"""
FastAPI routes for Audit Sessions & Sign-off functionality.

Sprint 3 Phase 3: Auditor-Verbesserungen

Endpoints:
- /audit/sessions: Manage audit sessions
- /audit/checklist: Audit checklist with sign-off

Phase 1 Step 4 refactor: handlers are thin and delegate to
``AuditSessionService`` / ``AuditSignOffService``. Domain errors raised by
the services are translated to HTTPException via
``translate_domain_errors``.
"""

import logging
from typing import Any, List, Optional

from fastapi import APIRouter, Depends, Query
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.schemas.audit_session import (
    AuditChecklistResponse,
    AuditSessionDetailResponse,
    AuditSessionResponse,
    AuditSessionSummary,
    CreateAuditSessionRequest,
    SignOffRequest,
    SignOffResponse,
)
from compliance.services.audit_session_service import AuditSessionService
from compliance.services.audit_signoff_service import AuditSignOffService

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


# ----------------------------------------------------------------------
# Dependency-injection factories
# ----------------------------------------------------------------------

def get_audit_session_service(db: Session = Depends(get_db)) -> AuditSessionService:
    return AuditSessionService(db)


def get_audit_signoff_service(db: Session = Depends(get_db)) -> AuditSignOffService:
    return AuditSignOffService(db)


# ============================================================================
# Audit Sessions
# ============================================================================

@router.post("/sessions", response_model=AuditSessionResponse)
async def create_audit_session(
    request: CreateAuditSessionRequest,
    service: AuditSessionService = Depends(get_audit_session_service),
) -> AuditSessionResponse:
    """Create a new audit session for structured compliance reviews."""
    with translate_domain_errors():
        return service.create(request)


@router.get("/sessions", response_model=List[AuditSessionSummary])
async def list_audit_sessions(
    status: Optional[str] = None,
    service: AuditSessionService = Depends(get_audit_session_service),
) -> List[AuditSessionSummary]:
    """List all audit sessions, optionally filtered by status."""
    with translate_domain_errors():
        return service.list(status)


@router.get("/sessions/{session_id}", response_model=AuditSessionDetailResponse)
async def get_audit_session(
    session_id: str,
    service: AuditSessionService = Depends(get_audit_session_service),
) -> AuditSessionDetailResponse:
    """Get detailed information about a specific audit session."""
    with translate_domain_errors():
        return service.get(session_id)


@router.put("/sessions/{session_id}/start")
async def start_audit_session(
    session_id: str,
    service: AuditSessionService = Depends(get_audit_session_service),
) -> dict[str, Any]:
    """Start an audit session (draft -> in_progress)."""
    with translate_domain_errors():
        return service.start(session_id)


@router.put("/sessions/{session_id}/complete")
async def complete_audit_session(
    session_id: str,
    service: AuditSessionService = Depends(get_audit_session_service),
) -> dict[str, Any]:
    """Complete an audit session (in_progress -> completed)."""
    with translate_domain_errors():
        return service.complete(session_id)


@router.put("/sessions/{session_id}/archive")
async def archive_audit_session(
    session_id: str,
    service: AuditSessionService = Depends(get_audit_session_service),
) -> dict[str, Any]:
    """Archive a completed audit session."""
    with translate_domain_errors():
        return service.archive(session_id)


@router.delete("/sessions/{session_id}")
async def delete_audit_session(
    session_id: str,
    service: AuditSessionService = Depends(get_audit_session_service),
) -> dict[str, Any]:
    """Delete a draft or archived audit session and all its sign-offs."""
    with translate_domain_errors():
        return service.delete(session_id)


# ============================================================================
# Audit Checklist & Sign-off
# ============================================================================

@router.get("/checklist/{session_id}", response_model=AuditChecklistResponse)
async def get_audit_checklist(
    session_id: str,
    page: int = Query(1, ge=1),
    page_size: int = Query(50, ge=1, le=200),
    status_filter: Optional[str] = None,
    regulation_filter: Optional[str] = None,
    search: Optional[str] = None,
    service: AuditSignOffService = Depends(get_audit_signoff_service),
) -> AuditChecklistResponse:
    """Get the paginated audit checklist for a session."""
    with translate_domain_errors():
        return service.get_checklist(
            session_id=session_id,
            page=page,
            page_size=page_size,
            status_filter=status_filter,
            regulation_filter=regulation_filter,
            search=search,
        )


@router.put(
    "/checklist/{session_id}/items/{requirement_id}/sign-off",
    response_model=SignOffResponse,
)
async def sign_off_item(
    session_id: str,
    requirement_id: str,
    request: SignOffRequest,
    service: AuditSignOffService = Depends(get_audit_signoff_service),
) -> SignOffResponse:
    """Sign off on a specific requirement in an audit session."""
    with translate_domain_errors():
        return service.sign_off(session_id, requirement_id, request)


@router.get(
    "/checklist/{session_id}/items/{requirement_id}",
    response_model=SignOffResponse,
)
async def get_sign_off(
    session_id: str,
    requirement_id: str,
    service: AuditSignOffService = Depends(get_audit_signoff_service),
) -> SignOffResponse:
    """Get the current sign-off status for a specific requirement."""
    with translate_domain_errors():
        return service.get_sign_off(session_id, requirement_id)


# ============================================================================
# PDF Report Generation
# ============================================================================

@router.get("/sessions/{session_id}/report/pdf")
async def generate_audit_pdf_report(
    session_id: str,
    language: str = Query("de", pattern="^(de|en)$"),
    include_signatures: bool = Query(True),
    service: AuditSessionService = Depends(get_audit_session_service),
) -> StreamingResponse:
    """Generate a PDF report for an audit session."""
    with translate_domain_errors():
        return service.generate_pdf(
            session_id=session_id,
            language=language,
            include_signatures=include_signatures,
        )