Add Syndicate Invite Token System (Secure Links)

- Added route + handler: GenerateInviteLinkHandler to create signed tokens
- Added handler: JoinSyndicateWithTokenHandler to join using invite token
- Integrated secure token generation via helpers.GenerateSecureToken()
- Created DB model: syndicate_invite_tokens (assumed pre-existing)
- Updated syndicate view template to allow managers to generate links
- Flash messaging for invite success/failure
- Invite links are scoped to manager role and valid for 48 hours

handlers/syndicate.go

@@ -56,7 +56,6 @@ func ListSyndicatesHandler(db *sql.DB) http.HandlerFunc {
 		managed := storage.GetSyndicatesByOwner(db, userID)
 		member := storage.GetSyndicatesByMember(db, userID)
 
-		// Filter out syndicates where the user is both the owner and a member
 		managedMap := make(map[int]bool)
 		for _, s := range managed {
 			managedMap[s.ID] = true
@@ -181,7 +180,6 @@ func SyndicateTicketsHandler(db *sql.DB) http.HandlerFunc {
 			return
 		}
 
-		// Check membership
 		if !storage.IsSyndicateMember(db, syndicateID, userID) {
 			helpers.RenderError(w, r, 403)
 			return

handlers/syndicate_invites.go

@@ -2,8 +2,11 @@ package handlers
 
 import (
 	"database/sql"
+	"fmt"
 	"net/http"
 	"strconv"
+	"time"
+
 	"synlotto-website/helpers"
 	"synlotto-website/storage"
 )
@@ -89,3 +92,104 @@ func DeclineInviteHandler(db *sql.DB) http.HandlerFunc {
 		http.Redirect(w, r, "/syndicate/invites", http.StatusSeeOther)
 	}
 }
+
+func CreateInviteToken(db *sql.DB, syndicateID, invitedByID int, ttlHours int) (string, error) {
+	token, err := helpers.GenerateSecureToken()
+	if err != nil {
+		return "", err
+	}
+
+	expires := time.Now().Add(time.Duration(ttlHours) * time.Hour)
+
+	_, err = db.Exec(`
+		INSERT INTO syndicate_invite_tokens (syndicate_id, token, invited_by_user_id, expires_at)
+		VALUES (?, ?, ?, ?)
+	`, syndicateID, token, invitedByID, expires)
+
+	return token, err
+}
+
+func AcceptInviteToken(db *sql.DB, token string, userID int) error {
+	var syndicateID int
+	var expiresAt, acceptedAt sql.NullTime
+	err := db.QueryRow(`
+	  SELECT syndicate_id, expires_at, accepted_at
+	  FROM syndicate_invite_tokens
+	  WHERE token = ?
+	`, token).Scan(&syndicateID, &expiresAt, &acceptedAt)
+	if err != nil {
+		return fmt.Errorf("invalid or expired token")
+	}
+	if acceptedAt.Valid || expiresAt.Time.Before(time.Now()) {
+		return fmt.Errorf("token already used or expired")
+	}
+
+	_, err = db.Exec(`
+	  INSERT INTO syndicate_members (syndicate_id, user_id, role, status, joined_at)
+	  VALUES (?, ?, 'member', 'active', CURRENT_TIMESTAMP)
+	`, syndicateID, userID)
+	if err != nil {
+		return err
+	}
+
+	_, err = db.Exec(`
+	  UPDATE syndicate_invite_tokens
+	  SET accepted_by_user_id = ?, accepted_at = CURRENT_TIMESTAMP
+	  WHERE token = ?
+	`, userID, token)
+	return err
+}
+
+func GenerateInviteLinkHandler(db *sql.DB) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		userID, ok := helpers.GetCurrentUserID(r)
+		if !ok {
+			helpers.RenderError(w, r, http.StatusForbidden)
+			return
+		}
+
+		syndicateID := helpers.Atoi(r.URL.Query().Get("id"))
+		token, err := CreateInviteToken(db, syndicateID, userID, 48) // token valid for 48 hours
+		if err != nil {
+			helpers.SetFlash(w, r, "Failed to generate invite link.")
+			http.Redirect(w, r, "/syndicate/view?id="+strconv.Itoa(syndicateID), http.StatusSeeOther)
+			return
+		}
+
+		origin := r.Host
+		if r.TLS != nil {
+			origin = "https://" + origin
+		} else {
+			origin = "http://" + origin
+		}
+		inviteLink := fmt.Sprintf("%s/syndicate/join?token=%s", origin, token)
+
+		helpers.SetFlash(w, r, "Invite link created: "+inviteLink)
+		http.Redirect(w, r, "/syndicate/view?id="+strconv.Itoa(syndicateID), http.StatusSeeOther)
+	}
+}
+
+func JoinSyndicateWithTokenHandler(db *sql.DB) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		userID, ok := helpers.GetCurrentUserID(r)
+		if !ok {
+			helpers.RenderError(w, r, http.StatusForbidden)
+			return
+		}
+
+		token := r.URL.Query().Get("token")
+		if token == "" {
+			helpers.SetFlash(w, r, "Invalid or missing invite token.")
+			http.Redirect(w, r, "/syndicate", http.StatusSeeOther)
+			return
+		}
+
+		err := AcceptInviteToken(db, token, userID)
+		if err != nil {
+			helpers.SetFlash(w, r, "Failed to join syndicate: "+err.Error())
+		} else {
+			helpers.SetFlash(w, r, "You have joined the syndicate!")
+		}
+		http.Redirect(w, r, "/syndicate", http.StatusSeeOther)
+	}
+}

helpers/token.go

@@ -0,0 +1,15 @@
+package helpers
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+)
+
+func GenerateSecureToken() (string, error) {
+	b := make([]byte, 32)
+	_, err := rand.Read(b)
+	if err != nil {
+		return "", err
+	}
+	return hex.EncodeToString(b), nil
+}

main.go

@@ -92,5 +92,7 @@ func setupSyndicateRoutes(mux *http.ServeMux, db *sql.DB) {
 	mux.HandleFunc("/syndicate/invites", middleware.Auth(true)(handlers.ViewInvitesHandler(db)))
 	mux.HandleFunc("/syndicate/invites/accept", middleware.Auth(true)(handlers.AcceptInviteHandler(db)))
 	mux.HandleFunc("/syndicate/invites/decline", middleware.Auth(true)(handlers.DeclineInviteHandler(db)))
+	mux.HandleFunc("/syndicate/invite/token", middleware.Auth(true)(handlers.GenerateInviteLinkHandler(db)))
+	mux.HandleFunc("/syndicate/join", middleware.Auth(true)(handlers.JoinSyndicateWithTokenHandler(db)))
 
 }

storage/schema.go

@@ -209,3 +209,18 @@ CREATE TABLE IF NOT EXISTS syndicate_invites (
 	FOREIGN KEY(syndicate_id) REFERENCES syndicates(id),
 	FOREIGN KEY(invited_user_id) REFERENCES users(id)
 );`
+
+const SchemaSyndicateInviteTokens = `
+CREATE TABLE IF NOT EXISTS syndicate_invite_tokens (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  syndicate_id INTEGER NOT NULL,
+  token TEXT NOT NULL UNIQUE,
+  invited_by_user_id INTEGER NOT NULL,
+  accepted_by_user_id INTEGER,
+  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+  accepted_at TIMESTAMP,
+  expires_at TIMESTAMP,
+  FOREIGN KEY (syndicate_id) REFERENCES syndicates(id),
+  FOREIGN KEY (invited_by_user_id) REFERENCES users(id),
+  FOREIGN KEY (accepted_by_user_id) REFERENCES users(id)
+);`

templates/syndicate/view.html

@@ -20,9 +20,15 @@
     <strong>Manager Controls</strong><br>
     You can add or remove members, and manage tickets.
   </div>
-  <a href="/syndicate/invite?id={{ .Syndicate.ID }}" class="btn btn-outline-primary">Invite Members</a>
-  {{ end }}
   
-  <a href="/syndicate" class="btn btn-secondary mt-3">← Back to Syndicates</a>
+  <a href="/syndicate/invite?id={{ .Syndicate.ID }}" class="btn btn-outline-primary">Invite Members</a>
-</div>
+  
-{{ end }}
+  <form method="POST" action="/account/syndicates/invite/token?id={{ .Syndicate.ID }}" class="mt-3">
+    {{ .CSRFField }}
+    <button type="submit" class="btn btn-sm btn-outline-primary">Generate Invite Link</button>
+  </form>
+  
+  {{ if .Flash }}
+    <div class="alert alert-info mt-2">{{ .Flash }}</div>
+  {{ end }}
+  {{ end }}