From 5ce9cfc0223a0c75c0e457b76bc8b95616853edb Mon Sep 17 00:00:00 2001
From: liquidev <liquidev@tutanota.com>
Date: Sat, 23 Nov 2024 19:12:00 +0100
Subject: [PATCH] add live reloading to the client

---
 crates/treehouse/src/cli/serve.rs                | 12 ++++++------
 crates/treehouse/src/generate.rs                 | 15 ++++-----------
 crates/treehouse/src/state.rs                    |  6 ++++++
 .../treehouse/src/vfs/content_version_cache.rs   |  1 -
 static/js/live-reload.js                         | 16 ++++++++++++++++
 template/components/_head.hbs                    |  6 ++++++
 6 files changed, 38 insertions(+), 18 deletions(-)
 create mode 100644 static/js/live-reload.js

diff --git a/crates/treehouse/src/cli/serve.rs b/crates/treehouse/src/cli/serve.rs
index 0a24a20..cf0b7d8 100644
--- a/crates/treehouse/src/cli/serve.rs
+++ b/crates/treehouse/src/cli/serve.rs
@@ -103,9 +103,9 @@ async fn vfs_entry(
     }
 }
 
-async fn system_page(target: &AsyncDir, path: &VPath) -> Response {
+async fn system_page(target: &AsyncDir, path: &VPath, status_code: StatusCode) -> Response {
     if let Some(content) = target.content(path).await {
-        (StatusCode::NOT_FOUND, Html(content)).into_response()
+        (status_code, Html(content)).into_response()
     } else {
         (
             StatusCode::INTERNAL_SERVER_ERROR,
@@ -116,11 +116,11 @@ async fn system_page(target: &AsyncDir, path: &VPath) -> Response {
 }
 
 async fn index(State(state): State<Arc<Server>>) -> Response {
-    system_page(&state.target, system::INDEX).await
+    system_page(&state.target, system::INDEX, StatusCode::OK).await
 }
 
 async fn four_oh_four(State(state): State<Arc<Server>>) -> Response {
-    system_page(&state.target, system::FOUR_OH_FOUR).await
+    system_page(&state.target, system::FOUR_OH_FOUR, StatusCode::NOT_FOUND).await
 }
 
 async fn branch(RawQuery(named_id): RawQuery, State(state): State<Arc<Server>>) -> Response {
@@ -175,8 +175,8 @@ async fn branch(RawQuery(named_id): RawQuery, State(state): State<Arc<Server>>)
             }
         }
 
-        system_page(&state.target, system::FOUR_OH_FOUR).await
+        system_page(&state.target, system::FOUR_OH_FOUR, StatusCode::NOT_FOUND).await
     } else {
-        system_page(&state.target, system::B_DOCS).await
+        system_page(&state.target, system::B_DOCS, StatusCode::OK).await
     }
 }
diff --git a/crates/treehouse/src/generate.rs b/crates/treehouse/src/generate.rs
index 9d63750..339505d 100644
--- a/crates/treehouse/src/generate.rs
+++ b/crates/treehouse/src/generate.rs
@@ -28,9 +28,7 @@ use crate::state::{FileId, Treehouse};
 #[derive(Debug, Clone)]
 pub struct ParsedTree {
     root_key: String,
-    tree_path: String,
     file_id: FileId,
-    target_path: VPathBuf,
 }
 
 #[derive(Serialize)]
@@ -55,6 +53,7 @@ struct BaseTemplateData<'a> {
     config: &'a Config,
     import_map: String,
     season: Option<Season>,
+    dev: bool,
 }
 
 #[derive(Serialize)]
@@ -117,15 +116,7 @@ fn parse_tree(
             let root_key = tree_path.clone();
             treehouse.roots.insert(root_key.clone(), roots);
 
-            Ok((
-                Some(ParsedTree {
-                    root_key,
-                    tree_path,
-                    file_id,
-                    target_path,
-                }),
-                diagnostics,
-            ))
+            Ok((Some(ParsedTree { root_key, file_id }), diagnostics))
         }
         Err(diagnostics) => Ok((None, diagnostics)),
     }
@@ -190,6 +181,7 @@ fn generate_simple_template(
         import_map: serde_json::to_string_pretty(&sources.import_map)
             .expect("import map should be serializable to JSON"),
         season: Season::current(),
+        dev: cfg!(debug_assertions),
     };
     handlebars
         .render(template_name, &base_template_data)
@@ -239,6 +231,7 @@ fn generate_tree(
         import_map: serde_json::to_string_pretty(&sources.import_map)
             .expect("import map should be serializable to JSON"),
         season: Season::current(),
+        dev: cfg!(debug_assertions),
     };
 
     let template_data = PageTemplateData {
diff --git a/crates/treehouse/src/state.rs b/crates/treehouse/src/state.rs
index f6a141a..eb2f80a 100644
--- a/crates/treehouse/src/state.rs
+++ b/crates/treehouse/src/state.rs
@@ -103,6 +103,12 @@ impl Treehouse {
     }
 }
 
+impl Default for Treehouse {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 pub struct TomlError {
     pub message: String,
     pub span: Option<Range<usize>>,
diff --git a/crates/treehouse/src/vfs/content_version_cache.rs b/crates/treehouse/src/vfs/content_version_cache.rs
index 0149b24..3dfe74b 100644
--- a/crates/treehouse/src/vfs/content_version_cache.rs
+++ b/crates/treehouse/src/vfs/content_version_cache.rs
@@ -1,7 +1,6 @@
 use std::fmt::{self, Debug};
 
 use dashmap::DashMap;
-use log::debug;
 
 use super::{Dir, DirEntry, EditPath, VPath, VPathBuf};
 
diff --git a/static/js/live-reload.js b/static/js/live-reload.js
new file mode 100644
index 0000000..b43b973
--- /dev/null
+++ b/static/js/live-reload.js
@@ -0,0 +1,16 @@
+// NOTE: The server never fulfills this request, it stalls forever.
+// Once the connection is closed, we try to connect with the server until we establish a successful
+// connection. Then we reload the page.
+await fetch("/dev/live-reload/stall").catch(async () => {
+    while (true) {
+        try {
+            let response = await fetch("/dev/live-reload/back-up");
+            if (response.status == 200) {
+                window.location.reload();
+                break;
+            }
+        } catch (e) {
+            await new Promise((resolve) => setTimeout(resolve, 100));
+        }
+    }
+});
diff --git a/template/components/_head.hbs b/template/components/_head.hbs
index c083103..3c31fa2 100644
--- a/template/components/_head.hbs
+++ b/template/components/_head.hbs
@@ -17,6 +17,12 @@ clever to do while browser vendors figure that out, we'll just have to do a cach
 --}}
 <script type="importmap">{{{ import_map }}}</script>
 
+{{#if dev}}
+<script type="module">
+    import "treehouse/live-reload.js";
+</script>
+{{/if}}
+
 <script>
     const TREEHOUSE_SITE = `{{ config.site }}`;