#!/bin/bash
# pwa-prereqs - check or install PWA development prerequisites (Xcode CLT, Homebrew, nvm, Node LTS)
#
# Usage:
#   pwa-prereqs              # check-only: report which components are installed
#   pwa-prereqs --install    # install any missing components
#   pwa-prereqs -h
#
# Options:
#   --install     Install missing components (default is check-only)
#   -h, --help    Show help message

_pwa_prereqs() (
    local SCRIPT_NAME; SCRIPT_NAME="$(basename "${BASH_SOURCE[0]}")"
    case "${BASH_SOURCE[0]}" in /dev/*|/proc/*) SCRIPT_NAME="" ;; esac
    case "$SCRIPT_NAME" in ""|bash|sh|zsh|dash) SCRIPT_NAME="pwa-prereqs" ;; esac

    _error() { echo "[ERR][$SCRIPT_NAME] $*" >&2; }

    _show_help() {
        local s; [ -t 1 ] && s=$'\033[4m'
        local r; [ -t 1 ] && r=$'\033[24m'
        echo "NAME"
        echo "  $SCRIPT_NAME - check or install PWA development prerequisites"
        echo "SYNOPSIS"
        echo "  $SCRIPT_NAME [${s}options${r}]"
        echo "  $SCRIPT_NAME -h"
        echo "DESCRIPTION"
        echo "  Checks or installs the prerequisites for Salesforce PWA Kit"
        echo "  development on macOS:"
        echo "    1. Xcode Command Line Tools (required for Homebrew)"
        echo "    2. Homebrew"
        echo "    3. nvm (Node Version Manager)"
        echo "    4. Latest LTS Node.js (via \`nvm install --lts\`)"
        echo ""
        echo "  Default (no flags): check-only mode. Reports [ok] or [missing]"
        echo "  for each component and exits 0 if all are present, 1 otherwise."
        echo ""
        echo "  With --install: actually installs any missing components."
        echo "  Skips anything already present. The Xcode CLT install is a"
        echo "  GUI flow (Apple's dialog); when missing, this script triggers"
        echo "  the installer and exits so you can re-run once CLT is in"
        echo "  place. Requires sudo access during the Homebrew install step."
        echo "OPTIONS"
        echo "  --install     Install missing components (default is check-only)"
        echo "  -h, --help    Show this help message"
        echo "EXIT STATUS"
        echo "  0  All prerequisites present (check mode) or installed (install mode)"
        echo "  1  Missing prerequisites (check mode) or installation failed (install mode)"
        echo "  2  Usage / argument error"
        echo "DEPENDENCIES"
        echo "  curl (for --install)"
        echo "CAVEATS"
        echo "  macOS only."
    }

    local mode="check"
    while [ $# -gt 0 ]; do
        case "$1" in
            -h|--help) _show_help; return 0 ;;
            --install) mode="install"; shift ;;
            -*)
                _error "Unknown argument '$1'. Run \`$SCRIPT_NAME -h\` for usage"
                return 2
                ;;
            *)
                _error "Unexpected argument '$1'. Run \`$SCRIPT_NAME -h\` for usage"
                return 2
                ;;
        esac
    done

    # Platform check: macOS only
    local platform; platform="$(uname -s)"
    if [ "$platform" != "Darwin" ]; then
        _error "macOS only (detected: $platform)"
        return 1
    fi

    # --- check mode ---
    if [ "$mode" = "check" ]; then
        local all_ok=0

        # Xcode Command Line Tools: `xcode-select -p` prints the active dev dir and exits 0 when present
        if xcode-select -p >/dev/null 2>&1; then
            echo "[ok]      Xcode Command Line Tools"
        else
            echo "[missing] Xcode Command Line Tools"
            all_ok=1
        fi

        # Homebrew
        if command -v brew >/dev/null 2>&1; then
            echo "[ok]      Homebrew"
        else
            echo "[missing] Homebrew"
            all_ok=1
        fi

        # nvm: command in PATH, or sourceable ~/.nvm/nvm.sh
        local nvm_present=1
        if command -v nvm >/dev/null 2>&1; then
            nvm_present=0
        elif [ -s "$HOME/.nvm/nvm.sh" ]; then
            # NVM_DIR must be exported -- nvm.sh reads it from the environment
            export NVM_DIR="$HOME/.nvm"
            # shellcheck disable=SC1091 # "Not following: (error message here)"
            . "$NVM_DIR/nvm.sh" >/dev/null 2>&1
            command -v nvm >/dev/null 2>&1 && nvm_present=0
        fi
        if [ "$nvm_present" -eq 0 ]; then
            echo "[ok]      nvm"
        else
            echo "[missing] nvm"
            all_ok=1
        fi

        # Node LTS: if nvm is present, ask it; otherwise fall back to `node` in PATH
        local node_present=1
        if [ "$nvm_present" -eq 0 ] && nvm ls --no-colors 2>/dev/null | grep -q 'lts'; then
            node_present=0
        elif command -v node >/dev/null 2>&1; then
            node_present=0
        fi
        if [ "$node_present" -eq 0 ]; then
            echo "[ok]      Node LTS"
        else
            echo "[missing] Node LTS"
            all_ok=1
        fi

        return "$all_ok"
    fi

    # --- install mode ---
    echo "--- START xcode ---"
    if xcode-select -p >/dev/null 2>&1; then
        echo "Xcode Command Line Tools already installed."
        echo "--- FINISH xcode ---"
    else
        echo "Installing Xcode Command Line Tools..."
        # Triggers Apple's GUI installer dialog. The command returns quickly;
        # the actual install happens asynchronously and requires user click-through
        xcode-select --install >/dev/null 2>&1 || :
        echo "A GUI installer was launched. Complete it, then re-run \`$SCRIPT_NAME --install\`."
        echo "--- FINISH xcode ---"
        return 1
    fi

    echo "--- START brew ---"
    if command -v brew >/dev/null 2>&1; then
        echo "Homebrew is already installed."
    else
        echo "Installing Homebrew..."
        if /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"; then
            echo "Homebrew installed successfully."
        else
            echo "Homebrew installation failed"
            return 1
        fi
    fi
    echo "--- FINISH brew ---"

    echo "--- START nvm ---"
    if command -v nvm >/dev/null 2>&1; then
        echo "nvm is already installed."
    elif [ -d "$HOME/.nvm" ]; then
        echo "nvm directory exists, but nvm command is not found. Attempting to source nvm..."
        # NVM_DIR must be exported -- nvm.sh and its child processes read it from
        # the environment (CONVENTIONS allows export for genuinely env-needed vars)
        export NVM_DIR="$HOME/.nvm"
        if [ -s "$NVM_DIR/nvm.sh" ]; then
            # shellcheck disable=SC1091 # "Not following: (error message here)"
            . "$NVM_DIR/nvm.sh"
            echo "nvm sourced successfully."
        else
            echo "nvm script not found in $NVM_DIR. Reinstalling nvm..."
            if curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.3/install.sh | bash; then
                echo "nvm reinstalled successfully."
            else
                echo "nvm reinstallation failed"
                return 1
            fi
        fi
    else
        if curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.3/install.sh | bash; then
            echo "nvm installed successfully."
            export NVM_DIR="$HOME/.nvm"
            if [ -s "$NVM_DIR/nvm.sh" ]; then
                # shellcheck disable=SC1091 # "Not following: (error message here)"
                . "$NVM_DIR/nvm.sh"
            else
                echo "nvm script not found in $NVM_DIR. Please check the installation."
                return 1
            fi
        else
            echo "nvm installation failed"
            return 1
        fi
    fi
    echo "--- FINISH nvm ---"

    echo "--- START node/npm ---"
    echo "Installing latest Long-Term Support (LTS) Node.js..."
    if nvm install --lts; then # automatically runs `nvm use --lts`
        echo "Node.js installed successfully."
    else
        echo "Node.js installation failed"
        return 1
    fi
    echo "--- FINISH node/npm ---"
)

_pwa_prereqs "$@"
__pwa_prereqs_rc=$?
unset -f _pwa_prereqs
if [ -n "${BASH_SOURCE[0]}" ] && [ "${BASH_SOURCE[0]}" != "$0" ]; then
    eval "unset __pwa_prereqs_rc; return $__pwa_prereqs_rc"
fi
eval "unset __pwa_prereqs_rc; exit $__pwa_prereqs_rc"