#!/usr/bin/env bash
set -e

REPO="monto-fe/smtp-probe"
BINARY="smtp-probe"
VERSION="${VERSION:-latest}"

info() {
  echo -e "\033[1;34m$1\033[0m" >&2
}

warn() {
  echo -e "\033[1;33m$1\033[0m" >&2
}

error() {
  echo -e "\033[1;31m$1\033[0m" >&2
  exit 1
}

detect_os() {
  local os
  os="$(uname -s)"
  case "${os}" in
    Linux*)  echo "linux";;
    Darwin*) echo "darwin";;
    MINGW*|MSYS*|CYGWIN*) echo "windows";;
    *) error "Unsupported operating system: ${os}";;
  esac
}

detect_arch() {
  local arch
  arch="$(uname -m)"
  case "${arch}" in
    x86_64|amd64)   echo "amd64";;
    arm64|aarch64)  echo "arm64";;
    *) error "Unsupported architecture: ${arch}";;
  esac
}

detect_install_dir() {
  if [ -n "${INSTALL_DIR}" ]; then
    echo "${INSTALL_DIR}"
    return
  fi

  local candidates=(
    /usr/local/bin
    /usr/bin
    "${HOME}/.local/bin"
  )

  for dir in "${candidates[@]}"; do
    if [[ ":$PATH:" == *":${dir}:"* ]]; then
      if [ -w "${dir}" ] 2>/dev/null || [ "$(id -u)" = "0" ]; then
        echo "${dir}"
        return
      fi
    fi
  done

  echo "${HOME}/.local/bin"
}

get_latest_version() {
  curl -fsSL "https://api.github.com/repos/${REPO}/releases/latest" | grep '"tag_name":' | sed -E 's/.*"([^"]+)".*/\1/'
}

download_binary() {
  local os="$1"
  local arch="$2"
  local version="$3"
  
  local url="https://github.com/${REPO}/releases/download/${version}/${BINARY}-${os}-${arch}.tar.gz"
  local tmp_dir
  tmp_dir="$(mktemp -d)"
  
  info "Downloading ${BINARY} ${version} for ${os}/${arch}..."
  
  if ! curl -fsSL -o "${tmp_dir}/${BINARY}.tar.gz" "${url}"; then
    error "Failed to download ${url}"
  fi
  
  tar -xzf "${tmp_dir}/${BINARY}.tar.gz" -C "${tmp_dir}"
  echo "${tmp_dir}/${BINARY}"
}

install_binary() {
  local binary_path="$1"
  local install_dir="$2"

  mkdir -p "${install_dir}"

  if [ -w "${install_dir}" ] 2>/dev/null; then
    mv "${binary_path}" "${install_dir}/${BINARY}"
    chmod +x "${install_dir}/${BINARY}"
    echo "${install_dir}"
  else
    warn "Permission denied for ${install_dir}, trying with sudo..."
    sudo mkdir -p "${install_dir}"
    sudo mv "${binary_path}" "${install_dir}/${BINARY}"
    sudo chmod +x "${install_dir}/${BINARY}"
    echo "${install_dir}"
  fi
}

ensure_in_path() {
  local install_dir="$1"

  if [[ ":$PATH:" == *":${install_dir}:"* ]]; then
    return 0
  fi

  local shell_profile=""
  if [ -n "$ZSH_VERSION" ] || [ "$SHELL" = "/bin/zsh" ]; then
    shell_profile="${HOME}/.zshrc"
  elif [ -n "$BASH_VERSION" ] || [ "$SHELL" = "/bin/bash" ]; then
    shell_profile="${HOME}/.bashrc"
  else
    shell_profile="${HOME}/.profile"
  fi

  local path_line="export PATH=\"${install_dir}:\$PATH\""

  if [ -f "${shell_profile}" ] && grep -qF "${install_dir}" "${shell_profile}" 2>/dev/null; then
    warn "\n${install_dir} already referenced in ${shell_profile}, but not in current PATH."
    warn "Run: source ${shell_profile}"
    return 0
  fi

  echo "${path_line}" >> "${shell_profile}"
  export PATH="${install_dir}:${PATH}"
  info "Added ${install_dir} to PATH in ${shell_profile}"
}

main() {
  info "Installing ${BINARY}...\n"

  local os arch version target_dir tmp_binary install_dir

  os="$(detect_os)"
  arch="$(detect_arch)"
  target_dir="$(detect_install_dir)"

  if [ "${VERSION}" = "latest" ]; then
    version="$(get_latest_version)"
    if [ -z "${version}" ]; then
      error "Failed to fetch latest version"
    fi
  else
    version="${VERSION}"
  fi

  info "Detected: ${os}/${arch}"
  info "Version: ${version}"
  info "Install target: ${target_dir}\n"

  tmp_binary="$(download_binary "${os}" "${arch}" "${version}")"
  install_dir="$(install_binary "${tmp_binary}" "${target_dir}")"

  rm -rf "$(dirname "${tmp_binary}")"

  ensure_in_path "${install_dir}"

  info "\n✓ ${BINARY} ${version} installed successfully to ${install_dir}/${BINARY}\n"
  info "Run 'smtp-probe --help' to get started.\n"
}

main "$@"