package fa

import (
	"context"
	"iter"
	"time"

	"github.com/PuerkitoBio/goquery"

	"git.anthrove.art/public/go-fa-api/internal/urls"
)

// Comment is one entry from a submission's or journal's comment thread.
// FA's beta theme renders the thread as a flat indented list; the parser
// fills Depth and Parent so callers can rebuild the tree if needed.
type Comment struct {
	ID       CommentID
	Author   UserRef
	PostedAt time.Time
	BodyHTML string
	BodyText string
	Depth    int       // 0 = top level
	Parent   CommentID // 0 when Depth is 0
	Deleted  bool
}

// SubmissionComments yields every comment on a submission's view page.
// Comments aren't paginated, so this iterator performs one fetch and then
// yields each comment in document order; early termination still avoids
// processing the rest of the slice.
func (c *Client) SubmissionComments(ctx context.Context, id SubmissionID, opts ...Option) iter.Seq2[*Comment, error] {
	return c.yieldComments(ctx, urls.Submission(int64(id)), opts)
}

// JournalComments yields every comment on a journal page. Same iteration
// shape as [Client.SubmissionComments].
func (c *Client) JournalComments(ctx context.Context, id JournalID, opts ...Option) iter.Seq2[*Comment, error] {
	return c.yieldComments(ctx, urls.Journal(int64(id)), opts)
}

// yieldComments performs the single fetch shared by submission and journal
// comment iterators, then yields parsed comments to the caller.
func (c *Client) yieldComments(ctx context.Context, pageURL string, opts []Option) iter.Seq2[*Comment, error] {
	return func(yield func(*Comment, error) bool) {
		var comments []*Comment
		err := c.fetch(ctx, pageURL, func(doc *goquery.Document) error {
			comments = parseComments(doc)
			return nil
		}, opts...)
		if err != nil {
			yield(nil, err)
			return
		}
		for _, cm := range comments {
			if !yield(cm, nil) {
				return
			}
		}
	}
}