package app

import (
	"io"
	"net/http"
	"time"

	"go.balki.me/tss/log"
	"go.balki.me/tss/proxy"
	"go.balki.me/tss/telegram"
)

func Run(configPath string) {
	cfg, err := ParseConfig(configPath)

	if err != nil {
		log.Panic("failed to parse config", "path", configPath, "err", err)
	}

	scheduler, err := NewScheduler(cfg.LastSuccessPath)
	if err != nil {
		log.Panic("failed to create scheduler", "path", cfg.LastSuccessPath, "error", err)
	}

	defer func() {
		if err := scheduler.Save(); err != nil {
			log.Panic("failed to save last success info", "path", cfg.LastSuccessPath, "err", err)
		}
	}()

	tgramProxy, err := proxy.GetTransport(cfg.TelegramProxy)
	if err != nil {
		log.Panic("failed to get proxy transport", "proxyURL", cfg.TelegramProxy, "error", err)
	}

	tgram := telegram.NewTelegramSender(tgramProxy, cfg.TelegramAuthToken)

	for _, feed := range cfg.Feeds {
		log.Info("processing feed", "feed", feed.Name)
		ProcessFeed(feed, scheduler, cfg.DbDir, tgram)
	}
}

func ProcessFeed(feed FeedCfg, scheduler *Scheduler, dbDir string, tgram telegram.TelegramSender) {
	sd, err := scheduler.ShouldDownload(feed.Name, feed.Cron)
	if err != nil {
		log.Error("shouldDownload failed", "feed", feed.Name, "err", err)
		return
	}

	if !sd {
		log.Info("skipping feed due to schedule", "feed", feed.Name)
		return
	}

	db, err := NewDB(dbDir, feed.Name)
	if err != nil {
		log.Error("failed to get db", "feed", feed.Name, "db_dir", dbDir, "error", err)
		return
	}

	data, err := Download(feed.Url, feed.Proxy)
	if err != nil {
		log.Error("download failed", "feed", feed.Name, "url", feed.Url, "proxy", feed.Proxy, "error", err)
		return
	}

	entries, err := ParseFeed(data)
	if err != nil {
		log.Error("feed parsing failed", "feed", feed.Name, "data", data, "error", err)
		return
	}

	filteredEntries, err := db.Filter(entries)
	if err != nil {
		log.Error("failed to filter entries", "feed", feed.Name, "error", err)
	}

	var records []Record
	for _, entry := range filteredEntries {
		now := time.Now()
		r := Record{
			Time:      now,
			FeedEntry: entry,
		}
		err := tgram.SendLink(entry.Link, feed.Channel, feed.Rhash)
		if err != nil {
			log.Error("failed to send to telegram", "feed", feed.Name, "link", entry.Link, "channel", feed.Channel, "rhash", feed.Rhash, "error", err)
			r.Status = Error
		} else {
			r.Status = Sent
		}
		records = append(records, r)
	}
	err = db.Save(records)
	if err != nil {
		log.Error("failed to save sent records", "feed", feed.Name, "num_records", len(records), "error", err)
	}
}

func Download(url string, proxyUrl string) ([]byte, error) {
	transport, err := proxy.GetTransport(proxyUrl)
	if err != nil {
		return nil, err
	}
	client := &http.Client{Transport: transport}
	res, err := client.Get(url)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()
	return io.ReadAll(res.Body)
}