"""
E-Mail-Template Routes — Benachrichtigungsvorlagen fuer DSGVO-Compliance.

Verwaltet Templates fuer DSR, Consent, Breach, Vendor und Training E-Mails.
Inklusive Versionierung, Approval-Workflow, Vorschau und Send-Logging.
"""

import uuid
import re
from datetime import datetime
from typing import Optional, List, Dict, Any

from fastapi import APIRouter, Depends, HTTPException, Query, Header
from pydantic import BaseModel
from sqlalchemy.orm import Session
from sqlalchemy import func

from classroom_engine.database import get_db
from ..db.email_template_models import (
    EmailTemplateDB, EmailTemplateVersionDB, EmailTemplateApprovalDB,
    EmailSendLogDB, EmailTemplateSettingsDB,
)

router = APIRouter(prefix="/email-templates", tags=["compliance-email-templates"])

DEFAULT_TENANT = "9282a473-5c95-4b3a-bf78-0ecc0ec71d3e"

# Template-Typen und zugehoerige Variablen
TEMPLATE_TYPES = {
    "welcome": {"name": "Willkommen", "category": "general", "variables": ["user_name", "company_name", "login_url"]},
    "verification": {"name": "E-Mail-Verifizierung", "category": "general", "variables": ["user_name", "verification_url", "expiry_hours"]},
    "password_reset": {"name": "Passwort zuruecksetzen", "category": "general", "variables": ["user_name", "reset_url", "expiry_hours"]},
    "dsr_receipt": {"name": "DSR Eingangsbestaetigung", "category": "dsr", "variables": ["requester_name", "reference_number", "request_type", "deadline"]},
    "dsr_identity_request": {"name": "DSR Identitaetsanfrage", "category": "dsr", "variables": ["requester_name", "reference_number"]},
    "dsr_completion": {"name": "DSR Abschluss", "category": "dsr", "variables": ["requester_name", "reference_number", "request_type", "completion_date"]},
    "dsr_rejection": {"name": "DSR Ablehnung", "category": "dsr", "variables": ["requester_name", "reference_number", "rejection_reason", "legal_basis"]},
    "dsr_extension": {"name": "DSR Fristverlaengerung", "category": "dsr", "variables": ["requester_name", "reference_number", "new_deadline", "extension_reason"]},
    "consent_request": {"name": "Einwilligungsanfrage", "category": "consent", "variables": ["user_name", "purpose", "consent_url"]},
    "consent_confirmation": {"name": "Einwilligungsbestaetigung", "category": "consent", "variables": ["user_name", "purpose", "consent_date"]},
    "consent_withdrawal": {"name": "Widerruf bestaetigt", "category": "consent", "variables": ["user_name", "purpose", "withdrawal_date"]},
    "consent_reminder": {"name": "Einwilligungs-Erinnerung", "category": "consent", "variables": ["user_name", "purpose", "expiry_date"]},
    "breach_notification_authority": {"name": "Datenpanne Aufsichtsbehoerde", "category": "breach", "variables": ["incident_date", "incident_description", "affected_count", "measures_taken", "authority_name"]},
    "breach_notification_affected": {"name": "Datenpanne Betroffene", "category": "breach", "variables": ["user_name", "incident_date", "incident_description", "measures_taken", "contact_info"]},
    "breach_internal": {"name": "Datenpanne intern", "category": "breach", "variables": ["reporter_name", "incident_date", "incident_description", "severity"]},
    "vendor_dpa_request": {"name": "AVV-Anfrage", "category": "vendor", "variables": ["vendor_name", "contact_name", "deadline", "requirements"]},
    "vendor_review_reminder": {"name": "Vendor-Pruefung Erinnerung", "category": "vendor", "variables": ["vendor_name", "review_due_date", "last_review_date"]},
    "training_invitation": {"name": "Schulungseinladung", "category": "training", "variables": ["user_name", "training_title", "training_date", "training_url"]},
    "training_reminder": {"name": "Schulungs-Erinnerung", "category": "training", "variables": ["user_name", "training_title", "deadline"]},
    "training_completion": {"name": "Schulung abgeschlossen", "category": "training", "variables": ["user_name", "training_title", "completion_date", "certificate_url"]},
}

VALID_STATUSES = ["draft", "review", "approved", "published"]
VALID_CATEGORIES = ["general", "dsr", "consent", "breach", "vendor", "training"]


# =============================================================================
# Pydantic Schemas
# =============================================================================

class TemplateCreate(BaseModel):
    template_type: str
    name: Optional[str] = None
    description: Optional[str] = None
    category: Optional[str] = None
    is_active: bool = True


class VersionCreate(BaseModel):
    version: str = "1.0"
    language: str = "de"
    subject: str
    body_html: str
    body_text: Optional[str] = None


class VersionUpdate(BaseModel):
    subject: Optional[str] = None
    body_html: Optional[str] = None
    body_text: Optional[str] = None


class PreviewRequest(BaseModel):
    variables: Optional[Dict[str, str]] = None


class SendTestRequest(BaseModel):
    recipient: str
    variables: Optional[Dict[str, str]] = None


class SettingsUpdate(BaseModel):
    sender_name: Optional[str] = None
    sender_email: Optional[str] = None
    reply_to: Optional[str] = None
    logo_url: Optional[str] = None
    primary_color: Optional[str] = None
    secondary_color: Optional[str] = None
    footer_text: Optional[str] = None
    company_name: Optional[str] = None
    company_address: Optional[str] = None


# =============================================================================
# Helpers
# =============================================================================

def _get_tenant(x_tenant_id: Optional[str] = Header(None, alias='X-Tenant-ID')) -> str:
    return x_tenant_id or DEFAULT_TENANT


def _template_to_dict(t: EmailTemplateDB, latest_version=None) -> dict:
    result = {
        "id": str(t.id),
        "tenant_id": str(t.tenant_id),
        "template_type": t.template_type,
        "name": t.name,
        "description": t.description,
        "category": t.category,
        "is_active": t.is_active,
        "sort_order": t.sort_order,
        "variables": t.variables or [],
        "created_at": t.created_at.isoformat() if t.created_at else None,
        "updated_at": t.updated_at.isoformat() if t.updated_at else None,
    }
    if latest_version:
        result["latest_version"] = _version_to_dict(latest_version)
    return result


def _version_to_dict(v: EmailTemplateVersionDB) -> dict:
    return {
        "id": str(v.id),
        "template_id": str(v.template_id),
        "version": v.version,
        "language": v.language,
        "subject": v.subject,
        "body_html": v.body_html,
        "body_text": v.body_text,
        "status": v.status,
        "submitted_at": v.submitted_at.isoformat() if v.submitted_at else None,
        "submitted_by": v.submitted_by,
        "published_at": v.published_at.isoformat() if v.published_at else None,
        "published_by": v.published_by,
        "created_at": v.created_at.isoformat() if v.created_at else None,
        "created_by": v.created_by,
    }


def _render_template(html: str, variables: Dict[str, str]) -> str:
    """Replace {{variable}} placeholders with values."""
    result = html
    for key, value in variables.items():
        result = result.replace(f"{{{{{key}}}}}", str(value))
    return result


# =============================================================================
# Template Type Info (MUST be before parameterized routes)
# =============================================================================

@router.get("/types")
async def get_template_types():
    """Gibt alle verfuegbaren Template-Typen mit Variablen zurueck."""
    return [
        {
            "type": ttype,
            "name": info["name"],
            "category": info["category"],
            "variables": info["variables"],
        }
        for ttype, info in TEMPLATE_TYPES.items()
    ]


@router.get("/stats")
async def get_stats(
    tenant_id: str = Depends(_get_tenant),
    db: Session = Depends(get_db),
):
    """Statistiken ueber E-Mail-Templates."""
    tid = uuid.UUID(tenant_id)
    base = db.query(EmailTemplateDB).filter(EmailTemplateDB.tenant_id == tid)

    total = base.count()
    active = base.filter(EmailTemplateDB.is_active == True).count()

    # Count templates with published versions
    published_count = 0
    templates = base.all()
    for t in templates:
        has_published = db.query(EmailTemplateVersionDB).filter(
            EmailTemplateVersionDB.template_id == t.id,
            EmailTemplateVersionDB.status == "published",
        ).count() > 0
        if has_published:
            published_count += 1

    # By category
    by_category = {}
    for cat in VALID_CATEGORIES:
        by_category[cat] = base.filter(EmailTemplateDB.category == cat).count()

    # Send logs stats
    total_sent = db.query(EmailSendLogDB).filter(EmailSendLogDB.tenant_id == tid).count()

    return {
        "total": total,
        "active": active,
        "published": published_count,
        "draft": total - published_count,
        "by_category": by_category,
        "total_sent": total_sent,
    }


@router.get("/settings")
async def get_settings(
    tenant_id: str = Depends(_get_tenant),
    db: Session = Depends(get_db),
):
    """Globale E-Mail-Einstellungen laden."""
    tid = uuid.UUID(tenant_id)
    settings = db.query(EmailTemplateSettingsDB).filter(
        EmailTemplateSettingsDB.tenant_id == tid,
    ).first()

    if not settings:
        return {
            "sender_name": "Datenschutzbeauftragter",
            "sender_email": "datenschutz@example.de",
            "reply_to": None,
            "logo_url": None,
            "primary_color": "#4F46E5",
            "secondary_color": "#7C3AED",
            "footer_text": "Datenschutzhinweis: Diese E-Mail enthaelt vertrauliche Informationen.",
            "company_name": None,
            "company_address": None,
        }

    return {
        "sender_name": settings.sender_name,
        "sender_email": settings.sender_email,
        "reply_to": settings.reply_to,
        "logo_url": settings.logo_url,
        "primary_color": settings.primary_color,
        "secondary_color": settings.secondary_color,
        "footer_text": settings.footer_text,
        "company_name": settings.company_name,
        "company_address": settings.company_address,
    }


@router.put("/settings")
async def update_settings(
    body: SettingsUpdate,
    tenant_id: str = Depends(_get_tenant),
    db: Session = Depends(get_db),
):
    """Globale E-Mail-Einstellungen speichern."""
    tid = uuid.UUID(tenant_id)
    settings = db.query(EmailTemplateSettingsDB).filter(
        EmailTemplateSettingsDB.tenant_id == tid,
    ).first()

    if not settings:
        settings = EmailTemplateSettingsDB(tenant_id=tid)
        db.add(settings)

    for field in ["sender_name", "sender_email", "reply_to", "logo_url",
                   "primary_color", "secondary_color", "footer_text",
                   "company_name", "company_address"]:
        val = getattr(body, field, None)
        if val is not None:
            setattr(settings, field, val)

    settings.updated_at = datetime.utcnow()
    db.commit()
    db.refresh(settings)

    return {
        "sender_name": settings.sender_name,
        "sender_email": settings.sender_email,
        "reply_to": settings.reply_to,
        "logo_url": settings.logo_url,
        "primary_color": settings.primary_color,
        "secondary_color": settings.secondary_color,
        "footer_text": settings.footer_text,
        "company_name": settings.company_name,
        "company_address": settings.company_address,
    }


@router.get("/logs")
async def get_send_logs(
    limit: int = Query(20, ge=1, le=100),
    offset: int = Query(0, ge=0),
    template_type: Optional[str] = Query(None),
    tenant_id: str = Depends(_get_tenant),
    db: Session = Depends(get_db),
):
    """Send-Logs (paginiert)."""
    tid = uuid.UUID(tenant_id)
    query = db.query(EmailSendLogDB).filter(EmailSendLogDB.tenant_id == tid)
    if template_type:
        query = query.filter(EmailSendLogDB.template_type == template_type)

    total = query.count()
    logs = query.order_by(EmailSendLogDB.sent_at.desc()).offset(offset).limit(limit).all()

    return {
        "logs": [
            {
                "id": str(l.id),
                "template_type": l.template_type,
                "recipient": l.recipient,
                "subject": l.subject,
                "status": l.status,
                "variables": l.variables or {},
                "error_message": l.error_message,
                "sent_at": l.sent_at.isoformat() if l.sent_at else None,
            }
            for l in logs
        ],
        "total": total,
        "limit": limit,
        "offset": offset,
    }


@router.post("/initialize")
async def initialize_defaults(
    tenant_id: str = Depends(_get_tenant),
    db: Session = Depends(get_db),
):
    """Default-Templates fuer einen Tenant initialisieren."""
    tid = uuid.UUID(tenant_id)
    existing = db.query(EmailTemplateDB).filter(EmailTemplateDB.tenant_id == tid).count()
    if existing > 0:
        return {"message": "Templates already initialized", "count": existing}

    created = 0
    for idx, (ttype, info) in enumerate(TEMPLATE_TYPES.items()):
        t = EmailTemplateDB(
            tenant_id=tid,
            template_type=ttype,
            name=info["name"],
            category=info["category"],
            sort_order=idx * 10,
            variables=info["variables"],
        )
        db.add(t)
        created += 1

    db.commit()
    return {"message": f"{created} templates created", "count": created}


@router.get("/default/{template_type}")
async def get_default_content(template_type: str):
    """Default-Content fuer einen Template-Typ."""
    if template_type not in TEMPLATE_TYPES:
        raise HTTPException(status_code=404, detail=f"Unknown template type: {template_type}")

    info = TEMPLATE_TYPES[template_type]
    vars_html = " ".join([f'<span style="color:#4F46E5">{{{{{v}}}}}</span>' for v in info["variables"]])

    return {
        "template_type": template_type,
        "name": info["name"],
        "category": info["category"],
        "variables": info["variables"],
        "default_subject": f"{info['name']} - {{{{company_name}}}}",
        "default_body_html": f"<p>Sehr geehrte(r) {{{{user_name}}}},</p>\n<p>[Inhalt hier einfuegen]</p>\n<p>Verfuegbare Variablen: {vars_html}</p>\n<p>Mit freundlichen Gruessen<br/>{{{{sender_name}}}}</p>",
    }


# =============================================================================
# Template CRUD (MUST be before /{id} parameterized routes)
# =============================================================================

@router.get("")
async def list_templates(
    category: Optional[str] = Query(None),
    tenant_id: str = Depends(_get_tenant),
    db: Session = Depends(get_db),
):
    """Alle Templates mit letzter publizierter Version."""
    tid = uuid.UUID(tenant_id)
    query = db.query(EmailTemplateDB).filter(EmailTemplateDB.tenant_id == tid)
    if category:
        query = query.filter(EmailTemplateDB.category == category)

    templates = query.order_by(EmailTemplateDB.sort_order).all()
    result = []
    for t in templates:
        latest = db.query(EmailTemplateVersionDB).filter(
            EmailTemplateVersionDB.template_id == t.id,
        ).order_by(EmailTemplateVersionDB.created_at.desc()).first()
        result.append(_template_to_dict(t, latest))

    return result


@router.post("")
async def create_template(
    body: TemplateCreate,
    tenant_id: str = Depends(_get_tenant),
    db: Session = Depends(get_db),
):
    """Template erstellen."""
    if body.template_type not in TEMPLATE_TYPES:
        raise HTTPException(status_code=400, detail=f"Unknown template type: {body.template_type}")

    tid = uuid.UUID(tenant_id)
    existing = db.query(EmailTemplateDB).filter(
        EmailTemplateDB.tenant_id == tid,
        EmailTemplateDB.template_type == body.template_type,
    ).first()
    if existing:
        raise HTTPException(status_code=409, detail=f"Template type '{body.template_type}' already exists")

    info = TEMPLATE_TYPES[body.template_type]
    t = EmailTemplateDB(
        tenant_id=tid,
        template_type=body.template_type,
        name=body.name or info["name"],
        description=body.description,
        category=body.category or info["category"],
        is_active=body.is_active,
        variables=info["variables"],
    )
    db.add(t)
    db.commit()
    db.refresh(t)
    return _template_to_dict(t)


# =============================================================================
# Version Management (static paths before parameterized)
# =============================================================================

@router.post("/versions")
async def create_version(
    body: VersionCreate,
    template_id: str = Query(..., alias="template_id"),
    tenant_id: str = Depends(_get_tenant),
    db: Session = Depends(get_db),
):
    """Neue Version erstellen (via query param template_id)."""
    try:
        tid = uuid.UUID(template_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="Invalid template ID")

    template = db.query(EmailTemplateDB).filter(
        EmailTemplateDB.id == tid,
        EmailTemplateDB.tenant_id == uuid.UUID(tenant_id),
    ).first()
    if not template:
        raise HTTPException(status_code=404, detail="Template not found")

    v = EmailTemplateVersionDB(
        template_id=tid,
        version=body.version,
        language=body.language,
        subject=body.subject,
        body_html=body.body_html,
        body_text=body.body_text,
        status="draft",
    )
    db.add(v)
    db.commit()
    db.refresh(v)
    return _version_to_dict(v)


# =============================================================================
# Single Template (parameterized — after all static paths)
# =============================================================================

@router.get("/{template_id}")
async def get_template(
    template_id: str,
    tenant_id: str = Depends(_get_tenant),
    db: Session = Depends(get_db),
):
    """Template-Detail."""
    try:
        tid = uuid.UUID(template_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="Invalid template ID")

    t = db.query(EmailTemplateDB).filter(
        EmailTemplateDB.id == tid,
        EmailTemplateDB.tenant_id == uuid.UUID(tenant_id),
    ).first()
    if not t:
        raise HTTPException(status_code=404, detail="Template not found")

    latest = db.query(EmailTemplateVersionDB).filter(
        EmailTemplateVersionDB.template_id == t.id,
    ).order_by(EmailTemplateVersionDB.created_at.desc()).first()

    return _template_to_dict(t, latest)


@router.get("/{template_id}/versions")
async def get_versions(
    template_id: str,
    tenant_id: str = Depends(_get_tenant),
    db: Session = Depends(get_db),
):
    """Versionen eines Templates."""
    try:
        tid = uuid.UUID(template_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="Invalid template ID")

    template = db.query(EmailTemplateDB).filter(
        EmailTemplateDB.id == tid,
        EmailTemplateDB.tenant_id == uuid.UUID(tenant_id),
    ).first()
    if not template:
        raise HTTPException(status_code=404, detail="Template not found")

    versions = db.query(EmailTemplateVersionDB).filter(
        EmailTemplateVersionDB.template_id == tid,
    ).order_by(EmailTemplateVersionDB.created_at.desc()).all()

    return [_version_to_dict(v) for v in versions]


@router.post("/{template_id}/versions")
async def create_version_for_template(
    template_id: str,
    body: VersionCreate,
    tenant_id: str = Depends(_get_tenant),
    db: Session = Depends(get_db),
):
    """Neue Version fuer ein Template erstellen."""
    try:
        tid = uuid.UUID(template_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="Invalid template ID")

    template = db.query(EmailTemplateDB).filter(
        EmailTemplateDB.id == tid,
        EmailTemplateDB.tenant_id == uuid.UUID(tenant_id),
    ).first()
    if not template:
        raise HTTPException(status_code=404, detail="Template not found")

    v = EmailTemplateVersionDB(
        template_id=tid,
        version=body.version,
        language=body.language,
        subject=body.subject,
        body_html=body.body_html,
        body_text=body.body_text,
        status="draft",
    )
    db.add(v)
    db.commit()
    db.refresh(v)
    return _version_to_dict(v)


# =============================================================================
# Version Workflow (parameterized by version_id)
# =============================================================================

@router.get("/versions/{version_id}")
async def get_version(
    version_id: str,
    db: Session = Depends(get_db),
):
    """Version-Detail."""
    try:
        vid = uuid.UUID(version_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="Invalid version ID")

    v = db.query(EmailTemplateVersionDB).filter(
        EmailTemplateVersionDB.id == vid,
    ).first()
    if not v:
        raise HTTPException(status_code=404, detail="Version not found")
    return _version_to_dict(v)


@router.put("/versions/{version_id}")
async def update_version(
    version_id: str,
    body: VersionUpdate,
    db: Session = Depends(get_db),
):
    """Draft aktualisieren."""
    try:
        vid = uuid.UUID(version_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="Invalid version ID")

    v = db.query(EmailTemplateVersionDB).filter(
        EmailTemplateVersionDB.id == vid,
    ).first()
    if not v:
        raise HTTPException(status_code=404, detail="Version not found")
    if v.status != "draft":
        raise HTTPException(status_code=400, detail="Only draft versions can be edited")

    if body.subject is not None:
        v.subject = body.subject
    if body.body_html is not None:
        v.body_html = body.body_html
    if body.body_text is not None:
        v.body_text = body.body_text

    db.commit()
    db.refresh(v)
    return _version_to_dict(v)


@router.post("/versions/{version_id}/submit")
async def submit_version(
    version_id: str,
    db: Session = Depends(get_db),
):
    """Zur Pruefung einreichen."""
    try:
        vid = uuid.UUID(version_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="Invalid version ID")

    v = db.query(EmailTemplateVersionDB).filter(
        EmailTemplateVersionDB.id == vid,
    ).first()
    if not v:
        raise HTTPException(status_code=404, detail="Version not found")
    if v.status != "draft":
        raise HTTPException(status_code=400, detail="Only draft versions can be submitted")

    v.status = "review"
    v.submitted_at = datetime.utcnow()
    v.submitted_by = "admin"
    db.commit()
    db.refresh(v)
    return _version_to_dict(v)


@router.post("/versions/{version_id}/approve")
async def approve_version(
    version_id: str,
    comment: Optional[str] = None,
    db: Session = Depends(get_db),
):
    """Genehmigen."""
    try:
        vid = uuid.UUID(version_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="Invalid version ID")

    v = db.query(EmailTemplateVersionDB).filter(
        EmailTemplateVersionDB.id == vid,
    ).first()
    if not v:
        raise HTTPException(status_code=404, detail="Version not found")
    if v.status != "review":
        raise HTTPException(status_code=400, detail="Only review versions can be approved")

    v.status = "approved"
    approval = EmailTemplateApprovalDB(
        version_id=vid,
        action="approve",
        comment=comment,
        approved_by="admin",
    )
    db.add(approval)
    db.commit()
    db.refresh(v)
    return _version_to_dict(v)


@router.post("/versions/{version_id}/reject")
async def reject_version(
    version_id: str,
    comment: Optional[str] = None,
    db: Session = Depends(get_db),
):
    """Ablehnen."""
    try:
        vid = uuid.UUID(version_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="Invalid version ID")

    v = db.query(EmailTemplateVersionDB).filter(
        EmailTemplateVersionDB.id == vid,
    ).first()
    if not v:
        raise HTTPException(status_code=404, detail="Version not found")
    if v.status != "review":
        raise HTTPException(status_code=400, detail="Only review versions can be rejected")

    v.status = "draft"  # Back to draft
    approval = EmailTemplateApprovalDB(
        version_id=vid,
        action="reject",
        comment=comment,
        approved_by="admin",
    )
    db.add(approval)
    db.commit()
    db.refresh(v)
    return _version_to_dict(v)


@router.post("/versions/{version_id}/publish")
async def publish_version(
    version_id: str,
    db: Session = Depends(get_db),
):
    """Publizieren."""
    try:
        vid = uuid.UUID(version_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="Invalid version ID")

    v = db.query(EmailTemplateVersionDB).filter(
        EmailTemplateVersionDB.id == vid,
    ).first()
    if not v:
        raise HTTPException(status_code=404, detail="Version not found")
    if v.status not in ("approved", "review", "draft"):
        raise HTTPException(status_code=400, detail="Version cannot be published")

    now = datetime.utcnow()
    v.status = "published"
    v.published_at = now
    v.published_by = "admin"
    db.commit()
    db.refresh(v)
    return _version_to_dict(v)


@router.post("/versions/{version_id}/preview")
async def preview_version(
    version_id: str,
    body: PreviewRequest,
    db: Session = Depends(get_db),
):
    """Vorschau mit Test-Variablen."""
    try:
        vid = uuid.UUID(version_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="Invalid version ID")

    v = db.query(EmailTemplateVersionDB).filter(
        EmailTemplateVersionDB.id == vid,
    ).first()
    if not v:
        raise HTTPException(status_code=404, detail="Version not found")

    variables = body.variables or {}
    # Fill in defaults for missing variables
    template = db.query(EmailTemplateDB).filter(
        EmailTemplateDB.id == v.template_id,
    ).first()
    if template and template.variables:
        for var in template.variables:
            if var not in variables:
                variables[var] = f"[{var}]"

    rendered_subject = _render_template(v.subject, variables)
    rendered_html = _render_template(v.body_html, variables)

    return {
        "subject": rendered_subject,
        "body_html": rendered_html,
        "variables_used": variables,
    }


@router.post("/versions/{version_id}/send-test")
async def send_test_email(
    version_id: str,
    body: SendTestRequest,
    tenant_id: str = Depends(_get_tenant),
    db: Session = Depends(get_db),
):
    """Test-E-Mail senden (Simulation — loggt nur)."""
    try:
        vid = uuid.UUID(version_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="Invalid version ID")

    v = db.query(EmailTemplateVersionDB).filter(
        EmailTemplateVersionDB.id == vid,
    ).first()
    if not v:
        raise HTTPException(status_code=404, detail="Version not found")

    template = db.query(EmailTemplateDB).filter(
        EmailTemplateDB.id == v.template_id,
    ).first()

    variables = body.variables or {}
    rendered_subject = _render_template(v.subject, variables)

    # Log the send attempt
    log = EmailSendLogDB(
        tenant_id=uuid.UUID(tenant_id),
        template_type=template.template_type if template else "unknown",
        version_id=vid,
        recipient=body.recipient,
        subject=rendered_subject,
        status="test_sent",
        variables=variables,
    )
    db.add(log)
    db.commit()

    return {
        "success": True,
        "message": f"Test-E-Mail an {body.recipient} gesendet (Simulation)",
        "subject": rendered_subject,
    }