package rss

import (
	"errors"
	"local/rssmon3/config"
	"log"
	"net/http"
	"regexp"
	"time"

	"github.com/mmcdole/gofeed"
)

const NSFeeds = "NSFeeds"

type Feed struct {
	Key           string
	URL           string
	Updated       time.Time
	TitleFilter   string
	ContentFilter string
	Tags          []string
}

func newFeed(key string) *Feed {
	return &Feed{
		Key: key,
	}
}

func (f *Feed) Encode() ([]byte, error) {
	return config.Encode(f)
}

func (f *Feed) Decode(b []byte) error {
	return config.Decode(b, f)
}

func (f *Feed) load() error {
	if f.Key == "" {
		return errors.New("cannot load nil feed")
	}
	db := config.Values().DB
	b, err := db.Get(f.Key, NSFeeds)
	if err != nil {
		return err
	}
	return f.Decode(b)
}

func (f *Feed) pull() error {
	if f.URL == "" {
		if err := f.load(); err != nil {
			return err
		}
	}
	resp, err := http.Get(f.URL)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	gofeed, err := gofeed.NewParser().Parse(resp.Body)
	if err != nil {
		return err
	}

	itemTSs := []*time.Time{}
	for _, i := range gofeed.Items {
		item, err := newItem(i, f.ContentFilter)
		if err != nil {
			log.Println(err)
			continue
		}
		itemTSs = append(itemTSs, &item.TS)
		if item.TS.Before(f.Updated) {
			log.Println("Skipping old item")
			continue
		}
		if ok := regexp.MustCompile(f.TitleFilter).MatchString(item.Title); !ok {
			log.Println("Skipping bad titled item")
			continue
		}
		if err := item.save(); err != nil {
			log.Println(err)
			continue
		}
	}

	f.Updated = latestTSPtr(gofeed.PublishedParsed, gofeed.UpdatedParsed)
	f.Updated = latestTSPtr(append(itemTSs, &f.Updated)...)
	return nil
}

func (f *Feed) save() error {
	b, err := f.Encode()
	if err != nil {
		return err
	}
	db := config.Values().DB
	return db.Set(f.Key, b, NSFeeds)
}

func latestTSPtr(times ...*time.Time) time.Time {
	var t time.Time
	for i := range times {
		if times[i] == nil {
			continue
		}
		if times[i].After(t) {
			t = *times[i]
		}
	}
	return t
}