itunes-vip-convert/convert.go

package main

import (
	"fmt"
	"strings"
	"strconv"
	"os"
	"bufio"
	"time"

	"github.com/beevik/etree"
)

func main() {

	// media locations to be replaced
	itunes_media := "file://localhost/Z:/Music/usb/" // original location
	web_media := "https://dtam.pw/music/tracks/" // final web location

	// playlist length counter
	playlist_length := 0

	// temporary variables to set up and gather information
	// next: will toggle so we know on the next loop to save information
	name_next := false
	artist_next := false
	location_next := false
	id_next := false
	// temp: temporarily store the song information before we insert it into our array
	name_temp := ""
	artist_temp := ""
	location_temp := ""
	id_temp := ""

	// struct containing a single song and it's information
	type Song_Information struct {
		name string
		artist string
		location string
		id string
	}

	// array of the playlist, but only it's ID. when we initially parse the xml,
	// it only gives us the playlist in ID form
	var playlist_tracks []string

	// array of the songs, but not in the correct order
	var songlist []Song_Information

	// array of the songs, in the correct order
	var playlist []Song_Information

	// import the playlist
	doc := etree.NewDocument()
	if err := doc.ReadFromFile("main.xml");  err != nil {
		panic(err)
	}

	// find the playlist in it's ID form
	for _, e := range doc.FindElements("./plist/dict/array/dict/array/dict/integer") {
		// add track to playlist
		playlist_tracks = append(playlist_tracks, e.Text())
	}

	// get the length of the playlist
	for _, e := range doc.FindElements("./plist/dict/dict/*") {
		_ = e
		playlist_length += 1
	}

	// cycle through the playlist and grab the song information
	for i := 0; i < (playlist_length/2)+1; i++ {
		// based on how the xml is formatted from itunes, it has 2 separate elements for each
		// key, so we need to mark when we find the key we need and say the next item is the item
		for _, e := range doc.FindElements("./plist/dict/dict/dict[" + strconv.Itoa(i) + "]/*") {

			// if we find an element with the name "Name", we know the next element is the actual
			// name, so mark it so that we know next loop to store it
			if(e.Text() == "Name") {
				name_next = true
				continue
			}

			if(e.Text() == "Artist") {
				artist_next = true
				continue
			}

			if(e.Text() == "Location") {
				location_next = true
				continue
			}

			if(e.Text() == "Track ID") {
				id_next = true
				continue
			}

			// once we have determined that this should be the information, save it
			// to a temporary variable
			if(name_next) {
				name_temp = e.Text()
				name_temp = strings.Replace(name_temp, "&", "&amp;", 5) // make the ampersand xml safe
				name_next = false
				continue
			}

			if(artist_next) {
				artist_temp = e.Text()
				artist_temp = strings.Replace(artist_temp, "&", "&amp;", 5)
				artist_next = false
				continue
			}

			if(location_next) {
				location_temp = e.Text()
				// replace the file name link with the web link
				location_temp = strings.Replace(location_temp, itunes_media, web_media, 1)
				location_temp = strings.Replace(location_temp, "&", "&amp;", 5)
				location_next = false
				continue
			}

			if(id_next) {
				id_temp = e.Text()
				id_next = false
				continue
			}

			// once we have found all the information we need, put it into a struct and append it
			// to our unordered array of songs
			if(name_temp != "" && artist_temp != "" && location_temp != "" && id_temp != "") {

				songlist = append(songlist, Song_Information{name_temp, artist_temp, location_temp, id_temp})
				name_temp = "" // clear our variables again
				artist_temp = ""
				location_temp = ""
				id_temp = ""
				continue
			}
		}
	}

	// put our tracks in the appropriate order based on the playlist
	for _, e := range playlist_tracks {
		// loop through our unordered array and find the correct song
		for _, f := range songlist {
			if(f.id == e) {
				// add the correct song to the final playlist
				playlist = append(playlist, Song_Information{f.name, f.artist, f.location, f.id})
				break
			}
		}
	}

	//  at this point, our playlist should be sorted

	// get date
	currentTime := time.Now()

	// create the xml file
	file, err := os.OpenFile("main_parsed.xml", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil {
		panic(err)
	}

	// write the initial information for the xml
	w := bufio.NewWriter(file)
	fmt.Fprintln(w, `<?xml version="1.0" encoding="UTF-8"?>`)
	fmt.Fprintln(w, `<playlist xmlns="https://xspf.org/ns/0/" version="1">`)
	fmt.Fprintln(w, "<tracklist>")

	// print out information at the header
	fmt.Fprintln(w, "<track>")
	fmt.Fprintln(w, "<creator>dtam playlist</creator>")
	fmt.Fprintln(w, "<title>" + strconv.Itoa(len(playlist_tracks)) + " tracks (Last updated: " + currentTime.Format("Jan 02, 2006") + ")</title>")
	fmt.Fprintln(w, "<location>https://dtam.pw/music/empty.m4a</location>")
	fmt.Fprintln(w, "</track>")

	// cycle through our ordered playlist and write it to the file
	for _, e := range playlist {
		fmt.Fprintln(w, "<track>")
		fmt.Fprintln(w, "<creator>" + e.artist + "</creator>")
		fmt.Fprintln(w, "<title>" + e.name + "</title>")
		fmt.Fprintln(w, "<location>" + e.location+ "</location>")
		fmt.Fprintln(w, "</track>")
	}

	// closing information
	fmt.Fprintln(w, "</tracklist>")
	fmt.Fprintln(w, "</playlist>")

	// write it out
	w.Flush()

}