//! The `ops-agent` HTTP wire contract, shared by the `AgentRpc` client
//! ([`crate::rpc`]) and the agent server ([`crate::agent`]).
//!
//! `/run` streams a body of newline-delimited JSON [`Frame`]s: zero or more
//! `chunk` frames (merged stdout+stderr as it arrives), then exactly one
//! terminal frame — `exit` on a clean run or `error` if the agent refused or
//! failed before the child produced an exit code.

use crate::step::Step;
use serde::{Deserialize, Serialize};

/// `POST /run` request body.
#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct RunRequest {
    pub step: Step,
}

/// One newline-delimited frame in a `/run` response stream.
#[derive(Clone, Debug, Serialize, Deserialize)]
#[serde(tag = "t", rename_all = "snake_case")]
pub enum Frame {
    /// A slice of merged stdout/stderr (UTF-8-lossy; not line-aligned).
    Chunk { text: String },
    /// Terminal: the child exited with this code.
    Exit { code: i32 },
    /// Terminal: the agent refused (capability/identity) or failed to spawn.
    Error { message: String },
}

impl Frame {
    /// Serialize as one NDJSON line (trailing `\n` included).
    pub fn to_line(&self) -> String {
        let mut s = serde_json::to_string(self).unwrap_or_else(|e| {
            format!("{{\"t\":\"error\",\"message\":\"frame serialize failed: {e}\"}}")
        });
        s.push('\n');
        s
    }
}

/// `GET /health` response body.
#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct HealthResponse {
    pub ok: bool,
    /// The agent's own actuate grant tokens (introspection / audit).
    pub actuate: Vec<String>,
    /// The agent's own observe grant tokens.
    pub observe: Vec<String>,
}