Initial commit

1 files changed, 188 insertions, 0 deletions

diff --git a/ytparser.go b/ytparser.go
new file mode 100644
index 0000000..1ebd783
--- /dev/null
+++ b/ytparser.go
@@ -0,0 +1,188 @@
+package ytparser
+
+import (
+	"text/template"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"bytes"
+	"os"
+	"io"
+	"io/ioutil"
+	"strings"
+	"net/url"
+	"regexp"
+)
+
+const windowInitDataString string = "window[\"ytInitialData\"] = "
+const initDataString string = "var ytInitialData = "
+const baseUrl string = "https://youtube.com"
+
+type Item struct {
+	Id    string
+	Title string
+	Url   string
+	Thumb string
+	ChannelTitle string
+	ChannelUrl string
+	Published string
+}
+
+func (item Item) Format(t *template.Template) string {
+	var b strings.Builder
+	err := t.Execute(&b, item)
+	if err != nil {
+		panic(err)
+	}
+	return b.String()
+}
+
+func (item Item) String() string {
+	return fmt.Sprintf("id: %s, title: %s, url: %s, thumb: %s", item.Id, item.Title, item.Url, item.Thumb)
+}
+
+func parsejson(data string) ([]Item, error) {
+	dec := json.NewDecoder(strings.NewReader(data))
+
+	depth := 0
+	isArray := false
+	isValue := false
+	var items []Item
+	var item Item
+	var names []string
+	nbItems := 0
+	for {
+		tok, err := dec.Token()
+		if err == io.EOF {
+			break
+		} else if err != nil {
+			return items, err
+		}
+
+		switch t := tok.(type) {
+		case json.Delim:
+			if t == '{' {
+				depth++
+			} else if t == '}' {
+				depth--
+				names = names[:depth]
+			}
+			isArray = t == '['
+			isValue = false
+		case string:
+			if !isArray {
+				if !isValue {
+					if t == "videoRenderer" {
+						if nbItems > 0 {
+							items = append(items, item)
+						}
+						item = Item{}
+						nbItems++
+					}
+					if depth > len(names) {
+						names = append(names, t)
+					} else {
+						names[depth - 1] = t
+					}
+					//fmt.Println(t, depth, len(names), names[depth - 1])
+					isValue = true
+				} else {
+					//fmt.Println(names[len(names) - 1])
+					if names[depth-1] == "videoId" {
+						item.Id = t
+						item.Url = fmt.Sprintf("https://youtube.com/watch?v=%s", t)
+					}
+					if depth >= 3 && names[depth-3] == "title" &&
+						names[depth-2] == "runs" &&
+						names[depth-1] == "text" {
+						item.Title = t
+					}
+					if depth >= 3 && names[depth-3] == "ownerText" &&
+						names[depth-2] == "runs" &&
+						names[depth-1] == "text" {
+						item.ChannelTitle = t
+					}
+					if depth >= 6 &&
+						names[depth-6] == "ownerText" &&
+						names[depth-5] == "runs" &&
+						names[depth-4] == "navigationEndpoint" &&
+						names[depth-3] == "commandMetadata" &&
+						names[depth-2] == "webCommandMetadata" &&
+						names[depth-1] == "url" {
+						item.ChannelUrl = baseUrl + t
+					}
+					if depth >= 4 &&
+						names[depth-4] == "videoRenderer" &&
+						names[depth-3] == "thumbnail" &&
+						names[depth-2] == "thumbnails" &&
+						names[depth-1] == "url" {
+							item.Thumb = t
+					}
+					if depth >= 3 &&
+						names[depth-3] == "videoRenderer" &&
+						names[depth-2] == "publishedTimeText" &&
+						names[depth-1] == "simpleText" {
+							item.Published = t
+					}
+					isValue = false
+				}
+			}
+		default:
+		}
+	}
+	return items, nil
+}
+
+func PrintItems(items []Item, format string) {
+	t := template.Must(template.New("items").Parse(format))
+	for _, i := range items {
+		fmt.Println(i.Format(t))
+	}
+}
+
+func request(query string, page int, lang string) (string, error) {
+	q := url.QueryEscape(query)
+	url := fmt.Sprintf("https://www.youtube.com/results?search_query=%s&page=%d&hl=%s", q, page, lang)
+	res, err := http.DefaultClient.Get(url)
+	if err != nil {
+		return "", err
+	}
+	body, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		return "", err
+	}
+	initString := windowInitDataString
+	idx := bytes.Index(body, []byte(windowInitDataString))
+	if idx == -1 {
+		initString = initDataString
+		idx = bytes.Index(body, []byte(initDataString))
+	}
+	idx += len(initString)
+	startData := body[idx:]
+	pattern := regexp.MustCompile(`; *\n`)
+	loc := pattern.FindIndex(startData)
+	startData = startData[:loc[0]]
+	return string(startData), nil
+}
+
+func isValidData(data string) bool {
+	return data != ""
+}
+
+func Search(query string, page int, lang string) ([]Item, error) {
+	if lang == "" {
+		lang = "en"
+	}
+	var data string = ""
+	var err error
+	for i := 1; i < 4 && !isValidData(data); i++ {
+		if i > 1 {
+			fmt.Fprintf(os.Stderr, "Yt data invalid, retrying (attempt %d)\n", i)
+		}
+		data, err = request(query, page, lang)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return parsejson(data)
+}