#!/usr/bin/env bash
set -Eeuo pipefail

SCRIPT_PATH="$(readlink -f -- "${BASH_SOURCE[0]}" 2>/dev/null || true)"
if [[ -z "${SCRIPT_PATH}" ]]; then
  SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
else
  SCRIPT_DIR="$(cd -- "$(dirname -- "${SCRIPT_PATH}")" && pwd)"
fi
cd -- "${SCRIPT_DIR}"

SERVER_DIR="${SCRIPT_DIR}"
VENV_DIR="${SERVER_DIR}/.venv"
REQUIREMENTS_FILE="${SERVER_DIR}/requirements-server.txt"
REQUIREMENTS_HASH_FILE="${VENV_DIR}/.requirements-server.sha256"
CONFIG_FILE="${SERVER_DIR}/commonwealth-server.json"
ENTRY_POINT="${SERVER_DIR}/consumer_server_cli.py"

UPDATE_DEPENDENCIES=0
SERVER_ARGS=()
ARGS=("$@")
ARG_INDEX=0
while [[ ${ARG_INDEX} -lt ${#ARGS[@]} ]]; do
  arg="${ARGS[${ARG_INDEX}]}"
  case "${arg}" in
    --update-dependencies)
      UPDATE_DEPENDENCIES=1
      ;;
    --config|-c)
      ARG_INDEX=$((ARG_INDEX + 1))
      if [[ ${ARG_INDEX} -ge ${#ARGS[@]} ]]; then
        echo "ERROR: ${arg} requires a config file path." >&2
        exit 1
      fi
      CONFIG_FILE="${ARGS[${ARG_INDEX}]}"
      ;;
    --config=*)
      CONFIG_FILE="${arg#--config=}"
      ;;
    --host|--port|-H|-p|--interactive|-i)
      SERVER_ARGS+=("${arg}")
      if [[ "${arg}" == "--host" || "${arg}" == "-H" || "${arg}" == "--port" || "${arg}" == "-p" ]]; then
        ARG_INDEX=$((ARG_INDEX + 1))
        if [[ ${ARG_INDEX} -ge ${#ARGS[@]} ]]; then
          echo "ERROR: ${arg} requires a value." >&2
          exit 1
        fi
        SERVER_ARGS+=("${ARGS[${ARG_INDEX}]}")
      fi
      ;;
    --host=*|--port=*)
      SERVER_ARGS+=("${arg}")
      ;;
    *.json)
      # File managers / "Open with" often pass the config path as $1.
      CONFIG_FILE="${arg}"
      ;;
    -*)
      echo "ERROR: Unknown option: ${arg}" >&2
      echo "Supported: --update-dependencies, --config PATH, --host HOST, --port PORT, --interactive" >&2
      exit 1
      ;;
    *)
      if [[ -f "${arg}" ]]; then
        CONFIG_FILE="${arg}"
      else
        echo "ERROR: Unexpected argument: ${arg}" >&2
        exit 1
      fi
      ;;
  esac
  ARG_INDEX=$((ARG_INDEX + 1))
done

echo
echo "================================================================================"
echo " Commonwealth Online Server - Start Script"
echo "================================================================================"
echo

die() {
  echo "ERROR: $*" >&2
  exit 1
}

detect_python() {
  local candidate
  for candidate in python3 python; do
    if command -v "${candidate}" >/dev/null 2>&1; then
      if "${candidate}" -c 'import sys; raise SystemExit(0 if sys.version_info >= (3, 9) else 1)'; then
        echo "${candidate}"
        return 0
      fi
    fi
  done
  return 1
}

if [[ ! -f "${REQUIREMENTS_FILE}" ]]; then
  die "Missing requirements file: ${REQUIREMENTS_FILE}"
fi

if [[ ! -f "${ENTRY_POINT}" ]]; then
  die "Missing server entry point: ${ENTRY_POINT}"
fi

if ! BASE_PYTHON="$(detect_python)"; then
  die "Python 3.9+ is required. Install python3 (and python3-venv on Debian/Ubuntu)."
fi

echo "Using system interpreter: ${BASE_PYTHON} ($("${BASE_PYTHON}" --version 2>&1))"

if [[ ! -x "${VENV_DIR}/bin/python" ]]; then
  echo "Creating virtual environment at ${VENV_DIR}..."
  if ! "${BASE_PYTHON}" -m venv "${VENV_DIR}"; then
    die "Failed to create virtual environment. On Debian/Ubuntu install python3-venv."
  fi
fi

VENV_PYTHON="${VENV_DIR}/bin/python"
if [[ ! -x "${VENV_PYTHON}" ]]; then
  die "Virtual environment interpreter missing: ${VENV_PYTHON}"
fi

if ! "${VENV_PYTHON}" -c 'import sys; raise SystemExit(0 if sys.version_info >= (3, 9) else 1)'; then
  die "Virtual environment Python is older than 3.9."
fi

hash_requirements() {
  if command -v sha256sum >/dev/null 2>&1; then
    sha256sum -- "${REQUIREMENTS_FILE}" | awk '{print $1}'
  else
    "${VENV_PYTHON}" - <<'PY'
from hashlib import sha256
from pathlib import Path
print(sha256(Path("requirements-server.txt").read_bytes()).hexdigest())
PY
  fi
}

CURRENT_HASH="$(hash_requirements)"
STORED_HASH=""
if [[ -f "${REQUIREMENTS_HASH_FILE}" ]]; then
  STORED_HASH="$(tr -d '[:space:]' < "${REQUIREMENTS_HASH_FILE}")"
fi

NEED_INSTALL=0
if [[ ! -f "${REQUIREMENTS_HASH_FILE}" ]]; then
  NEED_INSTALL=1
elif [[ "${CURRENT_HASH}" != "${STORED_HASH}" ]]; then
  NEED_INSTALL=1
elif [[ "${UPDATE_DEPENDENCIES}" -eq 1 ]]; then
  NEED_INSTALL=1
fi

if [[ "${NEED_INSTALL}" -eq 1 ]]; then
  echo "Installing dedicated-server dependencies into .venv..."
  if ! "${VENV_PYTHON}" -m pip install --upgrade pip >/dev/null 2>&1; then
    echo "WARNING: Could not upgrade pip quietly; continuing with existing pip."
  fi
  if ! "${VENV_PYTHON}" -m pip install -r "${REQUIREMENTS_FILE}"; then
    die "Failed to install dependencies from ${REQUIREMENTS_FILE}."
  fi
  printf '%s\n' "${CURRENT_HASH}" > "${REQUIREMENTS_HASH_FILE}"
  echo "Dependencies installed."
else
  echo "Dependencies are up to date."
fi
echo

if [[ ! -f "${CONFIG_FILE}" ]]; then
  echo "Generating default configuration file..."
  if ! "${VENV_PYTHON}" -u "${ENTRY_POINT}" config init "${CONFIG_FILE}"; then
    die "Failed to generate config file."
  fi
  echo
fi

INTERACTIVE_ARGS=()
if [[ -t 0 && -t 1 ]]; then
  INTERACTIVE_ARGS+=(--interactive)
  echo "Starting Commonwealth Online Server (interactive)..."
  echo "Type help for commands. Type quit or press Ctrl+C to stop."
else
  echo "Starting Commonwealth Online Server (non-interactive)..."
  echo "Manage the server with: ${VENV_PYTHON} -u consumer_server_cli.py status"
fi
echo

# Resolve config to an absolute path after cd'ing into the server directory.
if [[ "${CONFIG_FILE}" != /* ]]; then
  CONFIG_FILE="${SERVER_DIR}/${CONFIG_FILE}"
fi
CONFIG_FILE="$(cd -- "$(dirname -- "${CONFIG_FILE}")" && pwd)/$(basename -- "${CONFIG_FILE}")"

# Do not source .venv/bin/activate — invoke the venv interpreter directly.
# Always pass --config explicitly so a bare path is never a positional serve arg.
CMD=(
  "${VENV_PYTHON}"
  -u
  "${ENTRY_POINT}"
  serve
  --config
  "${CONFIG_FILE}"
)
if [[ ${#INTERACTIVE_ARGS[@]} -gt 0 ]]; then
  CMD+=("${INTERACTIVE_ARGS[@]}")
fi
if [[ ${#SERVER_ARGS[@]} -gt 0 ]]; then
  CMD+=("${SERVER_ARGS[@]}")
fi
exec "${CMD[@]}"