pub fn feed_prices(
    deps: DepsMut,
    env: Env,
    info: MessageInfo,
    prices: Vec<(String, Decimal256, u64)>,
) -> Result<Response, ContractError> {
    let mut attributes = vec![attr("action", "feed_prices")];
    let sender_raw = deps.api.addr_canonicalize(info.sender.as_str())?;
    for price in prices {
        let asset: String = price.0;
        let mut updated_time: u64 = price.2;
        let price: Decimal256 = price.1;

        // Check feeder permission
        let feeder = read_feeder(deps.storage, &asset)?;
        if feeder != sender_raw {
            return Err(ContractError::Unauthorized {});
        }

        let config: Config = read_config(deps.storage)?;
        if env.block.time.seconds() > updated_time {
            // reject stale price
            if env.block.time.seconds() - updated_time > config.valid_period {
                return Err(ContractError::InvalidInputs {});
            }
        } else {
            // reject future timestamp, graceFuturePeriod can be set to 3, which means < 3s is allowed
            if updated_time - env.block.time.seconds() > config.grace_future_period {
                return Err(ContractError::InvalidInputs {});
            }
            updated_time = env.block.time.seconds();
        }

        attributes.push(attr("asset", asset.to_string()));
        attributes.push(attr("price", price.to_string()));

        store_price(
            deps.storage,
            &asset,
            &PriceInfo {
                last_updated_time: updated_time,
                price,
            },
        )?;
    }

    Ok(Response::new().add_attributes(attributes))
}
