use std::time::Duration;

use rand::Rng;
use tracing::debug;
use tracing::error;

const INITIAL_DELAY_MS: u64 = 200;
const BACKOFF_FACTOR: f64 = 2.0;

pub(crate) fn backoff(attempt: u64) -> Duration {
    let exp = BACKOFF_FACTOR.powi(attempt.saturating_sub(1) as i32);
    let base = (INITIAL_DELAY_MS as f64 * exp) as u64;
    let jitter = rand::rng().random_range(0.9..1.1);
    Duration::from_millis((base as f64 * jitter) as u64)
}

pub(crate) fn error_or_panic(message: String) {
    if cfg!(debug_assertions) || env!("CARGO_PKG_VERSION").contains("alpha") {
        panic!("{message}");
    } else {
        error!("{message}");
    }
}

pub(crate) fn try_parse_error_message(text: &str) -> String {
    debug!("Parsing server error response: {}", text);
    let json = serde_json::from_str::<serde_json::Value>(text).unwrap_or_default();
    if let Some(error) = json.get("error")
        && let Some(message) = error.get("message")
        && let Some(message_str) = message.as_str()
    {
        return message_str.to_string();
    }
    if text.is_empty() {
        return "Unknown error".to_string();
    }
    text.to_string()
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_try_parse_error_message() {
        let text = r#"{
  "error": {
    "message": "Your refresh token has already been used to generate a new access token. Please try signing in again.",
    "type": "invalid_request_error",
    "param": null,
    "code": "refresh_token_reused"
  }
}"#;
        let message = try_parse_error_message(text);
        assert_eq!(
            message,
            "Your refresh token has already been used to generate a new access token. Please try signing in again."
        );
    }

    #[test]
    fn test_try_parse_error_message_no_error() {
        let text = r#"{"message": "test"}"#;
        let message = try_parse_error_message(text);
        assert_eq!(message, r#"{"message": "test"}"#);
    }
}