Auto download of helm_ls

Cargo.toml

@@ -10,4 +10,4 @@ path = "src/helm.rs"
 crate-type = ["cdylib"]
 
 [dependencies]
-zed_extension_api = "0.0.4"
+zed_extension_api = "0.1.0"

languages/helm/config.toml

@@ -1,5 +1,6 @@
 name = "Helm"
 grammar = "helm"
+path_suffixes = ["gotmpl", "helmfile.yaml", "tpl"]
 line_comments = ["# "]
 block_comment = ["{{/* ", " */}}"]
 brackets = [

src/helm.rs

@@ -1,23 +1,126 @@
+use std::fs;
+use zed::LanguageServerId;
 use zed_extension_api::{self as zed, Result};
 
-struct HelmExtension;
+struct HelmExtension {
+    cached_binary_path: Option<String>,
+}
+
+impl HelmExtension {
+    fn language_server_binary_path(
+        &mut self,
+        language_server_id: &LanguageServerId,
+        worktree: &zed::Worktree,
+    ) -> Result<String> {
+        if let Some(path) = &self.cached_binary_path {
+            if fs::metadata(path).map_or(false, |stat| stat.is_file()) {
+                return Ok(path.clone());
+            }
+        }
+
+        if let Some(path) = worktree.which("helm_ls") {
+            self.cached_binary_path = Some(path.clone());
+            return Ok(path);
+        }
+
+        zed::set_language_server_installation_status(
+            language_server_id,
+            &zed::LanguageServerInstallationStatus::CheckingForUpdate,
+        );
+        let release = zed::latest_github_release(
+            "mrjosh/helm-ls",
+            zed::GithubReleaseOptions {
+                require_assets: true,
+                pre_release: true,
+            },
+        )?;
+
+        let (platform, arch) = zed::current_platform();
+        let asset_name = format!(
+            "helm_ls_{os}_{arch}{extension}",
+            os = match platform {
+                zed::Os::Mac => "darwin",
+                zed::Os::Linux => "linux",
+                zed::Os::Windows => "windows",
+            },
+            arch = match arch {
+                zed::Architecture::Aarch64 => "arm64",
+                zed::Architecture::X86 => "x86",
+                zed::Architecture::X8664 => "x86_64",
+            },
+            extension = match platform {
+                zed::Os::Mac | zed::Os::Linux => "",
+                zed::Os::Windows => ".exe",
+            }
+        );
+
+        let asset = release
+            .assets
+            .iter()
+            .find(|asset| asset.name == asset_name)
+            .ok_or_else(|| format!("no asset found matching {:?}", asset_name))?;
+
+        let version_dir = format!("helm_ls_{}", release.version);
+        fs::create_dir_all(&version_dir)
+            .map_err(|err| format!("failed to create directory '{version_dir}': {err}"))?;
+        let binary_path = format!(
+            "{version_dir}/helm_ls_{os}_{arch}",
+            os = match platform {
+                zed::Os::Mac => "darwin",
+                zed::Os::Linux => "linux",
+                zed::Os::Windows => "windows",
+            },
+            arch = match arch {
+                zed::Architecture::Aarch64 => "arm64",
+                zed::Architecture::X86 => "x86",
+                zed::Architecture::X8664 => "x86_64",
+            },
+        );
+
+        if !fs::metadata(&binary_path).map_or(false, |stat| stat.is_file()) {
+            zed::set_language_server_installation_status(
+                language_server_id,
+                &zed::LanguageServerInstallationStatus::Downloading,
+            );
+
+            zed::download_file(
+                &asset.download_url,
+                &binary_path,
+                zed::DownloadedFileType::Uncompressed,
+            )
+            .map_err(|e| format!("failed to download file: {e}"))?;
+
+            zed::make_file_executable(&binary_path)?;
+
+            let entries =
+                fs::read_dir(".").map_err(|e| format!("failed to list working directory {e}"))?;
+            for entry in entries {
+                let entry = entry.map_err(|e| format!("failed to load directory entry {e}"))?;
+                if entry.file_name().to_str() != Some(&version_dir) {
+                    fs::remove_dir_all(entry.path()).ok();
+                }
+            }
+        }
+
+        self.cached_binary_path = Some(binary_path.clone());
+        Ok(binary_path)
+    }
+}
 
 impl zed::Extension for HelmExtension {
     fn new() -> Self {
-        Self
+        Self {
+            cached_binary_path: None,
+        }
     }
 
     fn language_server_command(
         &mut self,
-        _config: zed::LanguageServerConfig,
+        language_server_id: &LanguageServerId,
         worktree: &zed::Worktree,
     ) -> Result<zed::Command> {
-        let path = worktree
-            .which("helm_ls")
-            .ok_or_else(|| "The LSP for helm 'helm-ls' is not installed".to_string())?;
-
         Ok(zed::Command {
-            command: path,
+            command: self.language_server_binary_path(language_server_id, worktree)?,
             args: vec!["serve".to_string()],
             env: Default::default(),
         })