package models

import "time"

// A Chapter is a part of a story.
type Chapter struct {
	ID             string             `bson:"_id"`
	StoryID        string             `bson:"storyId"`
	Title          string             `bson:"title"`
	Author         string             `bson:"author"`
	Source         string             `bson:"source"`
	CreatedDate    time.Time          `bson:"createdDate"`
	FictionalDate  time.Time          `bson:"fictionalDate,omitempty"`
	EditedDate     time.Time          `bson:"editedDate"`
	CommentMode    ChapterCommentMode `bson:"commentMode"`
	CommentsLocked bool               `bson:"commentsLocked"`
}

func (chapter *Chapter) ApplyUpdate(update ChapterUpdate) {
	if update.Title != nil {
		chapter.Title = *update.Title
	}
	if update.Source != nil {
		chapter.Source = *update.Source
	}
	if update.FictionalDate != nil {
		chapter.FictionalDate = update.FictionalDate.UTC()
	}
	if update.CommentMode != nil {
		chapter.CommentMode = *update.CommentMode
	}
	if update.CommentsLocked != nil {
		chapter.CommentsLocked = *update.CommentsLocked
	}
}

// CanComment returns true if the chapter can be commented to.
func (chapter *Chapter) CanComment() bool {
	return !chapter.CommentsLocked && chapter.CommentMode.IsEnabled()
}

// IsChangeObject is an interface implementation to identify it as a valid
// ChangeObject in GQL.
func (*Chapter) IsChangeObject() {
	panic("this method is a dummy, and so is its caller")
}

type ChapterFilter struct {
	StoryID *string
	Limit   int
}

type ChapterUpdate struct {
	Title          *string
	Source         *string
	FictionalDate  *time.Time
	CommentMode    *ChapterCommentMode
	CommentsLocked *bool
}