feat: make generation timeout configurable via GENERATION_TIMEOUT_MINUTES

The hardcoded 15-minute timeout was too short for some syntheses.
Now configurable via env var with a default of 30 minutes.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.env.example

@@ -45,3 +45,8 @@ EMAIL_FROM=AI Weekly Synth <noreply@synth.example.com>
 # Sign up at https://dash.cloudflare.com/turnstile
 TURNSTILE_SECRET_KEY=0x4AAAAAAA_CHANGE_ME
 TURNSTILE_SITE_KEY=0x4BBBBBB_CHANGE_ME
+
+# --- Generation ---
+# Maximum time (in minutes) allowed for a synthesis generation before timeout.
+# Default: 30
+# GENERATION_TIMEOUT_MINUTES=30

backend/src/config.rs

@@ -27,6 +27,9 @@ pub struct AppConfig {
     // Captcha (Cloudflare Turnstile)
     pub turnstile_secret_key: String,
     pub turnstile_site_key: String,
+
+    // Generation
+    pub generation_timeout_secs: u64,
 }
 
 impl AppConfig {
@@ -51,6 +54,12 @@ impl AppConfig {
         let static_dir = env::var("STATIC_DIR")
             .unwrap_or_else(|_| "../frontend/dist".to_string());
 
+        let generation_timeout_secs = env::var("GENERATION_TIMEOUT_MINUTES")
+            .unwrap_or_else(|_| "30".to_string())
+            .parse::<u64>()
+            .map_err(|_| "GENERATION_TIMEOUT_MINUTES must be a valid positive integer".to_string())?
+            * 60;
+
         Ok(Self {
             database_url,
             master_encryption_key: Arc::new(master_encryption_key),
@@ -61,6 +70,7 @@ impl AppConfig {
             email_from,
             turnstile_secret_key,
             turnstile_site_key,
+            generation_timeout_secs,
         })
     }
 
@@ -115,6 +125,7 @@ mod tests {
             email_from: "test@example.com".into(),
             turnstile_secret_key: "0x4AAA".into(),
             turnstile_site_key: "0x4BBB".into(),
+            generation_timeout_secs: 1800,
         };
         assert!(config.validate().is_ok());
     }
@@ -131,6 +142,7 @@ mod tests {
             email_from: "test@example.com".into(),
             turnstile_secret_key: "0x4AAA".into(),
             turnstile_site_key: "0x4BBB".into(),
+            generation_timeout_secs: 1800,
         };
         let err = config.validate().unwrap_err();
         assert!(err.contains("MASTER_ENCRYPTION_KEY"));
@@ -148,6 +160,7 @@ mod tests {
             email_from: "test@example.com".into(),
             turnstile_secret_key: "0x4AAA".into(),
             turnstile_site_key: "0x4BBB".into(),
+            generation_timeout_secs: 1800,
         };
         let err = config.validate().unwrap_err();
         assert!(err.contains("MASTER_ENCRYPTION_KEY"));
@@ -165,6 +178,7 @@ mod tests {
             email_from: "test@example.com".into(),
             turnstile_secret_key: "0x4AAA".into(),
             turnstile_site_key: "0x4BBB".into(),
+            generation_timeout_secs: 1800,
         };
         let err = config.validate().unwrap_err();
         assert!(err.contains("APP_URL"));
@@ -182,6 +196,7 @@ mod tests {
             email_from: "test@example.com".into(),
             turnstile_secret_key: "0x4AAA".into(),
             turnstile_site_key: "0x4BBB".into(),
+            generation_timeout_secs: 1800,
         };
         let err = config.validate().unwrap_err();
         assert!(err.contains("trailing slash"));
@@ -199,6 +214,7 @@ mod tests {
             email_from: "test@example.com".into(),
             turnstile_secret_key: "0x4AAA".into(),
             turnstile_site_key: "0x4BBB".into(),
+            generation_timeout_secs: 1800,
         };
         assert!(config.is_secure());
 

backend/src/handlers/generation.rs

@@ -86,13 +86,15 @@ pub async fn trigger_generate(
     let state_for_panic = state.clone();
 
     let join_handle = tokio::spawn(async move {
-        let timeout_duration = std::time::Duration::from_secs(900);
+        let timeout_secs = state_clone.config.generation_timeout_secs;
+        let timeout_duration = std::time::Duration::from_secs(timeout_secs);
         match tokio::time::timeout(timeout_duration, synthesis::run_generation(job_id, state_clone.clone(), user_id, theme_id, tx.clone(), None, cancelled)).await {
             Ok(()) => {}
             Err(_) => {
-                tracing::error!(job_id = %job_id, user_id = %user_id, "Generation timed out after 15 minutes");
+                let timeout_mins = timeout_secs / 60;
+                tracing::error!(job_id = %job_id, user_id = %user_id, timeout_mins, "Generation timed out");
                 let _ = tx.send(ProgressEvent::Error {
-                    message: "La generation a depasse le delai maximum de 15 minutes.".into(),
+                    message: format!("La generation a depasse le delai maximum de {} minutes.", timeout_mins),
                 });
             }
         }

backend/src/services/scheduler.rs

@@ -54,8 +54,9 @@ pub async fn run_scheduled_jobs(state: &AppState) {
         let job_id = Uuid::new_v4();
         let cancelled = AtomicBool::new(false);
 
+        let timeout_secs = state.config.generation_timeout_secs;
         let timeout_result = tokio::time::timeout(
-            std::time::Duration::from_secs(900),
+            std::time::Duration::from_secs(timeout_secs),
             synthesis::run_generation_inner(
                 job_id, state, schedule.user_id, schedule.theme_id,
                 &tx, None, &cancelled,
@@ -65,7 +66,7 @@ pub async fn run_scheduled_jobs(state: &AppState) {
         let result = match timeout_result {
             Ok(inner) => inner,
             Err(_) => {
-                tracing::error!(schedule_id = %schedule.id, "Scheduled generation timed out after 15 minutes");
+                tracing::error!(schedule_id = %schedule.id, timeout_mins = timeout_secs / 60, "Scheduled generation timed out");
                 continue;
             }
         };

backend/tests/common/mod.rs

@@ -115,6 +115,7 @@ impl TestApp {
             email_from: "test@example.com".into(),
             turnstile_secret_key: TURNSTILE_TEST_KEY.into(),
             turnstile_site_key: "test-site-key".into(),
+            generation_timeout_secs: 1800,
         };
 
         let http_client = reqwest::Client::new();