From d1d2f73b4fb125362266168a9710e3b1e4700e87 Mon Sep 17 00:00:00 2001
From: Mikhail Klementyev <jollheef@riseup.net>
Date: Fri, 22 Jul 2016 15:43:23 +0300
Subject: [PATCH] Implements link walking

---
 main.go            | 83 +++++++++++++++++++++++++++++++++++++++++-----
 storage/storage.go | 55 ++++++++++++++++++++++++++++++
 2 files changed, 130 insertions(+), 8 deletions(-)
 create mode 100644 storage/storage.go

diff --git a/main.go b/main.go
index 5464c2b..d1f2db6 100644
--- a/main.go
+++ b/main.go
@@ -9,27 +9,32 @@
 package main
 
 import (
+	"bytes"
+	"database/sql"
+	"strings"
+
 	"fmt"
 	"io/ioutil"
 	"log"
 	"net/http"
 
+	"./storage"
+
 	"github.com/jaytaylor/html2text"
+	"golang.org/x/net/html"
 	"golang.org/x/net/html/charset"
 	kingpin "gopkg.in/alecthomas/kingpin.v2"
 )
 
 var (
-	url = kingpin.Flag("url", "Url").String()
+	arg_url  = kingpin.Flag("url", "Url").String()
+	arg_link = kingpin.Flag("link", "Link").Int()
 )
 
-func main() {
-
-	kingpin.Parse()
-
+func cmd_url(db *sql.DB, url string) {
 	client := &http.Client{}
 
-	req, err := http.NewRequest("GET", *url, nil)
+	req, err := http.NewRequest("GET", url, nil)
 	if err != nil {
 		log.Fatalln(err)
 	}
@@ -55,10 +60,72 @@ func main() {
 		return
 	}
 
-	text, err := html2text.FromString(string(body))
+	htmlPage := string(body)
+
+	z := html.NewTokenizer(bytes.NewReader(body))
+
+	for {
+		tt := z.Next()
+		if tt == html.ErrorToken {
+			break
+		}
+
+		for {
+			key, value, moreAttr := z.TagAttr()
+
+			if string(key) == "href" {
+
+				url, err := req.URL.Parse(string(value))
+				if err != nil {
+					panic(err)
+				}
+
+				linkNo, err := storage.AddLink(db, url.String())
+				if err != nil {
+					panic(err)
+				}
+
+				for _, s := range []string{string(value), html.EscapeString(string(value))} {
+					htmlPage = strings.Replace(htmlPage, "\""+s+"\"",
+						"\""+fmt.Sprintf("%d", linkNo)+"\"", -1)
+				}
+			}
+
+			if !moreAttr {
+				break
+			}
+		}
+	}
+
+	text, err := html2text.FromString(htmlPage)
+	if err != nil {
+		panic(err)
+	}
+	text += ""
+
+	fmt.Println(text)
+}
+
+func cmd_link(db *sql.DB, linkID int) {
+	url, err := storage.GetLink(db, linkID)
 	if err != nil {
 		panic(err)
 	}
 
-	fmt.Println(text)
+	cmd_url(db, url)
+}
+
+func main() {
+	db, err := storage.OpenDB("/tmp/wi.db")
+	if err != nil {
+		panic(err)
+	}
+
+	kingpin.Parse()
+
+	if *arg_url != "" {
+		cmd_url(db, *arg_url)
+	} else if *arg_link != 0 {
+		cmd_link(db, *arg_link)
+	}
 }
diff --git a/storage/storage.go b/storage/storage.go
new file mode 100644
index 0000000..b8819df
--- /dev/null
+++ b/storage/storage.go
@@ -0,0 +1,55 @@
+/**
+ * @file storage.go
+ * @author Mikhail Klementyev jollheef<AT>riseup.net
+ * @license GNU GPLv3
+ * @date July, 2016
+ */
+
+package storage
+
+import (
+	"database/sql"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+func OpenDB(path string) (db *sql.DB, err error) {
+	db, err = sql.Open("sqlite3", path)
+	if err != nil {
+		return
+	}
+
+	_, err = db.Exec("CREATE TABLE IF NOT EXISTS `links` " +
+		"( `id` INTEGER PRIMARY KEY AUTOINCREMENT, `url` TEXT );")
+
+	return
+}
+
+func AddLink(db *sql.DB, url string) (linkNo int64, err error) {
+	stmt, err := db.Prepare("INSERT INTO `links` (`url`) VALUES ($1);")
+	if err != nil {
+		return
+	}
+	defer stmt.Close()
+
+	r, err := stmt.Exec(url)
+	if err != nil {
+		return
+	}
+
+	linkNo, err = r.LastInsertId()
+
+	return
+}
+
+func GetLink(db *sql.DB, linkID int) (url string, err error) {
+	stmt, err := db.Prepare("SELECT `url` FROM `links` WHERE id=$1;")
+	if err != nil {
+		return
+	}
+	defer stmt.Close()
+
+	err = stmt.QueryRow(linkID).Scan(&url)
+
+	return
+}