//! P2P handlers — publish/resolve endpoints and health check.

use std::sync::Arc;

use bytes::Bytes;
use prost::Message;
use quicprochat_proto::qpc::v1;
use quicprochat_rpc::method::{HandlerResult, RequestContext};

use crate::domain::p2p::P2pService;
use crate::domain::types::{CallerAuth, PublishEndpointReq, ResolveEndpointReq};

use super::{domain_err, require_auth, ServerState};

fn caller_auth(identity_key: Vec<u8>) -> CallerAuth {
    CallerAuth {
        identity_key,
        token: Vec::new(),
        device_id: None,
    }
}

pub async fn handle_publish_endpoint(
    state: Arc<ServerState>,
    ctx: RequestContext,
) -> HandlerResult {
    let identity_key = match require_auth(&state, &ctx) {
        Ok(ik) => ik,
        Err(e) => return e,
    };

    let req = match v1::PublishEndpointRequest::decode(ctx.payload) {
        Ok(r) => r,
        Err(e) => {
            return HandlerResult::err(
                quicprochat_rpc::error::RpcStatus::BadRequest,
                &format!("decode: {e}"),
            )
        }
    };

    let svc = P2pService {
        store: Arc::clone(&state.store),
    };
    let auth = caller_auth(identity_key);

    let domain_req = PublishEndpointReq {
        identity_key: req.identity_key,
        node_addr: req.node_addr,
    };

    match svc.publish_endpoint(domain_req, &auth) {
        Ok(()) => {
            let proto = v1::PublishEndpointResponse {};
            HandlerResult::ok(Bytes::from(proto.encode_to_vec()))
        }
        Err(e) => domain_err(e),
    }
}

pub async fn handle_resolve_endpoint(
    state: Arc<ServerState>,
    ctx: RequestContext,
) -> HandlerResult {
    let identity_key = match require_auth(&state, &ctx) {
        Ok(ik) => ik,
        Err(e) => return e,
    };

    let req = match v1::ResolveEndpointRequest::decode(ctx.payload) {
        Ok(r) => r,
        Err(e) => {
            return HandlerResult::err(
                quicprochat_rpc::error::RpcStatus::BadRequest,
                &format!("decode: {e}"),
            )
        }
    };

    let svc = P2pService {
        store: Arc::clone(&state.store),
    };
    let auth = caller_auth(identity_key);

    let domain_req = ResolveEndpointReq {
        identity_key: req.identity_key,
    };

    match svc.resolve_endpoint(domain_req, &auth) {
        Ok(resp) => {
            let proto = v1::ResolveEndpointResponse {
                node_addr: resp.node_addr,
            };
            HandlerResult::ok(Bytes::from(proto.encode_to_vec()))
        }
        Err(e) => domain_err(e),
    }
}

pub async fn handle_health(
    state: Arc<ServerState>,
    _ctx: RequestContext,
) -> HandlerResult {
    let status = if state.draining.load(std::sync::atomic::Ordering::Relaxed) {
        "draining"
    } else {
        "ok"
    };
    let uptime = state.start_time.elapsed().as_secs();
    let resp = v1::HealthResponse {
        status: status.into(),
        node_id: state.node_id.clone(),
        version: env!("CARGO_PKG_VERSION").to_string(),
        uptime_secs: uptime,
        storage_backend: state.storage_backend.clone(),
    };
    HandlerResult::ok(Bytes::from(resp.encode_to_vec()))
}