part 2

5 files changed, 230 insertions, 0 deletions

diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..24d3d61
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,5 @@
+module main_server.go
+
+go 1.24.4
+
+require github.com/mattn/go-sqlite3 v1.14.28 // indirect
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..42e5bac
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,2 @@
+github.com/mattn/go-sqlite3 v1.14.28 h1:ThEiQrnbtumT+QMknw63Befp/ce/nUPgBPMlRFEum7A=
+github.com/mattn/go-sqlite3 v1.14.28/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
diff --git a/main_server.go b/main_server.go
new file mode 100644
index 0000000..ea41ce8
--- /dev/null
+++ b/main_server.go
@@ -0,0 +1,173 @@
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	"log"
+	"crypto/md5"
+	"strings"
+	"net"
+	"encoding/json"
+	_ "github.com/mattn/go-sqlite3"
+)
+
+type Data struct {
+	Type int `json:"type"`
+	URL string `json:"url"`
+}
+
+var DB *sql.DB
+func init_DB() {
+	var err error;
+	DB, err = sql.Open("sqlite3", "./app.db");
+	if err != nil {
+		log.Fatal(err);
+	}
+
+	sql_q := `
+		CREATE TABLE IF NOT EXISTS urls (
+			id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
+			url TEXT NOT NULL,
+			short TEXT NOT NULL UNIQUE
+		)`;
+
+	_, err = DB.Exec(sql_q);
+	if err != nil {
+		log.Fatal(err);
+	}
+}
+
+var units = [16]string{"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};
+func gen_hash(url string) string{
+	data := []byte(url);
+	hash := md5.Sum(data);
+	var ret string;
+	for i := 0; i < 3; i++ {
+		ret = ret + units[hash[i] / 16];
+		ret = ret + units[hash[i] % 16];
+	}
+	return ret;
+}
+
+func correct_url(url string) string {
+	if(len(url) <= 7) {
+		return "https://" + url;
+	}
+	if(url[:8] != "https://") {
+		return "https://" + url;
+	}
+	return url;
+}
+
+func add_url(url string) {
+	hurl := correct_url(url);
+	hsh  := gen_hash(hurl);
+	fmt.Printf("adding: %s -> %s \n", hurl, hsh);
+	_, err := DB.Exec("INSERT INTO urls (url, short) VALUES (?, ?)", hurl, hsh);
+	if err != nil {
+		var ok bool;
+		ok = false;
+		tmp := strings.Split(err.Error(), " ");
+		for i := 0; i < len(tmp); i++ {
+			if tmp[i] == "UNIQUE" {
+				ok = true;
+				break;
+			}
+		}
+		if ok{
+			fmt.Println("hash ja existe na tabela: Deletando valor antigo...");
+			_, err := DB.Exec("DELETE FROM urls WHERE short = ?", hsh);
+			if err != nil {
+				log.Fatal(err);
+			}
+
+			fmt.Println("Adicionando...");
+			_, err = DB.Exec("INSERT INTO urls (url, short) VALUES (?, ?)", hurl, hsh);
+			if err != nil {
+				log.Fatal(err);
+			}
+		}else{
+			log.Fatal(err);
+		}
+	}
+}
+
+func get_hash_from_db(hash string) string{
+	rows, err := DB.Query("SELECT url FROM urls WHERE short = ?", hash);
+	if err != nil {
+		log.Fatal(err);
+	}
+	defer rows.Close();
+
+	var url string;
+	for rows.Next() {
+		err = rows.Scan(&url);
+		if err != nil {
+			log.Fatal(err);
+		}
+		fmt.Println(url);
+	}
+	return url;
+}
+
+func read_json(cont []byte) (Data, error) {
+	var data Data;
+	err := json.Unmarshal(cont, &data);
+	if err != nil {
+		return data, err;
+	}
+
+	return data, nil;
+}
+
+func handle_request(conn net.Conn, data Data) {
+	if data.Type == 1 {
+		add_url(data.URL);
+	}else if data.Type == 2 {
+		ret := get_hash_from_db(data.URL);
+		conn.Write([]byte(fmt.Sprintf("%s\n", ret)));
+	}else {
+	}
+}
+func handle_client(conn net.Conn){
+	defer conn.Close();
+
+	buffer := make([]byte, 1024);
+	for {
+		n, err := conn.Read(buffer);
+		if err != nil {
+			log.Println(err);
+			return;
+		}
+		fmt.Printf("Recebido: %s\n", buffer[:n]);
+		data, err := read_json(buffer[:n]);
+		if err != nil {
+			log.Println(err);
+		}else {
+			handle_request(conn, data);
+		}
+	}
+}
+
+func main() {
+	init_DB();
+	/*add_url("google.com");
+	get_hash_from_db("99999e");*/
+	ln, err := net.Listen("tcp", "localhost:5555");
+	defer ln.Close();
+	fmt.Println("Listen on port 5555");
+	if err != nil {
+		log.Fatal(err);
+	}
+	
+	for {
+		conn, err := ln.Accept();
+		if err != nil {
+			log.Println(err);
+			continue;
+		}
+		fmt.Println("New connection accepted");
+		go handle_client(conn);
+
+	}
+}
diff --git a/web_server/go.mod b/web_server/go.mod
new file mode 100644
index 0000000..88f4151
--- /dev/null
+++ b/web_server/go.mod
@@ -0,0 +1,3 @@
+module web_server.go
+
+go 1.24.4
diff --git a/web_server/web_server.go b/web_server/web_server.go
new file mode 100644
index 0000000..7f1201c
--- /dev/null
+++ b/web_server/web_server.go
@@ -0,0 +1,47 @@
+package main
+
+import (
+	 "fmt"
+	 "log"
+    "net/http"
+	 "strings"
+	 "net"
+	 "bufio"
+)
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+	w.Header().Set("Expires", "0")
+
+	tmp := strings.Split(r.URL.Path, "/");
+	fmt.Println(tmp);
+	if len(tmp[1]) == 6 {
+		s := tmp[1];
+		fmt.Println(tmp[1]);
+		conn, err := net.Dial("tcp", "localhost:5555");
+		if err != nil {
+			log.Fatal(err);
+		}
+
+		fmt.Println(s);
+		fmt.Fprintf(conn, "{\"type\": 2, \"url\": \"%s\"}", s);
+		res, _ := bufio.NewReader(conn).ReadBytes('\n');
+		fmt.Println(string(res));
+		http.Redirect(w, r, string(res), http.StatusPermanentRedirect);
+
+	}else{
+		//fmt.Fprintf(w, "oi", r.URL.Path[1:]);
+	}
+}
+
+func main() {
+//	page := &Page{Title: "Redirect", Body: []byte("Redirecting...")};
+	fmt.Println("Port 5556");
+	server := &http.Server{
+		Addr: "localhost:5556",
+		Handler: http.HandlerFunc(handler),
+	};
+	server.SetKeepAlivesEnabled(false);
+	//http.HandleFunc("/", handler);
+	log.Fatal(server.ListenAndServe());
+}