add github login

main.go

@@ -2,6 +2,8 @@ package main
 
 import (
 	"context"
+	"encoding/json"
+	"fmt"
 	"html/template"
 	"net/http"
 	"net/url"
@@ -10,16 +12,38 @@ import (
 	"strings"
 	"systemdesigngame/internals/level"
 	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+	"github.com/joho/godotenv"
 )
 
+var jwtSecret []byte
+
 var tmpl = template.Must(template.ParseGlob("static/*.html"))
 
+type contextKey string
+
+const (
+	userIDKey     = contextKey("userID")
+	userLoginKey  = contextKey("userLogin")
+	userAvatarKey = contextKey("userAvatar")
+)
+
 func main() {
+	err := godotenv.Load()
+	if err != nil {
+		panic("failed to load .env")
+	}
+
+	jwtSecret = []byte(os.Getenv("JWT_SECRET"))
+
 	mux := http.NewServeMux()
 	mux.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("static"))))
 	mux.HandleFunc("/", index)
-	mux.HandleFunc("/game", game)
-	mux.HandleFunc("/play/", play)
+	mux.HandleFunc("/play/", requireAuth(play))
+	mux.HandleFunc("/login", loginHandler)
+	mux.HandleFunc("/callback", callbackHandler)
+
 	srv := &http.Server{
 		Addr:    ":8080",
 		Handler: mux,
@@ -35,7 +59,9 @@ func main() {
 	defer stop()
 
 	go func() {
-		srv.ListenAndServe()
+		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			fmt.Println("Server failed: " + err.Error())
+		}
 	}()
 
 	<-ctx.Done()
@@ -54,27 +80,16 @@ func index(w http.ResponseWriter, r *http.Request) {
 		Title: "Title",
 	}
 
-	tmpl.ExecuteTemplate(w, "index.html", data)
-}
-
-func game(w http.ResponseWriter, r *http.Request) {
-	var err error
-	levels, err := level.LoadLevels("data/levels.json")
-	if err != nil {
-		panic("failed to load levels: " + err.Error())
-	}
-
-	data := struct {
-		Levels []level.Level
-	}{
-		Levels: levels,
+	if err := tmpl.ExecuteTemplate(w, "index.html", data); err != nil {
+		http.Error(w, "Template Error", http.StatusInternalServerError)
 	}
-	tmpl.ExecuteTemplate(w, "game.html", data)
 }
 
 func play(w http.ResponseWriter, r *http.Request) {
 	levelName := r.URL.Path[len("/play/"):]
 	levelName, err := url.PathUnescape(levelName)
+	avatar := r.Context().Value(userAvatarKey).(string)
+	username := r.Context().Value(userLoginKey).(string)
 	if err != nil {
 		http.Error(w, "Invalid level name", http.StatusBadRequest)
 		return
@@ -87,12 +102,168 @@ func play(w http.ResponseWriter, r *http.Request) {
 	}
 	allLevels := level.AllLevels()
 	data := struct {
-		Levels []level.Level
-		Level  *level.Level
+		Levels   []level.Level
+		Level    *level.Level
+		Avatar   string
+		Username string
 	}{
-		Levels: allLevels,
-		Level:  lvl,
+		Levels:   allLevels,
+		Level:    lvl,
+		Avatar:   avatar,
+		Username: username,
 	}
 
 	tmpl.ExecuteTemplate(w, "game.html", data)
 }
+
+func loginHandler(w http.ResponseWriter, r *http.Request) {
+	cookie, err := r.Cookie("auth_token")
+	if err == nil {
+		token, err := jwt.Parse(cookie.Value, func(token *jwt.Token) (interface{}, error) {
+			return jwtSecret, nil
+		})
+
+		if err != nil && token.Valid {
+			http.Redirect(w, r, "/play", http.StatusFound)
+			return
+		}
+	}
+
+	clientId := os.Getenv("GITHUB_CLIENT_ID")
+	redirectURI := os.Getenv("GITHUB_CALLBACK")
+	scope := "read:user user:email"
+	url := fmt.Sprintf(
+		"https://github.com/login/oauth/authorize?client_id=%s&redirect_uri=%s&scope=%s",
+		clientId, url.QueryEscape(redirectURI),
+		url.QueryEscape(scope),
+	)
+	http.Redirect(w, r, url, http.StatusFound)
+}
+
+func callbackHandler(w http.ResponseWriter, r *http.Request) {
+	code := r.URL.Query().Get("code")
+	if code == "" {
+		http.Error(w, "No code in query", http.StatusBadRequest)
+		return
+	}
+
+	data := url.Values{}
+	data.Set("client_id", os.Getenv("GITHUB_CLIENT_ID"))
+	data.Set("client_secret", os.Getenv("GITHUB_CLIENT_SECRET"))
+	data.Set("code", code)
+
+	req, err := http.NewRequest("POST", "https://github.com/login/oauth/access_token", strings.NewReader(data.Encode()))
+	if err != nil {
+		http.Error(w, "Failed to create token request", http.StatusInternalServerError)
+		return
+	}
+
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req.Header.Set("Accept", "application/json")
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		http.Error(w, "Token exchange failed", http.StatusInternalServerError)
+		return
+	}
+
+	defer resp.Body.Close()
+
+	var tokenResp struct {
+		AccessToken string `json:"access_token"`
+	}
+
+	json.NewDecoder(resp.Body).Decode(&tokenResp)
+
+	// Use token to get user info
+	userReq, _ := http.NewRequest("GET", "https://api.github.com/user", nil)
+	userReq.Header.Set("Authorization", "Bearer "+tokenResp.AccessToken)
+
+	userResp, err := http.DefaultClient.Do(userReq)
+	if err != nil {
+		http.Error(w, "Failed to fetch user info", http.StatusInternalServerError)
+		return
+	}
+
+	defer userResp.Body.Close()
+
+	var userInfo struct {
+		Login     string `json:"login"`
+		ID        int    `json:"id"`
+		AvatarUrl string `json:"avatar_url"`
+	}
+
+	if err := json.NewDecoder(userResp.Body).Decode(&userInfo); err != nil {
+		http.Error(w, "Failed to parse user info", http.StatusInternalServerError)
+		return
+	}
+
+	// Generate JWT
+	fmt.Printf("generating jwt: %s, %s, %s\n", fmt.Sprintf("%d", userInfo.ID), userInfo.Login, userInfo.AvatarUrl)
+	jwtToken, err := generateJWT(fmt.Sprintf("%d", userInfo.ID), userInfo.Login, userInfo.AvatarUrl)
+	if err != nil {
+		http.Error(w, "Failed to generate token", http.StatusInternalServerError)
+		return
+	}
+
+	// Set JWT in cookie
+	http.SetCookie(w, &http.Cookie{
+		Name:     "auth_token",
+		Value:    jwtToken,
+		Path:     "/",
+		HttpOnly: true,
+		Secure:   true, // Set to true in production (HTTPS)
+	})
+
+	http.Redirect(w, r, "/play", http.StatusFound)
+}
+
+func generateJWT(userID string, login string, avatarUrl string) (string, error) {
+	claims := jwt.MapClaims{
+		"sub":    userID,
+		"login":  login,
+		"avatar": avatarUrl,
+		"exp":    time.Now().Add(24 * time.Hour).Unix(),
+		"iat":    time.Now().Unix(),
+	}
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	return token.SignedString(jwtSecret)
+}
+
+func requireAuth(next http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		cookie, err := r.Cookie("auth_token")
+		if err != nil {
+			http.Redirect(w, r, "/login", http.StatusFound)
+			return
+		}
+
+		token, err := jwt.Parse(cookie.Value, func(token *jwt.Token) (interface{}, error) {
+			return jwtSecret, nil
+		})
+
+		if err != nil || !token.Valid {
+			http.Redirect(w, r, "/login", http.StatusFound)
+			return
+		}
+
+		claims, ok := token.Claims.(jwt.MapClaims)
+		if !ok {
+			http.Redirect(w, r, "/login", http.StatusFound)
+			return
+		}
+
+		userID, ok1 := claims["sub"].(string)
+		login, ok2 := claims["login"].(string)
+		avatar, _ := claims["avatar"].(string)
+		if !ok1 || !ok2 {
+			http.Redirect(w, r, "/login", http.StatusFound)
+			return
+		}
+
+		ctx := context.WithValue(r.Context(), userIDKey, userID)
+		ctx = context.WithValue(ctx, userLoginKey, login)
+		ctx = context.WithValue(ctx, userAvatarKey, avatar)
+		next(w, r.WithContext(ctx))
+	}
+}

static/game.html

@@ -17,23 +17,18 @@
       --color-bg-hover: #2a2a2a;
       --color-bg-accent: #005f87;
       --color-bg-tab-active: #1a3d2a;
-
       --color-border: #444;
       --color-border-accent: #00ff88;
       --color-border-panel: #30363d;
-
       --color-text-primary: #ccc;
       --color-text-muted: #888;
       --color-text-accent: #00ff88;
       --color-text-white: #fff;
       --color-text-dark: #333;
-
       --color-button: #238636;
       --color-button-disabled: #555;
-
       --color-connection: #333;
       --color-connection-selected: #007bff;
-
       --color-tooltip-bg: #333;
       --color-tooltip-text: #fff;
 
@@ -41,15 +36,13 @@
       --radius-small: 4px;
       --radius-medium: 6px;
       --radius-large: 8px;
-
       --font-family-mono: 'JetBrains Mono', monospace;
       --font-family-code: 'Fira Code', monospace;
-
       --component-padding: 8px;
       --component-gap: 12px;
     }
 
-    /* === RESET === */
+    /* === RESET & BASE STYLES === */
     * {
       box-sizing: border-box;
     }
@@ -75,10 +68,17 @@
       width: 100%;
       background: none;
       padding: 12px 24px;
-      font-size: 24px;
       font-weight: bold;
       color: var(--color-text-accent);
       border-bottom: 1px solid var(--color-text-dark);
+      display: flex;
+      align-items: center;
+      justify-content: space-between;
+    }
+
+    .header-text {
+      font-size: 24px;
+      margin: 0;
     }
 
     #main-content {
@@ -99,6 +99,17 @@
       gap: var(--component-gap);
     }
 
+    .sidebar-title {
+      color: #8b949e;
+      font-size: 14px;
+      text-transform: uppercase;
+      letter-spacing: 1px;
+      margin-bottom: 15px;
+      padding-bottom: 8px;
+      padding-left: 8px;
+      border-bottom: 1px solid #303638;
+    }
+
     /* === COMPONENT ICONS === */
     .component-icon,
     #arrow-tool {
@@ -199,6 +210,7 @@
       stroke-width: 2;
     }
 
+    /* === TOOLBAR === */
     #canvas-toolbar {
       position: absolute;
       top: 12px;
@@ -234,6 +246,7 @@
       color: var(--color-text-white);
       border-color: var(--color-button);
     }
+
     /* === PANELS === */
     #info-panel {
       position: absolute;
@@ -270,14 +283,19 @@
       color: var(--color-text-primary);
     }
 
-    #node-props-save {
-      margin-top: 8px;
-      padding: 10px;
-      background-color: var(--color-button);
-      color: var(--color-text-white);
-      border: none;
-      border-radius: var(--radius-small);
-      cursor: pointer;
+    #node-props-panel .form-group {
+      margin-bottom: 10px;
+    }
+
+    #node-props-panel label {
+      display: block;
+      font-weight: bold;
+      margin-bottom: 4px;
+    }
+
+    #node-props-panel select {
+      width: 100%;
+      padding: 4px;
       font-size: 14px;
     }
 
@@ -294,6 +312,24 @@
       font-size: 13px;
     }
 
+    .panel-title {
+      font-weight: bold;
+      color: var(--color-text-white);
+      font-size: 15px;
+      margin-bottom: 0.5rem;
+    }
+
+    .panel-metric {
+      margin-bottom: 0.4rem;
+    }
+
+    .panel-metric .label {
+      display: inline-block;
+      width: 140px;
+      color: var(--color-text-muted);
+    }
+
+    /* === INPUTS & BUTTONS === */
     input[type="text"],
     input[type="number"] {
       padding: 6px;
@@ -304,9 +340,9 @@
       font-family: var(--font-family-code);
     }
 
-    /* === BUTTONS === */
+    #node-props-save,
     #run-button {
-      margin-top: auto;
+      margin-top: 8px;
       padding: 10px;
       background-color: var(--color-button);
       color: var(--color-text-white);
@@ -322,6 +358,32 @@
       cursor: not-allowed;
     }
 
+    #github-login-btn {
+      display: inline-flex;
+      align-items: center;
+      gap: 8px;
+      padding: 8px 14px;
+      background-color: #fff;
+      color: #000000;
+      text-decoration: none;
+      border-radius: var(--radius-medium);
+      font-weight: 500;
+      font-family: var(--font-family-mono);
+      font-size: 12px;
+      border: 1px solid #2ea043;
+      transition: background-color 0.2s ease;
+      float: right;
+    }
+
+    #github-login-btn:hover {
+      background-color: #ccc;
+    }
+
+    #github-login-btn img {
+      width: 18px;
+      height: 18px;
+    }
+
     /* === TABS === */
     .tabs {
       display: flex;
@@ -387,14 +449,9 @@
       padding: 0;
     }
 
-    .challenge-name {
-      font-weight: 500;
-      margin-bottom: 5px;
-    }
-
     .challenge-item {
       padding: 10px;
-      margin: 5px  0;
+      margin: 5px 0;
       background: #21262d;
       border-radius: 6px;
       cursor: pointer;
@@ -403,60 +460,38 @@
       list-style: none;
     }
 
-    .challenge-difficulty {
-      font-size: 0.8rem;
-      color: #0b949e;
-    }
-
-    .challenge-difficulty.easy {
-      color: #3fb950;
-    }
-
-    .challenge-difficulty.medium {
-      color: #d29922;
-    }
-
-    .challenge-difficulty.hard {
-      color: #f85149
-    }
-
     .challenge-item:hover {
       background: #30363d;
     }
+
     .challenge-item.active {
       background: #1a3d2a;
       border-left-color: #00ff88;
     }
 
-    /* === PANEL METRICS === */
-    .panel-title {
-      font-weight: bold;
-      color: var(--color-text-white);
-      font-size: 15px;
-      margin-bottom: 0.5rem;
+    .challenge-name {
+      font-weight: 500;
+      margin-bottom: 5px;
     }
 
-    .panel-metric {
-      margin-bottom: 0.4rem;
+    .challenge-difficulty {
+      font-size: 0.8rem;
+      color: #0b949e;
     }
 
-    .panel-metric .label {
-      display: inline-block;
-      width: 140px;
-      color: var(--color-text-muted);
+    .challenge-difficulty.easy {
+      color: #3fb950;
     }
 
-    .sidebar-title {
-      color: #8b949e;
-      font-size: 14px;
-      text-transform: uppercase;
-      letter-spacing: 1px;
-      margin-bottom: 15px;
-      padding-bottom: 8px;
-      padding-left: 8px;
-      border-bottom: 1px solid #303638;
+    .challenge-difficulty.medium {
+      color: #d29922;
+    }
+
+    .challenge-difficulty.hard {
+      color: #f85149;
     }
 
+    /* === REQUIREMENTS === */
     .requirements-section {
       background: #161b22;
       border: 1px solid #30363d;
@@ -475,8 +510,9 @@
       position: relative;
       padding: 8px 0 8px 25px;
       margin: 0;
-      border-bottom: 1px solid #30363d;;
+      border-bottom: 1px solid #30363d;
     }
+
     .requirement-item:before {
       content: "✓";
       color: #00ff88;
@@ -484,6 +520,7 @@
       left: 0;
     }
 
+    /* === MODAL === */
     .modal {
       position: absolute;
       top: 30%;
@@ -496,24 +533,18 @@
       z-index: 999;
       color: #ccc;
     }
+
     .modal-content label {
       display: block;
       margin: 10px 0;
     }
+
     .modal-actions {
       margin-top: 10px;
       text-align: right;
     }
-    .modal input {
-      width: 100%;
-      padding: 6px;
-      margin-top: 4px;
-      background: #222;
-      border: 1px solid #444;
-      color: #fff;
-      border-radius: 4px;
-    }
 
+    .modal input,
     .modal select {
       width: 100%;
       padding: 6px;
@@ -524,26 +555,40 @@
       border-radius: 4px;
     }
 
-    #node-props-panel .form-group {
-      margin-bottom: 10px;
+    /* === MISC === */
+    #score-panel {
+      margin-top: 16px;
     }
-
-    #node-props-panel label {
-      display: block;
-      font-weight: bold;
-      margin-bottom: 4px;
+    
+    .userbox {
+      display: flex;
+      align-items: center;
+      gap: 12px;
     }
-
-    #node-props-panel select {
-      width: 100%;
-      padding: 4px;
-      font-size: 14px;
+    .avatar {
+      width: 32px;
+      height: 32px;
+      border-radius: 12px;
     }
     </style>
   </head>
   <body>
     <div id="page-container">
-      <div id="sd-header">System Design Game</div>
+      <div id="sd-header">
+        <h1 class="header-text">System Design Game</h1>
+        {{ if and .Username .Avatar }}
+        <div class="userbox">
+          <img src="{{ .Avatar }}" class="avatar" />
+          <span class="username">{{ .Username }}</span> 
+        </div>
+        {{ else }}
+          <a href="/login" id="github-login-btn">
+            <img src="https://cdn.jsdelivr.net/gh/devicons/devicon/icons/github/github-original.svg" alt="GitHub Logo">
+            Login with GitHub
+          </a>
+        {{ end }}
+
+      </div>
       <div id="main-content">
         <div id="challenge-container">
           <h2 class="sidebar-title">Challenges</h2>
@@ -553,7 +598,7 @@
             <li class="challenge-item {{if and (eq .Name $.Level.Name) (eq .Difficulty $.Level.Difficulty)}}active{{end}}">
               <div class="challenge-name">{{.Name}}</div>
               <div class="challenge-difficulty {{.Difficulty}}">{{.Difficulty}}</div>
-              </li>
+            </li>
             {{end}}
           </ul>
         </div>
@@ -572,36 +617,36 @@
             <!-- Requirements -->
             <div id="content1" class="tab-content">
               {{ if .Level.InterviewerRequirements }}
-                <div class="requirements-section">
-                  <h3>Interviewer Requirements</h3>
-                  <ul class="requirements-list">
-                    {{ range .Level.InterviewerRequirements }}
-                      <li class="requirement-item">{{ . }}</li>
-                    {{ end }}
-                  </ul>
-                </div>
+              <div class="requirements-section">
+                <h3>Interviewer Requirements</h3>
+                <ul class="requirements-list">
+                  {{ range .Level.InterviewerRequirements }}
+                  <li class="requirement-item">{{ . }}</li>
+                  {{ end }}
+                </ul>
+              </div>
               {{ end }}
 
               {{ if .Level.FunctionalRequirements }}
-                <div class="requirements-section">
-                  <h3>Functional Requirements</h3>
-                  <ul class="requirements-list">
-                    {{ range .Level.FunctionalRequirements }}
-                      <li class="requirement-item">{{ . }}</li>
-                    {{ end }}
-                  </ul>
-                </div>
+              <div class="requirements-section">
+                <h3>Functional Requirements</h3>
+                <ul class="requirements-list">
+                  {{ range .Level.FunctionalRequirements }}
+                  <li class="requirement-item">{{ . }}</li>
+                  {{ end }}
+                </ul>
+              </div>
               {{ end }}
 
               {{ if .Level.NonFunctionalRequirements }}
-                <div class="requirements-section">
-                  <h3>Non-Functional Requirements</h3>
-                  <ul class="requirements-list">
-                    {{ range .Level.NonFunctionalRequirements }}
-                      <li class="requirement-item">{{ . }}</li>
-                    {{ end }}
-                  </ul>
-                </div>
+              <div class="requirements-section">
+                <h3>Non-Functional Requirements</h3>
+                <ul class="requirements-list">
+                  {{ range .Level.NonFunctionalRequirements }}
+                  <li class="requirement-item">{{ . }}</li>
+                  {{ end }}
+                </ul>
+              </div>
               {{ end }}
             </div>
 
@@ -695,18 +740,10 @@
                 <div id="info-panel">
                   <div id="constraints-panel">
                     <div class="panel-title">level constraints</div>
-                    <div class="panel-metric"><span class="label">🎯 target rps:</span> <span id="constraint-rps">–</span></div>
-                    <div class="panel-metric"><span class="label">⏱️ max p95 latency:</span> <span id="constraint-latency">–</span></div>
-                    <div class="panel-metric"><span class="label">💸 max cost:</span> <span id="constraint-cost">–</span></div>
-                    <div class="panel-metric"><span class="label">🔒 availability:</span> <span id="constraint-availability">–</span></div>
-                  </div>
-
-                  <div id="score-panel">
-                    <div class="panel-title">simulation results</div>
-                    <div class="panel-metric"><span class="label">✅ cost:</span> <span id="score-cost">–</span></div>
-                    <div class="panel-metric"><span class="label">⚡ p95 latency:</span> <span id="score-p95">–</span></div>
-                    <div class="panel-metric"><span class="label">📈 achieved rps:</span> <span id="score-rps">–</span></div>
-                    <div class="panel-metric"><span class="label">🛡️ availability:</span> <span id="score-availability">–</span></div>
+                    <div class="panel-metric"><span class="label">🎯 target rps:</span> <span id="constraint-rps">{{.Level.TargetRPS}}</span></div>
+                    <div class="panel-metric"><span class="label">⏱️ max p95 latency:</span> <span id="constraint-latency">{{.Level.MaxP95LatencyMs}}ms</span></div>
+                    <div class="panel-metric"><span class="label">💸 max cost:</span> <span id="constraint-cost">${{.Level.MaxMonthlyUSD}}</span></div>
+                    <div class="panel-metric"><span class="label">🔒 availability:</span> <span id="constraint-availability">{{printf "%.2f" .Level.RequiredAvailabilityPct}}%</span></div>
                   </div>
                 </div>