subscribe.go

package main

import (
	"bufio"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"strings"

	"github.com/mmcdole/gofeed"
)

func programDir() string {
	home, err := os.UserHomeDir()
	if err != nil {
		log.Fatal(err)
	}
	return home + "/.castd"
}

func subscribe(url string) {
	_, err := os.Stat(programDir())
	if os.IsNotExist(err) {
		err := os.MkdirAll(programDir(), os.ModePerm)
		if err != nil {
			log.Fatal(err)
		}
	}
	_, err = os.Stat(programDir() + "/feeds")
	if os.IsNotExist(err) {
		err := os.MkdirAll(programDir()+"/feeds", os.ModePerm)
		if err != nil {
			log.Fatal(err)
		}
	}
	fp := gofeed.NewParser()
	var urlstring string = strings.ReplaceAll(url, "\n", "")
	feed, err := fp.ParseURL(urlstring)
	if err != nil {
		log.Fatal(err)
	}
	writeSub(feed.Title, urlstring)
	cacheFeed(feed.Title, urlstring)
}

func updateFeed(name string) {
	fi, err := os.OpenFile(programDir()+"/subscribed.txt", os.O_RDONLY, 0644)
	if err != nil {
		log.Fatal(err)
	}

	url := "Not found"
	scanner := bufio.NewScanner(fi)
	for scanner.Scan() {
		fmt.Printf("print: %v\n", scanner.Text())
		if strings.Contains(scanner.Text(), strings.ReplaceAll(name, "\n", "")) {
			fmt.Printf("Match")
			url = strings.Split(scanner.Text(), ":")[1]
			break
		}
	}

	if url == "Not found" {
		return
	}

	cacheFeed(name, url)
}

func writeSub(name string, feedUrl string) {

	fi, err := os.OpenFile(programDir()+"/subscribed.txt", os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0644)
	if err != nil {
		log.Fatal(err)
	}

	if _, err = fi.WriteString(name + ":" + feedUrl + "\n"); err != nil {
		log.Fatal(err)
	}
}

func cacheFeed(name string, feedUrl string) {
	fi, err := os.OpenFile(programDir()+"/feeds/"+name+".rss", os.O_WRONLY|os.O_CREATE, os.ModePerm)
	if err != nil {
		log.Fatal(err)
	}

	response, err := http.Get(feedUrl) //use package "net/http"

	if err != nil {
		log.Fatal(err)
	}

	defer response.Body.Close()

	// Copy data from the response to standard output
	n, err := io.Copy(fi, response.Body) //use package "io" and "os"
	if err != nil {
		log.Fatal(err)
	}

	_ = n
}