package videostream

import (
	"context"
	"database/sql"
	"log"
	"strconv"

	appbsky "github.com/bluesky-social/indigo/api/bsky"
	"github.com/edavis/bsky-feeds/pkg/feeds"
	_ "github.com/mattn/go-sqlite3"
)

type PostRow struct {
	Uri string
}

func getPosts(ctx context.Context, dbCnx *sql.DB, limit, offset int) ([]PostRow, error) {
	rows, err := dbCnx.QueryContext(ctx, `select uri from posts where create_ts < unixepoch('now', '-2 minutes') order by create_ts desc limit ? offset ?`, limit, offset)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var posts []PostRow
	for rows.Next() {
		var post PostRow
		if err := rows.Scan(&post.Uri); err != nil {
			return nil, err
		}
		posts = append(posts, post)
	}
	return posts, nil
}

func Feed(params feeds.FeedgenParams) appbsky.FeedGetFeedSkeleton_Output {
	ctx := context.Background()
	dbCnx, err := sql.Open("sqlite3", "data/videostream.db?_journal=WAL&_fk=on")
	if err != nil {
		log.Printf("error opening db: %v\n", err)
	}
	defer dbCnx.Close()

	offset := 0
	if params.Cursor != "" {
		if parsed, err := strconv.Atoi(params.Cursor); err == nil {
			offset = parsed
		} else {
			log.Printf("error converting cursor: %v\n", err)
		}
	}

	rows, err := getPosts(ctx, dbCnx, params.Limit, offset)
	if err != nil {
		log.Printf("error fetching rows: %v\n", err)
	}

	var cursor string
	posts := make([]*appbsky.FeedDefs_SkeletonFeedPost, 0, params.Limit)

	for _, row := range rows {
		posts = append(posts, &appbsky.FeedDefs_SkeletonFeedPost{Post: row.Uri})
	}

	skeleton := appbsky.FeedGetFeedSkeleton_Output{
		Feed: posts,
	}

	offset += len(posts)
	cursor = strconv.Itoa(offset)

	if len(posts) == params.Limit {
		skeleton.Cursor = &cursor
	}

	return skeleton
}