#!/bin/bash
  #

  # Create isolated venv for one reranker backend.

  #
  set -euo pipefail
  
  PROJECT_ROOT="$(cd "$(dirname "$0")/.." && pwd)"
  cd "${PROJECT_ROOT}"
  

  PYTHON_BIN="${PYTHON_BIN:-python3}"
  TMP_DIR="${RERANKER_PIP_TMPDIR:-${PROJECT_ROOT}/.tmp/reranker-pip}"
  

  # shellcheck source=scripts/lib/load_env.sh
  source "${PROJECT_ROOT}/scripts/lib/load_env.sh"
  load_env_file "${PROJECT_ROOT}/.env"
  # shellcheck source=scripts/lib/reranker_backend_env.sh
  source "${PROJECT_ROOT}/scripts/lib/reranker_backend_env.sh"
  
  BACKEND="${1:-$(detect_rerank_backend "${PROJECT_ROOT}")}"
  VENV_DIR="${RERANKER_VENV:-$(reranker_backend_venv_dir "${PROJECT_ROOT}" "${BACKEND}")}"
  REQ_FILE="$(reranker_backend_requirements_file "${PROJECT_ROOT}" "${BACKEND}")"
  
  if [[ ! -f "${REQ_FILE}" ]]; then
    echo "ERROR: requirements file not found for reranker backend ${BACKEND}: ${REQ_FILE}" >&2
    exit 1
  fi
  

  if ! command -v "${PYTHON_BIN}" >/dev/null 2>&1; then
    echo "ERROR: python not found: ${PYTHON_BIN}" >&2
    exit 1
  fi
  
  if [[ -d "${VENV_DIR}" && ! -f "${VENV_DIR}/bin/activate" ]]; then
    echo "Found broken venv at ${VENV_DIR}, recreating..."
    rm -rf "${VENV_DIR}"
  fi
  
  if [[ ! -d "${VENV_DIR}" ]]; then
    echo "Creating ${VENV_DIR}"
    "${PYTHON_BIN}" -m venv "${VENV_DIR}"
  else
    echo "Reusing ${VENV_DIR}"
  fi
  
  mkdir -p "${TMP_DIR}"
  export TMPDIR="${TMP_DIR}"
  PIP_ARGS=(--no-cache-dir)
  
  echo "Using TMPDIR=${TMPDIR}"
  "${VENV_DIR}/bin/python" -m pip install "${PIP_ARGS[@]}" --upgrade pip wheel

  "${VENV_DIR}/bin/python" -m pip install "${PIP_ARGS[@]}" -r "${REQ_FILE}"

  if [[ "${BACKEND}" == qwen3_gguf* ]]; then
    if [[ -x "/usr/local/cuda/bin/nvcc" ]]; then
      "${VENV_DIR}/bin/python" -m pip install "${PIP_ARGS[@]}" \
        cmake \
        ninja \
        scikit-build-core \
        flit_core \
        setuptools-scm
      echo "Rebuilding llama-cpp-python with CUDA support for ${BACKEND}"
      PATH="/usr/local/cuda/bin:/usr/bin:/bin" \
      CC="/usr/bin/x86_64-linux-gnu-gcc" \
      CXX="/usr/bin/x86_64-linux-gnu-g++" \
      CUDACXX="/usr/local/cuda/bin/nvcc" \
      CMAKE_ARGS="-DGGML_CUDA=on" \
      FORCE_CMAKE=1 \
      "${VENV_DIR}/bin/python" -m pip install "${PIP_ARGS[@]}" \
        --force-reinstall \
        --no-build-isolation \
        "llama-cpp-python==0.3.18"
    else
      echo "WARNING: /usr/local/cuda/bin/nvcc not found; ${BACKEND} will be installed without CUDA support." >&2
    fi
  fi
  

  echo
  echo "Done."

  echo "Backend: ${BACKEND}"

  echo "Reranker venv: ${VENV_DIR}"

  echo "Requirements: ${REQ_FILE}"

  echo "Start service: ./scripts/start_reranker.sh"