"""
FastAPI routes for VVT — Verzeichnis von Verarbeitungstaetigkeiten (Art. 30 DSGVO).

Endpoints:
  GET    /vvt/organization                     — Load organization header
  PUT    /vvt/organization                     — Save organization header
  GET    /vvt/activities                       — List activities
  POST   /vvt/activities                       — Create new activity
  GET    /vvt/activities/{id}                  — Get single activity
  PUT    /vvt/activities/{id}                  — Update activity
  DELETE /vvt/activities/{id}                  — Delete activity
  GET    /vvt/audit-log                        — Audit trail
  GET    /vvt/export                           — JSON or CSV export
  GET    /vvt/stats                            — Statistics
  GET    /vvt/activities/{id}/versions         — List activity versions
  GET    /vvt/activities/{id}/versions/{n}     — Get specific version

Phase 1 Step 4 refactor: handlers delegate to VVTService.
"""

import logging
from typing import Any, List, Optional

from fastapi import APIRouter, Depends, Query, Request
from fastapi.responses import StreamingResponse
from sqlalchemy.orm import Session

from classroom_engine.database import get_db
from compliance.api._http_errors import translate_domain_errors
from compliance.api.tenant_utils import get_tenant_id
from compliance.schemas.vvt import (
    VVTActivityCreate,
    VVTActivityResponse,
    VVTActivityUpdate,
    VVTAuditLogEntry,
    VVTOrganizationResponse,
    VVTOrganizationUpdate,
    VVTStatsResponse,
)
from compliance.services.vvt_service import (
    VVTService,
    _activity_to_response,  # re-exported for legacy test imports
    _export_csv,  # re-exported for legacy test imports
    _log_audit,  # re-exported for legacy test imports
)

logger = logging.getLogger(__name__)
router = APIRouter(prefix="/vvt", tags=["compliance-vvt"])


def get_vvt_service(db: Session = Depends(get_db)) -> VVTService:
    return VVTService(db)


# ============================================================================
# Organization Header
# ============================================================================

@router.get("/organization", response_model=Optional[VVTOrganizationResponse])
async def get_organization(
    tid: str = Depends(get_tenant_id),
    service: VVTService = Depends(get_vvt_service),
) -> Optional[VVTOrganizationResponse]:
    """Load the VVT organization header for the given tenant."""
    with translate_domain_errors():
        return service.get_organization(tid)


@router.put("/organization", response_model=VVTOrganizationResponse)
async def upsert_organization(
    request: VVTOrganizationUpdate,
    tid: str = Depends(get_tenant_id),
    service: VVTService = Depends(get_vvt_service),
) -> VVTOrganizationResponse:
    """Create or update the VVT organization header."""
    with translate_domain_errors():
        return service.upsert_organization(tid, request)


# ============================================================================
# Activities
# ============================================================================

@router.get("/activities", response_model=List[VVTActivityResponse])
async def list_activities(
    status: Optional[str] = Query(None),
    business_function: Optional[str] = Query(None),
    search: Optional[str] = Query(None),
    review_overdue: Optional[bool] = Query(None),
    tid: str = Depends(get_tenant_id),
    service: VVTService = Depends(get_vvt_service),
) -> List[VVTActivityResponse]:
    """List all processing activities with optional filters."""
    with translate_domain_errors():
        return service.list_activities(
            tid, status, business_function, search, review_overdue
        )


@router.post("/activities", response_model=VVTActivityResponse, status_code=201)
async def create_activity(
    request: VVTActivityCreate,
    http_request: Request,
    tid: str = Depends(get_tenant_id),
    service: VVTService = Depends(get_vvt_service),
) -> VVTActivityResponse:
    """Create a new processing activity."""
    with translate_domain_errors():
        return service.create_activity(
            tid, request, http_request.headers.get("X-User-ID")
        )


@router.get("/activities/{activity_id}", response_model=VVTActivityResponse)
async def get_activity(
    activity_id: str,
    tid: str = Depends(get_tenant_id),
    service: VVTService = Depends(get_vvt_service),
) -> VVTActivityResponse:
    """Get a single processing activity by ID."""
    with translate_domain_errors():
        return service.get_activity(tid, activity_id)


@router.put("/activities/{activity_id}", response_model=VVTActivityResponse)
async def update_activity(
    activity_id: str,
    request: VVTActivityUpdate,
    tid: str = Depends(get_tenant_id),
    service: VVTService = Depends(get_vvt_service),
) -> VVTActivityResponse:
    """Update a processing activity."""
    with translate_domain_errors():
        return service.update_activity(tid, activity_id, request)


@router.delete("/activities/{activity_id}")
async def delete_activity(
    activity_id: str,
    tid: str = Depends(get_tenant_id),
    service: VVTService = Depends(get_vvt_service),
) -> dict[str, Any]:
    """Delete a processing activity."""
    with translate_domain_errors():
        return service.delete_activity(tid, activity_id)


# ============================================================================
# Audit Log
# ============================================================================

@router.get("/audit-log", response_model=List[VVTAuditLogEntry])
async def get_audit_log(
    limit: int = Query(50, ge=1, le=500),
    offset: int = Query(0, ge=0),
    tid: str = Depends(get_tenant_id),
    service: VVTService = Depends(get_vvt_service),
) -> List[VVTAuditLogEntry]:
    """Get the VVT audit trail."""
    with translate_domain_errors():
        return service.audit_log(tid, limit, offset)


# ============================================================================
# Export & Stats
# ============================================================================

@router.get("/export")
async def export_activities(
    format: str = Query("json", pattern="^(json|csv)$"),
    tid: str = Depends(get_tenant_id),
    service: VVTService = Depends(get_vvt_service),
) -> Any:
    """Export all activities as JSON or CSV (semicolon-separated, DE locale)."""
    with translate_domain_errors():
        return service.export(tid, format)


@router.get("/stats", response_model=VVTStatsResponse)
async def get_stats(
    tid: str = Depends(get_tenant_id),
    service: VVTService = Depends(get_vvt_service),
) -> VVTStatsResponse:
    """Get VVT statistics summary."""
    with translate_domain_errors():
        return service.stats(tid)


# ============================================================================
# Versioning
# ============================================================================

@router.get("/activities/{activity_id}/versions")
async def list_activity_versions(
    activity_id: str,
    tid: str = Depends(get_tenant_id),
    service: VVTService = Depends(get_vvt_service),
) -> Any:
    """List all versions for a VVT activity."""
    with translate_domain_errors():
        return service.list_versions(tid, activity_id)


@router.get("/activities/{activity_id}/versions/{version_number}")
async def get_activity_version(
    activity_id: str,
    version_number: int,
    tid: str = Depends(get_tenant_id),
    service: VVTService = Depends(get_vvt_service),
) -> Any:
    """Get a specific VVT activity version with full snapshot."""
    with translate_domain_errors():
        return service.get_version(tid, activity_id, version_number)


# ----------------------------------------------------------------------------
# Legacy re-exports for tests that import helpers directly.
# ----------------------------------------------------------------------------

__all__ = [
    "router",
    "_activity_to_response",
    "_log_audit",
    "_export_csv",
]