//! JSON-RPC wire envelopes used by exec-server.
//!
//! Exec-server uses the Codex JSON-RPC dialect, which omits the
//! `"jsonrpc": "2.0"` field on the wire.

use std::fmt;

use codex_protocol::protocol::W3cTraceContext;
use serde::Deserialize;
use serde::Serialize;

pub const JSONRPC_VERSION: &str = "2.0";

#[derive(Debug, Clone, PartialEq, PartialOrd, Ord, Deserialize, Serialize, Hash, Eq)]
#[serde(untagged)]
pub enum RequestId {
    String(String),
    Integer(i64),
}

impl fmt::Display for RequestId {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::String(value) => f.write_str(value),
            Self::Integer(value) => write!(f, "{value}"),
        }
    }
}

pub type Result = serde_json::Value;

/// Any valid exec-server JSON-RPC object that can be decoded from or encoded onto the wire.
#[derive(Debug, Clone, PartialEq, Deserialize, Serialize)]
#[serde(untagged)]
pub enum JSONRPCMessage {
    Request(JSONRPCRequest),
    Notification(JSONRPCNotification),
    Response(JSONRPCResponse),
    Error(JSONRPCError),
}

/// A request that expects a response.
#[derive(Debug, Clone, PartialEq, Deserialize, Serialize)]
pub struct JSONRPCRequest {
    pub id: RequestId,
    pub method: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub params: Option<serde_json::Value>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub trace: Option<W3cTraceContext>,
}

/// A notification that does not expect a response.
#[derive(Debug, Clone, PartialEq, Deserialize, Serialize)]
pub struct JSONRPCNotification {
    pub method: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub params: Option<serde_json::Value>,
}

/// A successful response to a request.
#[derive(Debug, Clone, PartialEq, Deserialize, Serialize)]
pub struct JSONRPCResponse {
    pub id: RequestId,
    pub result: Result,
}

/// A response indicating that a request failed.
#[derive(Debug, Clone, PartialEq, Deserialize, Serialize)]
pub struct JSONRPCError {
    pub error: JSONRPCErrorError,
    pub id: RequestId,
}

#[derive(Debug, Clone, PartialEq, Deserialize, Serialize)]
pub struct JSONRPCErrorError {
    pub code: i64,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub data: Option<serde_json::Value>,
    pub message: String,
}