use cm_domain::WorkspaceId;
use sqlx::PgPool;
use uuid::Uuid;

use crate::DbError;

/// Available credits = sum of remaining balances across all lots; credits
/// never expire (§8.4).
pub async fn balance(pool: &PgPool, workspace_id: WorkspaceId) -> Result<i64, DbError> {
    let row = sqlx::query!(
        r#"SELECT COALESCE(SUM(remaining), 0)::BIGINT AS "balance!"
           FROM credit_lots WHERE workspace_id = $1"#,
        workspace_id.as_uuid(),
    )
    .fetch_one(pool)
    .await?;
    Ok(row.balance)
}

pub async fn add_lot(
    pool: &PgPool,
    workspace_id: WorkspaceId,
    amount: i64,
    source: &str,
) -> Result<(), DbError> {
    sqlx::query!(
        "INSERT INTO credit_lots (id, workspace_id, amount, remaining, source)
         VALUES ($1, $2, $3, $3, $4)",
        Uuid::now_v7(),
        workspace_id.as_uuid(),
        sqlx::types::BigDecimal::from(amount),
        source,
    )
    .execute(pool)
    .await?;
    Ok(())
}