use std::{env, fs};use zed::{    serde_json::{self, Value},    settings::LspSettings,};use zed_extension_api::{self as zed, Result}; const SERVER_PATH: &str = "node_modules/@elm-tooling/elm-language-server/out/node/index.js";const PACKAGE_NAME: &str = "@elm-tooling/elm-language-server"; struct ElmExtension {    did_find_server: bool,} impl ElmExtension {    fn server_exists(&self) -> bool {        fs::metadata(SERVER_PATH).map_or(false, |stat| stat.is_file())    }     fn server_script_path(&mut self, server_id: &zed::LanguageServerId) -> Result<String> {        let server_exists = self.server_exists();        if self.did_find_server && server_exists {            return Ok(SERVER_PATH.to_string());        }         zed::set_language_server_installation_status(            server_id,            &zed::LanguageServerInstallationStatus::CheckingForUpdate,        );        let version = zed::npm_package_latest_version(PACKAGE_NAME)?;         if !server_exists            || zed::npm_package_installed_version(PACKAGE_NAME)?.as_ref() != Some(&version)        {            zed::set_language_server_installation_status(                server_id,                &zed::LanguageServerInstallationStatus::Downloading,            );            let result = zed::npm_install_package(PACKAGE_NAME, &version);            match result {                Ok(()) => {                    if !self.server_exists() {                        Err(format!(                            "installed package '{PACKAGE_NAME}' did not contain expected path '{SERVER_PATH}'",                        ))?;                    }                }                Err(error) => {                    if !self.server_exists() {                        Err(error)?;                    }                }            }        }         self.did_find_server = true;        Ok(SERVER_PATH.to_string())    }} impl zed::Extension for ElmExtension {    fn new() -> Self {        Self {            did_find_server: false,        }    }     fn language_server_command(        &mut self,        server_id: &zed::LanguageServerId,        _worktree: &zed::Worktree,    ) -> Result<zed::Command> {        let server_path = self.server_script_path(server_id)?;        Ok(zed::Command {            command: zed::node_binary_path()?,            args: vec![                env::current_dir()                    .unwrap()                    .join(&server_path)                    .to_string_lossy()                    .to_string(),                "--stdio".to_string(),            ],            env: Default::default(),        })    }     fn language_server_workspace_configuration(        &mut self,        server_id: &zed::LanguageServerId,        worktree: &zed::Worktree,    ) -> Result<Option<Value>> {        // elm-language-server expects workspace didChangeConfiguration notification        // params to be the same as lsp initialization_options        let initialization_options = LspSettings::for_worktree(server_id.as_ref(), worktree)?            .initialization_options            .clone()            .unwrap_or_default();         Ok(Some(match initialization_options.clone().as_object_mut() {            Some(op) => {                // elm-language-server requests workspace configuration                // for the `elmLS` section, so we have to nest                // another copy of initialization_options there                op.insert("elmLS".into(), initialization_options);                serde_json::to_value(op).unwrap_or_default()            }            None => initialization_options,        }))    }} zed::register_extension!(ElmExtension);