#!/bin/sh
# Haiphen CLI installer
# Usage: curl -fsSL https://get.haiphen.io | sh
#
# Detects OS/arch, downloads the latest release from GitHub, verifies the
# SHA-256 checksum, and installs to /usr/local/bin (or ~/.local/bin).

set -e

REPO="haiphenAI/haiphen-cli"
BINARY_NAME="haiphen"

# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------

info()  { printf "\033[1;34m==>\033[0m %s\n" "$1"; }
warn()  { printf "\033[1;33mwarning:\033[0m %s\n" "$1" >&2; }
error() { printf "\033[1;31merror:\033[0m %s\n" "$1" >&2; exit 1; }

need() {
  command -v "$1" >/dev/null 2>&1 || error "Required command '$1' not found. Please install it and retry."
}

# ---------------------------------------------------------------------------
# Detect platform
# ---------------------------------------------------------------------------

detect_os() {
  case "$(uname -s)" in
    Darwin*)  echo "darwin" ;;
    Linux*)   echo "linux" ;;
    MINGW*|MSYS*|CYGWIN*) error "Windows detected. Use install.ps1 instead: irm https://get.haiphen.io/install.ps1 | iex" ;;
    *)        error "Unsupported OS: $(uname -s)" ;;
  esac
}

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

# ---------------------------------------------------------------------------
# Fetch latest release tag
# ---------------------------------------------------------------------------

latest_version() {
  need curl
  local url="https://api.github.com/repos/${REPO}/releases/latest"
  local tag
  tag=$(curl -fsSL "$url" 2>/dev/null | grep '"tag_name"' | head -1 | sed 's/.*"tag_name": *"//;s/".*//')
  if [ -z "$tag" ]; then
    # Fall back to releases listing (in case latest is a draft)
    tag=$(curl -fsSL "https://api.github.com/repos/${REPO}/releases" 2>/dev/null \
      | grep '"tag_name"' | head -1 | sed 's/.*"tag_name": *"//;s/".*//')
  fi
  [ -z "$tag" ] && error "Could not determine latest release version."
  echo "$tag"
}

# ---------------------------------------------------------------------------
# Download, verify, install
# ---------------------------------------------------------------------------

main() {
  need curl
  need tar
  if ! command -v sha256sum >/dev/null 2>&1 && ! command -v shasum >/dev/null 2>&1; then
    error "Required command 'sha256sum' or 'shasum' not found. Please install one and retry."
  fi

  local os arch version
  os=$(detect_os)
  arch=$(detect_arch)
  version=$(latest_version)
  local version_no_v="${version#v}"

  info "Installing ${BINARY_NAME} ${version} (${os}/${arch})"

  local archive="${BINARY_NAME}_${version_no_v}_${os}_${arch}.tar.gz"
  local base_url="https://github.com/${REPO}/releases/download/${version}"
  local tmpdir
  tmpdir=$(mktemp -d)

  # Download archive and checksums
  info "Downloading ${archive}..."
  curl -fsSL -o "${tmpdir}/${archive}" "${base_url}/${archive}" \
    || error "Failed to download ${base_url}/${archive}"

  info "Downloading checksums..."
  curl -fsSL -o "${tmpdir}/checksums.txt" "${base_url}/checksums.txt" \
    || error "Failed to download checksums"

  # Verify checksum
  info "Verifying checksum..."
  local expected
  expected=$(grep "${archive}" "${tmpdir}/checksums.txt" | awk '{print $1}')
  [ -z "$expected" ] && error "Archive not found in checksums.txt"

  local actual
  if command -v sha256sum >/dev/null 2>&1; then
    actual=$(sha256sum "${tmpdir}/${archive}" | awk '{print $1}')
  else
    actual=$(shasum -a 256 "${tmpdir}/${archive}" | awk '{print $1}')
  fi

  if [ "$expected" != "$actual" ]; then
    error "Checksum mismatch!\n  expected: ${expected}\n  actual:   ${actual}"
  fi

  # Extract
  info "Extracting..."
  tar -xzf "${tmpdir}/${archive}" -C "${tmpdir}"

  # Install
  local install_dir="/usr/local/bin"
  if [ ! -w "$install_dir" ] && [ "$(id -u)" -ne 0 ]; then
    install_dir="${HOME}/.local/bin"
    mkdir -p "$install_dir"
    warn "No write access to /usr/local/bin. Installing to ${install_dir}"
    warn "Make sure ${install_dir} is in your PATH."
  fi

  install -m 755 "${tmpdir}/${BINARY_NAME}" "${install_dir}/${BINARY_NAME}"

  # Cleanup
  rm -rf "$tmpdir"

  info "Installed ${BINARY_NAME} ${version} to ${install_dir}/${BINARY_NAME}"
  printf "\n  Run '\033[1m%s --help\033[0m' to get started.\n\n" "${BINARY_NAME}"
}

main "$@"