package api

import (
	"time"

	"github.com/shurcooL/githubv4"
)

// Comments represents a paginated list of comments on an issue or pull request.
type Comments struct {
	Nodes      []Comment
	TotalCount int
	PageInfo   struct {
		HasNextPage bool
		EndCursor   string
	}
}

// CurrentUserComments returns only the comments authored by the current viewer.
func (cs Comments) CurrentUserComments() []Comment {
	var comments []Comment
	for _, c := range cs.Nodes {
		if c.ViewerDidAuthor {
			comments = append(comments, c)
		}
	}
	return comments
}

// Comment represents a single comment on an issue or pull request.
type Comment struct {
	ID                  string         `json:"id"`
	Author              CommentAuthor  `json:"author"`
	AuthorAssociation   string         `json:"authorAssociation"`
	Body                string         `json:"body"`
	CreatedAt           time.Time      `json:"createdAt"`
	IncludesCreatedEdit bool           `json:"includesCreatedEdit"`
	IsMinimized         bool           `json:"isMinimized"`
	MinimizedReason     string         `json:"minimizedReason"`
	ReactionGroups      ReactionGroups `json:"reactionGroups"`
	URL                 string         `json:"url,omitempty"`
	ViewerDidAuthor     bool           `json:"viewerDidAuthor"`
}

// CommentCreateInput defines the parameters for creating a new comment.
type CommentCreateInput struct {
	Body      string
	SubjectId string
}

// CommentDeleteInput defines the parameters for deleting a comment.
type CommentDeleteInput struct {
	CommentId string
}

// CommentUpdateInput defines the parameters for updating a comment.
type CommentUpdateInput struct {
	Body      string
	CommentId string
}

// CommentCreate creates a new comment on an issue or pull request and returns the URL of the created comment.
func CommentCreate(client *Client, repoHost string, params CommentCreateInput) (string, error) {
	var mutation struct {
		AddComment struct {
			CommentEdge struct {
				Node struct {
					URL string
				}
			}
		} `graphql:"addComment(input: $input)"`
	}

	variables := map[string]interface{}{
		"input": githubv4.AddCommentInput{
			Body:      githubv4.String(params.Body),
			SubjectID: githubv4.ID(params.SubjectId),
		},
	}

	err := client.Mutate(repoHost, "CommentCreate", &mutation, variables)
	if err != nil {
		return "", err
	}

	return mutation.AddComment.CommentEdge.Node.URL, nil
}

// CommentUpdate updates an existing issue comment and returns the URL of the updated comment.
func CommentUpdate(client *Client, repoHost string, params CommentUpdateInput) (string, error) {
	var mutation struct {
		UpdateIssueComment struct {
			IssueComment struct {
				URL string
			}
		} `graphql:"updateIssueComment(input: $input)"`
	}

	variables := map[string]interface{}{
		"input": githubv4.UpdateIssueCommentInput{
			Body: githubv4.String(params.Body),
			ID:   githubv4.ID(params.CommentId),
		},
	}

	err := client.Mutate(repoHost, "CommentUpdate", &mutation, variables)
	if err != nil {
		return "", err
	}

	return mutation.UpdateIssueComment.IssueComment.URL, nil
}

// CommentDelete deletes an issue comment via the GraphQL API.
func CommentDelete(client *Client, repoHost string, params CommentDeleteInput) error {
	var mutation struct {
		DeleteIssueComment struct {
			ClientMutationID string
		} `graphql:"deleteIssueComment(input: $input)"`
	}

	variables := map[string]interface{}{
		"input": githubv4.DeleteIssueCommentInput{
			ID: githubv4.ID(params.CommentId),
		},
	}

	err := client.Mutate(repoHost, "CommentDelete", &mutation, variables)
	if err != nil {
		return err
	}

	return nil
}

// Identifier returns the unique ID of the comment.
func (c Comment) Identifier() string {
	return c.ID
}

// AuthorLogin returns the login name of the comment author.
func (c Comment) AuthorLogin() string {
	return c.Author.Login
}

// Association returns the author's association with the repository.
func (c Comment) Association() string {
	return c.AuthorAssociation
}

// Content returns the body text of the comment.
func (c Comment) Content() string {
	return c.Body
}

// Created returns the time when the comment was created.
func (c Comment) Created() time.Time {
	return c.CreatedAt
}

// HiddenReason returns the reason the comment was minimized, if any.
func (c Comment) HiddenReason() string {
	return c.MinimizedReason
}

// IsEdited returns whether the comment has been edited.
func (c Comment) IsEdited() bool {
	return c.IncludesCreatedEdit
}

// IsHidden returns whether the comment has been minimized.
func (c Comment) IsHidden() bool {
	return c.IsMinimized
}

// Link returns the URL of the comment.
func (c Comment) Link() string {
	return c.URL
}

// Reactions returns the reaction groups associated with the comment.
func (c Comment) Reactions() ReactionGroups {
	return c.ReactionGroups
}

// Status returns the status of the comment; always empty for regular comments.
func (c Comment) Status() string {
	return ""
}