use chrono::Utc;

use crate::db::{Db, db_error};
use crate::error::AppResult;

/// Soma `bytes` ao total trafegado pelo proxy no mês corrente (UTC), usado
/// para cobrar o custo de consumo de dados no orçamento mensal.
pub async fn add_bytes(db: &Db, bytes: i64) -> AppResult<()> {
    if bytes <= 0 {
        return Ok(());
    }
    let client = db.client().await?;
    let month = Utc::now().format("%Y-%m").to_string();
    client
        .execute(
            "INSERT INTO data_usage_monthly (month, bytes) VALUES ($1, $2)
             ON CONFLICT (month) DO UPDATE SET bytes = data_usage_monthly.bytes + EXCLUDED.bytes",
            &[&month, &bytes],
        )
        .await
        .map_err(db_error)?;
    Ok(())
}

/// Total de bytes trafegados pelo proxy no mês corrente (UTC).
pub async fn monthly_bytes(db: &Db) -> AppResult<i64> {
    let client = db.client().await?;
    let month = Utc::now().format("%Y-%m").to_string();
    let bytes: Option<i64> = client
        .query_opt(
            "SELECT bytes FROM data_usage_monthly WHERE month = $1",
            &[&month],
        )
        .await
        .map_err(db_error)?
        .map(|row| row.get(0));
    Ok(bytes.unwrap_or(0))
}