#!/bin/bash

#############################################################################
# System Detection Library
# Runtime detection of control panels, OS, paths, and system resources
# No persistent caching - detects fresh every time
#############################################################################

# Source common functions if not already loaded
if [ -z "$TOOLKIT_BASE_DIR" ]; then
    SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
    source "$SCRIPT_DIR/common-functions.sh"
fi

# Global variables (session-only) - only initialize if not already set
if [ -z "$SYS_DETECTION_COMPLETE" ]; then
    export SYS_CONTROL_PANEL=""
    export SYS_CONTROL_PANEL_VERSION=""
    export SYS_OS_TYPE=""
    export SYS_OS_VERSION=""
    export SYS_WEB_SERVER=""
    export SYS_WEB_SERVER_VERSION=""
    export SYS_DB_TYPE=""
    export SYS_DB_VERSION=""
    export SYS_LOG_DIR=""
fi
export SYS_USER_HOME_BASE=""
export SYS_PHP_VERSIONS=()
export SYS_CLOUDFLARE_ACTIVE=""
export SYS_FIREWALL=""
export SYS_FIREWALL_VERSION=""
export SYS_FIREWALL_ACTIVE=""

#############################################################################
# CONTROL PANEL DETECTION
#############################################################################

detect_control_panel() {
    # Silent detection if already detected
    [ -n "$SYS_DETECTION_COMPLETE" ] || print_info "Detecting control panel..."

    # cPanel
    if [ -f "/usr/local/cpanel/version" ]; then
        SYS_CONTROL_PANEL="cpanel"
        SYS_CONTROL_PANEL_VERSION=$(cat /usr/local/cpanel/version)
        SYS_LOG_DIR="/var/log/apache2/domlogs"
        SYS_USER_HOME_BASE="/home"

        # Alternative log locations for cPanel
        [ ! -d "$SYS_LOG_DIR" ] && SYS_LOG_DIR="/usr/local/apache/domlogs"

        print_success "Detected cPanel v${SYS_CONTROL_PANEL_VERSION}"
        return 0
    fi

    # Plesk
    if [ -f "/usr/local/psa/version" ]; then
        SYS_CONTROL_PANEL="plesk"
        SYS_CONTROL_PANEL_VERSION=$(cat /usr/local/psa/version | head -1)

        # Plesk uses /var/www/vhosts as base
        SYS_USER_HOME_BASE="/var/www/vhosts"

        # Log directory depends on Plesk version
        # Plesk 18.0.50+ uses /var/www/vhosts/DOMAIN/logs
        # Plesk <18.0.50 uses /var/www/vhosts/system/DOMAIN/logs
        # Set marker path - tools will use plesk_get_logdir() for actual path
        SYS_LOG_DIR="/var/www/vhosts/system"

        # Source Plesk helpers for advanced functionality
        if [ -f "$LIB_DIR/plesk-helpers.sh" ]; then
            source "$LIB_DIR/plesk-helpers.sh"
        fi

        print_success "Detected Plesk v${SYS_CONTROL_PANEL_VERSION}"
        return 0
    fi

    # InterWorx
    if [ -d "/usr/local/interworx" ] || [ -f "/etc/interworx/iworx.ini" ]; then
        SYS_CONTROL_PANEL="interworx"
        if [ -f "/usr/local/interworx/iworx/version.php" ]; then
            SYS_CONTROL_PANEL_VERSION=$(grep -oP "VERSION = '\K[^']+" /usr/local/interworx/iworx/version.php 2>/dev/null || echo "Unknown")
        fi
        # InterWorx stores logs in /home/user/var/domain.com/logs/
        # We set a marker path that tools will recognize needs special handling
        SYS_LOG_DIR="/home/*/var/*/logs"
        # InterWorx uses /chroot/home (with /home as symlink)
        # Use actual path as system doesn't show /home properly
        SYS_USER_HOME_BASE="/chroot/home"

        print_success "Detected InterWorx v${SYS_CONTROL_PANEL_VERSION}"
        return 0
    fi

    # No control panel detected
    SYS_CONTROL_PANEL="none"
    SYS_LOG_DIR="/var/log/httpd"
    [ ! -d "$SYS_LOG_DIR" ] && SYS_LOG_DIR="/var/log/apache2"
    SYS_USER_HOME_BASE="/home"

    print_warning "No control panel detected (standalone server)"
    return 1
}

#############################################################################
# OPERATING SYSTEM DETECTION
#############################################################################

detect_os() {
    [ -n "$SYS_DETECTION_COMPLETE" ] || print_info "Detecting operating system..."

    if [ -f /etc/os-release ]; then
        source /etc/os-release
        SYS_OS_TYPE="$ID"
        SYS_OS_VERSION="$VERSION_ID"

        # Normalize OS names
        case "$SYS_OS_TYPE" in
            rhel|centos|almalinux|rocky|cloudlinux)
                SYS_OS_TYPE=$(echo "$NAME" | awk '{print tolower($1)}')
                ;;
        esac

        print_success "Detected $NAME $VERSION_ID"
    elif [ -f /etc/redhat-release ]; then
        local release_info=$(cat /etc/redhat-release)
        SYS_OS_TYPE="centos"
        SYS_OS_VERSION=$(echo "$release_info" | grep -oP '\d+\.\d+' | head -1)
        print_success "Detected $release_info"
    else
        SYS_OS_TYPE="unknown"
        SYS_OS_VERSION="unknown"
        print_warning "Could not detect OS"
    fi

    # Check for CloudLinux
    if [ -f /etc/sysconfig/cloudlinux ] || [ -f /usr/bin/cloudlinux-config ]; then
        print_info "CloudLinux detected"
        export SYS_CLOUDLINUX="yes"
    fi
}

#############################################################################
# WEB SERVER DETECTION
#############################################################################

detect_web_server() {
    [ -n "$SYS_DETECTION_COMPLETE" ] || print_info "Detecting web server..."

    # Apache
    if command_exists httpd; then
        SYS_WEB_SERVER="apache"
        SYS_WEB_SERVER_VERSION=$(httpd -v 2>/dev/null | grep -oP 'Apache/\K[\d.]+' | head -1)
        print_success "Detected Apache ${SYS_WEB_SERVER_VERSION}"
        return 0
    elif command_exists apache2; then
        SYS_WEB_SERVER="apache"
        SYS_WEB_SERVER_VERSION=$(apache2 -v 2>/dev/null | grep -oP 'Apache/\K[\d.]+' | head -1)
        print_success "Detected Apache ${SYS_WEB_SERVER_VERSION}"
        return 0
    fi

    # Nginx
    if command_exists nginx; then
        SYS_WEB_SERVER="nginx"
        SYS_WEB_SERVER_VERSION=$(nginx -v 2>&1 | grep -oP 'nginx/\K[\d.]+' 2>/dev/null)
        print_success "Detected Nginx ${SYS_WEB_SERVER_VERSION}"
        return 0
    fi

    # LiteSpeed
    if [ -f /usr/local/lsws/bin/lswsctrl ]; then
        SYS_WEB_SERVER="litespeed"
        SYS_WEB_SERVER_VERSION=$(/usr/local/lsws/bin/lswsctrl version 2>/dev/null | grep -oP 'LiteSpeed/\K[\d.]+' | head -1)
        print_success "Detected LiteSpeed ${SYS_WEB_SERVER_VERSION}"
        return 0
    fi

    # OpenLiteSpeed
    if command_exists /usr/local/lsws/bin/openlitespeed; then
        SYS_WEB_SERVER="openlitespeed"
        SYS_WEB_SERVER_VERSION=$(cat /usr/local/lsws/VERSION 2>/dev/null)
        print_success "Detected OpenLiteSpeed ${SYS_WEB_SERVER_VERSION}"
        return 0
    fi

    SYS_WEB_SERVER="unknown"
    print_warning "Could not detect web server"
    return 1
}

#############################################################################
# DATABASE DETECTION
#############################################################################

detect_database() {
    [ -n "$SYS_DETECTION_COMPLETE" ] || print_info "Detecting database server..."

    if command_exists mysql; then
        local version_output=$(mysql --version 2>/dev/null)

        if echo "$version_output" | grep -qi "mariadb"; then
            SYS_DB_TYPE="mariadb"
            SYS_DB_VERSION=$(echo "$version_output" | grep -oP '\d+\.\d+\.\d+' | head -1)
            print_success "Detected MariaDB ${SYS_DB_VERSION}"
        else
            SYS_DB_TYPE="mysql"
            SYS_DB_VERSION=$(echo "$version_output" | grep -oP '\d+\.\d+\.\d+' | head -1)
            print_success "Detected MySQL ${SYS_DB_VERSION}"
        fi
        return 0
    fi

    SYS_DB_TYPE="none"
    print_warning "No MySQL/MariaDB detected"
    return 1
}

#############################################################################
# PHP VERSION DETECTION
#############################################################################

detect_php_versions() {
    [ -n "$SYS_DETECTION_COMPLETE" ] || print_info "Detecting PHP versions..."

    SYS_PHP_VERSIONS=()

    # Check default PHP
    if command_exists php; then
        local default_version=$(php -v 2>/dev/null | grep -oP '^PHP \K[\d.]+' | head -1)
        [ -n "$default_version" ] && SYS_PHP_VERSIONS+=("$default_version")
    fi

    # Check EA-PHP versions (cPanel) - fast path parsing
    if [ "$SYS_CONTROL_PANEL" = "cpanel" ]; then
        for php_path in /opt/cpanel/ea-php*/root/usr/bin/php; do
            if [ -x "$php_path" ]; then
                # Extract version from path (ea-php82 -> 8.2)
                local ver=$(echo "$php_path" | grep -oP 'ea-php\K\d+')
                if [ -n "$ver" ]; then
                    # Convert 82 -> 8.2, 81 -> 8.1, etc
                    local major="${ver:0:1}"
                    local minor="${ver:1}"
                    # Get patch version from php -v only if needed (slower but accurate)
                    local full_version=$($php_path -v 2>/dev/null | grep -oP '^PHP \K[\d.]+' | head -1)
                    [ -n "$full_version" ] && SYS_PHP_VERSIONS+=("$full_version")
                fi
            fi
        done
    fi

    # Check Plesk PHP versions (/opt/plesk/php/)
    if [ "$SYS_CONTROL_PANEL" = "plesk" ]; then
        for php_path in /opt/plesk/php/*/bin/php; do
            if [ -x "$php_path" ]; then
                local full_version=$($php_path -v 2>/dev/null | grep -oP '^PHP \K[\d.]+' | head -1)
                [ -n "$full_version" ] && SYS_PHP_VERSIONS+=("$full_version")
            fi
        done
    fi

    # Check alt-php versions (CloudLinux) - fast path parsing
    for php_path in /opt/alt/php*/usr/bin/php; do
        if [ -x "$php_path" ]; then
            # Extract version from path (php74 -> 7.4)
            local ver=$(echo "$php_path" | grep -oP 'php\K\d+')
            if [ -n "$ver" ]; then
                local full_version=$($php_path -v 2>/dev/null | grep -oP '^PHP \K[\d.]+' | head -1)
                [ -n "$full_version" ] && SYS_PHP_VERSIONS+=("$full_version")
            fi
        fi
    done

    # Remove duplicates and sort by version
    SYS_PHP_VERSIONS=($(echo "${SYS_PHP_VERSIONS[@]}" | tr ' ' '\n' | sort -u -V))

    if [ ${#SYS_PHP_VERSIONS[@]} -gt 0 ]; then
        print_success "Detected PHP versions: ${SYS_PHP_VERSIONS[*]}"
    else
        print_warning "No PHP installations detected"
    fi
}

#############################################################################
# CLOUDFLARE DETECTION
#############################################################################

detect_cloudflare() {
    SYS_CLOUDFLARE_ACTIVE="no"

    # Check for mod_cloudflare
    if [ "$SYS_WEB_SERVER" = "apache" ]; then
        if httpd -M 2>/dev/null | grep -q cloudflare; then
            SYS_CLOUDFLARE_ACTIVE="yes"
            print_info "Cloudflare module detected"
        fi
    fi

    # Check for railgun - fast process check
    if pgrep -x railgun > /dev/null 2>&1; then
        SYS_CLOUDFLARE_ACTIVE="yes"
        print_info "Cloudflare Railgun detected"
    fi
}

#############################################################################
# FIREWALL DETECTION
#############################################################################

detect_firewall() {
    [ -n "$SYS_DETECTION_COMPLETE" ] || print_info "Detecting firewall..."

    # CSF/LFD
    if [ -f "/etc/csf/csf.conf" ]; then
        SYS_FIREWALL="csf"
        # Fast version check - read from version.txt or parse csf script
        SYS_FIREWALL_VERSION=$(head -1 /etc/csf/version.txt 2>/dev/null || grep -oP 'my \$version = "\K[^"]+' /usr/sbin/csf 2>/dev/null | head -1 || echo "unknown")
        # Fast check: just check if lfd process is running
        if pgrep -x lfd > /dev/null 2>&1; then
            SYS_FIREWALL_ACTIVE="yes"
            print_success "Detected CSF ${SYS_FIREWALL_VERSION} (active)"
        else
            SYS_FIREWALL_ACTIVE="no"
            print_warning "Detected CSF ${SYS_FIREWALL_VERSION} (inactive)"
        fi
        export SYS_CSF_ACTIVE="${SYS_FIREWALL_ACTIVE}"
        return 0
    fi

    # firewalld
    if command_exists firewall-cmd; then
        SYS_FIREWALL="firewalld"
        SYS_FIREWALL_VERSION=$(firewall-cmd --version 2>/dev/null || echo "unknown")
        if systemctl is-active --quiet firewalld 2>/dev/null; then
            SYS_FIREWALL_ACTIVE="yes"
            print_success "Detected firewalld ${SYS_FIREWALL_VERSION} (active)"
        else
            SYS_FIREWALL_ACTIVE="no"
            print_warning "Detected firewalld ${SYS_FIREWALL_VERSION} (inactive)"
        fi
        return 0
    fi

    # iptables
    if command_exists iptables; then
        SYS_FIREWALL="iptables"
        SYS_FIREWALL_VERSION=$(iptables --version 2>/dev/null | grep -oP 'v\K[\d.]+' | head -1 || echo "unknown")
        # Fast check: just check filter table INPUT chain only (much faster than full -L)
        if [ "$(iptables -L INPUT -n 2>/dev/null | wc -l)" -gt 2 ]; then
            SYS_FIREWALL_ACTIVE="yes"
            print_success "Detected iptables ${SYS_FIREWALL_VERSION} (active)"
        else
            SYS_FIREWALL_ACTIVE="no"
            print_warning "Detected iptables ${SYS_FIREWALL_VERSION} (no rules)"
        fi
        return 0
    fi

    # UFW
    if command_exists ufw; then
        SYS_FIREWALL="ufw"
        SYS_FIREWALL_VERSION=$(ufw version 2>/dev/null | grep -oP '\d+\.\d+\.\d+' | head -1 || echo "unknown")
        if ufw status 2>/dev/null | grep -q "Status: active"; then
            SYS_FIREWALL_ACTIVE="yes"
            print_success "Detected UFW ${SYS_FIREWALL_VERSION} (active)"
        else
            SYS_FIREWALL_ACTIVE="no"
            print_warning "Detected UFW ${SYS_FIREWALL_VERSION} (inactive)"
        fi
        return 0
    fi

    SYS_FIREWALL="none"
    SYS_FIREWALL_ACTIVE="no"
    print_warning "No firewall detected"
    return 1
}

#############################################################################
# SYSTEM RESOURCES (Comprehensive - like user's example)
#############################################################################

get_system_resources() {
    local resources_file="${TEMP_SESSION_DIR}/system_resources.tmp"

    # CPU Information
    local cores=$(nproc)
    local load=$(uptime | awk -F'load average:' '{print $2}' | awk '{print $1}' | sed 's/,//')
    local cpu_line=$(top -bn1 | grep "Cpu(s)")
    local cpu_idle=$(echo "$cpu_line" | awk '{print $8}' | sed 's/%id,//')
    local cpu_iowait=$(echo "$cpu_line" | awk '{print $10}' | sed 's/%wa,//')
    local cpu_used=$(awk "BEGIN {printf \"%.1f\", 100-$cpu_idle}")
    local load_percent=$(awk "BEGIN {printf \"%.0f\", ($load/$cores)*100}")

    # Memory Information - get all in one call
    local mem_info=$(free -h)
    local mem_total=$(echo "$mem_info" | awk '/^Mem:/ {print $2}')
    local mem_used=$(echo "$mem_info" | awk '/^Mem:/ {print $3}')
    local mem_available=$(echo "$mem_info" | awk '/^Mem:/ {print $7}')
    local mem_percent=$(free | awk '/^Mem:/ {printf "%.0f", $3/$2*100}')

    # Swap Information - from same free call
    local swap_total=$(echo "$mem_info" | awk '/^Swap:/ {print $2}')
    local swap_used=$(echo "$mem_info" | awk '/^Swap:/ {print $3}')
    local swap_percent=0
    if [ "$swap_total" != "0B" ] && [ -n "$swap_total" ]; then
        swap_percent=$(free | awk '/^Swap:/ {if($2>0) printf "%.0f", $3/$2*100; else print "0"}')
    fi

    # Disk Information - single df call
    local disk_info=$(df -h / | awk 'NR==2 {print $2,$3,$5}')
    local disk_root_total=$(echo "$disk_info" | awk '{print $1}')
    local disk_root_used=$(echo "$disk_info" | awk '{print $2}')
    local disk_root_percent=$(echo "$disk_info" | awk '{print $3}')

    # Uptime
    local uptime_str=$(uptime -p)

    # Save to session file
    cat > "$resources_file" << EOF
CPU_CORES=$cores
CPU_USED=$cpu_used
CPU_IOWAIT=$cpu_iowait
LOAD_AVERAGE=$load
LOAD_PERCENT=$load_percent
MEM_TOTAL=$mem_total
MEM_USED=$mem_used
MEM_PERCENT=$mem_percent
MEM_AVAILABLE=$mem_available
SWAP_TOTAL=$swap_total
SWAP_USED=$swap_used
SWAP_PERCENT=$swap_percent
DISK_ROOT_TOTAL=$disk_root_total
DISK_ROOT_USED=$disk_root_used
DISK_ROOT_PERCENT=$disk_root_percent
UPTIME=$uptime_str
EOF

    # Also export for immediate use
    export CPU_CORES=$cores
    export CPU_USED=$cpu_used
    export CPU_IOWAIT=$cpu_iowait
    export LOAD_AVERAGE=$load
    export LOAD_PERCENT=$load_percent
    export MEM_TOTAL=$mem_total
    export MEM_USED=$mem_used
    export MEM_PERCENT=$mem_percent
}

#############################################################################
# DISPLAY FUNCTIONS
#############################################################################

show_system_info() {
    echo ""
    print_banner "System Information"

    # Control Panel
    echo -e "${BOLD}Control Panel:${NC}"
    if [ "$SYS_CONTROL_PANEL" != "none" ]; then
        echo "  Type: $SYS_CONTROL_PANEL"
        echo "  Version: $SYS_CONTROL_PANEL_VERSION"
    else
        echo "  Type: Standalone (no control panel)"
    fi
    echo ""

    # Operating System
    echo -e "${BOLD}Operating System:${NC}"
    echo "  OS: $SYS_OS_TYPE $SYS_OS_VERSION"
    echo "  Kernel: $(uname -r)"
    [ "${SYS_CLOUDLINUX:-}" = "yes" ] && echo "  CloudLinux: Enabled"
    echo ""

    # Web Server
    echo -e "${BOLD}Web Server:${NC}"
    echo "  Type: $SYS_WEB_SERVER"
    echo "  Version: $SYS_WEB_SERVER_VERSION"
    [ "$SYS_CLOUDFLARE_ACTIVE" = "yes" ] && echo "  Cloudflare: Active"
    echo ""

    # Database
    echo -e "${BOLD}Database:${NC}"
    if [ "$SYS_DB_TYPE" != "none" ]; then
        echo "  Type: $SYS_DB_TYPE"
        echo "  Version: $SYS_DB_VERSION"
    else
        echo "  Type: Not installed"
    fi
    echo ""

    # PHP
    echo -e "${BOLD}PHP Versions:${NC}"
    if [ ${#SYS_PHP_VERSIONS[@]} -gt 0 ]; then
        for version in "${SYS_PHP_VERSIONS[@]}"; do
            echo "  - PHP $version"
        done
    else
        echo "  None detected"
    fi
    echo ""

    # System Resources
    echo -e "${BOLD}System Resources:${NC}"
    echo "  CPU Cores: $CPU_CORES"
    echo "  CPU Usage: ${CPU_USED}% (actual)"
    echo "  I/O Wait: ${CPU_IOWAIT}%"
    echo "  Load Average: $LOAD_AVERAGE (${LOAD_PERCENT}% of core capacity)"
    echo ""
    echo "  RAM Total: $MEM_TOTAL"
    echo "  RAM Used: $MEM_USED (${MEM_PERCENT}%)"
    echo "  RAM Available: $MEM_AVAILABLE"
    echo ""
    echo "  Swap Total: $SWAP_TOTAL"
    echo "  Swap Used: $SWAP_USED (${SWAP_PERCENT}%)"
    echo ""
    echo "  Disk (/) Total: $DISK_ROOT_TOTAL"
    echo "  Disk (/) Used: $DISK_ROOT_USED (${DISK_ROOT_PERCENT})"
    echo ""
    echo "  Uptime: $UPTIME"
    echo ""

    # Paths
    echo -e "${BOLD}Important Paths:${NC}"
    echo "  Log Directory: $SYS_LOG_DIR"
    echo "  User Home Base: $SYS_USER_HOME_BASE"
    echo ""
}

#############################################################################
# INITIALIZE ALL DETECTION
#############################################################################

initialize_system_detection() {
    # Create temp session directory
    create_temp_session

    # Run all detections
    detect_control_panel
    detect_os
    detect_web_server
    detect_database
    detect_php_versions
    detect_cloudflare
    detect_firewall
    get_system_resources

    # Mark as initialized
    export SYS_DETECTION_COMPLETE="yes"
}

# Export all functions for use in subshells and sourced scripts
export -f detect_control_panel
export -f detect_os
export -f detect_web_server
export -f detect_database
export -f detect_php_versions
export -f detect_cloudflare
export -f detect_firewall
export -f get_system_resources
export -f show_system_info
export -f initialize_system_detection

# Auto-initialize if not already done (when sourced)
if [ -z "${SYS_DETECTION_COMPLETE:-}" ]; then
    # Just run initialization - output suppression was breaking variable assignment
    initialize_system_detection
fi