add repo land page and 404 page per GRASP-01

4 files changed, 701 insertions, 7 deletions

diff --git a/grasp-audit/src/specs/grasp01/repository_creation.rs b/grasp-audit/src/specs/grasp01/repository_creation.rs
index 0b3eed5..1014aa3 100644
--- a/grasp-audit/src/specs/grasp01/repository_creation.rs
+++ b/grasp-audit/src/specs/grasp01/repository_creation.rs
@@ -27,6 +27,8 @@ impl RepositoryCreationTests {
         let mut results = crate::AuditResult::new("GRASP-01 Repository Creation Tests");
 
         results.add(Self::test_bare_repo_created_on_announcement(client, relay_domain).await);
+        results.add(Self::test_webpage_served_for_existing_repo(client, relay_domain).await);
+        results.add(Self::test_404_for_nonexistent_repo(client, relay_domain).await);
 
         results
     }
@@ -109,6 +111,144 @@ impl RepositoryCreationTests {
         )
         .pass()
     }
+
+    /// Test that a webpage is served for an existing repository
+    ///
+    /// This test verifies:
+    /// 1. Creates a valid repository announcement
+    /// 2. Accesses the repository URL without git service parameters
+    /// 3. Verifies a webpage is returned (any 2xx status with HTML content)
+    ///
+    /// GRASP-01: "SHOULD serve a webpage at the same endpoint linking to git nostr client(s)"
+    pub async fn test_webpage_served_for_existing_repo(
+        client: &AuditClient,
+        relay_domain: &str,
+    ) -> TestResult {
+        let test_name = "test_webpage_served_for_existing_repo";
+        let ctx = TestContext::new(client);
+
+        // Create a repository announcement
+        let repo = match ctx.get_fixture(FixtureKind::ValidRepo).await {
+            Ok(r) => r,
+            Err(e) => {
+                return TestResult::new(
+                    test_name,
+                    "GRASP-01",
+                    "Relay SHOULD serve a webpage for existing repositories",
+                )
+                .fail(format!("Failed to create repo fixture: {}", e))
+            }
+        };
+
+        // Wait for repository creation
+        tokio::time::sleep(std::time::Duration::from_millis(200)).await;
+
+        // Extract repo identifier and npub
+        let repo_id = match repo
+            .tags
+            .iter()
+            .find(|t| t.kind() == TagKind::d())
+            .and_then(|t| t.content())
+        {
+            Some(id) => id.to_string(),
+            None => {
+                return TestResult::new(
+                    test_name,
+                    "GRASP-01",
+                    "Relay SHOULD serve a webpage for existing repositories",
+                )
+                .fail("Repository announcement missing d tag")
+            }
+        };
+
+        let npub = match repo.pubkey.to_bech32() {
+            Ok(n) => n,
+            Err(e) => {
+                return TestResult::new(
+                    test_name,
+                    "GRASP-01",
+                    "Relay SHOULD serve a webpage for existing repositories",
+                )
+                .fail(format!("Failed to convert pubkey to npub: {}", e))
+            }
+        };
+
+        // Check that a webpage is served at the repository URL
+        if let Err(e) = check_webpage_served(relay_domain, &npub, &repo_id).await {
+            return TestResult::new(
+                test_name,
+                "GRASP-01",
+                "Relay SHOULD serve a webpage for existing repositories",
+            )
+            .fail(format!("Webpage not served: {}", e));
+        }
+
+        TestResult::new(
+            test_name,
+            "GRASP-01",
+            "Relay SHOULD serve a webpage for existing repositories",
+        )
+        .pass()
+    }
+
+    /// Test that 404 is returned for non-existent repositories
+    ///
+    /// This test verifies:
+    /// 1. Accesses a URL for a repository that doesn't exist
+    /// 2. Verifies a 404 status is returned
+    ///
+    /// GRASP-01: "...and a 404 page for repositories it doesn't host"
+    pub async fn test_404_for_nonexistent_repo(
+        client: &AuditClient,
+        relay_domain: &str,
+    ) -> TestResult {
+        let test_name = "test_404_for_nonexistent_repo";
+
+        let ctx = TestContext::new(client);
+
+        let repo = match ctx.get_fixture(FixtureKind::ValidRepo).await {
+            Ok(r) => r,
+            Err(e) => {
+                return TestResult::new(
+                    test_name,
+                    "GRASP-01",
+                    "Relay SHOULD serve a webpage for existing repositories",
+                )
+                .fail(format!("Failed to create repo fixture: {}", e))
+            }
+        };
+
+        let npub = match repo.pubkey.to_bech32() {
+            Ok(n) => n,
+            Err(e) => {
+                return TestResult::new(
+                    test_name,
+                    "GRASP-01",
+                    "Relay SHOULD serve a webpage for existing repositories",
+                )
+                .fail(format!("Failed to convert pubkey to npub: {}", e))
+            }
+        };
+        // Use a clearly non-existent repo id but real npub
+        let fake_repo_id = "nonexistent-repo-12345";
+
+        // Check that 404 is returned
+        if let Err(e) = check_404_for_nonexistent_repo(relay_domain, &npub, fake_repo_id).await {
+            return TestResult::new(
+                test_name,
+                "GRASP-01",
+                "Relay SHOULD return 404 for repositories it doesn't host",
+            )
+            .fail(format!("Expected 404, got: {}", e));
+        }
+
+        TestResult::new(
+            test_name,
+            "GRASP-01",
+            "Relay SHOULD return 404 for repositories it doesn't host",
+        )
+        .pass()
+    }
 }
 
 /// Helper function to check if a repository is accessible via Smart HTTP service
@@ -156,3 +296,56 @@ async fn check_repo_accessible_via_http(
 
     Ok(())
 }
+
+/// Helper function to check if a webpage is served for an existing repository
+///
+/// Verifies that accessing the repository URL returns a webpage (2xx status)
+/// URL format: http://domain/npub/identifier.git
+async fn check_webpage_served(relay_domain: &str, npub: &str, repo_id: &str) -> Result<(), String> {
+    let repo_url = format!("http://{}/{}/{}.git", relay_domain, npub, repo_id);
+
+    let http_client = reqwest::Client::new();
+    let response = http_client
+        .get(&repo_url)
+        .send()
+        .await
+        .map_err(|e| format!("HTTP request failed: {}", e))?;
+
+    if !response.status().is_success() {
+        return Err(format!(
+            "Expected 2xx status for existing repo webpage, got {} for URL: {}",
+            response.status(),
+            repo_url
+        ));
+    }
+
+    Ok(())
+}
+
+/// Helper function to check that 404 is returned for non-existent repository
+///
+/// Verifies that accessing a non-existent repository URL returns 404
+async fn check_404_for_nonexistent_repo(
+    relay_domain: &str,
+    npub: &str,
+    repo_id: &str,
+) -> Result<(), String> {
+    let repo_url = format!("http://{}/{}/{}.git", relay_domain, npub, repo_id);
+
+    let http_client = reqwest::Client::new();
+    let response = http_client
+        .get(&repo_url)
+        .send()
+        .await
+        .map_err(|e| format!("HTTP request failed: {}", e))?;
+
+    if response.status().as_u16() != 404 {
+        return Err(format!(
+            "Expected 404 status for non-existent repo, got {} for URL: {}",
+            response.status(),
+            repo_url
+        ));
+    }
+
+    Ok(())
+}
diff --git a/src/http/landing.rs b/src/http/landing.rs
index 55ffb26..ddde09a 100644
--- a/src/http/landing.rs
+++ b/src/http/landing.rs
@@ -13,3 +13,410 @@ pub fn get_html(config: &Config) -> String {
         bind_address = config.bind_address,
     )
 }
+
+/// Generate a generic 404 page for unknown paths
+///
+/// Used for any path that doesn't match a known route
+pub fn get_generic_404_html(config: &Config, path: &str) -> String {
+    format!(
+        r#"<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Not Found - {relay_name}</title>
+    <style>
+        * {{
+            margin: 0;
+            padding: 0;
+            box-sizing: border-box;
+        }}
+        body {{
+            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
+            line-height: 1.6;
+            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+            color: #333;
+            min-height: 100vh;
+            display: flex;
+            align-items: center;
+            justify-content: center;
+            padding: 20px;
+        }}
+        .container {{
+            max-width: 600px;
+            background: white;
+            padding: 40px;
+            border-radius: 12px;
+            box-shadow: 0 20px 60px rgba(0,0,0,0.3);
+            text-align: center;
+        }}
+        h1 {{
+            color: #e74c3c;
+            margin-bottom: 10px;
+            font-size: 4em;
+        }}
+        h2 {{
+            color: #333;
+            margin-bottom: 20px;
+            font-size: 1.5em;
+        }}
+        .path-info {{
+            background: #f9f9f9;
+            padding: 15px;
+            border-radius: 8px;
+            margin: 20px 0;
+            border-left: 4px solid #e74c3c;
+        }}
+        code {{
+            background: #f4f4f4;
+            padding: 3px 8px;
+            border-radius: 4px;
+            font-family: 'Courier New', monospace;
+            color: #667eea;
+            font-size: 0.85em;
+            word-break: break-all;
+        }}
+        .back-link {{
+            margin-top: 20px;
+        }}
+        a {{
+            color: #667eea;
+            text-decoration: none;
+        }}
+        a:hover {{
+            text-decoration: underline;
+        }}
+        .footer {{
+            margin-top: 30px;
+            padding-top: 20px;
+            border-top: 1px solid #eee;
+            color: #999;
+            font-size: 0.9em;
+        }}
+    </style>
+</head>
+<body>
+    <div class="container">
+        <h1>404</h1>
+        <h2>Not Found</h2>
+        <p>The page you're looking for doesn't exist.</p>
+        
+        <div class="path-info">
+            <p><strong>Requested path:</strong> <code>{path}</code></p>
+        </div>
+        
+        <div class="back-link">
+            <a href="/">← Back to {relay_name}</a>
+        </div>
+        
+        <div class="footer">
+            <p>Powered by <strong>ngit-grasp</strong></p>
+        </div>
+    </div>
+</body>
+</html>"#,
+        relay_name = config.relay_name,
+        path = path,
+    )
+}
+
+/// Generate a 404 page for a non-existent repository
+///
+/// GRASP-01: "...and a 404 page for repositories it doesn't host"
+pub fn get_404_html(config: &Config, npub: &str, identifier: &str) -> String {
+    format!(
+        r#"<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Repository Not Found - {relay_name}</title>
+    <style>
+        * {{
+            margin: 0;
+            padding: 0;
+            box-sizing: border-box;
+        }}
+        body {{
+            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
+            line-height: 1.6;
+            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+            color: #333;
+            min-height: 100vh;
+            display: flex;
+            align-items: center;
+            justify-content: center;
+            padding: 20px;
+        }}
+        .container {{
+            max-width: 600px;
+            background: white;
+            padding: 40px;
+            border-radius: 12px;
+            box-shadow: 0 20px 60px rgba(0,0,0,0.3);
+            text-align: center;
+        }}
+        h1 {{
+            color: #e74c3c;
+            margin-bottom: 10px;
+            font-size: 4em;
+        }}
+        h2 {{
+            color: #333;
+            margin-bottom: 20px;
+            font-size: 1.5em;
+        }}
+        .repo-info {{
+            background: #f9f9f9;
+            padding: 15px;
+            border-radius: 8px;
+            margin: 20px 0;
+            border-left: 4px solid #e74c3c;
+        }}
+        code {{
+            background: #f4f4f4;
+            padding: 3px 8px;
+            border-radius: 4px;
+            font-family: 'Courier New', monospace;
+            color: #667eea;
+            font-size: 0.85em;
+            word-break: break-all;
+        }}
+        .back-link {{
+            margin-top: 20px;
+        }}
+        a {{
+            color: #667eea;
+            text-decoration: none;
+        }}
+        a:hover {{
+            text-decoration: underline;
+        }}
+        .footer {{
+            margin-top: 30px;
+            padding-top: 20px;
+            border-top: 1px solid #eee;
+            color: #999;
+            font-size: 0.9em;
+        }}
+    </style>
+</head>
+<body>
+    <div class="container">
+        <h1>404</h1>
+        <h2>Repository Not Found</h2>
+        <p>The repository you're looking for doesn't exist on this GRASP server.</p>
+        
+        <div class="repo-info">
+            <p><strong>Owner:</strong> <code>{npub}</code></p>
+            <p><strong>Repository:</strong> <code>{identifier}</code></p>
+        </div>
+        
+        <p>This repository may not have been announced to this server, or the URL may be incorrect.</p>
+        
+        <div class="back-link">
+            <a href="/">← Back to {relay_name}</a>
+        </div>
+        
+        <div class="footer">
+            <p>Powered by <strong>ngit-grasp</strong></p>
+        </div>
+    </div>
+</body>
+</html>"#,
+        relay_name = config.relay_name,
+        npub = npub,
+        identifier = identifier,
+    )
+}
+
+/// Generate a webpage for an existing repository
+///
+/// GRASP-01: "SHOULD serve a webpage at the same endpoint linking to git nostr client(s)
+/// to browse the repository"
+pub fn get_repo_html(config: &Config, npub: &str, identifier: &str) -> String {
+    let clone_url = format!(
+        "http://{}/{}/{}.git",
+        config.domain, npub, identifier
+    );
+    
+    format!(
+        r#"<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>{identifier} - {relay_name}</title>
+    <style>
+        * {{
+            margin: 0;
+            padding: 0;
+            box-sizing: border-box;
+        }}
+        body {{
+            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
+            line-height: 1.6;
+            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+            color: #333;
+            min-height: 100vh;
+            display: flex;
+            align-items: center;
+            justify-content: center;
+            padding: 20px;
+        }}
+        .container {{
+            max-width: 800px;
+            background: white;
+            padding: 40px;
+            border-radius: 12px;
+            box-shadow: 0 20px 60px rgba(0,0,0,0.3);
+        }}
+        h1 {{
+            color: #667eea;
+            margin-bottom: 10px;
+            font-size: 2em;
+        }}
+        h2 {{
+            color: #764ba2;
+            margin-top: 25px;
+            margin-bottom: 15px;
+            font-size: 1.3em;
+            border-bottom: 2px solid #667eea;
+            padding-bottom: 8px;
+        }}
+        .subtitle {{
+            color: #666;
+            margin-bottom: 25px;
+            font-size: 1em;
+        }}
+        .repo-info {{
+            background: #f9f9f9;
+            padding: 15px;
+            border-radius: 8px;
+            margin: 15px 0;
+            border-left: 4px solid #667eea;
+        }}
+        code {{
+            background: #f4f4f4;
+            padding: 3px 8px;
+            border-radius: 4px;
+            font-family: 'Courier New', monospace;
+            color: #667eea;
+            font-size: 0.85em;
+            word-break: break-all;
+        }}
+        .clone-box {{
+            background: #2d3748;
+            color: #e2e8f0;
+            padding: 15px;
+            border-radius: 8px;
+            margin: 15px 0;
+            font-family: 'Courier New', monospace;
+            font-size: 0.9em;
+            overflow-x: auto;
+        }}
+        .clone-box code {{
+            background: transparent;
+            color: #68d391;
+            padding: 0;
+        }}
+        ul {{
+            margin: 15px 0;
+            padding-left: 25px;
+        }}
+        li {{
+            margin: 10px 0;
+        }}
+        a {{
+            color: #667eea;
+            text-decoration: none;
+        }}
+        a:hover {{
+            text-decoration: underline;
+        }}
+        .client-list {{
+            display: grid;
+            gap: 10px;
+            margin: 15px 0;
+        }}
+        .client-item {{
+            background: #f9f9f9;
+            padding: 12px 15px;
+            border-radius: 8px;
+            display: flex;
+            justify-content: space-between;
+            align-items: center;
+        }}
+        .badge {{
+            display: inline-block;
+            background: #667eea;
+            color: white;
+            padding: 4px 10px;
+            border-radius: 12px;
+            font-size: 0.8em;
+        }}
+        .footer {{
+            margin-top: 30px;
+            padding-top: 20px;
+            border-top: 1px solid #eee;
+            text-align: center;
+            color: #999;
+            font-size: 0.9em;
+        }}
+        .back-link {{
+            margin-bottom: 20px;
+        }}
+    </style>
+</head>
+<body>
+    <div class="container">
+        <div class="back-link">
+            <a href="/">← Back to {relay_name}</a>
+        </div>
+        
+        <h1>📦 {identifier}</h1>
+        <p class="subtitle">Git repository hosted on {relay_name}</p>
+        
+        <h2>📋 Repository Information</h2>
+        <div class="repo-info">
+            <p><strong>Owner:</strong> <code>{npub}</code></p>
+            <p><strong>Repository:</strong> <code>{identifier}</code></p>
+        </div>
+        
+        <h2>🔗 Clone this Repository</h2>
+        <div class="clone-box">
+            git clone <code>{clone_url}</code>
+        </div>
+        
+        <h2>🌐 Browse with Git Nostr Clients</h2>
+        <p>You can browse this repository using these Git Nostr clients:</p>
+        <div class="client-list">
+            <div class="client-item">
+                <span><strong>gitworkshop.dev</strong> - Web-based repository browser</span>
+                <a href="https://gitworkshop.dev" target="_blank">Visit →</a>
+            </div>
+            <div class="client-item">
+                <span><strong>ngit</strong> - Command-line Git + Nostr tool</span>
+                <a href="https://github.com/DanConwayDev/ngit-cli" target="_blank">GitHub →</a>
+            </div>
+        </div>
+        
+        <h2>📚 About GRASP</h2>
+        <p>This repository is hosted using the <strong>GRASP</strong> (Git Relays Authorized via Signed-Nostr Proofs) protocol.</p>
+        <ul>
+            <li><a href="https://gitworkshop.dev/repo/grasp/01.md" target="_blank">GRASP-01 Specification</a></li>
+            <li><a href="https://github.com/nostr-protocol/nips/blob/master/34.md" target="_blank">NIP-34: Git Stuff</a></li>
+        </ul>
+        
+        <div class="footer">
+            <p>Powered by <strong>ngit-grasp</strong></p>
+        </div>
+    </div>
+</body>
+</html>"#,
+        relay_name = config.relay_name,
+        npub = npub,
+        identifier = identifier,
+        clone_url = clone_url,
+    )
+}
diff --git a/src/http/mod.rs b/src/http/mod.rs
index f43cf86..6da027c 100644
--- a/src/http/mod.rs
+++ b/src/http/mod.rs
@@ -32,6 +32,47 @@ const CORS_ALLOW_ORIGIN: &str = "*";
 const CORS_ALLOW_METHODS: &str = "GET, POST";
 const CORS_ALLOW_HEADERS: &str = "Content-Type";
 
+/// Extract npub and identifier from a repository URL path (no git subpath required)
+///
+/// Parses paths like `/<npub>/<identifier>.git` (for repository webpage/404)
+///
+/// Returns (npub, identifier) if the path matches a repository URL pattern
+fn parse_repo_url(path: &str) -> Option<(&str, &str)> {
+    // Remove leading slash
+    let path = path.strip_prefix('/').unwrap_or(path);
+
+    // Split into components
+    let parts: Vec<&str> = path.split('/').collect();
+
+    // Must be exactly 2 parts: npub and repo.git (no subpath)
+    if parts.len() != 2 {
+        return None;
+    }
+
+    let npub = parts[0];
+    let repo_part = parts[1];
+
+    // The repo part must end with .git
+    if !repo_part.ends_with(".git") {
+        return None;
+    }
+
+    // Must have an npub that looks valid (starts with npub1)
+    if !npub.starts_with("npub1") {
+        return None;
+    }
+
+    // Extract identifier (remove .git suffix)
+    let identifier = repo_part.strip_suffix(".git").unwrap_or(repo_part);
+
+    // Identifier must not be empty
+    if identifier.is_empty() {
+        return None;
+    }
+
+    Some((npub, identifier))
+}
+
 /// Add CORS headers to a response builder
 fn add_cors_headers(builder: hyper::http::response::Builder) -> hyper::http::response::Builder {
     builder
@@ -230,6 +271,45 @@ impl Service<Request<Incoming>> for HttpService {
             }
         }
 
+        // Check for repository URL pattern (e.g., /npub/repo.git without subpath)
+        // GRASP-01: "SHOULD serve a webpage at the same endpoint linking to git nostr client(s)
+        // to browse the repository and a 404 page for repositories it doesn't host"
+        if let Some((npub, identifier)) = parse_repo_url(&path) {
+            let npub = npub.to_string();
+            let identifier = identifier.to_string();
+            let config = self.config.clone();
+            let repo_path = git::resolve_repo_path(&git_data_path, &npub, &identifier);
+
+            tracing::debug!(
+                "Repository URL request: {} (npub={}, id={}, path={:?})",
+                path,
+                npub,
+                identifier,
+                repo_path
+            );
+
+            return Box::pin(async move {
+                // Check if repository exists
+                if repo_path.exists() {
+                    // Serve repository webpage
+                    let html = landing::get_repo_html(&config, &npub, &identifier);
+                    Ok(add_cors_headers(Response::builder().header("server", "ngit-grasp"))
+                        .status(200)
+                        .header("content-type", "text/html; charset=utf-8")
+                        .body(Full::new(Bytes::from(html)))
+                        .unwrap())
+                } else {
+                    // Serve 404 page for non-existent repository
+                    let html = landing::get_404_html(&config, &npub, &identifier);
+                    Ok(add_cors_headers(Response::builder().header("server", "ngit-grasp"))
+                        .status(404)
+                        .header("content-type", "text/html; charset=utf-8")
+                        .body(Full::new(Bytes::from(html)))
+                        .unwrap())
+                }
+            });
+        }
+
         // Check if this is a WebSocket upgrade request
         if let (Some(c), Some(w)) = (
             req.headers().get("connection"),
@@ -275,14 +355,26 @@ impl Service<Request<Incoming>> for HttpService {
             }
         }
 
-        // Serve landing page for HTTP requests
-        let html = landing::get_html(&self.config);
+        // Only serve landing page for root path "/", 404 for everything else
+        let config = self.config.clone();
         Box::pin(async move {
-            Ok(base
-                .status(200)
-                .header("content-type", "text/html; charset=utf-8")
-                .body(Full::new(Bytes::from(html)))
-                .unwrap())
+            if path == "/" {
+                // Serve landing page for root
+                let html = landing::get_html(&config);
+                Ok(add_cors_headers(Response::builder().header("server", "ngit-grasp"))
+                    .status(200)
+                    .header("content-type", "text/html; charset=utf-8")
+                    .body(Full::new(Bytes::from(html)))
+                    .unwrap())
+            } else {
+                // Serve generic 404 for unknown paths
+                let html = landing::get_generic_404_html(&config, &path);
+                Ok(add_cors_headers(Response::builder().header("server", "ngit-grasp"))
+                    .status(404)
+                    .header("content-type", "text/html; charset=utf-8")
+                    .body(Full::new(Bytes::from(html)))
+                    .unwrap())
+            }
         })
     }
 }
diff --git a/tests/repository_creation.rs b/tests/repository_creation.rs
index 301203b..352e2cc 100644
--- a/tests/repository_creation.rs
+++ b/tests/repository_creation.rs
@@ -59,3 +59,5 @@ macro_rules! isolated_test {
 
 // Generate isolated tests for all repository creation tests
 isolated_test!(test_bare_repo_created_on_announcement);
+isolated_test!(test_webpage_served_for_existing_repo);
+isolated_test!(test_404_for_nonexistent_repo);