//! JSON-RPC 2.0 request/response types and helpers.

use poem::http::StatusCode;
use poem::{Body, Response};
use serde::{Deserialize, Serialize};
use serde_json::Value;

// ── JSON-RPC types ──────────────────────────────────────────────────────────

/// JSON-RPC request.
#[derive(Deserialize)]
pub(super) struct JsonRpcRequest {
    pub(super) jsonrpc: String,
    pub(super) id: Option<Value>,
    pub(super) method: String,
    #[serde(default)]
    pub(super) params: Value,
}

/// JSON-RPC response.
#[derive(Serialize)]
pub(crate) struct JsonRpcResponse {
    jsonrpc: &'static str,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub(crate) id: Option<Value>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub(crate) result: Option<Value>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub(crate) error: Option<JsonRpcError>,
}

#[derive(Debug, Serialize)]
pub(crate) struct JsonRpcError {
    code: i64,
    pub(crate) message: String,
}

impl JsonRpcResponse {
    pub(crate) fn success(id: Option<Value>, result: Value) -> Self {
        Self {
            jsonrpc: "2.0",
            id,
            result: Some(result),
            error: None,
        }
    }

    pub(crate) fn error(id: Option<Value>, code: i64, message: String) -> Self {
        Self {
            jsonrpc: "2.0",
            id,
            result: None,
            error: Some(JsonRpcError { code, message }),
        }
    }
}

pub(super) fn to_json_response(resp: JsonRpcResponse) -> Response {
    let body = serde_json::to_vec(&resp).unwrap_or_default();
    Response::builder()
        .status(StatusCode::OK)
        .header("Content-Type", "application/json")
        .body(Body::from(body))
}