package main

import (
	"context"
	"database/sql"
	"log"
	"strings"
	"sync"
	"time"

	"git.rpuzonas.com/rpuzonas/go-rss-aggregator/internal/database"
)

func startScraping(
	db *database.Queries,
	concurrency int,
	timeBetweenRequests time.Duration,
) {
	log.Printf("Scraping on %v goroutines every %s duration", concurrency, timeBetweenRequests)

	ticker := time.NewTicker(timeBetweenRequests)
	for ; ; <-ticker.C {
		feeds, err := db.GetNextFeedToFetch(context.Background(), int64(concurrency))
		if err != nil {
			log.Println("Error fetching feeds:", err)
			continue
		}

		wg := sync.WaitGroup{}
		for _, feed := range feeds {
			wg.Add(1)
			go scrapeFeed(&wg, db, feed)
		}
		wg.Wait()
	}
}

func scrapeFeed(wg *sync.WaitGroup, db *database.Queries, feed database.Feed) {
	defer wg.Done()

	ctx := context.Background()

	_, err := db.MarkFeedAsFetched(ctx, feed.ID)
	if err != nil {
		log.Println("Error makrking feed as fetched:", err)
		return
	}

	rssFeed, err := urlToFeed(feed.Url)
	if err != nil {
		log.Println("Error fetching feed:", err)
		return
	}

	for _, item := range rssFeed.Channel.Items {
		description := sql.NullString{}
		if item.Description != "" {
			description.String = item.Description
			description.Valid = true
		}

		publishedAt, err := time.Parse(time.RFC1123Z, item.PubDate)
		if err != nil {
			log.Printf("Couldn't parse date %v with err %v\n", item.PubDate, err)
			continue
		}

		now := time.Now().UTC()
		_, err = db.CreatePost(ctx, database.CreatePostParams{
			UpdatedAt:   now,
			CreatedAt:   now,
			Title:       item.Title,
			Description: description,
			PublishedAt: publishedAt,
			Url:         item.Link,
			FeedID:      feed.ID,
		})
		if err != nil {
			if strings.Contains(err.Error(), "UNIQUE constraint failed: posts.url") {
				continue
			}
			log.Println("Failed to add post:", err)
		}
	}
	log.Printf("Feed %s collected, %v posts found", feed.Name, len(rssFeed.Channel.Items))
}