Refactor the database interactions out of the commands

src/database.rs

@@ -0,0 +1,67 @@
+use sqlx::PgPool;
+
+pub async fn set_fact(
+    pg_pool: &PgPool,
+    interaction_id: String,
+    channel_id: Option<String>,
+    author_id: String,
+    fact_name: String,
+    fact_value: String,
+) -> Result<(), String> {
+    let Ok(rows) = sqlx::query!("
+INSERT INTO facts (\"last_interaction_id\", \"channel_id\", \"author_id\", \"name\", \"value\") 
+VALUES ($1, $2, $3, $4, $5)
+ON CONFLICT ON CONSTRAINT facts_origin_key DO UPDATE SET value = $5, version = facts.version + 1
+    ",
+        interaction_id.to_string(),
+        channel_id.map(|cid| cid.to_string()),
+        author_id.to_string(),
+        fact_name,
+        fact_value,
+    ).execute(pg_pool).await.map(|rows| rows.rows_affected()) else {
+        return Err("Error saving fact.".to_string());
+    };
+
+    if rows != 1 {
+        return Err("Error saving fact".to_string());
+    }
+
+    Ok(())
+}
+
+#[derive(Clone)]
+pub struct FactResponse {
+    pub value: String,
+    pub version: i32,
+    pub created_at: time::OffsetDateTime,
+    pub updated_at: time::OffsetDateTime,
+}
+
+pub async fn get_fact(
+    pg_pool: &PgPool,
+    channel_id: Option<String>,
+    author_id: String,
+    fact_name: String,
+) -> Result<Option<FactResponse>, String>{
+    let Ok(facts) = sqlx::query_as!(FactResponse, 
+        "
+SELECT \"value\", \"version\", \"created_at\", \"updated_at\"
+FROM facts
+WHERE
+    channel_id IS NOT DISTINCT FROM $1 AND
+    author_id = $2 AND
+    name = $3
+        ", channel_id.map(|cid| cid.to_string()), author_id.to_string(), fact_name).fetch_all(pg_pool).await else {
+            return Err("Querying facts failed".to_string());
+        };
+
+    if facts.is_empty() {
+        return Ok(None);
+    }
+
+    if facts.len() > 1 {
+        return Err("Too many facts found, wtf, impossible".to_string());
+    }
+
+    Ok(Some(facts[0].clone()))
+}