refactor: read client_secret.json from disk instead of env vars

src/main.rs

@@ -4,6 +4,7 @@ mod infrastructure;
 mod ui;
 
 use std::io;
+use std::path::PathBuf;
 use std::sync::Arc;
 
 use crossterm::event::{self, Event};
@@ -19,9 +20,33 @@ use crate::infrastructure::api::ApiClient;
 use crate::infrastructure::db::Db;
 use crate::ui::{draw, AppView, NetworkStatus};
 
+fn find_secret_file() -> Option<PathBuf> {
+    if let Ok(path) = std::env::var("GOOGLE_CLIENT_SECRET_FILE") {
+        let p = PathBuf::from(&path);
+        if p.exists() {
+            return Some(p);
+        }
+    }
+
+    let config_path = dirs::config_dir()
+        .unwrap_or_else(|| PathBuf::from("."))
+        .join("task_app")
+        .join("client_secret.json");
+    if config_path.exists() {
+        return Some(config_path);
+    }
+
+    let local_path = PathBuf::from("client_secret.json");
+    if local_path.exists() {
+        return Some(local_path);
+    }
+
+    None
+}
+
 fn main() -> io::Result<()> {
     let db_path = dirs::data_dir()
-        .unwrap_or_else(|| std::path::PathBuf::from("."))
+        .unwrap_or_else(|| PathBuf::from("."))
         .join("task_app")
         .join("tasks.db");
 
@@ -29,6 +54,17 @@ fn main() -> io::Result<()> {
 
     let db = Arc::new(Db::new(db_path.to_str().unwrap()).expect("Failed to open database"));
 
+    let secret_path = find_secret_file().unwrap_or_else(|| {
+        eprintln!(
+            "ERROR: Google client secret file not found.\n\
+             Place client_secret.json in one of:\n\
+             - Set GOOGLE_CLIENT_SECRET_FILE env var\n\
+             - ~/.config/task_app/client_secret.json\n\
+             - ./client_secret.json (current directory)"
+        );
+        std::process::exit(1);
+    });
+
     enable_raw_mode()?;
     let mut stdout = io::stdout();
     stdout.execute(EnterAlternateScreen)?;
@@ -39,12 +75,9 @@ fn main() -> io::Result<()> {
         tokio::runtime::Runtime::new()
             .unwrap()
             .block_on(async {
-                ApiClient::new(
-                    std::env::var("GOOGLE_CLIENT_ID").unwrap_or_default(),
-                    std::env::var("GOOGLE_CLIENT_SECRET").unwrap_or_default(),
-                )
-                .await
-                .expect("Failed to create ApiClient")
+                ApiClient::new(&secret_path)
+                    .await
+                    .expect("Failed to create ApiClient")
             }),
     );