#!/bin/bash

# NUPST Installer Script (v4.0+)
# Downloads and installs pre-compiled NUPST binary from Gitea releases
#
# Usage:
#   Direct piped installation (recommended):
#     curl -sSL https://code.foss.global/serve.zone/nupst/raw/branch/main/install.sh | sudo bash
#
#   With version specification:
#     curl -sSL https://code.foss.global/serve.zone/nupst/raw/branch/main/install.sh | sudo bash -s -- --version v4.0.0
#
#   Non-interactive mode (auto-confirm):
#     curl -sSL https://code.foss.global/serve.zone/nupst/raw/branch/main/install.sh | sudo bash -s -- -y
#
#   Downloaded script:
#     curl -sSL https://code.foss.global/serve.zone/nupst/raw/branch/main/install.sh -o nupst-install.sh
#     sudo bash nupst-install.sh
#
# Options:
#   -y, --yes              Automatically answer yes to all prompts
#   -h, --help             Show this help message
#   --version VERSION      Install specific version (e.g., v4.0.0)
#   --install-dir DIR      Installation directory (default: /opt/nupst)

set -e

# Default values
AUTO_YES=0
SHOW_HELP=0
SPECIFIED_VERSION=""
INSTALL_DIR="/opt/nupst"
GITEA_BASE_URL="https://code.foss.global"
GITEA_REPO="serve.zone/nupst"

# Parse command line arguments
while [[ $# -gt 0 ]]; do
  case $1 in
    -y|--yes)
      AUTO_YES=1
      shift
      ;;
    -h|--help)
      SHOW_HELP=1
      shift
      ;;
    --version)
      SPECIFIED_VERSION="$2"
      shift 2
      ;;
    --install-dir)
      INSTALL_DIR="$2"
      shift 2
      ;;
    *)
      echo "Unknown option: $1"
      echo "Use -h or --help for usage information"
      exit 1
      ;;
  esac
done

if [ $SHOW_HELP -eq 1 ]; then
  echo "NUPST Installer Script (v4.0+)"
  echo "Downloads and installs pre-compiled NUPST binary"
  echo ""
  echo "Usage: $0 [options]"
  echo ""
  echo "Options:"
  echo "  -y, --yes              Automatically answer yes to all prompts"
  echo "  -h, --help             Show this help message"
  echo "  --version VERSION      Install specific version (e.g., v4.0.0)"
  echo "  --install-dir DIR      Installation directory (default: /opt/nupst)"
  echo ""
  echo "Examples:"
  echo "  # Install latest version"
  echo "  curl -sSL https://code.foss.global/serve.zone/nupst/raw/branch/main/install.sh | sudo bash"
  echo ""
  echo "  # Install specific version"
  echo "  curl -sSL https://code.foss.global/serve.zone/nupst/raw/branch/main/install.sh | sudo bash -s -- --version v4.0.0"
  echo ""
  echo "  # Non-interactive installation"
  echo "  curl -sSL https://code.foss.global/serve.zone/nupst/raw/branch/main/install.sh | sudo bash -s -- -y"
  exit 0
fi

# Check if running as root
if [ "$EUID" -ne 0 ]; then
  echo "Please run as root (sudo bash install.sh or pipe to sudo bash)"
  exit 1
fi

# Detect if script is being piped or run directly
INTERACTIVE=1
if [ ! -t 0 ] || [ ! -t 1 ]; then
  # Either stdin or stdout is not a terminal
  if [ $AUTO_YES -ne 1 ]; then
    echo "Script detected it's running in a non-interactive environment without -y flag."
    echo "Attempting to find a controlling terminal for interactive prompts..."
    # Try to use a controlling terminal for user input
    exec < /dev/tty 2>/dev/null || INTERACTIVE=0

    if [ $INTERACTIVE -eq 0 ]; then
      echo "ERROR: No controlling terminal available for interactive prompts."
      echo ""
      echo "For interactive installation (RECOMMENDED):"
      echo "  curl -sSL https://code.foss.global/serve.zone/nupst/raw/branch/main/install.sh -o nupst-install.sh"
      echo "  sudo bash nupst-install.sh"
      echo ""
      echo "For non-interactive installation with auto-confirm:"
      echo "  curl -sSL https://code.foss.global/serve.zone/nupst/raw/branch/main/install.sh | sudo bash -s -- -y"
      exit 1
    else
      echo "Interactive terminal found, continuing with prompts..."
    fi
  fi
fi

# Helper function to detect OS and architecture
detect_platform() {
  local os=$(uname -s)
  local arch=$(uname -m)

  # Map OS
  case "$os" in
    Linux)
      os_name="linux"
      ;;
    Darwin)
      os_name="macos"
      ;;
    MINGW*|MSYS*|CYGWIN*)
      os_name="windows"
      ;;
    *)
      echo "Error: Unsupported operating system: $os"
      echo "Supported: Linux, macOS, Windows"
      exit 1
      ;;
  esac

  # Map architecture
  case "$arch" in
    x86_64|amd64)
      arch_name="x64"
      ;;
    aarch64|arm64)
      arch_name="arm64"
      ;;
    *)
      echo "Error: Unsupported architecture: $arch"
      echo "Supported: x86_64/amd64 (x64), aarch64/arm64 (arm64)"
      exit 1
      ;;
  esac

  # Construct binary name
  if [ "$os_name" = "windows" ]; then
    echo "nupst-${os_name}-${arch_name}.exe"
  else
    echo "nupst-${os_name}-${arch_name}"
  fi
}

# Get latest release version from Gitea API
get_latest_version() {
  echo "Fetching latest release version from Gitea..." >&2

  local api_url="${GITEA_BASE_URL}/api/v1/repos/${GITEA_REPO}/releases/latest"
  local response=$(curl -sSL "$api_url" 2>/dev/null)

  if [ $? -ne 0 ] || [ -z "$response" ]; then
    echo "Error: Failed to fetch latest release information from Gitea API" >&2
    echo "URL: $api_url" >&2
    exit 1
  fi

  # Extract tag_name from JSON response
  local version=$(echo "$response" | grep -o '"tag_name":"[^"]*"' | cut -d'"' -f4)

  if [ -z "$version" ]; then
    echo "Error: Could not determine latest version from API response" >&2
    exit 1
  fi

  echo "$version"
}

# Main installation process
echo "================================================"
echo "  NUPST Installation Script (v4.0+)"
echo "================================================"
echo ""

# Detect platform
BINARY_NAME=$(detect_platform)
echo "Detected platform: $BINARY_NAME"
echo ""

# Determine version to install
if [ -n "$SPECIFIED_VERSION" ]; then
  VERSION="$SPECIFIED_VERSION"
  echo "Installing specified version: $VERSION"
else
  VERSION=$(get_latest_version)
  echo "Installing latest version: $VERSION"
fi
echo ""

# Construct download URL
DOWNLOAD_URL="${GITEA_BASE_URL}/${GITEA_REPO}/releases/download/${VERSION}/${BINARY_NAME}"
echo "Download URL: $DOWNLOAD_URL"
echo ""

# Check if installation directory exists
if [ -d "$INSTALL_DIR" ]; then
  if [ $AUTO_YES -eq 0 ] && [ $INTERACTIVE -eq 1 ]; then
    echo "Installation directory already exists: $INSTALL_DIR"
    echo "Do you want to update/reinstall? (Y/n): "
    read -r update_confirm

    if [[ "$update_confirm" =~ ^[Nn]$ ]]; then
      echo "Installation cancelled."
      exit 0
    fi
  fi

  echo "Updating existing installation at $INSTALL_DIR..."
else
  if [ $AUTO_YES -eq 0 ] && [ $INTERACTIVE -eq 1 ]; then
    echo "NUPST will be installed to: $INSTALL_DIR"
    echo "Continue? (Y/n): "
    read -r install_confirm

    if [[ "$install_confirm" =~ ^[Nn]$ ]]; then
      echo "Installation cancelled."
      exit 0
    fi
  fi

  echo "Creating installation directory: $INSTALL_DIR"
  mkdir -p "$INSTALL_DIR"
fi

# Download binary
echo "Downloading NUPST binary..."
TEMP_FILE="$INSTALL_DIR/nupst.download"
curl -sSL "$DOWNLOAD_URL" -o "$TEMP_FILE"

if [ $? -ne 0 ]; then
  echo "Error: Failed to download binary from $DOWNLOAD_URL"
  echo ""
  echo "Please check:"
  echo "  1. Your internet connection"
  echo "  2. The specified version exists: ${GITEA_BASE_URL}/${GITEA_REPO}/releases"
  echo "  3. The platform binary is available for this release"
  rm -f "$TEMP_FILE"
  exit 1
fi

# Check if download was successful (file exists and not empty)
if [ ! -s "$TEMP_FILE" ]; then
  echo "Error: Downloaded file is empty or does not exist"
  rm -f "$TEMP_FILE"
  exit 1
fi

# Move to final location
BINARY_PATH="$INSTALL_DIR/nupst"
mv "$TEMP_FILE" "$BINARY_PATH"

# Make executable
chmod +x "$BINARY_PATH"

echo "Binary installed successfully to: $BINARY_PATH"
echo ""

# Check if /usr/local/bin is in PATH
if [[ ":$PATH:" == *":/usr/local/bin:"* ]]; then
  BIN_DIR="/usr/local/bin"
else
  BIN_DIR="/usr/bin"
fi

# Create symlink for global access
if [ $AUTO_YES -eq 0 ] && [ $INTERACTIVE -eq 1 ]; then
  echo "Create symlink in $BIN_DIR for global access? (Y/n): "
  read -r symlink_confirm

  if [[ ! "$symlink_confirm" =~ ^[Nn]$ ]]; then
    ln -sf "$BINARY_PATH" "$BIN_DIR/nupst"
    echo "Symlink created: $BIN_DIR/nupst -> $BINARY_PATH"
  else
    echo "Symlink creation skipped."
    echo "To use NUPST, run: $BINARY_PATH"
    echo "Or manually create symlink: sudo ln -sf $BINARY_PATH $BIN_DIR/nupst"
  fi
else
  ln -sf "$BINARY_PATH" "$BIN_DIR/nupst"
  echo "Symlink created: $BIN_DIR/nupst -> $BINARY_PATH"
fi

echo ""
echo "================================================"
echo "  NUPST Installation Complete!"
echo "================================================"
echo ""
echo "Installation details:"
echo "  Binary location: $BINARY_PATH"
echo "  Symlink location: $BIN_DIR/nupst"
echo "  Version: $VERSION"
echo ""
echo "Get started:"
echo "  nupst --version"
echo "  nupst help"
echo "  nupst ups add       # Add a UPS device"
echo "  nupst service enable # Enable systemd service"
echo ""