#!/usr/bin/env bash

set -euo pipefail

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

BACKEND_PID_FILE="$RUN_DIR/backend.pid"
FRONTEND_PID_FILE="$RUN_DIR/frontend.pid"
BACKEND_LOG_FILE="$LOG_DIR/backend.log"
FRONTEND_LOG_FILE="$LOG_DIR/frontend.log"

BACKEND_HOST="${BACKEND_HOST:-0.0.0.0}"
BACKEND_PORT="${BACKEND_PORT:-8000}"
FRONTEND_HOST="${FRONTEND_HOST:-0.0.0.0}"
FRONTEND_PORT="${FRONTEND_PORT:-8451}"
CORS_ORIGINS="${CORS_ORIGINS:-http://localhost:${FRONTEND_PORT},http://127.0.0.1:${FRONTEND_PORT}}"
VITE_PROXY_TARGET="${VITE_PROXY_TARGET:-http://127.0.0.1:${BACKEND_PORT}}"

mkdir -p "$RUN_DIR" "$LOG_DIR"

require_command() {
  if ! command -v "$1" >/dev/null 2>&1; then
    echo "Missing command: $1" >&2
    exit 1
  fi
}

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

wait_for_port() {
  local host="$1"
  local port="$2"
  local name="$3"
  local retries=30

  while (( retries > 0 )); do
    if python3 - "$host" "$port" <<'PY'
import socket
import sys

host = sys.argv[1]
port = int(sys.argv[2])
sock = socket.socket()
sock.settimeout(0.5)
try:
    sock.connect((host, port))
except OSError:
    sys.exit(1)
finally:
    sock.close()
sys.exit(0)
PY
    then
      echo "$name is ready on ${host}:${port}"
      return 0
    fi
    sleep 1
    retries=$((retries - 1))
  done

  echo "$name failed to start on ${host}:${port}. Check logs in $LOG_DIR" >&2
  return 1
}

require_command python3
require_command node
require_command npm
require_command ffmpeg

if ! python3 - <<'PY' >/dev/null 2>&1
import fastapi
import uvicorn
import multipart
PY
then
  echo "Missing Python packages. Run: cd backend && python3 -m pip install --user -r requirements.txt" >&2
  exit 1
fi

if [[ ! -d "$ROOT_DIR/frontend/node_modules" ]]; then
  echo "Installing frontend dependencies..."
  (
    cd "$ROOT_DIR/frontend"
    npm install
  )
fi

if cleanup_stale_pid "$BACKEND_PID_FILE"; then
  echo "Backend already running with PID $(cat "$BACKEND_PID_FILE")"
else
  echo "Starting backend..."
  (
    cd "$ROOT_DIR/backend"
    nohup env \
      CORS_ORIGINS="$CORS_ORIGINS" \
      python3 -m uvicorn app.main:app \
      --host "$BACKEND_HOST" \
      --port "$BACKEND_PORT" \
      >"$BACKEND_LOG_FILE" 2>&1 &
    echo $! > "$BACKEND_PID_FILE"
  )
fi

wait_for_port "127.0.0.1" "$BACKEND_PORT" "backend"

if cleanup_stale_pid "$FRONTEND_PID_FILE"; then
  echo "Frontend already running with PID $(cat "$FRONTEND_PID_FILE")"
else
  echo "Starting frontend..."
  (
    cd "$ROOT_DIR/frontend"
    nohup env \
      VITE_PROXY_TARGET="$VITE_PROXY_TARGET" \
      npm run dev -- --host "$FRONTEND_HOST" --port "$FRONTEND_PORT" \
      >"$FRONTEND_LOG_FILE" 2>&1 &
    echo $! > "$FRONTEND_PID_FILE"
  )
fi

wait_for_port "127.0.0.1" "$FRONTEND_PORT" "frontend"

SERVER_IP="$(hostname -I 2>/dev/null | awk '{print $1}')"
if [[ -z "$SERVER_IP" ]]; then
  SERVER_IP="127.0.0.1"
fi

cat <<EOF
VPlatform started in background.
Frontend: http://${SERVER_IP}:${FRONTEND_PORT}
Backend:  http://${SERVER_IP}:${BACKEND_PORT}

Logs:
  $BACKEND_LOG_FILE
  $FRONTEND_LOG_FILE
EOF