package main

import (
	"encoding/xml"
	"fmt"
	"log"
	"net/http"
	"time"
)

type Item struct {
	Guid        string  `xml:"guid"`
	Title       string  `xml:"title"`
	Link        string  `xml:"link"`
	Description string  `xml:"description"`
	PubDate     RssDate `xml:"pubDate"`
}

type Channel struct {
	Title         string  `xml:"title"`
	Description   string  `xml:"description"`
	Link          string  `xml:"link"`
	Items         []Item  `xml:"item"`
	LastBuildDate RssDate `xml:"lastBuildDate"`
}

type Rss struct {
	Channel Channel `xml:"channel"`
}

type RssDate struct {
	time.Time
}

func (c *RssDate) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
	var v string
	dateFormat := "Mon, 02 Jan 2006 15:04:05 GMT"
	d.DecodeElement(&v, &start)
	parse, err := time.Parse(dateFormat, v)
	if err != nil {
		return err
	}
	*c = RssDate{parse}
	return nil
}

var (
	StackerNewsRssFeedUrl = "https://stacker.news/rss"
)

func FetchStackerNewsRssFeed() (*Rss, error) {
	resp, err := http.Get(StackerNewsRssFeedUrl)
	if err != nil {
		err = fmt.Errorf("error fetching RSS feed: %w\n", err)
		log.Println(err)
		return nil, err
	}
	defer resp.Body.Close()

	var rss Rss
	err = xml.NewDecoder(resp.Body).Decode(&rss)
	if err != nil {
		err = fmt.Errorf("error decoding RSS feed XML: %w\n", err)
		return nil, err
	}

	return &rss, nil

}