"""
Command-builder module for managing ModSecurity WAF with OWASP CRS on Nginx.
Each function returns a bash command string for execution on a Linux VPS.
"""

MODSEC_CONF = "/etc/nginx/modsec/modsecurity.conf"
CRS_SETUP_CONF = "/etc/nginx/modsec/owasp-crs/crs-setup.conf"
CRS_RULES_DIR = "/etc/nginx/modsec/owasp-crs/rules"
MAIN_CONF = "/etc/nginx/modsec/main.conf"
EXCLUSIONS_CONF = "/etc/nginx/modsec/exclusions.conf"
AUDIT_LOG = "/var/log/modsec_audit.log"
DEBUG_LOG = "/var/log/modsecurity/modsec_debug.log"
CRS_DIR = "/etc/nginx/modsec/owasp-crs"


def status_cmd():
    """Check if modsecurity module is loaded in nginx, rules active, and SecRuleEngine setting."""
    return (
        "echo '=== Nginx ModSecurity Module ===' && "
        "nginx -V 2>&1 | grep -i modsecurity && "
        "echo '' && "
        "echo '=== SecRuleEngine Setting ===' && "
        f"grep -i 'SecRuleEngine' {MODSEC_CONF} 2>/dev/null || echo 'modsecurity.conf not found' && "
        "echo '' && "
        "echo '=== Active Rules ===' && "
        f"ls {CRS_RULES_DIR}/*.conf 2>/dev/null | wc -l && "
        "echo 'rule files loaded' && "
        "echo '' && "
        "echo '=== Nginx Config Test ===' && "
        "nginx -t 2>&1"
    )


def install_cmd():
    """Install libmodsecurity3, nginx module, download OWASP CRS, configure."""
    return (
        "apt-get update && "
        "apt-get install -y libmodsecurity3 libmodsecurity-dev libnginx-mod-http-modsecurity && "
        "mkdir -p /etc/nginx/modsec && "
        f"cd /etc/nginx/modsec && "
        "if [ ! -d owasp-crs ]; then "
        "git clone https://github.com/coreruleset/coreruleset.git owasp-crs; "
        "fi && "
        f"cp {CRS_DIR}/crs-setup.conf.example {CRS_SETUP_CONF} && "
        "cp /etc/modsecurity/modsecurity.conf-recommended /etc/nginx/modsec/modsecurity.conf && "
        f"sed -i 's/SecRuleEngine DetectionOnly/SecRuleEngine On/' {MODSEC_CONF} && "
        f"touch {EXCLUSIONS_CONF} && "
        f"cat > {MAIN_CONF} << 'MAINEOF'\n"
        f"Include {MODSEC_CONF}\n"
        f"Include {CRS_SETUP_CONF}\n"
        f"Include {CRS_RULES_DIR}/*.conf\n"
        f"Include {EXCLUSIONS_CONF}\n"
        "MAINEOF\n"
        "&& nginx -t && systemctl reload nginx"
    )


def enable_cmd():
    """Set SecRuleEngine On in modsecurity.conf."""
    return (
        f"sed -i 's/^SecRuleEngine .*/SecRuleEngine On/' {MODSEC_CONF} && "
        f"grep 'SecRuleEngine' {MODSEC_CONF} && "
        "nginx -t && systemctl reload nginx"
    )


def disable_cmd():
    """Set SecRuleEngine to DetectionOnly (log only, don't block)."""
    return (
        f"sed -i 's/^SecRuleEngine .*/SecRuleEngine DetectionOnly/' {MODSEC_CONF} && "
        f"grep 'SecRuleEngine' {MODSEC_CONF} && "
        "nginx -t && systemctl reload nginx"
    )


def audit_log_cmd(lines=50):
    """Tail the modsecurity audit log."""
    return f"tail -n {int(lines)} {AUDIT_LOG}"


def debug_log_cmd(lines=50):
    """Tail the modsecurity debug log."""
    return f"tail -n {int(lines)} {DEBUG_LOG}"


def rules_list_cmd():
    """List rule files in the OWASP CRS rules directory."""
    return f"ls -la {CRS_RULES_DIR}/*.conf 2>/dev/null"


def rule_disable_cmd(rule_id):
    """Add SecRuleRemoveById to the custom exclusion conf."""
    rid = str(int(rule_id))
    return (
        f"if grep -q 'SecRuleRemoveById {rid}' {EXCLUSIONS_CONF} 2>/dev/null; then "
        f"echo 'Rule {rid} is already disabled'; "
        "else "
        f"echo 'SecRuleRemoveById {rid}' >> {EXCLUSIONS_CONF} && "
        f"echo 'Disabled rule {rid}' && "
        "nginx -t && systemctl reload nginx; "
        "fi"
    )


def rule_enable_cmd(rule_id):
    """Remove a rule ID from the exclusion conf (re-enable it)."""
    rid = str(int(rule_id))
    return (
        f"if grep -q 'SecRuleRemoveById {rid}' {EXCLUSIONS_CONF} 2>/dev/null; then "
        f"sed -i '/SecRuleRemoveById {rid}/d' {EXCLUSIONS_CONF} && "
        f"echo 'Re-enabled rule {rid}' && "
        "nginx -t && systemctl reload nginx; "
        "else "
        f"echo 'Rule {rid} is not in exclusions'; "
        "fi"
    )


def exclusions_cmd():
    """Show current rule exclusions."""
    return (
        f"echo '=== Rule Exclusions ({EXCLUSIONS_CONF}) ===' && "
        f"cat {EXCLUSIONS_CONF} 2>/dev/null || echo 'No exclusions file found'"
    )


def crs_update_cmd():
    """Git pull in the OWASP CRS directory to update rules."""
    return (
        f"cd {CRS_DIR} && "
        "git pull && "
        "echo '' && echo '=== Updated CRS Rules ===' && "
        "nginx -t && systemctl reload nginx"
    )


def config_cmd():
    """Show modsecurity.conf."""
    return f"cat {MODSEC_CONF}"


def config_crs_cmd():
    """Show crs-setup.conf."""
    return f"cat {CRS_SETUP_CONF}"


def test_cmd():
    """Curl localhost with test XSS and SQLi payloads to verify WAF is working."""
    return (
        "echo '=== XSS Test ===' && "
        "curl -s -o /dev/null -w 'HTTP %{http_code}' "
        "'http://localhost/?q=<script>alert(1)</script>' && "
        "echo '' && "
        "echo '=== SQLi Test ===' && "
        "curl -s -o /dev/null -w 'HTTP %{http_code}' "
        "\"http://localhost/?id=1' OR '1'='1\" && "
        "echo '' && "
        "echo '=== Path Traversal Test ===' && "
        "curl -s -o /dev/null -w 'HTTP %{http_code}' "
        "'http://localhost/../../etc/passwd' && "
        "echo '' && "
        "echo '(403 = blocked by WAF, 200 = WAF not blocking)'"
    )


def nginx_status_cmd():
    """Check which nginx server blocks have modsecurity enabled."""
    return (
        "echo '=== Server Blocks with ModSecurity ===' && "
        "grep -rn 'modsecurity' /etc/nginx/sites-enabled/ /etc/nginx/conf.d/ 2>/dev/null || "
        "echo 'No modsecurity directives found in server blocks' && "
        "echo '' && "
        "echo '=== Nginx Module Status ===' && "
        "nginx -V 2>&1 | grep -io 'modsecurity[^ ]*' || echo 'ModSecurity module not found'"
    )


def uninstall_cmd():
    """Remove modsec configs and apt remove packages."""
    return (
        "echo 'Removing ModSecurity configuration...' && "
        "rm -rf /etc/nginx/modsec && "
        "apt-get remove -y libmodsecurity3 libmodsecurity-dev libnginx-mod-http-modsecurity && "
        "apt-get autoremove -y && "
        "echo 'Removed modsec configs and packages' && "
        "echo 'NOTE: Check nginx server blocks and remove modsecurity directives manually' && "
        "nginx -t && systemctl reload nginx"
    )