#!/bin/bash

# ==============================================================================
# SFTP User Diagnostic Script
# Use this script to diagnose SFTP/SSH account creation issues
# ==============================================================================

# Get username from argument or prompt
if [ -z "$1" ]; then
    echo "Usage: $0 <username>"
    echo "Example: $0 mightyuser1"
    exit 1
fi

USERNAME="$1"

echo "=============================================================================="
echo "SFTP/SSH User Diagnostic Script"
echo "Checking user: $USERNAME"
echo "Timestamp: $(date)"
echo "=============================================================================="
echo

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

# Function to print colored output
print_status() {
    local status=$1
    local message=$2
    if [ "$status" = "OK" ]; then
        echo -e "${GREEN}[OK]${NC} $message"
    elif [ "$status" = "ERROR" ]; then
        echo -e "${RED}[ERROR]${NC} $message"
    elif [ "$status" = "WARNING" ]; then
        echo -e "${YELLOW}[WARNING]${NC} $message"
    else
        echo "[INFO] $message"
    fi
}

echo "=== 1. USER ACCOUNT CHECK ==="
if id "$USERNAME" &>/dev/null; then
    print_status "OK" "User account exists: $USERNAME"
    echo "  User ID: $(id -u $USERNAME)"
    echo "  Group ID: $(id -g $USERNAME)"
    echo "  Groups: $(id -Gn $USERNAME)"
    echo "  Home Directory: $(getent passwd $USERNAME | cut -d: -f6)"
    echo "  Shell: $(getent passwd $USERNAME | cut -d: -f7)"
else
    print_status "ERROR" "User account does NOT exist: $USERNAME"
    echo "  Run: id $USERNAME"
fi
echo

echo "=== 2. USER GROUPS CHECK ==="
if id "$USERNAME" &>/dev/null; then
    # Get groups using id command - ensure we capture the output correctly
    GROUPS_OUTPUT=$(id -Gn "$USERNAME" 2>&1)
    GROUPS_EXIT=$?
    
    if [ $GROUPS_EXIT -eq 0 ] && [ -n "$GROUPS_OUTPUT" ]; then
        GROUPS_LIST="$GROUPS_OUTPUT"
        echo "  All groups: $GROUPS_LIST"
        
        # Check for sftpusers or sshusers group
        if echo "$GROUPS_LIST" | grep -qw "sftpusers"; then
            print_status "OK" "User is in sftpusers group (SFTP-only access)"
        elif echo "$GROUPS_LIST" | grep -qw "sshusers"; then
            print_status "OK" "User is in sshusers group (SSH+SFTP access)"
        else
            print_status "ERROR" "User is NOT in sftpusers or sshusers group!"
            echo "  Current groups: $GROUPS_LIST"
            echo "  Fix: usermod -aG sftpusers $USERNAME (for SFTP-only)"
            echo "  Fix: usermod -aG sshusers $USERNAME (for SSH+SFTP)"
        fi
        
        # Check for litespeed group
        if echo "$GROUPS_LIST" | grep -qw "litespeed"; then
            print_status "OK" "User is in litespeed group"
        else
            print_status "WARNING" "User is NOT in litespeed group (may affect file access)"
        fi
    else
        print_status "ERROR" "Failed to retrieve groups for user $USERNAME"
        echo "  Command exit code: $GROUPS_EXIT"
        echo "  Output: $GROUPS_OUTPUT"
    fi
else
    print_status "ERROR" "User $USERNAME does not exist"
fi
echo

echo "=== 3. HOME DIRECTORY CHECK ==="
if id "$USERNAME" &>/dev/null; then
    USER_HOME=$(getent passwd $USERNAME | cut -d: -f6)
    if [ -d "$USER_HOME" ]; then
        print_status "OK" "Home directory exists: $USER_HOME"
        echo "  Ownership: $(stat -c '%U:%G' $USER_HOME)"
        echo "  Permissions: $(stat -c '%a' $USER_HOME)"
        
        # Check if home directory is owned by root (required for chroot)
        if [ "$(stat -c '%U' $USER_HOME)" = "root" ]; then
            print_status "OK" "Home directory is owned by root (required for chroot)"
        else
            print_status "ERROR" "Home directory must be owned by root for chroot!"
            echo "  Fix: chown root:root $USER_HOME"
        fi
        
        # Check permissions
        PERMS=$(stat -c '%a' $USER_HOME)
        if [ "$PERMS" = "755" ] || [ "$PERMS" = "751" ]; then
            print_status "OK" "Home directory permissions are correct: $PERMS"
        else
            print_status "WARNING" "Home directory permissions should be 755 or 751, current: $PERMS"
            echo "  Fix: chmod 755 $USER_HOME"
        fi
    else
        print_status "ERROR" "Home directory does NOT exist: $USER_HOME"
    fi
fi
echo

echo "=== 4. DIRECTORY STRUCTURE CHECK ==="
if id "$USERNAME" &>/dev/null; then
    USER_HOME=$(getent passwd $USERNAME | cut -d: -f6)
    if [ -d "$USER_HOME/data" ]; then
        print_status "OK" "Data directory exists: $USER_HOME/data"
        echo "  Ownership: $(stat -c '%U:%G' $USER_HOME/data 2>/dev/null || echo 'N/A')"
        echo "  Permissions: $(stat -c '%a' $USER_HOME/data 2>/dev/null || echo 'N/A')"
        
        if [ -d "$USER_HOME/data/ROOT" ]; then
            print_status "OK" "ROOT directory exists: $USER_HOME/data/ROOT"
            # Check if it's a mount point
            # mountpoint command is part of util-linux (installed by default on AlmaLinux 9.6)
            # Fallback to checking /proc/mounts if mountpoint is not available
            IS_MOUNTED=false
            if command -v mountpoint >/dev/null 2>&1; then
                if mountpoint -q "$USER_HOME/data/ROOT" 2>/dev/null; then
                    IS_MOUNTED=true
                fi
            else
                # Fallback: check /proc/mounts
                if grep -q " $USER_HOME/data/ROOT " /proc/mounts 2>/dev/null; then
                    IS_MOUNTED=true
                fi
            fi
            
            if [ "$IS_MOUNTED" = true ]; then
                print_status "OK" "ROOT is properly mounted (bind mount)"
                MOUNT_INFO=$(mount | grep "$USER_HOME/data/ROOT" 2>/dev/null || echo "No mount info found")
                echo "  Mount info: $MOUNT_INFO"
                
                # Check webroot permissions
                WEBROOT_DIR="/var/www/webroot/ROOT"
                if [ -d "$WEBROOT_DIR" ]; then
                    WEBROOT_PERMS=$(stat -c '%a' "$WEBROOT_DIR" 2>/dev/null)
                    WEBROOT_GROUP=$(stat -c '%G' "$WEBROOT_DIR" 2>/dev/null)
                    WEBROOT_OWNER=$(stat -c '%U:%G' "$WEBROOT_DIR" 2>/dev/null)
                    echo "  Webroot permissions: $WEBROOT_PERMS ($WEBROOT_OWNER)"
                    
                    # Check if group has write permission
                    GROUP_WRITE_BIT=$(echo "$WEBROOT_PERMS" | cut -c2)
                    if [ "$GROUP_WRITE_BIT" = "4" ] || [ "$GROUP_WRITE_BIT" = "5" ] || [ "$GROUP_WRITE_BIT" = "1" ] || [ "$GROUP_WRITE_BIT" = "0" ]; then
                        print_status "WARNING" "Webroot does NOT have group write permissions (current: $WEBROOT_PERMS)"
                        echo "  Fix: chmod -R g+w $WEBROOT_DIR"
                    else
                        print_status "OK" "Webroot has group write permissions"
                    fi
                    
                    if [ "$WEBROOT_GROUP" != "litespeed" ]; then
                        print_status "WARNING" "Webroot group is not litespeed (current: $WEBROOT_GROUP)"
                        echo "  Fix: chgrp -R litespeed $WEBROOT_DIR"
                    fi
                fi
            else
                print_status "WARNING" "ROOT directory exists but is not mounted"
                echo "  Fix: mount --bind /var/www/webroot/ROOT $USER_HOME/data/ROOT"
            fi
        else
            print_status "ERROR" "ROOT directory does NOT exist: $USER_HOME/data/ROOT"
        fi
    else
        print_status "ERROR" "Data directory does NOT exist: $USER_HOME/data"
    fi
fi
echo

echo "=== 5. PASSWORD CHECK ==="
if id "$USERNAME" &>/dev/null; then
    # Check if password is set (this is tricky - we can only check if shadow entry exists)
    if grep -q "^$USERNAME:" /etc/shadow; then
        print_status "OK" "User has shadow entry (password record exists)"
        # Check if password field is empty or has '!' (locked)
        PWD_FIELD=$(grep "^$USERNAME:" /etc/shadow | cut -d: -f2)
        if [ -z "$PWD_FIELD" ] || [ "$PWD_FIELD" = "*" ] || [ "$PWD_FIELD" = "!" ]; then
            print_status "ERROR" "User password appears to be LOCKED or NOT SET!"
            echo "  Password field: $PWD_FIELD"
            echo "  Fix: echo '$USERNAME:NEW_PASSWORD' | chpasswd"
        else
            print_status "OK" "User password appears to be set (hashed)"
        fi
    else
        print_status "ERROR" "User does NOT have shadow entry!"
    fi
fi
echo

echo "=== 6. SSH CONFIGURATION CHECK ==="
echo "Checking SSH daemon configuration..."

# Check if sshd_config.d directory exists and is included
if [ -d "/etc/ssh/sshd_config.d" ]; then
    print_status "OK" "SSH config.d directory exists"
    if grep -q "^Include" /etc/ssh/sshd_config | grep -q "sshd_config.d"; then
        print_status "OK" "sshd_config.d is included in main config"
    else
        print_status "WARNING" "sshd_config.d may not be included (check Include directive)"
    fi
else
    print_status "WARNING" "sshd_config.d directory does not exist"
fi

# Check addon config file
ADDON_CONFIG="/etc/ssh/sshd_config.d/99-sftp-addon.conf"
if [ -f "$ADDON_CONFIG" ]; then
    print_status "OK" "Addon config file exists: $ADDON_CONFIG"
    echo "  Contents:"
    cat "$ADDON_CONFIG" | sed 's/^/    /'
else
    print_status "WARNING" "Addon config file does NOT exist: $ADDON_CONFIG"
fi

# Check main sshd_config
if grep -qE "^PasswordAuthentication\s+yes" /etc/ssh/sshd_config; then
    print_status "OK" "PasswordAuthentication is enabled in main config"
elif grep -qE "^PasswordAuthentication\s+no" /etc/ssh/sshd_config; then
    print_status "ERROR" "PasswordAuthentication is DISABLED in main config!"
    echo "  Fix: sed -i 's/^PasswordAuthentication no/PasswordAuthentication yes/' /etc/ssh/sshd_config"
else
    print_status "WARNING" "PasswordAuthentication setting not found in main config (may use default)"
fi

# Check Match Group configuration
if grep -q "Match Group sftpusers" /etc/ssh/sshd_config; then
    print_status "OK" "Match Group sftpusers found in main config"
elif [ -f "$ADDON_CONFIG" ] && grep -q "Match Group sftpusers" "$ADDON_CONFIG"; then
    print_status "OK" "Match Group sftpusers found in addon config"
else
    print_status "ERROR" "Match Group sftpusers NOT found in SSH config!"
fi

if grep -q "Match Group sshusers" /etc/ssh/sshd_config; then
    print_status "OK" "Match Group sshusers found in main config"
elif [ -f "$ADDON_CONFIG" ] && grep -q "Match Group sshusers" "$ADDON_CONFIG"; then
    print_status "OK" "Match Group sshusers found in addon config"
else
    print_status "WARNING" "Match Group sshusers NOT found (needed for SSH access)"
fi

# Test SSH config syntax
if sshd -t 2>/dev/null; then
    print_status "OK" "SSH configuration syntax is valid"
else
    print_status "ERROR" "SSH configuration syntax is INVALID!"
    echo "  Run: sshd -t (as root) to see errors"
fi
echo

echo "=== 7. SSH SERVICE STATUS ==="
if systemctl is-active --quiet sshd; then
    print_status "OK" "SSH service is running"
else
    print_status "ERROR" "SSH service is NOT running!"
    echo "  Fix: systemctl start sshd"
fi

if systemctl is-enabled --quiet sshd; then
    print_status "OK" "SSH service is enabled (will start on boot)"
else
    print_status "WARNING" "SSH service is NOT enabled"
fi
echo

echo "=== 8. RECENT LOGS CHECK ==="
LOG_DIR="/opt/add-sftp-user-addon/logs"
if [ -d "$LOG_DIR" ]; then
    print_status "OK" "Log directory exists: $LOG_DIR"
    
    # Find user creation log
    USER_LOG=$(ls -t $LOG_DIR/user_creation-*.log 2>/dev/null | head -1)
    if [ -n "$USER_LOG" ]; then
        echo "  Most recent user creation log: $USER_LOG"
        echo "  Last 10 lines:"
        tail -10 "$USER_LOG" | sed 's/^/    /'
    else
        print_status "WARNING" "No user creation logs found"
    fi
    
    # Check error log
    if [ -f "$LOG_DIR/errors.log" ]; then
        ERROR_COUNT=$(wc -l < "$LOG_DIR/errors.log")
        if [ "$ERROR_COUNT" -gt 0 ]; then
            print_status "WARNING" "Found $ERROR_COUNT lines in error log"
            echo "  Last 5 errors:"
            tail -5 "$LOG_DIR/errors.log" | sed 's/^/    /'
        fi
    fi
else
    print_status "WARNING" "Log directory does not exist: $LOG_DIR"
fi
echo

echo "=== 9. AUTHENTICATION TEST (SIMULATED) ==="
if id "$USERNAME" &>/dev/null; then
    USER_SHELL=$(getent passwd $USERNAME | cut -d: -f7)
    AUTH_GROUPS_OUTPUT=$(id -Gn "$USERNAME" 2>&1)
    AUTH_GROUPS_EXIT=$?
    
    if [ $AUTH_GROUPS_EXIT -eq 0 ] && [ -n "$AUTH_GROUPS_OUTPUT" ]; then
        AUTH_GROUPS="$AUTH_GROUPS_OUTPUT"
        
        if [ "$USER_SHELL" = "/sbin/nologin" ]; then
            if echo "$AUTH_GROUPS" | grep -qw "sftpusers"; then
                print_status "OK" "User configured for SFTP-only (nologin shell + sftpusers group)"
                echo "  Note: This user can ONLY use SFTP, not SSH shell access"
            else
                print_status "ERROR" "User has nologin shell but NOT in sftpusers group!"
                echo "  Current groups: $AUTH_GROUPS"
            fi
        elif [ "$USER_SHELL" = "/bin/bash" ] || [ "$USER_SHELL" = "/bin/sh" ]; then
            if echo "$AUTH_GROUPS" | grep -qw "sshusers"; then
                print_status "OK" "User configured for SSH+SFTP (bash shell + sshusers group)"
            else
                print_status "ERROR" "User has bash shell but NOT in sshusers group!"
                echo "  Current groups: $AUTH_GROUPS"
                echo "  Fix: usermod -aG sshusers $USERNAME"
            fi
        else
            print_status "WARNING" "Unexpected shell: $USER_SHELL"
        fi
    else
        print_status "ERROR" "Failed to retrieve groups for authentication check"
        echo "  Command exit code: $AUTH_GROUPS_EXIT"
        echo "  Output: $AUTH_GROUPS_OUTPUT"
    fi
else
    print_status "ERROR" "User $USERNAME does not exist"
fi
echo

echo "=== 10. QUICK FIXES ==="
echo "If user exists but login fails, try these commands (as root):"
echo
if id "$USERNAME" &>/dev/null; then
    echo "1. Reset password:"
    echo "   echo '$USERNAME:NEW_PASSWORD' | chpasswd"
    echo
    echo "2. Fix group membership (choose one based on desired access):"
    echo "   # For SFTP-only:"
    echo "   usermod -aG sftpusers,litespeed $USERNAME"
    echo "   usermod -s /sbin/nologin $USERNAME"
    echo "   # For SSH+SFTP:"
    echo "   usermod -aG sshusers,litespeed $USERNAME"
    echo "   usermod -s /bin/bash $USERNAME"
    echo
    echo "3. Fix home directory permissions:"
    USER_HOME=$(getent passwd $USERNAME | cut -d: -f6)
    echo "   chown root:root $USER_HOME"
    echo "   chmod 755 $USER_HOME"
    echo
    echo "4. Remount ROOT directory:"
    echo "   mount --bind /var/www/webroot/ROOT $USER_HOME/data/ROOT"
    echo
    echo "5. Restart SSH service:"
    echo "   systemctl restart sshd"
else
    echo "User does not exist. Cannot provide fixes."
fi
echo

echo "=============================================================================="
echo "Diagnostic complete!"
echo "=============================================================================="

# Exit with success status
exit 0