#!/bin/sh
# Backup Ring agent installer
# Usage: curl -fsSL https://get.backupring.app | sh
#
# Options (env vars):
#   BACKUPRING_VERSION  - specific version to install (default: latest)
#   BACKUPRING_DIR      - install directory (default: ~/.local/bin)

set -e

REPO="backup-rings/repo"
API_URL="https://api.backupring.app"
BINARY_NAME="backupring"

# --- Platform detection ---

detect_os() {
  case "$(uname -s)" in
    Linux*)  echo "linux" ;;
    Darwin*) echo "darwin" ;;
    *)       echo "unsupported"; return 1 ;;
  esac
}

detect_arch() {
  case "$(uname -m)" in
    x86_64|amd64)  echo "amd64" ;;
    aarch64|arm64)  echo "arm64" ;;
    *)              echo "unsupported"; return 1 ;;
  esac
}

# --- Helpers ---

info()  { printf '  \033[1;32m%s\033[0m %s\n' "$1" "$2"; }
warn()  { printf '  \033[1;33m%s\033[0m %s\n' "$1" "$2"; }
error() { printf '  \033[1;31m%s\033[0m %s\n' "error:" "$1" >&2; exit 1; }

need_cmd() {
  if ! command -v "$1" > /dev/null 2>&1; then
    error "need '$1' (command not found)"
  fi
}

# --- Main ---

main() {
  need_cmd uname
  need_cmd curl

  OS=$(detect_os)   || error "unsupported operating system: $(uname -s)"
  ARCH=$(detect_arch) || error "unsupported architecture: $(uname -m)"

  info "platform:" "${OS}/${ARCH}"

  # Resolve version
  if [ -n "$BACKUPRING_VERSION" ]; then
    VERSION="$BACKUPRING_VERSION"
  else
    info "fetching:" "latest version"
    VERSION=$(curl -fsSL "${API_URL}/v1/releases/latest" | grep -o '"version":"[^"]*"' | head -1 | cut -d'"' -f4)
    if [ -z "$VERSION" ]; then
      # Fallback: check GitHub releases
      VERSION=$(curl -fsSL "https://api.github.com/repos/${REPO}/releases/latest" | grep -o '"tag_name":"[^"]*"' | head -1 | cut -d'"' -f4)
      VERSION="${VERSION#v}"
    fi
    if [ -z "$VERSION" ]; then
      error "could not determine latest version"
    fi
  fi

  info "version:" "$VERSION"

  # Install directory
  INSTALL_DIR="${BACKUPRING_DIR:-$HOME/.local/bin}"
  mkdir -p "$INSTALL_DIR"

  # Download URL
  ARCHIVE="${BINARY_NAME}-v${VERSION}-${OS}-${ARCH}.tar.gz"
  DOWNLOAD_URL="https://github.com/${REPO}/releases/download/v${VERSION}/${ARCHIVE}"

  info "downloading:" "$DOWNLOAD_URL"

  TMPDIR=$(mktemp -d)
  trap 'rm -rf "$TMPDIR"' EXIT

  curl -fsSL "$DOWNLOAD_URL" -o "${TMPDIR}/${ARCHIVE}"

  # Verify checksum if available
  CHECKSUM_URL="https://github.com/${REPO}/releases/download/v${VERSION}/checksums.txt"
  if curl -fsSL "$CHECKSUM_URL" -o "${TMPDIR}/checksums.txt" 2>/dev/null; then
    EXPECTED=$(grep "$ARCHIVE" "${TMPDIR}/checksums.txt" | awk '{print $1}')
    if [ -n "$EXPECTED" ]; then
      if command -v b3sum > /dev/null 2>&1; then
        ACTUAL=$(b3sum "${TMPDIR}/${ARCHIVE}" | awk '{print $1}')
        if [ "$ACTUAL" != "$EXPECTED" ]; then
          error "checksum mismatch: expected ${EXPECTED}, got ${ACTUAL}"
        fi
        info "checksum:" "verified (blake3)"
      elif command -v sha256sum > /dev/null 2>&1; then
        warn "note:" "b3sum not found, skipping checksum verification"
      fi
    fi
  fi

  # Extract and install
  tar -xzf "${TMPDIR}/${ARCHIVE}" -C "$TMPDIR"
  mv "${TMPDIR}/${BINARY_NAME}" "${INSTALL_DIR}/${BINARY_NAME}"
  chmod +x "${INSTALL_DIR}/${BINARY_NAME}"

  info "installed:" "${INSTALL_DIR}/${BINARY_NAME}"

  # Check if install dir is in PATH
  case ":${PATH}:" in
    *":${INSTALL_DIR}:"*) ;;
    *)
      warn "note:" "${INSTALL_DIR} is not in your PATH"
      echo ""
      echo "  Add it with:"
      echo "    export PATH=\"${INSTALL_DIR}:\$PATH\""
      echo ""
      echo "  Or add to your shell profile (~/.bashrc, ~/.zshrc, etc.):"
      echo "    echo 'export PATH=\"${INSTALL_DIR}:\$PATH\"' >> ~/.bashrc"
      ;;
  esac

  echo ""
  info "done!" "Run 'backupring init' to get started."
  echo ""
}

main "$@"