attachments []*repo_model.Attachment `xorm:"-"`
	Reactions   ReactionList             `xorm:"-"`

	// For view issue page.
	ShowRole RoleDescriptor `xorm:"-"`

	Review      *Review `xorm:"-"`
	ReviewID    int64   `xorm:"index"`
	Invalidated bool

	// Reference an issue or pull from another comment, issue or PR
	// All information is about the origin of the reference
	RefRepoID    int64                 `xorm:"index"` // Repo where the referencing
	RefIssueID   int64                 `xorm:"index"`
	RefCommentID int64                 `xorm:"index"`    // 0 if origin is Issue title or content (or PR's)
	RefAction    references.XRefAction `xorm:"SMALLINT"` // What happens if RefIssueID resolves
	RefIsPull    bool

	CommentMetaData *CommentMetaData `xorm:"JSON TEXT"` // put all non-index metadata in a single field

	RefRepo    *repo_model.Repository `xorm:"-"`
	RefIssue   *Issue                 `xorm:"-"`
	RefComment *Comment               `xorm:"-"`

	Commits     []*git_model.SignCommitWithStatuses `xorm:"-"`
	OldCommit   string                              `xorm:"-"`
	NewCommit   string                              `xorm:"-"`
	CommitsNum  int64                               `xorm:"-"`
	IsForcePush bool                                `xorm:"-"`
}

func init() {
	db.RegisterModel(new(Comment))
}

// PushActionContent is content of push pull comment
type PushActionContent struct {
	IsForcePush bool     `json:"is_force_push"`
	CommitIDs   []string `json:"commit_ids"`
}

// LoadIssue loads the issue reference for the comment
func (c *Comment) LoadIssue(ctx context.Context) (err error) {
	if c.Issue != nil {
		return nil
	}
	c.Issue, err = GetIssueByID(ctx, c.IssueID)
	return err
}

// BeforeInsert will be invoked by XORM before inserting a record
func (c *Comment) BeforeInsert() {
	c.PatchQuoted = c.Patch
	if !utf8.ValidString(c.Patch) {
		c.PatchQuoted = strconv.Quote(c.Patch)
	}
}

// BeforeUpdate will be invoked by XORM before updating a record
func (c *Comment) BeforeUpdate() {
	c.PatchQuoted = c.Patch
	if !utf8.ValidString(c.Patch) {
		c.PatchQuoted = strconv.Quote(c.Patch)
	}
}

// AfterLoad is invoked from XORM after setting the values of all fields of this object.
func (c *Comment) AfterLoad() {
	c.Patch = c.PatchQuoted
	if len(c.PatchQuoted) > 0 && c.PatchQuoted[0] == '"' {
		unquoted, err := strconv.Unquote(c.PatchQuoted)
		if err == nil {
			c.Patch = unquoted
		}
	}
}

// LoadPoster loads comment poster
func (c *Comment) LoadPoster(ctx context.Context) (err error) {
	if c.Poster != nil {
		return nil
	}

	c.Poster, err = user_model.GetPossibleUserByID(ctx, c.PosterID)
	if err != nil {
		if user_model.IsErrUserNotExist(err) {
			c.PosterID = user_model.GhostUserID
			c.Poster = user_model.NewGhostUser()
		} else {
			log.Error("getUserByID[%d]: %v", c.ID, err)
		}
	}
	return err
}

// AfterDelete is invoked from XORM after the object is deleted.
func (c *Comment) AfterDelete(ctx context.Context) {
	if c.ID <= 0 {
		return
	}

	_, err := repo_model.DeleteAttachmentsByComment(ctx, c.ID, true)
	if err != nil {
		log.Info("Could not delete files for comment %d on issue #%d: %s", c.ID, c.IssueID, err)
	}
}

// HTMLURL formats a URL-string to the issue-comment
func (c *Comment) HTMLURL(ctx context.Context) string {
	err := c.LoadIssue(ctx)
	if err != nil { // Silently dropping errors :unamused:
		log.Error("LoadIssue(%d): %v", c.IssueID, err)
		return ""
	}
	err = c.Issue.LoadRepo(ctx)
	if err != nil { // Silently dropping errors :unamused:
		log.Error("loadRepo(%d): %v", c.Issue.RepoID, err)
		return ""
	}
	return c.Issue.HTMLURL(ctx) + c.hashLink(ctx)
}

// Link formats a relative URL-string to the issue-comment
func (c *Comment) Link(ctx context.Context) string {
	err := c.LoadIssue(ctx)
	if err != nil { // Silently dropping errors :unamused:
		log.Error("LoadIssue(%d): %v", c.IssueID, err)
		return ""
	}
	err = c.Issue.LoadRepo(ctx)
	if err != nil { // Silently dropping errors :unamused:
		log.Error("loadRepo(%d): %v", c.Issue.RepoID, err)
		return ""
	}
	return c.Issue.Link() + c.hashLink(ctx)
}

func (c *Comment) hashLink(ctx context.Context) string {
	if c.Type == CommentTypeCode {
		if c.ReviewID == 0 {
			return "/files#" + c.HashTag()
		}
		if c.Review == nil {
			if err := c.LoadReview(ctx); err != nil {
				log.Warn("LoadReview(%d): %v", c.ReviewID, err)
				return "/files#" + c.HashTag()
			}
		}
		if c.Review.Type <= ReviewTypePending {
			return "/files#" + c.HashTag()
		}
	}
	return "#" + c.HashTag()
}

// APIURL formats a API-string to the issue-comment
func (c *Comment) APIURL(ctx context.Context) string {
	err := c.LoadIssue(ctx)
	if err != nil { // Silently dropping errors :unamused:
		log.Error("LoadIssue(%d): %v", c.IssueID, err)
		return ""
	}
	err = c.Issue.LoadRepo(ctx)
	if err != nil { // Silently dropping errors :unamused:
		log.Error("loadRepo(%d): %v", c.Issue.RepoID, err)
		return ""
	}

	return fmt.Sprintf("%s/issues/comments/%d", c.Issue.Repo.APIURL(), c.ID)
}

// IssueURL formats a URL-string to the issue
func (c *Comment) IssueURL(ctx context.Context) string {
	err := c.LoadIssue(ctx)
	if err != nil { // Silently dropping errors :unamused:
		log.Error("LoadIssue(%d): %v", c.IssueID, err)
		return ""
	}

	if c.Issue.IsPull {
		return ""
	}

	err = c.Issue.LoadRepo(ctx)
	if err != nil { // Silently dropping errors :unamused:
		log.Error("loadRepo(%d): %v", c.Issue.RepoID, err)
		return ""
	}
	return c.Issue.HTMLURL(ctx)
}

// PRURL formats a URL-string to the pull-request
func (c *Comment) PRURL(ctx context.Context) string {
	err := c.LoadIssue(ctx)
	if err != nil { // Silently dropping errors :unamused:
		log.Error("LoadIssue(%d): %v", c.IssueID, err)
		return ""
	}

	err = c.Issue.LoadRepo(ctx)
	if err != nil { // Silently dropping errors :unamused:
		log.Error("loadRepo(%d): %v", c.Issue.RepoID, err)
		return ""
	}

	if !c.Issue.IsPull {
		return ""
	}
	return c.Issue.HTMLURL(ctx)
}

// CommentHashTag returns unique hash tag for comment id.
func CommentHashTag(id int64) string {
	return fmt.Sprintf("issuecomment-%d", id)
}

// HashTag returns unique hash tag for comment.
func (c *Comment) HashTag() string {
	return CommentHashTag(c.ID)
}

// EventTag returns unique event hash tag for comment.
func (c *Comment) EventTag() string {
	return fmt.Sprintf("event-%d", c.ID)
}

// LoadLabel if comment.Type is CommentTypeLabel, then load Label
func (c *Comment) LoadLabel(ctx context.Context) error {
	var label Label
	has, err := db.GetEngine(ctx).ID(c.LabelID).Get(&label)
	if err != nil {
		return err
	} else if has {
		c.Label = &label
	} else {
		// Ignore Label is deleted, but not clear this table
		log.Warn("Commit %d cannot load label %d", c.ID, c.LabelID)
	}

	return nil
}

// LoadProject if comment.Type is CommentTypeProject, then load project.
func (c *Comment) LoadProject(ctx context.Context) error {
	if c.OldProjectID > 0 {
		var oldProject project_model.Project
		has, err := db.GetEngine(ctx).ID(c.OldProjectID).Get(&oldProject)
		if err != nil {
			return err
		} else if has {
			c.OldProject = &oldProject
		}
	}

	if c.ProjectID > 0 {
		var project project_model.Project
		has, err := db.GetEngine(ctx).ID(c.ProjectID).Get(&project)
		if err != nil {
			return err
		} else if has {
			c.Project = &project
		}
	}

	return nil
}

// LoadMilestone if comment.Type is CommentTypeMilestone, then load milestone
func (c *Comment) LoadMilestone(ctx context.Context) error {
	if c.OldMilestoneID > 0 {
		var oldMilestone Milestone
		has, err := db.GetEngine(ctx).ID(c.OldMilestoneID).Get(&oldMilestone)
		if err != nil {
			return err
		} else if has {
			c.OldMilestone = &oldMilestone
		}
	}

	if c.MilestoneID > 0 {
		var milestone Milestone
		has, err := db.GetEngine(ctx).ID(c.MilestoneID).Get(&milestone)
		if err != nil {
			return err
		} else if has {
			c.Milestone = &milestone
		}
	}
	return nil
}

// LoadAttachments loads attachments (it never returns error, the error during `GetAttachmentsByCommentIDCtx` is ignored)
func (c *Comment) LoadAttachments(ctx context.Context) error {
	if len(c.Attachments) > 0 {
		return nil
	}

	var err error
	c.Attachments, err = repo_model.GetAttachmentsByCommentID(ctx, c.ID)
	if err != nil {
		log.Error("getAttachmentsByCommentID[%d]: %v", c.ID, err)
	}
	return nil
}

// UpdateCommentAttachments update attachments by UUIDs for the comment
func UpdateCommentAttachments(ctx context.Context, c *Comment, uuids []string) error {
	if len(uuids) == 0 {
		return nil
	}
	return db.WithTx(ctx, func(ctx context.Context) error {
		attachments, err := repo_model.GetAttachmentsByUUIDs(ctx, uuids)
		if err != nil {
			return fmt.Errorf("getAttachmentsByUUIDs [uuids: %v]: %w", uuids, err)
		}
		for i := range attachments {
			attachments[i].IssueID = c.IssueID
			attachments[i].CommentID = c.ID
			if err := repo_model.UpdateAttachment(ctx, attachments[i]); err != nil {
				return fmt.Errorf("update attachment [id: %d]: %w", attachments[i].ID, err)
			}
		}
		c.Attachments = attachments
		return nil
	})
}

// LoadAssigneeUserAndTeam if comment.Type is CommentTypeAssignees, then load assignees
func (c *Comment) LoadAssigneeUserAndTeam(ctx context.Context) error {
	var err error

	if c.AssigneeID > 0 && c.Assignee == nil {
		c.Assignee, err = user_model.GetUserByID(ctx, c.AssigneeID)
		if err != nil {
			if !user_model.IsErrUserNotExist(err) {
				return err
			}
			c.Assignee = user_model.NewGhostUser()
		}
	} else if c.AssigneeTeamID > 0 && c.AssigneeTeam == nil {
		if err = c.LoadIssue(ctx); err != nil {
			return err
		}

		if err = c.Issue.LoadRepo(ctx); err != nil {
			return err
		}

		if err = c.Issue.Repo.LoadOwner(ctx); err != nil {
			return err
		}

		if c.Issue.Repo.Owner.IsOrganization() {
			c.AssigneeTeam, err = organization.GetTeamByID(ctx, c.AssigneeTeamID)
			if err != nil && !organization.IsErrTeamNotExist(err) {
				return err
			}
		}
	}
	return nil
}

// LoadResolveDoer if comment.Type is CommentTypeCode and ResolveDoerID not zero, then load resolveDoer
func (c *Comment) LoadResolveDoer(ctx context.Context) (err error) {
	if c.ResolveDoerID == 0 || c.Type != CommentTypeCode {
		return nil
	}
	c.ResolveDoer, err = user_model.GetUserByID(ctx, c.ResolveDoerID)
	if err != nil {
		if user_model.IsErrUserNotExist(err) {
			c.ResolveDoer = user_model.NewGhostUser()
			err = nil
		}
	}
	return err
}

// IsResolved check if an code comment is resolved
func (c *Comment) IsResolved() bool {
	return c.ResolveDoerID != 0 && c.Type == CommentTypeCode
}

// LoadDepIssueDetails loads Dependent Issue Details
func (c *Comment) LoadDepIssueDetails(ctx context.Context) (err error) {
	if c.DependentIssueID <= 0 || c.DependentIssue != nil {
		return nil
	}
	c.DependentIssue, err = GetIssueByID(ctx, c.DependentIssueID)
	return err
}

// LoadTime loads the associated time for a CommentTypeAddTimeManual
func (c *Comment) LoadTime(ctx context.Context) error {
	if c.Time != nil || c.TimeID == 0 {
		return nil
	}
	var err error
	c.Time, err = GetTrackedTimeByID(ctx, c.TimeID)
	return err
}

// LoadReactions loads comment reactions
func (c *Comment) LoadReactions(ctx context.Context, repo *repo_model.Repository) (err error) {
	if c.Reactions != nil {
		return nil
	}
	c.Reactions, _, err = FindReactions(ctx, FindReactionsOptions{
		IssueID:   c.IssueID,
		CommentID: c.ID,
	})
	if err != nil {
		return err
	}
	// Load reaction user data
	if _, err := c.Reactions.LoadUsers(ctx, repo); err != nil {
		return err
	}
	return nil
}

// LoadReview loads the associated review
func (c *Comment) LoadReview(ctx context.Context) (err error) {
	if c.ReviewID == 0 {
		return nil
	}
	if c.Review == nil {
		if c.Review, err = GetReviewByID(ctx, c.ReviewID); err != nil {
			// review request which has been replaced by actual reviews doesn't exist in database anymore, so ignorem them.
			if c.Type == CommentTypeReviewRequest {
				return nil
			}
			return err
		}
	}
	c.Review.Issue = c.Issue
	return nil
}

// DiffSide returns "previous" if Comment.Line is a LOC of the previous changes and "proposed" if it is a LOC of the proposed changes.
func (c *Comment) DiffSide() string {
	if c.Line < 0 {
		return "previous"
	}
	return "proposed"
}

// UnsignedLine returns the LOC of the code comment without + or -
func (c *Comment) UnsignedLine() uint64 {
	if c.Line < 0 {
		return uint64(c.Line * -1)
	}
	return uint64(c.Line)
}

// CodeCommentLink returns the url to a comment in code
func (c *Comment) CodeCommentLink(ctx context.Context) string {
	err := c.LoadIssue(ctx)
	if err != nil { // Silently dropping errors :unamused:
		log.Error("LoadIssue(%d): %v", c.IssueID, err)
		return ""
	}
	err = c.Issue.LoadRepo(ctx)
	if err != nil { // Silently dropping errors :unamused:
		log.Error("loadRepo(%d): %v", c.Issue.RepoID, err)
		return ""
	}
	return fmt.Sprintf("%s/files#%s", c.Issue.Link(), c.HashTag())
}

// CreateComment creates comment with context
func CreateComment(ctx context.Context, opts *CreateCommentOptions) (_ *Comment, err error) {
	return db.WithTx2(ctx, func(ctx context.Context) (*Comment, error) {
		var LabelID int64
		if opts.Label != nil {
			LabelID = opts.Label.ID
		}

		var commentMetaData *CommentMetaData
		if opts.ProjectColumnTitle != "" {
			commentMetaData = &CommentMetaData{
				ProjectColumnID:    opts.ProjectColumnID,
				ProjectColumnTitle: opts.ProjectColumnTitle,
				ProjectTitle:       opts.ProjectTitle,
			}
		}

		comment := &Comment{
			Type:             opts.Type,
			PosterID:         opts.Doer.ID,
			Poster:           opts.Doer,
			IssueID:          opts.Issue.ID,
			LabelID:          LabelID,
			OldMilestoneID:   opts.OldMilestoneID,
			MilestoneID:      opts.MilestoneID,
			OldProjectID:     opts.OldProjectID,
			ProjectID:        opts.ProjectID,
			TimeID:           opts.TimeID,
			RemovedAssignee:  opts.RemovedAssignee,
			AssigneeID:       opts.AssigneeID,
			AssigneeTeamID:   opts.AssigneeTeamID,
			CommitID:         opts.CommitID,
			CommitSHA:        opts.CommitSHA,
			Line:             opts.LineNum,
			Content:          opts.Content,
			OldTitle:         opts.OldTitle,
			NewTitle:         opts.NewTitle,
			OldRef:           opts.OldRef,
			NewRef:           opts.NewRef,
			DependentIssueID: opts.DependentIssueID,
			TreePath:         opts.TreePath,
			ReviewID:         opts.ReviewID,
			Patch:            opts.Patch,
			RefRepoID:        opts.RefRepoID,
			RefIssueID:       opts.RefIssueID,
			RefCommentID:     opts.RefCommentID,
			RefAction:        opts.RefAction,
			RefIsPull:        opts.RefIsPull,
			IsForcePush:      opts.IsForcePush,
			Invalidated:      opts.Invalidated,
			CommentMetaData:  commentMetaData,
		}
		if err = db.Insert(ctx, comment); err != nil {
			return nil, err
		}

		if err = opts.Repo.LoadOwner(ctx); err != nil {
			return nil, err
		}

		if err = updateCommentInfos(ctx, opts, comment); err != nil {
			return nil, err
		}

		if err = comment.AddCrossReferences(ctx, opts.Doer, false); err != nil {
			return nil, err
		}
		return comment, nil
	})
}

func updateCommentInfos(ctx context.Context, opts *CreateCommentOptions, comment *Comment) (err error) {
	// Check comment type.
	switch opts.Type {
	case CommentTypeCode:
		if err = UpdateCommentAttachments(ctx, comment, opts.Attachments); err != nil {
			return err
		}
		if comment.ReviewID != 0 {
			if comment.Review == nil {
				if err := comment.LoadReview(ctx); err != nil {
					return err
				}
			}
			if comment.Review.Type <= ReviewTypePending {
				return nil
			}
		}
		fallthrough
	case CommentTypeComment:
		if err := UpdateIssueNumComments(ctx, opts.Issue.ID); err != nil {
			return err
		}
		fallthrough
	case CommentTypeReview:
		if err = UpdateCommentAttachments(ctx, comment, opts.Attachments); err != nil {
			return err
		}
	case CommentTypeReopen, CommentTypeClose:
		if err = repo_model.UpdateRepoIssueNumbers(ctx, opts.Issue.RepoID, opts.Issue.IsPull, true); err != nil {
			return err
		}
	}
	// update the issue's updated_unix column
	return UpdateIssueCols(ctx, opts.Issue, "updated_unix")
}

func createDeadlineComment(ctx context.Context, doer *user_model.User, issue *Issue, newDeadlineUnix timeutil.TimeStamp) (*Comment, error) {
	var content string
	var commentType CommentType

	// newDeadline = 0 means deleting
	if newDeadlineUnix == 0 {
		commentType = CommentTypeRemovedDeadline
		content = issue.DeadlineUnix.FormatDate()
	} else if issue.DeadlineUnix == 0 {
		// Check if the new date was added or modified
		// If the actual deadline is 0 => deadline added
		commentType = CommentTypeAddedDeadline
		content = newDeadlineUnix.FormatDate()
	} else { // Otherwise modified
		commentType = CommentTypeModifiedDeadline
		content = newDeadlineUnix.FormatDate() + "|" + issue.DeadlineUnix.FormatDate()
	}

	if err := issue.LoadRepo(ctx); err != nil {
		return nil, err
	}

	opts := &CreateCommentOptions{
		Type:    commentType,
		Doer:    doer,
		Repo:    issue.Repo,
		Issue:   issue,
		Content: content,
	}
	comment, err := CreateComment(ctx, opts)
	if err != nil {
		return nil, err
	}
	return comment, nil
}

// Creates issue dependency comment
func createIssueDependencyComment(ctx context.Context, doer *user_model.User, issue, dependentIssue *Issue, add bool) (err error) {
	cType := CommentTypeAddDependency
	if !add {
		cType = CommentTypeRemoveDependency
	}
	if err = issue.LoadRepo(ctx); err != nil {
		return err
	}

	// Make two comments, one in each issue
	opts := &CreateCommentOptions{
		Type:             cType,
		Doer:             doer,
		Repo:             issue.Repo,
		Issue:            issue,
		DependentIssueID: dependentIssue.ID,
	}
	if _, err = CreateComment(ctx, opts); err != nil {
		return err
	}

	opts = &CreateCommentOptions{
		Type:             cType,
		Doer:             doer,
		Repo:             issue.Repo,
		Issue:            dependentIssue,
		DependentIssueID: issue.ID,
	}
	_, err = CreateComment(ctx, opts)
	return err
}

// CreateCommentOptions defines options for creating comment
type CreateCommentOptions struct {
	Type  CommentType
	Doer  *user_model.User
	Repo  *repo_model.Repository
	Issue *Issue
	Label *Label

	DependentIssueID   int64
	OldMilestoneID     int64
	MilestoneID        int64
	OldProjectID       int64
	ProjectID          int64
	ProjectTitle       string
	ProjectColumnID    int64
	ProjectColumnTitle string
	TimeID             int64
	AssigneeID         int64
	AssigneeTeamID     int64
	RemovedAssignee    bool
	OldTitle           string
	NewTitle           string
	OldRef             string
	NewRef             string
	CommitID           int64
	CommitSHA          string
	Patch              string
	LineNum            int64
	TreePath           string
	ReviewID           int64
	Content            string
	Attachments        []string // UUIDs of attachments
	RefRepoID          int64
	RefIssueID         int64
	RefCommentID       int64
	RefAction          references.XRefAction
	RefIsPull          bool
	IsForcePush        bool
	Invalidated        bool
}

// GetCommentByID returns the comment by given ID.
func GetCommentByID(ctx context.Context, id int64) (*Comment, error) {
	c := new(Comment)
	has, err := db.GetEngine(ctx).ID(id).Get(c)
	if err != nil {
		return nil, err
	} else if !has {
		return nil, ErrCommentNotExist{id, 0}
	}
	return c, nil
}

// FindCommentsOptions describes the conditions to Find comments
type FindCommentsOptions struct {
	db.ListOptions
	RepoID      int64
	IssueID     int64
	ReviewID    int64
	Since       int64
	Before      int64
	Line        int64
	TreePath    string
	Type        CommentType
	IssueIDs    []int64
	Invalidated optional.Option[bool]
	IsPull      optional.Option[bool]
}

// ToConds implements FindOptions interface
func (opts FindCommentsOptions) ToConds() builder.Cond {
	cond := builder.NewCond()
	if opts.RepoID > 0 {
		cond = cond.And(builder.Eq{"issue.repo_id": opts.RepoID})
	}
	if opts.IssueID > 0 {
		cond = cond.And(builder.Eq{"comment.issue_id": opts.IssueID})
	} else if len(opts.IssueIDs) > 0 {
		cond = cond.And(builder.In("comment.issue_id", opts.IssueIDs))
	}
	if opts.ReviewID > 0 {
		cond = cond.And(builder.Eq{"comment.review_id": opts.ReviewID})
	}
	if opts.Since > 0 {
		cond = cond.And(builder.Gte{"comment.updated_unix": opts.Since})
	}
	if opts.Before > 0 {
		cond = cond.And(builder.Lte{"comment.updated_unix": opts.Before})
	}
	if opts.Type != CommentTypeUndefined {
		cond = cond.And(builder.Eq{"comment.type": opts.Type})
	}
	if opts.Line != 0 {
		cond = cond.And(builder.Eq{"comment.line": opts.Line})
	}
	if len(opts.TreePath) > 0 {
		cond = cond.And(builder.Eq{"comment.tree_path": opts.TreePath})
	}
	if opts.Invalidated.Has() {
		cond = cond.And(builder.Eq{"comment.invalidated": opts.Invalidated.Value()})
	}
	if opts.IsPull.Has() {
		cond = cond.And(builder.Eq{"issue.is_pull": opts.IsPull.Value()})
	}
	return cond
}

// FindComments returns all comments according options
func FindComments(ctx context.Context, opts *FindCommentsOptions) (CommentList, error) {
	comments := make([]*Comment, 0, 10)
	sess := db.GetEngine(ctx).Where(opts.ToConds())
	if opts.RepoID > 0 || opts.IsPull.Has() {
		sess.Join("INNER", "issue", "issue.id = comment.issue_id")
	}

	if opts.Page > 0 {
		sess = db.SetSessionPagination(sess, opts)
	}

	// WARNING: If you change this order you will need to fix createCodeComment

	return comments, sess.
		Asc("comment.created_unix").
		Asc("comment.id").
		Find(&comments)
}

// CountComments count all comments according options by ignoring pagination
func CountComments(ctx context.Context, opts *FindCommentsOptions) (int64, error) {
	sess := db.GetEngine(ctx).Where(opts.ToConds())
	if opts.RepoID > 0 {
		sess.Join("INNER", "issue", "issue.id = comment.issue_id")
	}
	return sess.Count(&Comment{})
}

// UpdateCommentInvalidate updates comment invalidated column
func UpdateCommentInvalidate(ctx context.Context, c *Comment) error {
	_, err := db.GetEngine(ctx).ID(c.ID).Cols("invalidated").Update(c)
	return err
}

// UpdateComment updates information of comment.
func UpdateComment(ctx context.Context, c *Comment, contentVersion int, doer *user_model.User) error {
	return db.WithTx(ctx, func(ctx context.Context) error {
		c.ContentVersion = contentVersion + 1

		affected, err := db.GetEngine(ctx).ID(c.ID).AllCols().Where("content_version = ?", contentVersion).Update(c)
		if err != nil {
			return err
		}
		if affected == 0 {
			return ErrCommentAlreadyChanged
		}
		if err := c.LoadIssue(ctx); err != nil {
			return err
		}
		return c.AddCrossReferences(ctx, doer, true)
	})
}

// DeleteComment deletes the comment
func DeleteComment(ctx context.Context, comment *Comment) error {
	e := db.GetEngine(ctx)
	if _, err := e.ID(comment.ID).NoAutoCondition().Delete(comment); err != nil {
		return err
	}

	if _, err := db.DeleteByBean(ctx, &ContentHistory{
		CommentID: comment.ID,
	}); err != nil {
		return err
	}

	if comment.Type.CountedAsConversation() {
		if err := UpdateIssueNumComments(ctx, comment.IssueID); err != nil {
			return err
		}
	}
	if _, err := e.Table("action").
		Where("comment_id = ?", comment.ID).
		Update(map[string]any{
			"is_deleted": true,
		}); err != nil {
		return err
	}

	if err := comment.neuterCrossReferences(ctx); err != nil {
		return err
	}

	return DeleteReaction(ctx, &ReactionOptions{CommentID: comment.ID})
}

// UpdateCommentsMigrationsByType updates comments' migrations information via given git service type and original id and poster id
func UpdateCommentsMigrationsByType(ctx context.Context, tp structs.GitServiceType, originalAuthorID string, posterID int64) error {
	_, err := db.GetEngine(ctx).Table("comment").
		Join("INNER", "issue", "issue.id = comment.issue_id").
		Join("INNER", "repository", "issue.repo_id = repository.id").
		Where("repository.original_service_type = ?", tp).
		And("comment.original_author_id = ?", originalAuthorID).
		Update(map[string]any{
			"poster_id":          posterID,
			"original_author":    "",
			"original_author_id": 0,
		})
	return err
}

// CreateAutoMergeComment is a internal function, only use it for CommentTypePRScheduledToAutoMerge and CommentTypePRUnScheduledToAutoMerge CommentTypes
func CreateAutoMergeComment(ctx context.Context, typ CommentType, pr *PullRequest, doer *user_model.User) (comment *Comment, err error) {
	if typ != CommentTypePRScheduledToAutoMerge && typ != CommentTypePRUnScheduledToAutoMerge {
		return nil, fmt.Errorf("comment type %d cannot be used to create an auto merge comment", typ)
	}
	if err = pr.LoadIssue(ctx); err != nil {
		return nil, err
	}

	if err = pr.LoadBaseRepo(ctx); err != nil {
		return nil, err
	}

	comment, err = CreateComment(ctx, &CreateCommentOptions{
		Type:  typ,
		Doer:  doer,
		Repo:  pr.BaseRepo,
		Issue: pr.Issue,
	})
	return comment, err
}

// RemapExternalUser ExternalUserRemappable interface
func (c *Comment) RemapExternalUser(externalName string, externalID, userID int64) error {
	c.OriginalAuthor = externalName
	c.OriginalAuthorID = externalID
	c.PosterID = userID
	return nil
}

// GetUserID ExternalUserRemappable interface
func (c *Comment) GetUserID() int64 { return c.PosterID }

// GetExternalName ExternalUserRemappable interface
func (c *Comment) GetExternalName() string { return c.OriginalAuthor }

// GetExternalID ExternalUserRemappable interface
func (c *Comment) GetExternalID() int64 { return c.OriginalAuthorID }

// CountCommentTypeLabelWithEmptyLabel count label comments with empty label
func CountCommentTypeLabelWithEmptyLabel(ctx context.Context) (int64, error) {
	return db.GetEngine(ctx).Where(builder.Eq{"type": CommentTypeLabel, "label_id": 0}).Count(new(Comment))
}

// FixCommentTypeLabelWithEmptyLabel count label comments with empty label
func FixCommentTypeLabelWithEmptyLabel(ctx context.Context) (int64, error) {
	return db.GetEngine(ctx).Where(builder.Eq{"type": CommentTypeLabel, "label_id": 0}).Delete(new(Comment))
}

// CountCommentTypeLabelWithOutsideLabels count label comments with outside label
func CountCommentTypeLabelWithOutsideLabels(ctx context.Context) (int64, error) {
	return db.GetEngine(ctx).Where("comment.type = ? AND ((label.org_id = 0 AND issue.repo_id != label.repo_id) OR (label.repo_id = 0 AND label.org_id != repository.owner_id))", CommentTypeLabel).
		Table("comment").
		Join("inner", "label", "label.id = comment.label_id").
		Join("inner", "issue", "issue.id = comment.issue_id ").
		Join("inner", "repository", "issue.repo_id = repository.id").
		Count()
}

// FixCommentTypeLabelWithOutsideLabels count label comments with outside label
func FixCommentTypeLabelWithOutsideLabels(ctx context.Context) (int64, error) {
	res, err := db.GetEngine(ctx).Exec(`DELETE FROM comment WHERE comment.id IN (
		SELECT il_too.id FROM (
			SELECT com.id
				FROM comment AS com
					INNER JOIN label ON com.label_id = label.id
					INNER JOIN issue on issue.id = com.issue_id
					INNER JOIN repository ON issue.repo_id = repository.id
				WHERE
					com.type = ? AND ((label.org_id = 0 AND issue.repo_id != label.repo_id) OR (label.repo_id = 0 AND label.org_id != repository.owner_id))
	) AS il_too)`, CommentTypeLabel)
	if err != nil {
		return 0, err
	}

	return res.RowsAffected()
}

// HasOriginalAuthor returns if a comment was migrated and has an original author.
func (c *Comment) HasOriginalAuthor() bool {
	return c.OriginalAuthor != "" && c.OriginalAuthorID != 0
}

func UpdateIssueNumCommentsBuilder(issueID int64) *builder.Builder {
	subQuery := builder.Select("COUNT(*)").From("`comment`").Where(
		builder.Eq{"issue_id": issueID}.And(
			builder.In("`type`", ConversationCountedCommentType()),
		))

	return builder.Update(builder.Eq{"num_comments": subQuery}).
		From("`issue`").Where(builder.Eq{"id": issueID})
}

func UpdateIssueNumComments(ctx context.Context, issueID int64) error {
	_, err := db.GetEngine(ctx).Exec(UpdateIssueNumCommentsBuilder(issueID))
	return err
}

// InsertIssueComments inserts many comments of issues.
func InsertIssueComments(ctx context.Context, comments []*Comment) error {
	if len(comments) == 0 {
		return nil
	}

	issueIDs := container.FilterSlice(comments, func(comment *Comment) (int64, bool) {
		return comment.IssueID, true
	})

	return db.WithTx(ctx, func(ctx context.Context) error {
		for _, comment := range comments {
			if _, err := db.GetEngine(ctx).NoAutoTime().Insert(comment); err != nil {
				return err
			}

			for _, reaction := range comment.Reactions {
				reaction.IssueID = comment.IssueID
				reaction.CommentID = comment.ID
			}
			if len(comment.Reactions) > 0 {
				if err := db.Insert(ctx, comment.Reactions); err != nil {
					return err
				}
			}
		}

		for _, issueID := range issueIDs {
			if err := UpdateIssueNumComments(ctx, issueID); err != nil {
				return err
			}
		}
		return nil
	})
}
