#!/usr/bin/env bash

set -euo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
RUN_DIR="$ROOT_DIR/.run"
LOG_DIR="$RUN_DIR/logs"

BACKEND_PID_FILE="$RUN_DIR/backend.pid"
FRONTEND_PID_FILE="$RUN_DIR/frontend.pid"
BACKEND_LOG="$LOG_DIR/backend.log"
FRONTEND_LOG="$LOG_DIR/frontend.log"

BACKEND_HOST="${BACKEND_HOST:-127.0.0.1}"
BACKEND_PORT="${BACKEND_PORT:-8001}"
FRONTEND_HOST="${FRONTEND_HOST:-127.0.0.1}"
FRONTEND_PORT="${FRONTEND_PORT:-3001}"
API_BASE_URL="${NEXT_PUBLIC_API_BASE_URL:-http://${BACKEND_HOST}:${BACKEND_PORT}}"

mkdir -p "$LOG_DIR"

is_running() {
  local pid_file="$1"
  if [[ -f "$pid_file" ]]; then
    local pid
    pid="$(cat "$pid_file")"
    if [[ -n "$pid" ]] && kill -0 "$pid" 2>/dev/null; then
      return 0
    fi
    rm -f "$pid_file"
  fi
  return 1
}

require_file() {
  local path="$1"
  local label="$2"
  if [[ ! -e "$path" ]]; then
    echo "$label not found: $path" >&2
    exit 1
  fi
}

require_file "$ROOT_DIR/backend/.venv/bin/uvicorn" "Backend virtualenv executable"
require_file "$ROOT_DIR/frontend/node_modules" "Frontend dependencies"

if is_running "$BACKEND_PID_FILE"; then
  echo "Backend already running on PID $(cat "$BACKEND_PID_FILE")"
else
  (
    cd "$ROOT_DIR/backend"
    exec .venv/bin/uvicorn app.main:app --reload --host "$BACKEND_HOST" --port "$BACKEND_PORT"
  ) >"$BACKEND_LOG" 2>&1 &
  echo $! >"$BACKEND_PID_FILE"
  echo "Started backend on http://${BACKEND_HOST}:${BACKEND_PORT} (PID $(cat "$BACKEND_PID_FILE"))"
fi

if is_running "$FRONTEND_PID_FILE"; then
  echo "Frontend already running on PID $(cat "$FRONTEND_PID_FILE")"
else
  (
    cd "$ROOT_DIR/frontend"
    export NEXT_PUBLIC_API_BASE_URL="$API_BASE_URL"
    exec npm run dev -- --hostname "$FRONTEND_HOST" --port "$FRONTEND_PORT"
  ) >"$FRONTEND_LOG" 2>&1 &
  echo $! >"$FRONTEND_PID_FILE"
  echo "Started frontend on http://${FRONTEND_HOST}:${FRONTEND_PORT} (PID $(cat "$FRONTEND_PID_FILE"))"
fi

cat <<EOF

Stack status
- Frontend: http://${FRONTEND_HOST}:${FRONTEND_PORT}
- Backend:  http://${BACKEND_HOST}:${BACKEND_PORT}
- API base: $API_BASE_URL
- Logs:     $LOG_DIR

Stop both services with:
  ./scripts/stop-stack.sh
EOF