Implement path-based downloads with blob redirect system

- Add fctdrive stat command to get blob IDs from paths
- Add Drive_stat function to drive_server.ts for backend integration
- Create /download/[...path] endpoint that redirects to /blob/{blobId}
- Update UI file links to use /download/ paths instead of direct blob links
- Update permalinks to use immutable /blob/{blobId} URLs
- Fix host preservation in redirects for remote access

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

4 files changed, 83 insertions, 4 deletions

diff --git a/frontend/app/download/[...path]/route.ts b/frontend/app/download/[...path]/route.ts
new file mode 100644
index 0000000..966a89e
--- /dev/null
+++ b/frontend/app/download/[...path]/route.ts
@@ -0,0 +1,37 @@
+import { NextRequest, NextResponse } from 'next/server'
+import { Drive_stat } from '@/lib/drive_server'
+
+// GET /download/[...path] - Download file by path (redirects to blob endpoint)
+export async function GET(
+  request: NextRequest,
+  { params }: { params: Promise<{ path: string[] }> }
+) {
+  try {
+    const { path } = await params
+    
+    // Reconstruct the full path
+    const fullPath = '/' + path.join('/')
+    
+    // Get filename from path for the download
+    const filename = path[path.length - 1] || 'download'
+    
+    // Get blob ID using Drive_stat
+    const blobId = await Drive_stat(fullPath)
+    
+    // Redirect to blob endpoint with filename - preserve original host
+    // Use X-Forwarded-Host or Host header to get the correct host
+    const forwardedHost = request.headers.get('x-forwarded-host')
+    const host = forwardedHost || request.headers.get('host') || new URL(request.url).host
+    const protocol = request.headers.get('x-forwarded-proto') || (new URL(request.url).protocol.replace(':', ''))
+    const redirectUrl = `${protocol}://${host}/blob/${blobId}?filename=${encodeURIComponent(filename)}`
+    
+    return NextResponse.redirect(redirectUrl)
+    
+  } catch (error) {
+    console.error('Download error:', error)
+    return new NextResponse(
+      error instanceof Error ? error.message : 'File not found',
+      { status: 404 }
+    )
+  }
+}
\ No newline at end of file
diff --git a/frontend/components/drive/DriveDirectoryClient.tsx b/frontend/components/drive/DriveDirectoryClient.tsx
index 6089ec2..c405341 100644
--- a/frontend/components/drive/DriveDirectoryClient.tsx
+++ b/frontend/components/drive/DriveDirectoryClient.tsx
@@ -125,11 +125,21 @@ export function DriveDirectoryClient({ path, files, breadcrumbs }: DriveDirector
   }
 
   const copyPermalink = (item: DriveLsEntry) => {
-    const permalink = `${window.location.origin}/drive/file/${item.path}`
+    if (!item.blob) {
+      toast({
+        title: "Cannot copy permalink",
+        description: "This item does not have a blob ID",
+        variant: "destructive"
+      })
+      return
+    }
+    
+    const filename = item.path.split('/').pop() || 'download'
+    const permalink = `${window.location.origin}/blob/${item.blob}?filename=${encodeURIComponent(filename)}`
     navigator.clipboard.writeText(permalink).then(() => {
       toast({
-        title: "Link copied!",
-        description: "Permalink has been copied to clipboard",
+        title: "Permalink copied!",
+        description: "Permanent blob link has been copied to clipboard",
       })
     })
   }
@@ -531,7 +541,7 @@ export function DriveDirectoryClient({ path, files, breadcrumbs }: DriveDirector
                             <div className="min-w-0 max-w-[60vw]">
                               {file.blob ? (
                                 <a
-                                  href={`/blob/${file.blob}?filename=${encodeURIComponent(fileName)}`}
+                                  href={`/download${file.path}`}
                                   className="text-blue-600 hover:text-blue-800 hover:underline cursor-pointer block truncate"
                                   target="_blank"
                                   rel="noopener noreferrer"
diff --git a/frontend/lib/drive_server.ts b/frontend/lib/drive_server.ts
index 2a94fe9..41b9c71 100644
--- a/frontend/lib/drive_server.ts
+++ b/frontend/lib/drive_server.ts
@@ -108,6 +108,18 @@ export async function Drive_rename(oldPath: string, newPath: string, email: stri
   }
 }
 
+/// gets the blob ID for a given path
+export async function Drive_stat(path: string): Promise<string> {
+  const result = spawnSync('fctdrive', ['stat', path], { encoding: 'utf-8' });
+  if (result.error) {
+    throw new Error(`Failed to execute fctdrive: ${result.error.message}`);
+  }
+  if (result.status !== 0) {
+    throw new Error(`fctdrive exited with code ${result.status}: ${result.stderr}`);
+  }
+  return result.stdout.trim();
+}
+
 /// builds a filesystem tree from Drive_ls entries
 export async function Drive_tree(): Promise<DriveTreeResponse> {
   const entries = await Drive_ls('/', true);
diff --git a/src/main.rs b/src/main.rs
index 6431a88..ebbc817 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -747,6 +747,7 @@ enum Cmd {
     Import(ImportArgs),
     Blob(BlobArgs),
     Log(LogArgs),
+    Stat(StatArgs),
 }
 
 #[derive(Debug, Args)]
@@ -847,6 +848,14 @@ struct LogArgs {
     common: CliCommon,
 }
 
+#[derive(Debug, Args)]
+struct StatArgs {
+    #[clap(flatten)]
+    common: CliCommon,
+
+    path: DrivePath,
+}
+
 fn main() {
     let cli = Cli::parse();
 
@@ -858,6 +867,7 @@ fn main() {
         Cmd::Import(args) => cmd_import(args),
         Cmd::Blob(args) => cmd_blob(args),
         Cmd::Log(args) => cmd_log(args),
+        Cmd::Stat(args) => cmd_stat(args),
     }
 }
 
@@ -1111,6 +1121,16 @@ fn cmd_log(args: LogArgs) {
     }
 }
 
+fn cmd_stat(args: StatArgs) {
+    let ops = common_read_log_file(&args.common);
+    let mut fs = Fs::default();
+    ops.iter().for_each(|op| apply(&mut fs, op).unwrap());
+
+    let node_id = find_node(&fs, &args.path).unwrap();
+    let node = &fs.nodes[node_id];
+    println!("{}", node.blob);
+}
+
 fn collect_all_file_paths(root: &Path) -> Vec<PathBuf> {
     let mut queue = vec![root.to_path_buf()];
     let mut files = vec![];