// Copyright 2023 Greptime Team
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use std::any::Any;
use std::time::Duration;

use common_error::ext::{ErrorExt, RetryHint};
use common_error::status_code::StatusCode;
use common_macro::stack_trace_debug;
use snafu::Snafu;

pub type Result<T> = std::result::Result<T, Error>;

#[derive(Snafu)]
#[snafu(visibility(pub))]
#[stack_trace_debug]
pub enum Error {
    #[snafu(display(
        "Memory limit exceeded: requested {requested_bytes} bytes, limit {limit_bytes} bytes"
    ))]
    MemoryLimitExceeded {
        requested_bytes: u64,
        limit_bytes: u64,
    },

    #[snafu(display("Memory semaphore unexpectedly closed"))]
    MemorySemaphoreClosed,

    #[snafu(display(
        "Timeout waiting for memory quota: requested {requested_bytes} bytes, waited {waited:?}"
    ))]
    MemoryAcquireTimeout {
        requested_bytes: u64,
        waited: Duration,
    },
}

impl ErrorExt for Error {
    fn status_code(&self) -> StatusCode {
        use Error::*;

        match self {
            MemoryLimitExceeded { .. } => StatusCode::RuntimeResourcesExhausted,
            MemorySemaphoreClosed => StatusCode::Unexpected,
            MemoryAcquireTimeout { .. } => StatusCode::RuntimeResourcesExhausted,
        }
    }

    fn as_any(&self) -> &dyn Any {
        self
    }

    fn retry_hint(&self) -> RetryHint {
        match self {
            Error::MemoryLimitExceeded { .. } | Error::MemoryAcquireTimeout { .. } => {
                RetryHint::Retryable
            }
            _ => RetryHint::NonRetryable,
        }
    }
}
