#!/usr/bin/env bash
#
# install.sh - Comprehensive interactive installation script for GridFire.
#
# This script performs the following actions:
# 1. Checks for essential system dependencies against required minimum versions.
# 2. If run with the --tui flag, it provides a comprehensive text-based user interface
#    to select and install dependencies, configure the build, and run build steps.
# 3. If run without flags, it prompts the user interactively for each missing dependency.
# 4. Provides detailed installation instructions for various Linux distributions and macOS.
# 5. Once all dependencies are met, it can run the meson setup, compile, install, and test commands.
# 6. Logs all operations to a file for easy debugging.

set -o pipefail

# --- Configuration ---
LOGFILE="GridFire_Installer.log"
NOTES_FILE="notes.txt"
CONFIG_FILE="gridfire_build.conf"
MIN_GCC_VER="13.0.0"
MIN_CLANG_VER="16.0.0"
MIN_MESON_VER="1.5.0"

# --- Build Configuration Globals ---
BUILD_DIR="build"
INSTALL_PREFIX="/usr/local"
MESON_BUILD_TYPE="debug" # Default to debug to match Meson's default and avoid optimization warnings
MESON_LOG_LEVEL="info"
MESON_PKG_CONFIG="true"
MESON_NUM_CORES=$(getconf _NPROCESSORS_ONLN 2>/dev/null || sysctl -n hw.ncpu 2>/dev/null || echo 1)
C_COMPILER=""
CC_COMPILER=""
FC_COMPILER=""
declare -A VALID_COMPILERS
declare -A MESON_ADVANCED_OPTS
# --- Initialize default advanced options ---
MESON_ADVANCED_OPTS["b_lto"]="false"
MESON_ADVANCED_OPTS["strip"]="false"
MESON_ADVANCED_OPTS["unity"]="off"
MESON_ADVANCED_OPTS["warning_level"]="1"
MESON_ADVANCED_OPTS["backend"]="ninja"
MESON_ADVANCED_OPTS["werror"]="false"
MESON_ADVANCED_OPTS["b_pch"]="true"
MESON_ADVANCED_OPTS["b_coverage"]="false"
MESON_ADVANCED_OPTS["default_library"]="shared"


# --- ANSI Color Codes ---
RED="\033[0;31m"
GREEN="\033[0;32m"
YELLOW="\033[0;33m"
BLUE="\033[0;34m"
NC="\033[0m" # No Color

# --- Logging and Utility Functions ---

# Log a message to stdout and to the log file.
log() {
  local message="$1"
  # Print the colored message to the terminal.
  echo -e "${message}"
  # Strip ANSI color codes and append to the log file.
  echo -e "${message}" | sed 's/\x1B\[[0-9;]*[mK]//g' >> "$LOGFILE"
}

# Version comparison function. Returns 0 if v1=v2, 1 if v1>v2, 2 if v1<v2
vercomp() {
    local v1=$1 v2=$2
    if [[ "$v1" == "$v2" ]]; then return 0; fi
    local IFS=.
    read -ra v1_parts <<< "$v1"
    read -ra v2_parts <<< "$v2"

    local i
    # Pad the shorter version array with zeros
    local len1=${#v1_parts[@]}
    local len2=${#v2_parts[@]}
    if (( len1 > len2 )); then
        for ((i=len2; i<len1; i++)); do v2_parts[i]=0; done
    elif (( len2 > len1 )); then
        for ((i=len1; i<len2; i++)); do v1_parts[i]=0; done
    fi

    for i in "${!v1_parts[@]}"; do
        local p1=${v1_parts[i]}
        local p2=${v2_parts[i]}

        # Ensure parts are integers before comparison
        if ! [[ "$p1" =~ ^[0-9]+$ ]]; then p1=0; fi
        if ! [[ "$p2" =~ ^[0-9]+$ ]]; then p2=0; fi

        if (( p1 > p2 )); then return 1; fi
        if (( p1 < p2 )); then return 2; fi
    done

    return 0
}


# Show the help message and exit.
show_help() {
  echo "Usage: ./install.sh [options]"
  echo
  echo "This script checks for dependencies, installs them, and builds the project."
  echo
  echo "Options:"
  echo "  --tui         Run in Text-based User Interface mode for interactive dependency installation and build control."
  echo "  --help, -h    Show this help message and exit."
  echo "  --clean       Remove the build directory and log file before starting."
  echo "  --config FILE Load a configuration file on startup."
  echo
  echo "The script will automatically detect your OS and suggest the correct package manager commands."
  echo "All output is logged to ${LOGFILE}."
}

# --- OS Detection ---
OS_NAME=$(uname -s)
DISTRO_ID="unknown"
if [ -f /etc/os-release ]; then
  . /etc/os-release
  DISTRO_ID=$ID
fi
if [[ "$OS_NAME" == "Darwin" ]]; then
  OS_NAME="macOS"
fi

# --- Dependency Check Functions ---

check_command() {
  command -v "$1" &>/dev/null
}

set_compilers() {
    if [[ "$CC_COMPILER" == *"clang++"* ]]; then
        C_COMPILER=$(echo "$CC_COMPILER" | sed 's/clang++/clang/')
        # Try to find a corresponding flang or fallback to gfortran
        local fc_ver=$(echo "$C_COMPILER" | grep -oE '[0-9]+')
        if check_command "flang-$fc_ver"; then
            FC_COMPILER="flang-$fc_ver"
        elif check_command "flang"; then
            FC_COMPILER="flang"
        elif check_command "gfortran"; then
            FC_COMPILER="gfortran"
        else
            FC_COMPILER=""
        fi
    elif [[ "$CC_COMPILER" == *"g++"* ]]; then
        C_COMPILER=$(echo "$CC_COMPILER" | sed 's/g++/gcc/')
        FC_COMPILER=$(echo "$CC_COMPILER" | sed 's/g++/gfortran/')
        if ! check_command "$FC_COMPILER"; then
             # Fallback to generic gfortran if versioned one not found
             if check_command "gfortran"; then
                 FC_COMPILER="gfortran"
             else
                 FC_COMPILER=""
             fi
        fi
    else
        C_COMPILER=""
        FC_COMPILER=""
    fi
}

check_compiler() {
    VALID_COMPILERS=()
    local potential_gccs=("g++-14" "g++-13" "g++")
    local potential_clangs=("clang++-17" "clang++-16" "clang++")

    for cc in "${potential_gccs[@]}"; do
        if check_command "$cc"; then
            local ver; ver=$($cc -dumpversion | grep -oE '[0-9]+(\.[0-9]+)*' | head -n1)
            if [[ -n "$ver" ]]; then
                vercomp "$ver" "$MIN_GCC_VER"
                if [[ $? -ne 2 ]]; then
                    VALID_COMPILERS["g++ ($ver)"]="$cc"
                    break # Found a valid one, stop searching for g++
                fi
            fi
        fi
    done

    for cc in "${potential_clangs[@]}"; do
        if check_command "$cc"; then
            local ver; ver=$($cc --version | head -n1 | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' | head -n1)
            if [[ -n "$ver" ]]; then
                vercomp "$ver" "$MIN_CLANG_VER"
                if [[ $? -ne 2 ]]; then
                    VALID_COMPILERS["clang++ ($ver)"]="$cc"
                    break # Found a valid one
                fi
            fi
        fi
    done

    if [ ${#VALID_COMPILERS[@]} -gt 0 ]; then
        if ! [[ " ${VALID_COMPILERS[*]} " =~ " ${CC_COMPILER} " ]]; then
            # Correctly get the first value from the associative array
            local keys=("${!VALID_COMPILERS[@]}")
            local first_key="${keys[0]}"
            CC_COMPILER="${VALID_COMPILERS[$first_key]}"
        fi
        set_compilers
        log "${GREEN}[OK] Found valid C++ compiler(s). Using C: '${C_COMPILER}', C++: '${CC_COMPILER}', FC: '${FC_COMPILER}'.${NC}"
        return 0
    else
        log "${RED}[FAIL] No valid C++ compiler found (GCC >= ${MIN_GCC_VER} or Clang >= ${MIN_CLANG_VER}).${NC}"
        CC_COMPILER=""
        C_COMPILER=""
        FC_COMPILER=""
        return 1
    fi
}

check_python_dev() {
  if check_command python3 && python3-config --includes &>/dev/null; then
    log "${GREEN}[OK] Found Python 3 development headers.${NC}"
    return 0
  else
    log "${RED}[FAIL] Python 3 development headers not found.${NC}"
    return 1
  fi
}

check_meson_python() {
    if python3 -c "import mesonpy" &>/dev/null; then
        log "${GREEN}[OK] Found meson-python package.${NC}"
        return 0
    else
        log "${RED}[FAIL] meson-python package not found.${NC}"
        return 1
    fi
}

check_cmake() {
  if check_command cmake; then
    log "${GREEN}[OK] Found CMake: $(cmake --version | head -n1)${NC}"
    return 0
  else
    log "${RED}[FAIL] CMake not found.${NC}"
    return 1
  fi
}

check_meson() {
    if check_command meson; then
        local ver; ver=$(meson --version)
        vercomp "$ver" "$MIN_MESON_VER"
        if [[ $? -ne 2 ]]; then
            log "${GREEN}[OK] Found Meson ${ver}.${NC}"
            return 0
        else
            log "${RED}[FAIL] Meson version ${ver} is too old. Need >= ${MIN_MESON_VER}.${NC}"
            return 1
        fi
    else
        log "${RED}[FAIL] Meson not found.${NC}"
        return 1
    fi
}

check_boost() {
  log "${BLUE}[Info] Checking for Boost dependency using Meson...${NC}"
  local test_dir="meson-boost-test"
  rm -rf "$test_dir" && mkdir -p "$test_dir"
  cat > "$test_dir/meson.build" <<EOF
project('boost-check', 'cpp')
boost_dep = dependency('boost', required: true)
EOF
  if meson setup "$test_dir/build" "$test_dir" &>/dev/null; then
    log "${GREEN}[OK] Found Boost libraries.${NC}"
    rm -rf "$test_dir"
    return 0
  else
    log "${RED}[FAIL] Boost libraries not found by Meson.${NC}"
    rm -rf "$test_dir"
    return 1
  fi
}

# --- Dependency Installation Functions ---

get_compiler_install_cmd() {
    local compiler_to_install="$1" # e.g., g++ or clang++
    local cmd=""
    case "$OS_NAME" in
        "macOS")
            local brew_cmd; brew_cmd=$(command -v brew)
            case "$compiler_to_install" in
                "g++") cmd="$brew_cmd install gcc" ;;
                "clang++") cmd="$brew_cmd install llvm" ;; # llvm provides clang
            esac
            ;;
        "Linux")
            case "$DISTRO_ID" in
                "ubuntu"|"debian"|"linuxmint")
                    case "$compiler_to_install" in
                        "g++") cmd="sudo apt-get install -y g++-13 gfortran-13" ;;
                        "clang++") cmd="sudo apt-get install -y clang-16" ;;
                    esac
                    ;;
                "fedora")
                    # Fedora usually has recent versions in main repos
                    case "$compiler_to_install" in
                        "g++") cmd="sudo dnf install -y gcc-c++ gcc-gfortran" ;;
                        "clang++") cmd="sudo dnf install -y clang" ;;
                    esac
                    ;;
                "arch"|"manjaro")
                     # Arch is rolling release, should be fine
                    case "$compiler_to_install" in
                        "g++") cmd="sudo pacman -S --noconfirm gcc gcc-fortran" ;;
                        "clang++") cmd="sudo pacman -S --noconfirm clang" ;;
                    esac
                    ;;
            esac
            ;;
    esac
    echo "$cmd"
}


get_install_cmd() {
  local dep_name="$1"
  local cmd=""
  case "$OS_NAME" in
    "macOS")
      [ ! -f /opt/homebrew/bin/brew ] && [ ! -f /usr/local/bin/brew ] && log "${YELLOW}Homebrew not found. Please install from https://brew.sh${NC}"
      local brew_cmd
      brew_cmd=$(command -v brew)
      case "$dep_name" in
        "compiler") cmd="$brew_cmd install gcc llvm" ;; # Install both
        "python-dev") cmd="$brew_cmd install python3" ;;
        "meson-python") cmd="python3 -m pip install meson-python" ;;
        "meson") cmd="python3 -m pip install --upgrade meson" ;;
        "cmake") cmd="$brew_cmd install cmake" ;;
        "boost") cmd="$brew_cmd install boost" ;;
        "dialog") cmd="$brew_cmd install dialog" ;;
      esac
      ;;
    "Linux")
      case "$DISTRO_ID" in
        "ubuntu"|"debian"|"linuxmint")
          case "$dep_name" in
            "compiler") cmd="sudo apt-get install -y g++-13 gfortran-13 clang-16" ;;
            "python-dev") cmd="sudo apt-get install -y python3-dev" ;;
            "meson-python") cmd="python3 -m pip install meson-python" ;;
            "meson") cmd="python3 -m pip install --upgrade meson" ;;
            "cmake") cmd="sudo apt-get install -y cmake" ;;
            "boost") cmd="sudo apt-get install -y libboost-all-dev" ;;
            "dialog") cmd="sudo apt-get install -y dialog" ;;
          esac
          ;;
        "fedora")
          case "$dep_name" in
            "compiler") cmd="sudo dnf install -y gcc-c++ gcc-gfortran clang" ;;
            "python-dev") cmd="sudo dnf install -y python3-devel" ;;
            "meson-python") cmd="python3 -m pip install meson-python" ;;
            "meson") cmd="python3 -m pip install --upgrade meson" ;;
            "cmake") cmd="sudo dnf install -y cmake" ;;
            "boost") cmd="sudo dnf install -y boost-devel" ;;
            "dialog") cmd="sudo dnf install -y dialog" ;;
          esac
          ;;
        "arch"|"manjaro")
          case "$dep_name" in
            "compiler") cmd="sudo pacman -S --noconfirm gcc gcc-fortran clang" ;;
            "python-dev") cmd="sudo pacman -S --noconfirm python" ;;
            "meson-python") cmd="python3 -m pip install meson-python" ;;
            "meson") cmd="python3 -m pip install --upgrade meson" ;;
            "cmake") cmd="sudo pacman -S --noconfirm cmake" ;;
            "boost") cmd="sudo pacman -S --noconfirm boost" ;;
            "dialog") cmd="sudo pacman -S --noconfirm dialog" ;;
          esac
          ;;
        *) log "${YELLOW}[Warn] Unsupported Linux distribution: ${DISTRO_ID}.${NC}" ;;
      esac
      ;;
    *) log "${YELLOW}[Warn] Unsupported OS: ${OS_NAME}.${NC}" ;;
  esac
  echo "$cmd"
}

# --- Build Functions ---

run_meson_setup() {
    log "\n${BLUE}--- Configuring Meson Build ---${NC}"
    if [ ! -f "meson.build" ]; then
        log "${RED}[FATAL] meson.build file not found. Cannot proceed.${NC}"; return 1;
    fi
    if [ -z "$CC_COMPILER" ] || [ -z "$C_COMPILER" ]; then
        log "${RED}[FATAL] No valid C/C++ compiler selected. Configure one first.${NC}"; return 1;
    fi
    local reconfigure_flag=""
    if [ -d "$BUILD_DIR" ]; then
        reconfigure_flag="--reconfigure"
        log "${YELLOW}[Info] Existing build directory found. Will reconfigure.${NC}"
    fi

    local meson_opts=()
    meson_opts+=("-Dbuildtype=${MESON_BUILD_TYPE}")
    meson_opts+=("-Dlog_level=${MESON_LOG_LEVEL}")
    meson_opts+=("-Dpkg-config=${MESON_PKG_CONFIG}")
    meson_opts+=("--prefix=${INSTALL_PREFIX}")

    # Add advanced options
    for key in "${!MESON_ADVANCED_OPTS[@]}"; do
        meson_opts+=("-D${key}=${MESON_ADVANCED_OPTS[$key]}")
    done

    log "${BLUE}[Info] Using C compiler:       ${C_COMPILER}${NC}"
    log "${BLUE}[Info] Using C++ compiler:     ${CC_COMPILER}${NC}"
    log "${BLUE}[Info] Using Fortran compiler: ${FC_COMPILER}${NC}"
    log "${BLUE}[Info] Running meson setup with options: ${meson_opts[*]}${NC}"
    # Set CC, CXX, and FC environment variables for the meson command
    if ! CC="${C_COMPILER}" CXX="${CC_COMPILER}" FC="${FC_COMPILER}" meson setup "${BUILD_DIR}" "${meson_opts[@]}" ${reconfigure_flag}; then
        log "${RED}[FATAL] Meson setup failed. See log for details.${NC}"; return 1;
    fi
    log "${GREEN}[Success] Meson setup complete.${NC}"
}

run_meson_compile() {
    log "\n${BLUE}--- Compiling Project ---${NC}"
    if [ ! -d "$BUILD_DIR" ]; then
        log "${RED}[FATAL] Build directory not found. Run setup first.${NC}"; return 1;
    fi
    log "${BLUE}[Info] Running meson compile with ${MESON_NUM_CORES} cores...${NC}"
    if ! meson compile -C "${BUILD_DIR}" -j "${MESON_NUM_CORES}"; then
        log "${RED}[FATAL] Meson compile failed. See log for details.${NC}"; return 1;
    fi
    log "${GREEN}[Success] Meson compile complete.${NC}"
}

run_meson_install() {
    log "\n${BLUE}--- Installing Project ---${NC}"
    if [ ! -d "$BUILD_DIR" ]; then
        log "${RED}[FATAL] Build directory not found. Run setup and compile first.${NC}"; return 1;
    fi
    log "${BLUE}[Info] Running meson install (prefix: ${INSTALL_PREFIX})...${NC}"
    if ! sudo meson install -C "${BUILD_DIR}"; then
        log "${RED}[FATAL] Meson install failed. See log for details.${NC}"; return 1;
    fi
    log "${GREEN}[Success] Meson install complete.${NC}"
}

run_meson_tests() {
    log "\n${BLUE}--- Running Tests ---${NC}"
    if [ ! -d "$BUILD_DIR" ]; then
        log "${RED}[FATAL] Build directory not found. Run setup and compile first.${NC}"; return 1;
    fi
    log "${BLUE}[Info] Running meson test...${NC}"
    if ! meson test -C "${BUILD_DIR}"; then
        log "${RED}[FATAL] Meson tests failed. See log for details.${NC}"; return 1;
    fi
    log "${GREEN}[Success] Tests passed.${NC}"
}

# --- TUI Functions ---

check_dialog_installed() {
  if ! check_command dialog; then
    log "${YELLOW}[Warn] The 'dialog' utility is required for TUI mode.${NC}"
    local install_cmd
    install_cmd=$(get_install_cmd "dialog")
    if [ -n "$install_cmd" ]; then
      if prompt_yes_no "Attempt to install it now? (y/n):"; then
        eval "$install_cmd"
        if ! check_command dialog; then
          log "${RED}[FATAL] Failed to install 'dialog'. Cannot run in TUI mode.${NC}"
          return 1
        fi
      else
        log "${RED}[FATAL] Cannot run in TUI mode without 'dialog'. Exiting.${NC}"
        return 1
      fi
    else
      log "${RED}[FATAL] Cannot auto-install 'dialog'. Please install it manually.${NC}"
      return 1
    fi
  fi
  return 0
}

run_dependency_installer_tui() {
  # This function now just calls the check functions to populate status
  declare -A DEP_STATUS
  check_compiler >/dev/null; DEP_STATUS[compiler]=$?
  check_python_dev >/dev/null; DEP_STATUS[python-dev]=$?
  check_meson_python >/dev/null; DEP_STATUS[meson-python]=$?
  check_cmake >/dev/null; DEP_STATUS[cmake]=$?
  check_meson >/dev/null; DEP_STATUS[meson]=$?
  check_boost >/dev/null; DEP_STATUS[boost]=$?

  local choices
  choices=$(dialog --clear --backtitle "Project Dependency Installer" \
    --title "Install System Dependencies" \
    --checklist "Select dependencies to install. Already found dependencies are unchecked." 20 70 6 \
    "compiler" "C++ Compilers (g++, clang++)" "$([[ ${DEP_STATUS[compiler]} -ne 0 ]] && echo "on" || echo "off")" \
    "python-dev" "Python 3 Dev Headers" "$([[ ${DEP_STATUS[python-dev]} -ne 0 ]] && echo "on" || echo "off")" \
    "meson-python" "meson-python (for Python bindings)" "$([[ ${DEP_STATUS[meson-python]} -ne 0 ]] && echo "on" || echo "off")" \
    "cmake" "CMake" "$([[ ${DEP_STATUS[cmake]} -ne 0 ]] && echo "on" || echo "off")" \
    "meson" "Meson Build System (>=${MIN_MESON_VER})" "$([[ ${DEP_STATUS[meson]} -ne 0 ]] && echo "on" || echo "off")" \
    "boost" "Boost Libraries" "$([[ ${DEP_STATUS[boost]} -ne 0 ]] && echo "on" || echo "off")" \
    3>&1 1>&2 2>&3)

  clear
  if [ -z "$choices" ]; then log "${YELLOW}[Info] No dependencies selected.${NC}"; return; fi

  for choice in $choices; do
    local dep; dep=$(echo "$choice" | tr -d '"')
    log "\n${BLUE}--- Installing ${dep} ---${NC}"
    local install_cmd; install_cmd=$(get_install_cmd "$dep")
    if [ -n "$install_cmd" ]; then
      eval "$install_cmd" 2>&1 | tee -a "$LOGFILE"
    else
      log "${RED}[Error] No automatic installation command for '${dep}'. Please install manually.${NC}"
      dialog --msgbox "Could not find an automatic installation command for '${dep}' on your system. Please install it manually." 8 60
    fi
  done
  # Re-run check to update status
  check_compiler
}

run_python_bindings_tui() {
    if ! check_meson_python; then
        dialog --msgbox "The 'meson-python' package is required to build Python bindings. Please install it from the 'Install System Dependencies' menu first." 10 70
        return
    fi
    if [ -z "$CC_COMPILER" ]; then
        dialog --msgbox "No C++ compiler is selected. Please configure one from the 'Configure Build Options' menu before building the Python bindings." 10 70
        return
    fi

    local python_exec
    python_exec=$(command -v python3)
    if [ -z "$python_exec" ]; then
        dialog --msgbox "Could not find 'python3' executable. Please ensure Python 3 is installed and in your PATH." 8 60
        return
    fi

    local choice
    choice=$(dialog --clear --backtitle "Python Bindings Installer" \
        --title "Install Python Bindings" \
        --menu "Using Python: ${python_exec}\nUsing C++ Compiler: ${CC_COMPILER}\n\nSelect installation mode:" 15 70 2 \
        "1" "Developer Mode (pip install -e .)" \
        "2" "User Mode (pip install .)" \
        3>&1 1>&2 2>&3)

    clear
    case "$choice" in
        1)
            log "${BLUE}[Info] Installing Python bindings in Developer Mode...${NC}"
            if ! CC="${C_COMPILER}" CXX="${CC_COMPILER}" FC="${FC_COMPILER}" pip install -e . --no-build-isolation -vv; then
                log "${RED}[Error] Failed to install Python bindings in developer mode.${NC}"
                dialog --msgbox "Developer mode installation failed. Check the log for details." 8 60
            else
                log "${GREEN}[Success] Python bindings installed in developer mode.${NC}"
                dialog --msgbox "Successfully installed Python bindings in developer mode." 8 60
            fi
            ;;
        2)
            log "${BLUE}[Info] Installing Python bindings in User Mode...${NC}"
            if ! CC="${C_COMPILER}" CXX="${CC_COMPILER}" FC="${FC_COMPILER}" pip install .; then
                log "${RED}[Error] Failed to install Python bindings in user mode.${NC}"
                dialog --msgbox "User mode installation failed. Check the log for details." 8 60
            else
                log "${GREEN}[Success] Python bindings installed in user mode.${NC}"
                dialog --msgbox "Successfully installed Python bindings in user mode." 8 60
            fi
            ;;
        *)
            log "${YELLOW}[Info] Python binding installation cancelled.${NC}"
            ;;
    esac
}

run_compiler_selection_tui() {
    local gpp_ver; gpp_ver=$(g++ -dumpversion 2>/dev/null | grep -oE '[0-9]+(\.[0-9]+)*' | head -n1)
    local clang_ver; clang_ver=$(clang++ --version 2>/dev/null | head -n1 | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' | head -n1)

    local gpp_ok=false
    local clang_ok=false
    if [[ -n "$gpp_ver" ]]; then vercomp "$gpp_ver" "$MIN_GCC_VER"; [[ $? -ne 2 ]] && gpp_ok=true; fi
    if [[ -n "$clang_ver" ]]; then vercomp "$clang_ver" "$MIN_CLANG_VER"; [[ $? -ne 2 ]] && clang_ok=true; fi

    if ! $gpp_ok && ! $clang_ok; then
        # No valid compilers found
        local choices
        choices=$(dialog --title "Compiler Installation" --checklist "No valid C++ compiler found. Please select which to install:" 15 70 2 \
            "g++" "GNU C++ Compiler (>=${MIN_GCC_VER})" "on" \
            "clang++" "Clang C++ Compiler (>=${MIN_CLANG_VER}, often faster)" "off" 3>&1 1>&2 2>&3)
        if [ -n "$choices" ]; then
            for choice in $choices; do
                local compiler_to_install; compiler_to_install=$(echo "$choice" | tr -d '"')
                local install_cmd; install_cmd=$(get_compiler_install_cmd "$compiler_to_install")
                if [ -n "$install_cmd" ]; then eval "$install_cmd" 2>&1 | tee -a "$LOGFILE"; fi
            done
        fi
    elif ! $gpp_ok && [[ -n "$gpp_ver" ]]; then
        # g++ found but too old
        if dialog --title "Compiler Update" --yesno "Found g++ version ${gpp_ver}, but require >= ${MIN_GCC_VER}.\n\nAttempt to install a compatible version?" 10 70; then
            local install_cmd; install_cmd=$(get_compiler_install_cmd "g++")
            if [ -n "$install_cmd" ]; then eval "$install_cmd" 2>&1 | tee -a "$LOGFILE"; fi
        fi
    elif ! $clang_ok && [[ -n "$clang_ver" ]]; then
        # clang++ found but too old
        if dialog --title "Compiler Update" --yesno "Found clang++ version ${clang_ver}, but require >= ${MIN_CLANG_VER}.\n\nAttempt to install a compatible version?" 10 70; then
            local install_cmd; install_cmd=$(get_compiler_install_cmd "clang++")
            if [ -n "$install_cmd" ]; then eval "$install_cmd" 2>&1 | tee -a "$LOGFILE"; fi
        fi
    fi

    # Re-check compilers and let user choose if multiple are available
    check_compiler
    if [ ${#VALID_COMPILERS[@]} -gt 0 ]; then
        local menu_items=()
        for name in "${!VALID_COMPILERS[@]}"; do
             menu_items+=("$name" "")
        done
        local compiler_choice_key
        compiler_choice_key=$(dialog --title "Select C++ Compiler" --menu "Select the C++ compiler to use:" 15 70 ${#VALID_COMPILERS[@]} "${menu_items[@]}" 3>&1 1>&2 2>&3)
        if [ -n "$compiler_choice_key" ]; then
            CC_COMPILER="${VALID_COMPILERS[$compiler_choice_key]}"
            set_compilers
            log "${BLUE}[Config] Set C compiler to: ${C_COMPILER}${NC}"
            log "${BLUE}[Config] Set C++ compiler to: ${CC_COMPILER}${NC}"
            log "${BLUE}[Config] Set Fortran compiler to: ${FC_COMPILER}${NC}"
        fi
    else
        dialog --msgbox "No valid C++ compiler could be found or installed. Please install one manually that meets the version requirements." 8 70
    fi
}

run_advanced_options_tui() {
    while true; do
        local choice
        choice=$(dialog --clear --backtitle "Advanced Build Options" \
            --title "Advanced Meson Core & Base Options" \
            --menu "Select an option to configure:" 20 78 10 \
            "1" "Backend (current: ${MESON_ADVANCED_OPTS[backend]})" \
            "2" "Default Library (current: ${MESON_ADVANCED_OPTS[default_library]})" \
            "3" "LTO (Link-Time Opt) (current: ${MESON_ADVANCED_OPTS[b_lto]})" \
            "4" "PCH (Precompiled H) (current: ${MESON_ADVANCED_OPTS[b_pch]})" \
            "5" "Coverage (current: ${MESON_ADVANCED_OPTS[b_coverage]})" \
            "6" "Strip on install (current: ${MESON_ADVANCED_OPTS[strip]})" \
            "7" "Unity build (current: ${MESON_ADVANCED_OPTS[unity]})" \
            "8" "Warning Level (current: ${MESON_ADVANCED_OPTS[warning_level]})" \
            "9" "Warnings as Errors (current: ${MESON_ADVANCED_OPTS[werror]})" \
            "10" "Back to main config" \
            3>&1 1>&2 2>&3)

        case "$choice" in
            1)
                local backend_choice
                backend_choice=$(dialog --title "Select Backend" --menu "" 15 70 4 \
                    "ninja" "Ninja build system" \
                    "vs" "Visual Studio" \
                    "xcode" "Xcode" \
                    "none" "No backend" 3>&1 1>&2 2>&3)
                if [ -n "$backend_choice" ]; then MESON_ADVANCED_OPTS["backend"]="$backend_choice"; fi
                ;;
            2)
                local lib_choice
                lib_choice=$(dialog --title "Default Library Type" --menu "" 15 70 3 \
                    "shared" "Shared (.so, .dylib)" \
                    "static" "Static (.a)" \
                    "both" "Build both types" 3>&1 1>&2 2>&3)
                if [ -n "$lib_choice" ]; then MESON_ADVANCED_OPTS["default_library"]="$lib_choice"; fi
                ;;
            3)
                if dialog --title "LTO (Link-Time Optimization)" --yesno "Enable Link-Time Optimization?\n(Can improve performance but increases link time)" 8 70; then
                    MESON_ADVANCED_OPTS["b_lto"]="true"
                else
                    MESON_ADVANCED_OPTS["b_lto"]="false"
                fi
                ;;
            4)
                if dialog --title "PCH (Precompiled Headers)" --yesno "Use precompiled headers?\n(Can speed up compilation)" 8 70; then
                    MESON_ADVANCED_OPTS["b_pch"]="true"
                else
                    MESON_ADVANCED_OPTS["b_pch"]="false"
                fi
                ;;
            5)
                if dialog --title "Enable Coverage Tracking" --yesno "Enable code coverage tracking?\n(For generating coverage reports)" 8 70; then
                    MESON_ADVANCED_OPTS["b_coverage"]="true"
                else
                    MESON_ADVANCED_OPTS["b_coverage"]="false"
                fi
                ;;
            6)
                if dialog --title "Strip on Install" --yesno "Strip binaries on install?\n(Reduces size, removes debug symbols)" 8 70; then
                    MESON_ADVANCED_OPTS["strip"]="true"
                else
                    MESON_ADVANCED_OPTS["strip"]="false"
                fi
                ;;
            7)
                local unity_choice
                unity_choice=$(dialog --title "Unity Build" --menu "" 15 70 3 \
                    "on" "Enable for all targets" \
                    "subprojects" "Enable for subprojects only" \
                    "off" "Disable unity builds" 3>&1 1>&2 2>&3)
                if [ -n "$unity_choice" ]; then MESON_ADVANCED_OPTS["unity"]="$unity_choice"; fi
                ;;
            8)
                local warn_choice
                warn_choice=$(dialog --title "Compiler Warning Level" --menu "" 15 70 5 \
                    "0" "No warnings" \
                    "1" "Normal warnings" \
                    "2" "More warnings" \
                    "3" "All warnings" \
                    "everything" "Pedantic warnings" 3>&1 1>&2 2>&3)
                if [ -n "$warn_choice" ]; then MESON_ADVANCED_OPTS["warning_level"]="$warn_choice"; fi
                ;;
            9)
                if dialog --title "Treat Warnings as Errors" --yesno "Enable -Werror?\n(Build will fail on any compiler warning)" 8 70; then
                    MESON_ADVANCED_OPTS["werror"]="true"
                else
                    MESON_ADVANCED_OPTS["werror"]="false"
                fi
                ;;
            10) break ;;
            *) break ;;
        esac
    done
}


run_build_config_tui() {
    local choice
    choice=$(dialog --clear --backtitle "Build Configuration" \
        --title "Configure Build Options" \
        --menu "Select an option to configure:" 20 70 8 \
        "1" "Build Directory (current: ${BUILD_DIR})" \
        "2" "Install Prefix (current: ${INSTALL_PREFIX})" \
        "3" "Manage & Select C/C++/Fortran Compiler" \
        "4" "Build Type (current: ${MESON_BUILD_TYPE})" \
        "5" "Log Level (current: ${MESON_LOG_LEVEL})" \
        "6" "Generate pkg-config (current: ${MESON_PKG_CONFIG})" \
        "7" "Number of Cores (current: ${MESON_NUM_CORES})" \
        "8" "Advanced Build Options" \
        3>&1 1>&2 2>&3)

    clear
    case "$choice" in
        1)
            local new_dir
            new_dir=$(dialog --title "Set Build Directory" --inputbox "Enter new build directory name:" 10 60 "${BUILD_DIR}" 3>&1 1>&2 2>&3)
            if [ -n "$new_dir" ]; then
                BUILD_DIR="$new_dir"
                log "${BLUE}[Config] Set build directory to: ${BUILD_DIR}${NC}"
            fi
            ;;
        2)
            local new_prefix
            new_prefix=$(dialog --title "Set Install Prefix" --inputbox "Enter absolute path for installation prefix:" 10 60 "${INSTALL_PREFIX}" 3>&1 1>&2 2>&3)
            if [ -n "$new_prefix" ]; then
                INSTALL_PREFIX="$new_prefix"
                log "${BLUE}[Config] Set install prefix to: ${INSTALL_PREFIX}${NC}"
            fi
            ;;
        3)
            run_compiler_selection_tui
            ;;
        4)
            local build_type_choice
            build_type_choice=$(dialog --title "Select Build Type" --menu "" 15 70 4 \
                "debug" "No optimizations, with debug symbols" \
                "release" "Optimized for performance" \
                "debugoptimized" "With debug symbols and optimization" \
                "plain" "Custom flags only" \
                3>&1 1>&2 2>&3)
            if [ -n "$build_type_choice" ]; then
                MESON_BUILD_TYPE="$build_type_choice"
                log "${BLUE}[Config] Set build type to: ${MESON_BUILD_TYPE}${NC}"
            fi
            ;;
        5)
            local log_level_choice
            log_level_choice=$(dialog --title "Select Log Level" --menu "" 15 70 8 \
                "traceL3" "" "traceL2" "" "traceL1" "" "debug" "" "info" "" "warning" "" "error" "" "critical" "" \
                3>&1 1>&2 2>&3)
            if [ -n "$log_level_choice" ]; then
                MESON_LOG_LEVEL="$log_level_choice"
                log "${BLUE}[Config] Set log level to: ${MESON_LOG_LEVEL}${NC}"
            fi
            ;;
        6)
            if dialog --title "Generate pkg-config" --yesno "Generate gridfire.pc file?" 7 60; then
                MESON_PKG_CONFIG="true"
            else
                MESON_PKG_CONFIG="false"
            fi
            log "${BLUE}[Config] Set pkg-config generation to: ${MESON_PKG_CONFIG}${NC}"
            ;;
        7)
            local max_cores; max_cores=$(getconf _NPROCESSORS_ONLN 2>/dev/null || sysctl -n hw.ncpu 2>/dev/null || echo 1)
            local core_choice
            core_choice=$(dialog --title "Set Number of Cores" --inputbox "Enter number of cores for compilation.\nAvailable: ${max_cores}" 10 60 "${MESON_NUM_CORES}" 3>&1 1>&2 2>&3)
            if [[ "$core_choice" =~ ^[0-9]+$ ]] && [ "$core_choice" -gt 0 ]; then
                MESON_NUM_CORES="$core_choice"
                log "${BLUE}[Config] Set number of cores to: ${MESON_NUM_CORES}${NC}"
            elif [ -n "$core_choice" ]; then
                 dialog --msgbox "Invalid input. Please enter a positive number." 6 40
            fi
            ;;
        8)
            run_advanced_options_tui
            ;;
    esac
}

run_notes_tui() {
    if [ ! -f "$NOTES_FILE" ]; then
        dialog --msgbox "Notes file '${NOTES_FILE}' not found." 8 50
        return
    fi

    local notes_content=""
    local counter=1
    # Read file, filter comments, and process non-empty lines
    while IFS= read -r line; do
        # Skip empty or comment lines
        if [[ -z "$line" || "$line" =~ ^[[:space:]]*# ]]; then
            continue
        fi
        notes_content+="${counter}. ${line}\n\n"
        ((counter++))
    done < "$NOTES_FILE"

    if [ -z "$notes_content" ]; then
        dialog --msgbox "No notes found in '${NOTES_FILE}'." 8 50
    else
        dialog --title "Installer Notes" --msgbox "$notes_content" 20 70
    fi
}

run_save_config_tui() {
    local file_to_save
    file_to_save=$(dialog --title "Save Configuration" --inputbox "Enter filename to save configuration:" 10 60 "$CONFIG_FILE" 3>&1 1>&2 2>&3)
    if [ -z "$file_to_save" ]; then
        dialog --msgbox "Save cancelled." 8 50
        return
    fi

    # Write main settings
    {
        echo "# GridFire Build Configuration"
        echo "BUILD_DIR=\"$BUILD_DIR\""
        echo "INSTALL_PREFIX=\"$INSTALL_PREFIX\""
        echo "MESON_BUILD_TYPE=\"$MESON_BUILD_TYPE\""
        echo "MESON_LOG_LEVEL=\"$MESON_LOG_LEVEL\""
        echo "MESON_PKG_CONFIG=\"$MESON_PKG_CONFIG\""
        echo "MESON_NUM_CORES=\"$MESON_NUM_CORES\""
        echo "C_COMPILER=\"$C_COMPILER\""
        echo "CC_COMPILER=\"$CC_COMPILER\""
        echo "FC_COMPILER=\"$FC_COMPILER\""
        echo ""
        echo "# Advanced Meson Options"
        for key in "${!MESON_ADVANCED_OPTS[@]}"; do
            echo "MESON_ADVANCED_OPTS[\"$key\"]=\"${MESON_ADVANCED_OPTS[$key]}\""
        done
    } > "$file_to_save"

    dialog --title "Success" --msgbox "Configuration saved to:\n${file_to_save}" 8 60
}

run_load_config_tui() {
    local file_to_load
    file_to_load=$(dialog --title "Load Configuration" --inputbox "Enter filename to load configuration:" 10 60 "$CONFIG_FILE" 3>&1 1>&2 2>&3)
    if [ -z "$file_to_load" ]; then
        dialog --msgbox "Load cancelled." 8 50
        return
    fi

    if [ ! -f "$file_to_load" ]; then
        dialog --msgbox "Error: File not found:\n${file_to_load}" 8 60
        return
    fi

    # Source the file to load the variables
    # We need to re-declare the associative array for it to be populated by source
    declare -A MESON_ADVANCED_OPTS
    # shellcheck source=/dev/null
    . "$file_to_load"

    # Re-validate the compiler
    check_compiler
    if ! check_command "$CC_COMPILER"; then
        dialog --title "Warning" --msgbox "Compiler '${CC_COMPILER}' from config file not found.\nRe-detecting a valid compiler." 10 60
        check_compiler
    fi

    dialog --title "Success" --msgbox "Configuration loaded from:\n${file_to_load}" 8 60
}


run_main_tui() {
    if ! check_dialog_installed; then return 1; fi
    # Initial check to populate compiler list and set a default
    check_compiler

    local sudo_status="User Mode"
    if [ "$EUID" -eq 0 ]; then
        sudo_status="Root/Sudo Mode"
    fi

    while true; do
        local choice
        choice=$(dialog --clear --backtitle "GridFire Installer - [${sudo_status}]" \
            --title "Main Menu" \
            --menu "C: ${C_COMPILER:-N/A} C++: ${CC_COMPILER:-N/A} FC: ${FC_COMPILER:-N/A}\nDIR: ${BUILD_DIR} | TYPE: ${MESON_BUILD_TYPE} | CORES: ${MESON_NUM_CORES}\nPREFIX: ${INSTALL_PREFIX}\nLOG: ${MESON_LOG_LEVEL} | PKG-CONFIG: ${MESON_PKG_CONFIG}" 24 78 13 \
            "1" "Install System Dependencies" \
            "2" "Configure Build Options" \
            "3" "Install Python Bindings" \
            "4" "Run Full Build (Setup + Compile)" \
            "5" "Run Meson Setup/Reconfigure" \
            "6" "Run Meson Compile" \
            "7" "Run Meson Install (requires sudo)" \
            "8" "Run Tests" \
            "9" "View Notes" \
            "10" "Save Configuration" \
            "11" "Load Configuration" \
            "12" "Exit" \
            3>&1 1>&2 2>&3)

        clear
        case "$choice" in
            1) run_dependency_installer_tui ;;
            2) run_build_config_tui ;;
            3) run_python_bindings_tui ;;
            4) run_meson_setup && run_meson_compile ;;
            5) run_meson_setup ;;
            6) run_meson_compile ;;
            7) run_meson_install ;;
            8) run_meson_tests ;;
            9) run_notes_tui ;;
            10) run_save_config_tui ;;
            11) run_load_config_tui ;;
            12) break ;;
            *) log "${YELLOW}[Info] TUI cancelled.${NC}"; break ;;
        esac
    done
    clear
}

# --- Script Entry Point ---
main() {
  # shellcheck disable=SC2199
  if [[ " $@ " =~ " --help " ]] || [[ " $@ " =~ " -h " ]]; then show_help; exit 0; fi
  # shellcheck disable=SC2199
  if [[ " $@ " =~ " --clean " ]]; then log "${BLUE}[Info] Cleaning up...${NC}"; rm -rf "$BUILD_DIR" "$LOGFILE"; fi

  echo "" > "$LOGFILE" # Clear log file
  log "--- GridFire Installation Log ---"
  log "Date: $(date)"
  log "OS: ${OS_NAME}, Distro: ${DISTRO_ID}"

  if [[ " $@ " =~ " --tui " ]]; then
    log "${BLUE}[Info] Running in TUI mode...${NC}"
    run_main_tui
    exit 0
  fi


  # Handle --config argument
  while [ $# -gt 0 ]; do
    case "$1" in
      --config)
        if [ -f "$2" ]; then
            log "${BLUE}[Info] Loading configuration from $2...${NC}"
            declare -A MESON_ADVANCED_OPTS
            # shellcheck source=/dev/null
            . "$2"
        else
            log "${RED}[Error] Configuration file not found: $2${NC}"
            exit 1
        fi
        shift 2
        ;;
      *)
        shift
        ;;
    esac
  done


  # --- Non-TUI path ---
  log "\n${BLUE}--- Checking System Dependencies (CLI Mode) ---${NC}"
  # Run check_compiler first to set the default
  check_compiler
  declare -A CHECKS=(
      [python-dev]="check_python_dev" [meson-python]="check_meson_python" [cmake]="check_cmake"
      [meson]="check_meson" [boost]="check_boost"
  )
  if ! check_compiler; then
      # Handle case where no compiler is found
      local install_cmd; install_cmd=$(get_install_cmd "compiler")
      if [ -n "$install_cmd" ]; then
          if prompt_yes_no "Dependency 'compiler' is missing. Attempt to install? (y/n):"; then
              eval "$install_cmd" 2>&1 | tee -a "$LOGFILE"
          fi
      else
          log "${RED}[Error] No automatic installation for 'compiler'. Please install manually.${NC}"
      fi
  fi

  for dep in "${!CHECKS[@]}"; do
      if ! ${CHECKS[$dep]}; then
          local install_cmd; install_cmd=$(get_install_cmd "$dep")
          if [ -n "$install_cmd" ]; then
              if prompt_yes_no "Dependency '${dep}' is missing. Attempt to install? (y/n):"; then
                  eval "$install_cmd" 2>&1 | tee -a "$LOGFILE"
              fi
          else
              log "${RED}[Error] No automatic installation for '${dep}'. Please install manually.${NC}"
          fi
      fi
  done

  log "\n${BLUE}--- Re-checking all dependencies ---${NC}"
  local final_fail=false
  # Re-add compiler check to the list for final verification
  CHECKS[compiler]="check_compiler"
  for dep in "${!CHECKS[@]}"; do
      if ! ${CHECKS[$dep]}; then
          log "${RED}[FATAL] Dependency still missing: ${dep}${NC}"
          final_fail=true
      fi
  done

  if $final_fail; then
      log "${RED}Please install missing dependencies and re-run.${NC}"
      exit 1
  fi

  log "\n${GREEN}--- All dependencies met. Proceeding with build. ---${NC}"
  run_meson_setup && run_meson_compile
}

main "$@"