#!/usr/bin/env bash
# Ensure single-line JSON emission with stdout discipline.
set -euo pipefail
# Track outgoing requests awaiting responses using files for Bash 3.2 compatibility
MCPBASH_NEXT_OUTGOING_ID="${MCPBASH_NEXT_OUTGOING_ID:-1}"
mcp_rpc_pending_path() {
local request_id="$1"
printf '%s/pending.%s.path' "${MCPBASH_STATE_DIR}" "${request_id}"
}
mcp_rpc_callback_path() {
local request_id="$1"
printf '%s/pending.%s.cb' "${MCPBASH_STATE_DIR}" "${request_id}"
}
mcp_rpc_next_outgoing_id() {
local id_file="${MCPBASH_STATE_DIR}/next.outgoing.id"
local id next_id
# Fallback to in-process counter if state/locks are unavailable (minimal mode)
if [ -z "${MCPBASH_STATE_DIR:-}" ] || [ -z "${MCPBASH_LOCK_ROOT:-}" ] || ! command -v mcp_lock_acquire >/dev/null 2>&1; then
id="${MCPBASH_NEXT_OUTGOING_ID}"
MCPBASH_NEXT_OUTGOING_ID=$((MCPBASH_NEXT_OUTGOING_ID + 1))
printf '%s' "${id}"
return 0
fi
mcp_lock_acquire "next_outgoing_id"
id="$(cat "${id_file}" 2>/dev/null || true)"
case "${id}" in
'' | *[!0-9]*) id="${MCPBASH_NEXT_OUTGOING_ID:-1}" ;;
esac
next_id=$((id + 1))
printf '%s' "${next_id}" >"${id_file}"
mcp_lock_release "next_outgoing_id"
printf '%s' "${id}"
}
mcp_rpc_register_pending() {
local request_id="$1"
local response_file="$2"
printf '%s' "${response_file}" >"$(mcp_rpc_pending_path "${request_id}")"
}
mcp_rpc_register_callback() {
local request_id="$1"
local callback="$2"
local generation="${3:-0}"
printf '%s %s' "${callback}" "${generation}" >"$(mcp_rpc_callback_path "${request_id}")"
}
mcp_rpc_unregister_pending() {
local request_id="$1"
rm -f "$(mcp_rpc_pending_path "${request_id}")"
}
mcp_rpc_cancel_pending() {
local request_id="$1"
rm -f "$(mcp_rpc_pending_path "${request_id}")" 2>/dev/null || true
rm -f "$(mcp_rpc_callback_path "${request_id}")" 2>/dev/null || true
}
mcp_rpc_handle_response() {
local json_payload="$1"
local id
id="$(mcp_json_extract_id "${json_payload}")"
# Callback-based responses (e.g., roots/list)
local callback_file
callback_file="$(mcp_rpc_callback_path "${id}")"
if [ -f "${callback_file}" ]; then
local callback generation
callback="$(cut -d' ' -f1 <"${callback_file}" 2>/dev/null || true)"
generation="$(cut -d' ' -f2 <"${callback_file}" 2>/dev/null || true)"
rm -f "${callback_file}"
if [ -z "${callback}" ]; then
return 1
fi
if [ -n "${generation}" ] && [ "${generation}" != "0" ] && [ -n "${MCPBASH_ROOTS_GENERATION:-}" ] && [ "${generation}" != "${MCPBASH_ROOTS_GENERATION}" ]; then
mcp_logging_debug "mcp.rpc" "Discarding stale response (gen ${generation}, current ${MCPBASH_ROOTS_GENERATION:-0})"
return 0
fi
"${callback}" "${json_payload}" "${generation}"
return 0
fi
local response_file
response_file="$(cat "$(mcp_rpc_pending_path "${id}")" 2>/dev/null || true)"
if [ -z "${response_file}" ]; then
mcp_logging_warning "mcp.rpc" "Received response for unknown request id=${id}"
return 1
fi
rm -f "$(mcp_rpc_pending_path "${id}")"
# Clear worker mapping if available (elicitation)
if declare -F mcp_elicitation_clear_request_id >/dev/null 2>&1; then
mcp_elicitation_clear_request_id "${id}"
fi
local normalized
if mcp_json_has_key "${json_payload}" "error"; then
local error_code error_message
error_code="$(printf '%s' "${json_payload}" | "${MCPBASH_JSON_TOOL_BIN}" -r '.error.code // -32603' 2>/dev/null || printf '%s' "-32603")"
error_message="$(printf '%s' "${json_payload}" | "${MCPBASH_JSON_TOOL_BIN}" -r '.error.message // "Unknown error"' 2>/dev/null || printf '%s' "Unknown error")"
mcp_logging_warning "mcp.elicitation" "Client error: code=${error_code} message=${error_message}"
normalized='{"action":"error","content":null}'
else
local action content action_json
action="$(printf '%s' "${json_payload}" | "${MCPBASH_JSON_TOOL_BIN}" -r '.result.action // "error"' 2>/dev/null || printf '%s' "error")"
content="$(printf '%s' "${json_payload}" | "${MCPBASH_JSON_TOOL_BIN}" -c '.result.content // null' 2>/dev/null || printf 'null')"
action_json="$(mcp_json_quote_text "${action}")"
normalized="$(printf '{"action":%s,"content":%s}' "${action_json}" "${content}")"
fi
printf '%s' "${normalized}" >"${response_file}"
return 0
}
rpc_send_line() {
local payload="$1"
mcp_io_send_line "${payload}"
}
rpc_send_line_direct() {
local payload="$1"
if [ -z "${payload}" ]; then
return 0
fi
if [ -z "${MCPBASH_DIRECT_FD:-}" ]; then
rpc_send_line "${payload}"
return 0
fi
(
exec 1>&"${MCPBASH_DIRECT_FD}"
rpc_send_line "${payload}"
)
}
