package fa

import (
	"context"
	"fmt"
	"iter"
	"time"

	"github.com/PuerkitoBio/goquery"

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

// Journal is a single journal entry, as seen on /journal/{id}/.
type Journal struct {
	ID       JournalID
	Title    string
	Author   UserRef
	PostedAt time.Time
	BodyHTML string
	BodyText string
}

// GetJournal fetches a journal entry by its numeric ID.
func (c *Client) GetJournal(ctx context.Context, id JournalID) (*Journal, error) {
	if id <= 0 {
		return nil, fmt.Errorf("fa: GetJournal: id must be > 0")
	}
	var out *Journal
	err := c.fetch(ctx, urls.Journal(int64(id)), func(doc *goquery.Document) error {
		j, err := parseJournal(id, doc)
		if err != nil {
			return err
		}
		out = j
		return nil
	})
	if err != nil {
		return nil, err
	}
	return out, nil
}

// UserJournals iterates a user's journals across pages. The iterator yields
// each [Journal] preview (full body included on FA's listing page).
//
// Use [ListOptions.MaxPages] to bound the crawl.
func (c *Client) UserJournals(ctx context.Context, name string, opts ListOptions) iter.Seq2[*Journal, error] {
	return func(yield func(*Journal, error) bool) {
		page := opts.firstPage()
		pagesFetched := 0
		for {
			if opts.reachedLimit(pagesFetched) {
				return
			}
			var (
				items   []*Journal
				hasNext bool
			)
			err := c.fetch(ctx, urls.UserJournals(name, page), func(doc *goquery.Document) error {
				items, hasNext = parseUserJournalsPage(doc)
				return nil
			})
			if err != nil {
				yield(nil, err)
				return
			}
			pagesFetched++
			for _, j := range items {
				if !yield(j, nil) {
					return
				}
			}
			if !hasNext {
				return
			}
			page++
		}
	}
}