"""
Command-builder module for managing AIDE (Advanced Intrusion Detection Environment)
file integrity monitoring on a Linux VPS. Each function returns a bash command string.
"""


def status_cmd() -> str:
    """Check if AIDE is installed, show version and database file dates."""
    return (
        "echo '=== AIDE Status ===';"
        " if command -v aide >/dev/null 2>&1; then"
        " echo 'AIDE is installed';"
        " aide --version 2>&1 | head -1;"
        " else"
        " echo 'AIDE is NOT installed';"
        " fi;"
        " echo;"
        " echo '=== Database Files ===';"
        " ls -lh /var/lib/aide/aide.db /var/lib/aide/aide.db.new 2>/dev/null"
        " || echo 'No AIDE database files found'"
    )


def install_cmd() -> str:
    """Install AIDE, initialize the database, and copy it into place."""
    return (
        "export DEBIAN_FRONTEND=noninteractive;"
        " apt-get update -qq"
        " && apt-get install -y -qq aide"
        " && echo 'Running aideinit (this may take a while)...'"
        " && aideinit"
        " && cp /var/lib/aide/aide.db.new /var/lib/aide/aide.db"
        " && echo 'AIDE installed and database initialized successfully'"
    )


def check_cmd() -> str:
    """Run AIDE integrity check showing changed, added, and removed files."""
    return (
        "echo '=== AIDE Integrity Check ===';"
        " aide --check 2>&1;"
        " echo;"
        " echo 'Exit code:' $?"
    )


def update_cmd() -> str:
    """Update AIDE database, accepting current filesystem state as the new baseline."""
    return (
        "echo '=== AIDE Database Update ===';"
        " aide --update"
        " && cp /var/lib/aide/aide.db.new /var/lib/aide/aide.db"
        " && echo 'Database updated — current state is now the baseline'"
    )


def init_cmd() -> str:
    """Re-initialize the AIDE database from scratch."""
    return (
        "echo '=== AIDE Database Re-initialization ===';"
        " aideinit"
        " && cp /var/lib/aide/aide.db.new /var/lib/aide/aide.db"
        " && echo 'Database re-initialized successfully'"
    )


def log_cmd(lines: int = 50) -> str:
    """Show the AIDE log file."""
    return (
        f"if [ -f /var/log/aide/aide.log ]; then"
        f" tail -n {lines} /var/log/aide/aide.log;"
        f" else"
        f" echo 'No AIDE log found at /var/log/aide/aide.log';"
        f" fi"
    )


def config_cmd() -> str:
    """Display the full AIDE configuration file."""
    return "cat /etc/aide/aide.conf"


def config_rules_cmd() -> str:
    """Show just the rule definitions from aide.conf (lines starting with / or =)."""
    return (
        "echo '=== AIDE Rule Definitions ===';"
        " grep -E '^(/|!|=)' /etc/aide/aide.conf"
    )


def compare_cmd() -> str:
    """Compare two AIDE databases (current baseline vs new)."""
    return (
        "echo '=== AIDE Database Comparison ===';"
        " aide --compare 2>&1"
    )


def schedule_cmd(schedule: str = "daily") -> str:
    """Set up a cron job for periodic AIDE checks (daily or weekly)."""
    cron_script = "/etc/cron.{schedule}/aide-check".format(schedule=schedule)
    script_body = (
        "#!/bin/bash\\n"
        "/usr/bin/aide --check > /var/log/aide/aide.log 2>&1"
    )
    return (
        f"echo -e '{script_body}' > {cron_script}"
        f" && chmod 755 {cron_script}"
        f" && echo 'AIDE {schedule} check scheduled at {cron_script}'"
    )


def schedule_status_cmd() -> str:
    """Show any existing AIDE cron jobs."""
    return (
        "echo '=== AIDE Scheduled Jobs ===';"
        " ls -la /etc/cron.daily/aide-check /etc/cron.weekly/aide-check 2>/dev/null"
        " || echo 'No AIDE cron jobs found';"
        " echo;"
        " echo '=== Crontab entries ===';"
        " crontab -l 2>/dev/null | grep -i aide"
        " || echo 'No AIDE entries in crontab'"
    )


def schedule_remove_cmd() -> str:
    """Remove all AIDE cron jobs."""
    return (
        "rm -f /etc/cron.daily/aide-check /etc/cron.weekly/aide-check"
        " && echo 'AIDE scheduled checks removed'"
    )


def uninstall_cmd() -> str:
    """Remove AIDE and its databases."""
    return (
        "export DEBIAN_FRONTEND=noninteractive;"
        " apt-get remove --purge -y -qq aide"
        " && rm -rf /var/lib/aide /var/log/aide"
        " && echo 'AIDE uninstalled and data removed'"
    )