From 3c24ad83e11698b7f1bf888d88bc89f2b91db3e7 Mon Sep 17 00:00:00 2001
From: Andras Schmelczer <andras@schmelczer.dev>
Date: Sun, 8 Dec 2024 15:00:57 +0000
Subject: [PATCH] Write default config if it doesn't exist

---
 backend/sync_server/src/config.rs             | 20 ++++++++++++++-----
 .../sync_server/src/config/database_config.rs |  9 +++++++++
 .../sync_server/src/config/server_config.rs   | 10 ++++++++++
 backend/sync_server/src/config/user_config.rs |  2 +-
 4 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/backend/sync_server/src/config.rs b/backend/sync_server/src/config.rs
index 6582fb7e..07f952af 100644
--- a/backend/sync_server/src/config.rs
+++ b/backend/sync_server/src/config.rs
@@ -2,6 +2,7 @@ use std::path::Path;
 
 use anyhow::{Context, Result};
 use database_config::DatabaseConfig;
+use log::warn;
 use serde::{Deserialize, Serialize};
 use server_config::ServerConfig;
 use tokio::fs;
@@ -11,24 +12,33 @@ pub mod database_config;
 pub mod server_config;
 pub mod user_config;
 
-#[derive(Debug, Deserialize, Serialize, Clone)]
+#[derive(Debug, Deserialize, Serialize, Clone, Default)]
 pub struct Config {
+    #[serde(default)]
     pub database: DatabaseConfig,
+    #[serde(default)]
     pub server: ServerConfig,
+    #[serde(default)]
     pub users: UserConfig,
 }
 
 impl Config {
     pub async fn read(path: &Path) -> Result<Self> {
-        Self::load_from_file(path)
-            .await
-            .with_context(|| format!("Cannot load configuration from disk from ({path:?})"))
+        if path.exists() {
+            Self::load_from_file(path).await
+        } else {
+            warn!("Configuration file not found, writing default configuration to {path:?}");
+
+            let config = Config::default();
+            config.write(path).await?;
+            Ok(config)
+        }
     }
 
     pub async fn load_from_file(path: &Path) -> Result<Self> {
         let contents = fs::read_to_string(path)
             .await
-            .context("Failed to read configuration file")?;
+            .with_context(|| format!("Cannot load configuration from disk from ({path:?})"))?;
 
         let config = serde_yaml::from_str(&contents).context("Failed to parse configuration")?;
 
diff --git a/backend/sync_server/src/config/database_config.rs b/backend/sync_server/src/config/database_config.rs
index a84d6aa9..3c314023 100644
--- a/backend/sync_server/src/config/database_config.rs
+++ b/backend/sync_server/src/config/database_config.rs
@@ -21,3 +21,12 @@ fn default_max_connections() -> u32 {
     debug!("Using default max connections: {}", DEFAULT_MAX_CONNECTIONS);
     DEFAULT_MAX_CONNECTIONS
 }
+
+impl Default for DatabaseConfig {
+    fn default() -> Self {
+        Self {
+            sqlite_url: default_sqlite_url(),
+            max_connections: default_max_connections(),
+        }
+    }
+}
diff --git a/backend/sync_server/src/config/server_config.rs b/backend/sync_server/src/config/server_config.rs
index 94f6b7ef..dd0b06d8 100644
--- a/backend/sync_server/src/config/server_config.rs
+++ b/backend/sync_server/src/config/server_config.rs
@@ -31,3 +31,13 @@ fn default_max_body_size_mb() -> usize {
     );
     DEFAULT_MAX_BODY_SIZE_MB
 }
+
+impl Default for ServerConfig {
+    fn default() -> Self {
+        Self {
+            host: default_host(),
+            port: default_port(),
+            max_body_size_mb: default_max_body_size_mb(),
+        }
+    }
+}
diff --git a/backend/sync_server/src/config/user_config.rs b/backend/sync_server/src/config/user_config.rs
index 25a08010..5980b746 100644
--- a/backend/sync_server/src/config/user_config.rs
+++ b/backend/sync_server/src/config/user_config.rs
@@ -1,6 +1,6 @@
 use serde::{Deserialize, Serialize};
 
-#[derive(Debug, Deserialize, Serialize, Clone)]
+#[derive(Debug, Deserialize, Serialize, Clone, Default)]
 pub struct UserConfig {
     #[serde(default = "Vec::new")]
     pub users: Vec<User>,