breakpilot-compliance/backend-compliance/compliance/services/banner_consent_service.py

# mypy: disable-error-code="arg-type,assignment"
# SQLAlchemy 1.x Column() descriptors are Column[T] statically, T at runtime.
"""
Banner consent service — SDK-facing endpoints.

Phase 1 Step 4: extracted from ``compliance.api.banner_routes``.
Covers public device consent CRUD, site config retrieval (for banner
display), export, and per-site consent statistics.

Admin-side site/category/vendor management lives in
``compliance.services.banner_admin_service.BannerAdminService``.
DSR-facing email linking lives in
``compliance.services.banner_dsr_service.BannerDSRService``.
"""

import hashlib
import json
import uuid
from datetime import datetime, timedelta, timezone
from typing import Any, Optional

from sqlalchemy.orm import Session

from compliance.db.banner_models import (
    BannerCategoryConfigDB,
    BannerConsentAuditLogDB,
    BannerConsentDB,
    BannerSiteConfigDB,
    BannerVendorConfigDB,
)
from compliance.domain import NotFoundError, ValidationError
from compliance.services._banner_serializers import (
    category_to_dict,
    consent_to_dict,
    site_config_to_dict,
    vendor_to_dict,
)

# Default consent expiration per banner category (days).
# Based on: DSGVO Art. 5(1)(e), CNIL guidelines, EDPB recommendations.
CATEGORY_RETENTION_DAYS = {
    "necessary": 365,      # Session + functional = max 12 months
    "statistics": 790,     # Max 26 months (Google Analytics default)
    "marketing": 90,       # Max 90 days for retargeting
    "functional": 365,     # Max 12 months
}


class BannerConsentService:
    """Business logic for public SDK banner consent endpoints."""

    def __init__(self, db: Session) -> None:
        self.db = db

    # ------------------------------------------------------------------
    # Internal helpers
    # ------------------------------------------------------------------

    @staticmethod
    def _hash_ip(ip: Optional[str]) -> Optional[str]:
        if not ip:
            return None
        return hashlib.sha256(ip.encode()).hexdigest()[:16]

    def _log(
        self,
        tenant_id: uuid.UUID,
        consent_id: Any,
        action: str,
        site_id: str,
        device_fingerprint: Optional[str] = None,
        categories: Optional[list[str]] = None,
        ip_hash: Optional[str] = None,
        banner_config_hash: Optional[str] = None,
        consent_version: Optional[int] = None,
    ) -> None:
        entry = BannerConsentAuditLogDB(
            tenant_id=tenant_id,
            consent_id=consent_id,
            action=action,
            site_id=site_id,
            device_fingerprint=device_fingerprint,
            categories=categories or [],
            ip_hash=ip_hash,
            banner_config_hash=banner_config_hash,
            consent_version=consent_version,
        )
        self.db.add(entry)

    def _compute_config_hash(self, tenant_id: uuid.UUID, site_id: str) -> tuple[Optional[str], Optional[int]]:
        """Compute SHA256 hash of current site config for consent proof (Art. 7(1) DSGVO)."""
        config = (
            self.db.query(BannerSiteConfigDB)
            .filter(
                BannerSiteConfigDB.tenant_id == tenant_id,
                BannerSiteConfigDB.site_id == site_id,
            )
            .first()
        )
        if not config:
            return None, None
        snapshot = json.dumps({
            "banner_title": config.banner_title,
            "banner_description": config.banner_description,
            "privacy_url": config.privacy_url,
            "imprint_url": config.imprint_url,
        }, sort_keys=True)
        return hashlib.sha256(snapshot.encode()).hexdigest()[:32], config.config_version

    def _get_max_retention(self, tenant_id: uuid.UUID, site_id: str, categories: list[str]) -> int:
        """Determine consent expiration based on accepted categories and vendor retention."""
        config = (
            self.db.query(BannerSiteConfigDB)
            .filter(BannerSiteConfigDB.tenant_id == tenant_id, BannerSiteConfigDB.site_id == site_id)
            .first()
        )
        if not config:
            return 365
        vendors = (
            self.db.query(BannerVendorConfigDB)
            .filter(
                BannerVendorConfigDB.site_config_id == config.id,
                BannerVendorConfigDB.category_key.in_(categories),
                BannerVendorConfigDB.is_active,
            )
            .all()
        )
        if vendors:
            return max(v.retention_days for v in vendors if v.retention_days)
        return max((CATEGORY_RETENTION_DAYS.get(c, 365) for c in categories), default=365)

    # ------------------------------------------------------------------
    # Consent CRUD (public SDK)
    # ------------------------------------------------------------------

    def record_consent(
        self,
        tenant_id: str,
        site_id: str,
        device_fingerprint: str,
        categories: list[str],
        vendors: list[str],
        ip_address: Optional[str],
        user_agent: Optional[str],
        consent_string: Optional[str],
    ) -> dict[str, Any]:
        """Upsert a device consent row for (tenant, site, device_fingerprint).

        Expiration is derived from the maximum vendor retention for the
        accepted categories (Phase 2 — DSGVO Art. 5(1)(e)).
        A SHA256 hash of the banner config is stored in the audit log
        for consent proof (Phase 6 — Art. 7(1) DSGVO).
        """
        tid = uuid.UUID(tenant_id)
        ip_hash = self._hash_ip(ip_address)
        now = datetime.now(timezone.utc)
        retention = self._get_max_retention(tid, site_id, categories)
        expires_at = now + timedelta(days=retention)
        config_hash, config_ver = self._compute_config_hash(tid, site_id)

        existing = (
            self.db.query(BannerConsentDB)
            .filter(
                BannerConsentDB.tenant_id == tid,
                BannerConsentDB.site_id == site_id,
                BannerConsentDB.device_fingerprint == device_fingerprint,
            )
            .first()
        )

        if existing:
            existing.categories = categories
            existing.vendors = vendors
            existing.ip_hash = ip_hash
            existing.user_agent = user_agent
            existing.consent_string = consent_string
            existing.expires_at = expires_at
            existing.updated_at = now
            self.db.flush()
            self._log(
                tid, existing.id, "consent_updated", site_id, device_fingerprint,
                categories, ip_hash, config_hash, config_ver,
            )
            self.db.commit()
            self.db.refresh(existing)
            return consent_to_dict(existing)

        consent = BannerConsentDB(
            tenant_id=tid,
            site_id=site_id,
            device_fingerprint=device_fingerprint,
            categories=categories,
            vendors=vendors,
            ip_hash=ip_hash,
            user_agent=user_agent,
            consent_string=consent_string,
            expires_at=expires_at,
        )
        self.db.add(consent)
        self.db.flush()
        self._log(
            tid, consent.id, "consent_given", site_id, device_fingerprint,
            categories, ip_hash, config_hash, config_ver,
        )
        self.db.commit()
        self.db.refresh(consent)
        return consent_to_dict(consent)

    def get_consent(
        self, tenant_id: str, site_id: str, device_fingerprint: str
    ) -> dict[str, Any]:
        """Return the consent envelope for a device, or has_consent=false."""
        tid = uuid.UUID(tenant_id)
        consent = (
            self.db.query(BannerConsentDB)
            .filter(
                BannerConsentDB.tenant_id == tid,
                BannerConsentDB.site_id == site_id,
                BannerConsentDB.device_fingerprint == device_fingerprint,
            )
            .first()
        )
        if not consent:
            return {"has_consent": False, "consent": None}
        return {"has_consent": True, "consent": consent_to_dict(consent)}

    def withdraw_consent(self, tenant_id: str, consent_id: str) -> dict[str, Any]:
        """Delete a consent row + audit the withdrawal."""
        tid = uuid.UUID(tenant_id)
        try:
            cid = uuid.UUID(consent_id)
        except ValueError as exc:
            raise ValidationError("Invalid consent ID") from exc

        consent = (
            self.db.query(BannerConsentDB)
            .filter(BannerConsentDB.id == cid, BannerConsentDB.tenant_id == tid)
            .first()
        )
        if not consent:
            raise NotFoundError("Consent not found")

        self._log(
            tid, cid, "consent_withdrawn", consent.site_id, consent.device_fingerprint,
        )
        self.db.delete(consent)
        self.db.commit()
        return {"success": True, "message": "Consent withdrawn"}

    # ------------------------------------------------------------------
    # Site config retrieval (SDK embed)
    # ------------------------------------------------------------------

    def get_site_config(self, tenant_id: str, site_id: str) -> dict[str, Any]:
        """Load site config + active categories + active vendors for banner display."""
        tid = uuid.UUID(tenant_id)
        config = (
            self.db.query(BannerSiteConfigDB)
            .filter(
                BannerSiteConfigDB.tenant_id == tid,
                BannerSiteConfigDB.site_id == site_id,
            )
            .first()
        )
        if not config:
            return {
                "site_id": site_id,
                "banner_title": "Cookie-Einstellungen",
                "banner_description": (
                    "Wir verwenden Cookies, um Ihnen die bestmoegliche Erfahrung zu bieten."
                ),
                "categories": [],
                "vendors": [],
            }

        categories = (
            self.db.query(BannerCategoryConfigDB)
            .filter(
                BannerCategoryConfigDB.site_config_id == config.id,
                BannerCategoryConfigDB.is_active,
            )
            .order_by(BannerCategoryConfigDB.sort_order)
            .all()
        )
        vendors = (
            self.db.query(BannerVendorConfigDB)
            .filter(
                BannerVendorConfigDB.site_config_id == config.id,
                BannerVendorConfigDB.is_active,
            )
            .all()
        )
        result = site_config_to_dict(config)
        result["categories"] = [category_to_dict(c) for c in categories]
        result["vendors"] = [vendor_to_dict(v) for v in vendors]
        return result

    # ------------------------------------------------------------------
    # DSGVO export + stats
    # ------------------------------------------------------------------

    def export_consent(
        self, tenant_id: str, site_id: str, device_fingerprint: str
    ) -> dict[str, Any]:
        """DSGVO export of all consent + audit rows for a device."""
        tid = uuid.UUID(tenant_id)
        consents = (
            self.db.query(BannerConsentDB)
            .filter(
                BannerConsentDB.tenant_id == tid,
                BannerConsentDB.site_id == site_id,
                BannerConsentDB.device_fingerprint == device_fingerprint,
            )
            .all()
        )
        audit = (
            self.db.query(BannerConsentAuditLogDB)
            .filter(
                BannerConsentAuditLogDB.tenant_id == tid,
                BannerConsentAuditLogDB.site_id == site_id,
                BannerConsentAuditLogDB.device_fingerprint == device_fingerprint,
            )
            .order_by(BannerConsentAuditLogDB.created_at.desc())
            .all()
        )
        return {
            "device_fingerprint": device_fingerprint,
            "site_id": site_id,
            "consents": [consent_to_dict(c) for c in consents],
            "audit_trail": [
                {
                    "id": str(a.id),
                    "action": a.action,
                    "categories": a.categories or [],
                    "created_at": a.created_at.isoformat() if a.created_at else None,
                }
                for a in audit
            ],
        }

    def get_site_stats(self, tenant_id: str, site_id: str) -> dict[str, Any]:
        """Compute consent count + per-category acceptance rates for a site."""
        tid = uuid.UUID(tenant_id)
        base = self.db.query(BannerConsentDB).filter(
            BannerConsentDB.tenant_id == tid,
            BannerConsentDB.site_id == site_id,
        )
        total = base.count()
        category_stats: dict[str, int] = {}
        for c in base.all():
            cats: list[str] = list(c.categories or [])
            for cat in cats:
                category_stats[cat] = category_stats.get(cat, 0) + 1
        return {
            "site_id": site_id,
            "total_consents": total,
            "category_acceptance": {
                cat: {
                    "count": count,
                    "rate": round(count / total * 100, 1) if total > 0 else 0,
                }
                for cat, count in category_stats.items()
            },
        }