#!/bin/bash
# ── Hermes Workspace Combined Entrypoint ──
# Waits for the Hermes gateway container (hermes:8642) to become healthy,
# then starts the Hermes Workspace web UI in the foreground.
# Supports graceful shutdown via SIGTERM/SIGINT.
# ──────────────────────────────────────────

set -euo pipefail

# ── Configuration ──────────────────────────────────────────────
GATEWAY_HOST="${GATEWAY_HOST:-hermes}"
GATEWAY_PORT="${GATEWAY_PORT:-8642}"
GATEWAY_URL="http://${GATEWAY_HOST}:${GATEWAY_PORT}"

HEALTH_ENDPOINT="${HEALTH_ENDPOINT:-/health}"
MAX_RETRIES="${HEALTH_MAX_RETRIES:-60}"
RETRY_INTERVAL="${HEALTH_RETRY_INTERVAL:-2}"

WORKSPACE_DIR="${WORKSPACE_DIR:-/workspace}"
WORKSPACE_ENTRY="${WORKSPACE_ENTRY:-server-entry.js}"

PID_FILE="${PID_FILE:-/tmp/workspace.pid}"

# ── Logging ────────────────────────────────────────────────────
log_info()  { echo "[$(date '+%Y-%m-%d %H:%M:%S')] [INFO]  $*"; }
log_warn()  { echo "[$(date '+%Y-%m-%d %H:%M:%S')] [WARN]  $*"; }
log_error() { echo "[$(date '+%Y-%m-%d %H:%M:%S')] [ERROR] $*"; }

# ── Graceful Shutdown ──────────────────────────────────────────
_workspace_pid=""
_shutting_down=false

cleanup() {
    if [ "$_shutting_down" = true ]; then
        return
    fi
    _shutting_down=true

    log_info "Shutdown signal received, cleaning up..."

    # Stop workspace process if running
    if [ -n "$_workspace_pid" ] && kill -0 "$_workspace_pid" 2>/dev/null; then
        log_info "Stopping workspace (PID: $_workspace_pid)..."
        kill -TERM "$_workspace_pid" 2>/dev/null || true

        # Give it time to shut down gracefully
        local wait_sec=10
        while kill -0 "$_workspace_pid" 2>/dev/null && [ "$wait_sec" -gt 0 ]; do
            sleep 1
            wait_sec=$((wait_sec - 1))
        done

        # Force kill if still running
        if kill -0 "$_workspace_pid" 2>/dev/null; then
            log_warn "Workspace did not shut down gracefully, force killing..."
            kill -KILL "$_workspace_pid" 2>/dev/null || true
        fi
    fi

    # Clean up PID file
    [ -f "$PID_FILE" ] && rm -f "$PID_FILE"

    log_info "Shutdown complete."
    exit 0
}

# Trap termination signals for graceful shutdown
trap cleanup SIGTERM SIGINT

# ── Gateway Health Check ───────────────────────────────────────
wait_for_gateway() {
    local url="${GATEWAY_URL}${HEALTH_ENDPOINT}"
    local retries="$MAX_RETRIES"
    local interval="$RETRY_INTERVAL"
    local attempt=0

    log_info "Waiting for Hermes gateway at ${GATEWAY_URL}..."
    log_info "Max retries: ${retries}, interval: ${interval}s"

    while [ "$attempt" -lt "$retries" ]; do
        attempt=$((attempt + 1))

        if curl -fsS "${url}" >/dev/null 2>&1; then
            log_info "Gateway is healthy after ${attempt} attempt(s) (${GATEWAY_URL})"
            return 0
        fi

        if [ "$attempt" -lt "$retries" ]; then
            log_info "Gateway not ready yet (attempt ${attempt}/${retries}), retrying in ${interval}s..."
            sleep "$interval"
        fi
    done

    log_error "Gateway did not become healthy after ${retries} attempts (${retries * interval}s)"
    return 1
}

# ── Workspace Startup ──────────────────────────────────────────
start_workspace() {
    local entry="${WORKSPACE_DIR}/${WORKSPACE_ENTRY}"

    if [ ! -d "$WORKSPACE_DIR" ]; then
        log_error "Workspace directory not found: ${WORKSPACE_DIR}"
        return 1
    fi

    if [ ! -f "$entry" ]; then
        log_error "Workspace entry point not found: ${entry}"
        return 1
    fi

    log_info "Starting Hermes Workspace web UI..."
    log_info "  Directory: ${WORKSPACE_DIR}"
    log_info "  Entry:     ${entry}"

    cd "$WORKSPACE_DIR"

    # Start workspace in background so we can trap signals
    exec node --max-old-space-size=2048 "${entry}" &
    _workspace_pid=$!
    echo "$_workspace_pid" > "$PID_FILE"

    log_info "Workspace started (PID: ${_workspace_pid})"

    # Wait for workspace process
    wait "$_workspace_pid"
    local exit_code=$?

    log_info "Workspace exited with code ${exit_code}"
    return "$exit_code"
}

# ── Main ───────────────────────────────────────────────────────
main() {
    log_info "=== Hermes Workspace Combined Entrypoint ==="
    log_info "Gateway:   ${GATEWAY_URL}"
    log_info "Workspace: ${WORKSPACE_DIR}/${WORKSPACE_ENTRY}"
    log_info "PID file:  ${PID_FILE}"

    # Wait for gateway to be healthy
    if ! wait_for_gateway; then
        log_warn "Proceeding without confirmed gateway health..."
    fi

    # Start the workspace
    start_workspace
    local exit_code=$?

    log_info "Entrypoint exiting with code ${exit_code}"
    return "$exit_code"
}

# Run main; exit with its return code
main "$@"