integrity_scanner_fuer_statische_Webseiten/scanner/alerter.py

"""
Alert dispatch: e-mail (smtplib) and HTTP webhook.

Alerts are only sent when the assessment level meets or exceeds min_level.
"""
import logging
import os
import smtplib
from datetime import datetime, timezone
from email.message import EmailMessage

import requests

logger = logging.getLogger(__name__)

_LEVEL_ORDER = {"green": 0, "yellow": 1, "red": 2}


def send_alert(report: dict, cfg: dict) -> None:
    """Send alert if the report's level is at or above min_level."""
    alerting = cfg.get("alerting", {})
    level = report.get("assessment", {}).get("level", "green")
    min_level = alerting.get("min_level", "yellow")

    if _LEVEL_ORDER.get(level, 0) < _LEVEL_ORDER.get(min_level, 1):
        logger.debug("Alert suppressed: level=%s < min_level=%s", level, min_level)
        return

    subject = _make_subject(report)
    body = _format_body(report)

    email_cfg = alerting.get("email", {})
    if email_cfg.get("enabled"):
        _send_email(subject, body, email_cfg)

    webhook_cfg = alerting.get("webhook", {})
    if webhook_cfg.get("enabled") and webhook_cfg.get("url"):
        _send_webhook(webhook_cfg["url"], report, subject)


# ---------------------------------------------------------------------------
# Formatting
# ---------------------------------------------------------------------------

def _make_subject(report: dict) -> str:
    level = report.get("assessment", {}).get("level", "?").upper()
    target = report.get("target", "?")
    ts = datetime.now(timezone.utc).strftime("%Y-%m-%d %H:%M UTC")
    return f"[{level}] Integrity Alert: {target} — {ts}"


def _format_body(report: dict) -> str:
    lines = [
        "=" * 60,
        "WEBSITE INTEGRITY ALERT",
        "=" * 60,
        f"Ziel:      {report.get('target', '?')}",
        f"Zeitpunkt: {datetime.now(timezone.utc).isoformat()}",
    ]

    assessment = report.get("assessment", {})
    level = assessment.get("level", "?").upper()
    score = assessment.get("score", "?")
    lines += [
        f"Level:     {level}",
        f"Score:     {score}",
        "",
        "--- Gruende ---",
    ]
    for reason in assessment.get("reasons", []):
        lines.append(f"  * {reason}")

    diff = report.get("diff", {})

    _section(lines, "Neue externe Domains", diff.get("new_external_domains", []), "+")
    _section(lines, "Neue interne URLs", diff.get("new_internal_urls", []), "+")
    _section(lines, "Fehlende URLs", diff.get("missing_internal_urls", []), "-")

    for pd in diff.get("page_diffs", [])[:10]:
        lines += ["", f"--- Aenderung: {pd['url']} ---"]
        if pd.get("text_diff"):
            lines.append(f"  Text-Diff: {pd['added_chars']} Zeichen zugefügt")
            lines += [f"  {l}" for l in pd["text_diff"][:30]]
        if pd.get("new_hidden_content"):
            lines.append(f"  Hidden Content: {len(pd['new_hidden_content'])} neue(r) Fund(e)")
        if pd.get("new_meta_refresh"):
            lines.append(f"  Meta-Refresh: {pd['new_meta_refresh']}")
        if pd.get("canonical_changed"):
            lines.append(f"  Canonical geaendert: {pd.get('old_canonical')} -> {pd.get('new_canonical')}")
        if pd.get("new_comment_links"):
            lines.append(f"  Kommentar-Links: {pd['new_comment_links']}")

    lines += [
        "",
        "--- Empfehlung ---",
    ]
    level_lower = assessment.get("level", "green")
    if level_lower == "red":
        lines += [
            "  SOFORT HANDELN: Website moeglicherweise kompromittiert.",
            "  Zugriff auf Hosting-Backend prüfen, Dateien vergleichen.",
        ]
    elif level_lower == "yellow":
        lines += [
            "  PRÜFEN: Unerwartete Aenderungen gefunden.",
            "  Alle markierten URLs manuell kontrollieren.",
            "  Falls legitim: python -m scanner approve --all",
        ]
    else:
        lines.append("  OK — nur zur Information.")

    lines += [
        "",
        "--- Workflow ---",
        "  Details:   python -m scanner report",
        "  Freigabe:  python -m scanner approve --url <URL>",
        "  Rebuild:   python -m scanner approve --rebuild",
        "=" * 60,
    ]
    return "\n".join(lines)


def _section(lines: list, title: str, items: list, prefix: str) -> None:
    if not items:
        return
    lines += ["", f"--- {title} ---"]
    for item in items[:50]:
        lines.append(f"  {prefix} {item}")
    if len(items) > 50:
        lines.append(f"  ... und {len(items) - 50} weitere")


# ---------------------------------------------------------------------------
# Transport
# ---------------------------------------------------------------------------

def _send_email(subject: str, body: str, cfg: dict) -> None:
    password = os.environ.get(cfg.get("smtp_password_env", "SCANNER_SMTP_PASSWORD"), "")
    recipients = cfg.get("to", [])
    if not recipients:
        logger.warning("E-Mail alert enabled but no recipients configured.")
        return

    msg = EmailMessage()
    msg["Subject"] = subject
    msg["From"] = cfg.get("from", "scanner@localhost")
    msg["To"] = ", ".join(recipients)
    msg.set_content(body)

    host = cfg.get("smtp_host", "localhost")
    port = cfg.get("smtp_port", 587)
    use_tls = cfg.get("smtp_tls", True)

    try:
        with smtplib.SMTP(host, port) as server:
            if use_tls:
                server.starttls()
            user = cfg.get("smtp_user", "")
            if user and password:
                server.login(user, password)
            server.send_message(msg)
        logger.info("Alert e-mail sent to %s", recipients)
    except Exception as exc:
        logger.error("E-mail alert failed: %s", exc)


def _send_webhook(url: str, report: dict, subject: str) -> None:
    payload = {
        "text": subject,
        "target": report.get("target"),
        "level": report.get("assessment", {}).get("level"),
        "score": report.get("assessment", {}).get("score"),
        "reasons": report.get("assessment", {}).get("reasons", []),
        "new_external_domains": report.get("diff", {}).get("new_external_domains", []),
        "new_internal_urls": report.get("diff", {}).get("new_internal_urls", []),
        "missing_internal_urls": report.get("diff", {}).get("missing_internal_urls", []),
        "changed_pages": report.get("diff", {}).get("changed_pages", 0),
    }
    try:
        resp = requests.post(url, json=payload, timeout=10)
        logger.info("Webhook delivered: HTTP %s", resp.status_code)
    except Exception as exc:
        logger.error("Webhook alert failed: %s", exc)