// file: crates/ksp-offchain-transport-lib/src/http_settings.rs
// version: 3

//! Crate-wide bounded HTTP runtime settings shared by off-chain capability families.

const DEFAULT_CONNECT_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(5);
const DEFAULT_MAX_RESPONSE_BODY_BYTES: usize = 1_048_576;
const DEFAULT_REQUEST_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
#[cfg(test)]
const MAX_CONNECT_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(30);
#[cfg(test)]
const MAX_REQUEST_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(120);
#[cfg(test)]
const MAX_RESPONSE_BODY_BYTES: usize = 4_194_304;

/// Crate-internal HTTP client settings with defensive hard bounds.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub(crate) struct HttpClientSettings {
    connect_timeout: std::time::Duration,
    max_response_body_bytes: usize,
    request_timeout: std::time::Duration,
}

impl crate::HttpClientSettings {
    /// Creates one validated HTTP settings value for deterministic settings tests until runtime configuration consumes this constructor.
    #[cfg(test)]
    pub(crate) fn new(
        connect_timeout: std::time::Duration,
        request_timeout: std::time::Duration,
        max_response_body_bytes: usize,
    ) -> ksp_core_lib::Result<Self> {
        if connect_timeout.is_zero() || connect_timeout > MAX_CONNECT_TIMEOUT {
            return invalid_http_settings("HTTP connect timeout is outside the supported bounds", "connect_timeout");
        }
        if request_timeout.is_zero() || request_timeout > MAX_REQUEST_TIMEOUT {
            return invalid_http_settings("HTTP request timeout is outside the supported bounds", "request_timeout");
        }
        if connect_timeout > request_timeout {
            return invalid_http_settings("HTTP connect timeout cannot exceed the total request timeout", "connect_timeout");
        }
        if max_response_body_bytes == 0 || max_response_body_bytes > MAX_RESPONSE_BODY_BYTES {
            return invalid_http_settings("HTTP response-body limit is outside the supported bounds", "max_response_body_bytes");
        }
        return std::result::Result::Ok(Self { connect_timeout, max_response_body_bytes, request_timeout });
    }

    /// Returns the bounded connect timeout.
    #[must_use]
    pub(crate) const fn connect_timeout(&self) -> std::time::Duration {
        return self.connect_timeout;
    }

    /// Returns the maximum decoded response body accepted before JSON parsing.
    #[must_use]
    pub(crate) const fn max_response_body_bytes(&self) -> usize {
        return self.max_response_body_bytes;
    }

    /// Returns the end-to-end request timeout.
    #[must_use]
    pub(crate) const fn request_timeout(&self) -> std::time::Duration {
        return self.request_timeout;
    }
}

impl std::default::Default for crate::HttpClientSettings {
    fn default() -> Self {
        return Self {
            connect_timeout: DEFAULT_CONNECT_TIMEOUT,
            max_response_body_bytes: DEFAULT_MAX_RESPONSE_BODY_BYTES,
            request_timeout: DEFAULT_REQUEST_TIMEOUT,
        };
    }
}

#[cfg(test)]
fn invalid_http_settings(message: &str, field: &'static str) -> ksp_core_lib::Result<crate::HttpClientSettings> {
    ksp_logging_lib::warn!(target: crate::TRACING_TARGET, field = field, "rejected invalid off-chain HTTP client settings");
    return std::result::Result::Err(ksp_core_lib::Error::new(crate::ERROR_CODE_HTTP_SETTINGS_INVALID, message).with_context("field", field));
}

#[cfg(test)]
#[path = "../unit_tests/http_settings.rs"]
mod tests;