"""
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
from datetime import datetime
from typing import Optional, Dict

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

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).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,
    }