"""
FastAPI routes for LLM Generation Audit Trail.

Endpoints:
- POST /llm-audit: Record an LLM generation event
- GET  /llm-audit: List audit records with filters
"""

import logging
import uuid as uuid_module
from datetime import datetime
from typing import Optional

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

from classroom_engine.database import get_db
from ..db.models import LLMGenerationAuditDB

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


# ============================================================================
# Schemas
# ============================================================================

class LLMAuditCreate(BaseModel):
    entity_type: str
    entity_id: Optional[str] = None
    generation_mode: str
    truth_status: str = "generated"
    may_be_used_as_evidence: bool = False
    llm_model: Optional[str] = None
    llm_provider: Optional[str] = None
    prompt_hash: Optional[str] = None
    input_summary: Optional[str] = None
    output_summary: Optional[str] = None
    metadata: Optional[dict] = None
    tenant_id: Optional[str] = None


class LLMAuditResponse(BaseModel):
    id: str
    tenant_id: Optional[str] = None
    entity_type: str
    entity_id: Optional[str] = None
    generation_mode: str
    truth_status: str
    may_be_used_as_evidence: bool
    llm_model: Optional[str] = None
    llm_provider: Optional[str] = None
    prompt_hash: Optional[str] = None
    input_summary: Optional[str] = None
    output_summary: Optional[str] = None
    metadata: Optional[dict] = None
    created_at: datetime

    class Config:
        from_attributes = True


# ============================================================================
# Routes
# ============================================================================

@router.post("/llm-audit", response_model=LLMAuditResponse)
async def create_llm_audit(
    data: LLMAuditCreate,
    db: Session = Depends(get_db),
):
    """Record an LLM generation event for audit trail."""
    from ..db.models import EvidenceTruthStatusEnum

    # Validate truth_status
    try:
        truth_enum = EvidenceTruthStatusEnum(data.truth_status)
    except ValueError:
        truth_enum = EvidenceTruthStatusEnum.GENERATED

    record = LLMGenerationAuditDB(
        id=str(uuid_module.uuid4()),
        tenant_id=data.tenant_id,
        entity_type=data.entity_type,
        entity_id=data.entity_id,
        generation_mode=data.generation_mode,
        truth_status=truth_enum,
        may_be_used_as_evidence=data.may_be_used_as_evidence,
        llm_model=data.llm_model,
        llm_provider=data.llm_provider,
        prompt_hash=data.prompt_hash,
        input_summary=data.input_summary[:500] if data.input_summary else None,
        output_summary=data.output_summary[:500] if data.output_summary else None,
        extra_metadata=data.metadata or {},
    )
    db.add(record)
    db.commit()
    db.refresh(record)

    return LLMAuditResponse(
        id=record.id,
        tenant_id=record.tenant_id,
        entity_type=record.entity_type,
        entity_id=record.entity_id,
        generation_mode=record.generation_mode,
        truth_status=record.truth_status.value if record.truth_status else "generated",
        may_be_used_as_evidence=record.may_be_used_as_evidence,
        llm_model=record.llm_model,
        llm_provider=record.llm_provider,
        prompt_hash=record.prompt_hash,
        input_summary=record.input_summary,
        output_summary=record.output_summary,
        metadata=record.extra_metadata,
        created_at=record.created_at,
    )


@router.get("/llm-audit")
async def list_llm_audit(
    entity_type: Optional[str] = Query(None),
    entity_id: Optional[str] = Query(None),
    page: int = Query(1, ge=1),
    limit: int = Query(50, ge=1, le=200),
    db: Session = Depends(get_db),
):
    """List LLM generation audit records with optional filters."""
    query = db.query(LLMGenerationAuditDB)

    if entity_type:
        query = query.filter(LLMGenerationAuditDB.entity_type == entity_type)
    if entity_id:
        query = query.filter(LLMGenerationAuditDB.entity_id == entity_id)

    total = query.count()
    offset = (page - 1) * limit
    records = query.order_by(LLMGenerationAuditDB.created_at.desc()).offset(offset).limit(limit).all()

    return {
        "records": [
            LLMAuditResponse(
                id=r.id,
                tenant_id=r.tenant_id,
                entity_type=r.entity_type,
                entity_id=r.entity_id,
                generation_mode=r.generation_mode,
                truth_status=r.truth_status.value if r.truth_status else "generated",
                may_be_used_as_evidence=r.may_be_used_as_evidence,
                llm_model=r.llm_model,
                llm_provider=r.llm_provider,
                prompt_hash=r.prompt_hash,
                input_summary=r.input_summary,
                output_summary=r.output_summary,
                metadata=r.extra_metadata,
                created_at=r.created_at,
            )
            for r in records
        ],
        "total": total,
        "page": page,
        "limit": limit,
    }