add seed ability

src/seed.rs

@@ -0,0 +1,64 @@
+use std::path::Path;
+
+use serde::Deserialize;
+use tracing::{info, warn};
+
+use crate::db::Database;
+
+#[derive(Debug, Deserialize)]
+pub struct SeedConfig {
+    #[serde(default)]
+    pub user: Option<SeedUser>,
+}
+
+#[derive(Debug, Deserialize)]
+pub struct SeedUser {
+    pub email: String,
+    pub display_name: String,
+    pub password: String,
+}
+
+/// Reads the seed config file and creates the configured default user if the
+/// database has no users yet. The file is optional; if it does not exist (or
+/// cannot be parsed) seeding is skipped.
+pub async fn seed_if_needed(db: &Database, path: &Path) {
+    let Ok(contents) = std::fs::read_to_string(path) else {
+        return;
+    };
+    let config: SeedConfig = match serde_json::from_str(&contents) {
+        Ok(config) => config,
+        Err(error) => {
+            warn!(path = %path.display(), %error, "could not parse seed config; skipping");
+            return;
+        }
+    };
+    let Some(user) = config.user else {
+        return;
+    };
+    if user.email.trim().is_empty() {
+        warn!("seed user requires a non-empty email; skipping");
+        return;
+    }
+    if db.has_users().await.unwrap_or(true) {
+        info!("database already has users; skipping seed");
+        return;
+    }
+    let password_hash = match crate::hash_password(&user.password) {
+        Ok(hash) => hash,
+        Err(error) => {
+            warn!(%error, "could not hash seed password; skipping");
+            return;
+        }
+    };
+    match db
+        .create_user(
+            user.email.trim().to_lowercase(),
+            user.display_name.trim().to_owned(),
+            password_hash,
+        )
+        .await
+    {
+        Ok(user) => info!(id = user.id, email = %user.email, "seeded default user"),
+        Err(error) => warn!(%error, "could not seed default user"),
+    }
+}