package main

import (
	"github.com/jbowtie/gokogiri"
	"github.com/pebbe/util"

	"encoding/xml"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"os"
	"strings"
	"time"
)

type Rss struct {
	XMLName xml.Name `xml:"rss"`
	Items   []ItemT  `xml:"channel>item"`
}

type ItemT struct {
	Title    string `xml:"title"`
	PubDate  string `xml:"pubDate"`
	UnixTime int64  `xml:"unixTime"`
	Guid     string `xml:"guid"`
	Link     string `xml:"link"`
	Data     []byte `xml:",innerxml"`
}

var (
	x = util.CheckErr
	w = util.WarnErr
	//	agent = "AhrefsBot/7.0"
	agent = "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36"
)

func exists(filename string) bool {
	_, err := os.Stat(filename)
	return err == nil
}

func fileDate(filename string) string {
	b, err := os.ReadFile(filename)
	if err != nil {
		return ""
	}
	s := string(b)
	i1 := strings.Index(s, "<unixTime>") + 10
	i2 := strings.Index(s, "</unixTime>")
	return s[i1:i2]
}

func main() {
	req, err := http.NewRequest("GET", "https://gemeente.groningen.nl/feed/rss/nieuws", nil)
	x(err)
	req.Header.Set("User-Agent", agent)

	client := &http.Client{}
	resp, err := client.Do(req)
	x(err)
	body, err := io.ReadAll(resp.Body)
	x(err)
	x(resp.Body.Close())

	var rss Rss
	x(xml.Unmarshal(body, &rss))

	if len(rss.Items) == 0 {
		x(fmt.Errorf("len(rss.Items) == 0"))
	}

	for _, item := range rss.Items {
		t, err := time.Parse(time.RFC1123Z, item.PubDate)
		if err != nil {
			t, err = time.Parse(time.RFC1123, item.PubDate)
		}
		x(err)
		year, week := t.ISOWeek()
		dirname := fmt.Sprintf("/net/corpora/nlnieuws/GG/%d/%02d", year, week)
		if exists(dirname + "/lock") {
			continue
		}
		filename := dirname + "/" + url.PathEscape(item.Guid)

		ts := fmt.Sprintf("%d", t.Unix())
		needUpdate := fileDate(filename+".xml") != ts

		x(os.MkdirAll(dirname, 0777))
		fp, err := os.Create(filename + ".xml")
		x(err)
		_, err = fp.WriteString("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<item>\n")
		x(err)
		_, err = fmt.Fprintf(fp, "<unixTime>%d</unixTime>", t.Unix())
		x(err)
		_, err = fp.Write(item.Data)
		x(err)
		_, err = fp.WriteString("</item>\n")
		x(err)
		x(fp.Close())
		x(os.Chtimes(filename+".xml", t, t))
		if !doArticle(filename, item.Link, item.Title, t, needUpdate) {
			x(os.Remove(filename + ".xml"))
		}
	}
}

func doArticle(filename string, url string, title string, timestamp time.Time, needUpdate bool) bool {
	if needUpdate {
		_ = os.Remove(filename + ".err")
		_ = os.Remove(filename + ".html")
		_ = os.Remove(filename + ".txt")
		_ = os.Remove(filename + ".skip")
	} else {
		if exists(filename+".txt") || exists(filename+".skip") {
			return true
		}
	}
	time.Sleep(2 * time.Second)

	req, err := http.NewRequest("GET", url, nil)
	x(err)
	req.Header.Set("User-Agent", agent)

	client := &http.Client{}
	resp, err := client.Do(req)
	x(err)
	body, err := io.ReadAll(resp.Body)
	x(err)
	x(resp.Body.Close())

	doc, err := gokogiri.ParseHtml(body)
	x(err)

	root := doc.Root()

	ell, err := root.Search(
		`//div[contains(@class,"component-richtext")]/p` +
			` | ` +
			`//div[contains(@class,"component-richtext")]/h2`)
	x(err)
	if len(ell) == 0 {
		_ = w(fmt.Errorf("empty: %s", url))

		fp, err := os.Create(filename + ".err")
		x(err)
		_, err = fmt.Fprintf(fp, "empty: %s\n", url)
		x(err)
		x(fp.Close())
		x(os.Chtimes(filename+".err", timestamp, timestamp))

		fp, err = os.Create(filename + ".html")
		x(err)
		_, err = fp.Write(body)
		x(err)
		x(fp.Close())
		x(os.Chtimes(filename+".html", timestamp, timestamp))

		return false
	}

	fp, err := os.Create(filename + ".txt")
	x(err)

	_, err = fp.WriteString(addEnd(fixSpace(title)))
	x(err)

	for _, el := range ell {
		_, err = fp.WriteString(addEnd(fixSpace(el.Content())))
		x(err)
	}

	x(fp.Close())

	x(os.Chtimes(filename+".txt", timestamp, timestamp))

	return true
}

func addEnd(s string) string {
	s = strings.TrimSpace(s)
	n := len(s)
	if n == 0 {
		return ""
	}
	if n > 0 {
		if strings.ContainsAny(s[n-1:], ".!?") {
			return s + "\n"
		}
	}
	if n > 1 {
		s2 := s[n-2:]
		if s2 == `."` || s2 == `!"` || s2 == `?"` || s2 == `.'` || s2 == `!'` || s2 == `?'` {
			return s + "\n"
		}
	}
	return s + ".\n"
}

func fixSpace(s string) string {
	return strings.Join(strings.Fields(s), " ")
}