"""
Audit Endpoints - ServiceManagerWeb

Endpoints para consulta de logs de auditoría.
Solo accesible por roles: ADMIN, SUPPORT_MANAGER, AUDITOR
"""

from fastapi import APIRouter, Depends, HTTPException, status, Query
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, func, and_, or_, desc
from sqlalchemy.orm import selectinload
from typing import Optional, List
from datetime import datetime, timedelta
import uuid
import structlog

from app.core.database import get_db
from app.api.deps import get_current_user, get_current_tenant
from app.models.user import User, UserRole
from app.models.tenant import Tenant
from app.models.audit import AuditLog
from app.api.schemas.audit import (
    AuditLogResponse,
    AuditLogListResponse,
    AuditLogFilters,
    AuditLogStats
)

router = APIRouter()
logger = structlog.get_logger(__name__)


def require_auditor_role(current_user: User = Depends(get_current_user)) -> User:
    """
    Dependency que verifica que el usuario tenga rol de auditor.
    
    Solo ADMIN, SUPPORT_MANAGER y AUDITOR pueden ver logs de auditoría.
    """
    allowed_roles = [UserRole.ADMIN, UserRole.SUPPORT_MANAGER, UserRole.AUDITOR]
    
    if current_user.role not in allowed_roles:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Solo usuarios con rol ADMIN, SUPPORT_MANAGER o AUDITOR pueden acceder a logs de auditoría"
        )
    
    return current_user


@router.get("/", response_model=AuditLogListResponse)
async def get_audit_logs(
    # Paginaci├│n
    page: int = Query(default=1, ge=1, description="Número de página"),
    per_page: int = Query(default=50, ge=1, le=100, description="Registros por página"),
    
    # Filtros
    user_id: Optional[uuid.UUID] = Query(None, description="Filtrar por usuario"),
    action: Optional[str] = Query(None, description="Filtrar por acci├│n"),
    resource_type: Optional[str] = Query(None, description="Filtrar por tipo de recurso"),
    resource_id: Optional[uuid.UUID] = Query(None, description="Filtrar por ID de recurso"),
    date_from: Optional[datetime] = Query(None, description="Fecha desde"),
    date_to: Optional[datetime] = Query(None, description="Fecha hasta"),
    search: Optional[str] = Query(None, description="B├║squeda en acci├│n o email"),
    
    # Dependencies
    current_user: User = Depends(require_auditor_role),
    current_tenant: Tenant = Depends(get_current_tenant),
    db: AsyncSession = Depends(get_db)
):
    """
    Obtener logs de auditoría con filtros y paginación.
    
    **Permisos**: ADMIN, SUPPORT_MANAGER, AUDITOR
    
    **Filtros disponibles**:
    - `user_id`: Acciones de un usuario específico
    - `action`: Tipo de acci├│n (ej: "ticket.create")
    - `resource_type`: Tipo de recurso (ej: "ticket")
    - `resource_id`: ID de recurso específico
    - `date_from`, `date_to`: Rango de fechas
    - `search`: B├║squeda en acciones
    
    **Retorna**: Lista paginada de audit logs
    """
    logger.info(
        "Fetching audit logs",
        user_id=str(current_user.id),
        tenant_id=str(current_tenant.id),
        filters={
            "user_id": str(user_id) if user_id else None,
            "action": action,
            "resource_type": resource_type,
            "page": page
        }
    )
    
    # Query base - solo logs del tenant actual
    # Usar selectinload para cargar la relaci├│n user (eager loading para async)
    query = (
        select(AuditLog)
        .where(AuditLog.tenant_id == current_tenant.id)
        .options(selectinload(AuditLog.user))
    )
    
    # Aplicar filtros
    if user_id:
        query = query.where(AuditLog.user_id == user_id)
    
    if action:
        query = query.where(AuditLog.action == action)
    
    if resource_type:
        query = query.where(AuditLog.resource_type == resource_type)
    
    if resource_id:
        query = query.where(AuditLog.resource_id == resource_id)
    
    if date_from:
        query = query.where(AuditLog.created_at >= date_from)
    
    if date_to:
        # Agregar 1 día para incluir todo el día
        date_to_end = date_to + timedelta(days=1)
        query = query.where(AuditLog.created_at < date_to_end)
    
    if search:
        # B├║squeda en action
        search_filter = AuditLog.action.ilike(f"%{search}%")
        query = query.where(search_filter)
    
    # Ordenar por fecha descendente (más recientes primero)
    query = query.order_by(desc(AuditLog.created_at))
    
    # Contar total antes de paginar
    count_query = select(func.count()).select_from(query.subquery())
    total_result = await db.execute(count_query)
    total = total_result.scalar() or 0
    
    # Aplicar paginaci├│n
    offset = (page - 1) * per_page
    query = query.offset(offset).limit(per_page)
    
    # Ejecutar query
    result = await db.execute(query)
    logs = result.scalars().all()
    
    # Calcular total de páginas
    total_pages = (total + per_page - 1) // per_page
    
    # Convertir a response schema (agregar info del usuario)
    logs_response = []
    for log in logs:
        log_dict = {
            "id": log.id,
            "tenant_id": log.tenant_id,
            "user_id": log.user_id,
            "action": log.action,
            "resource_type": log.resource_type,
            "resource_id": log.resource_id,
            "ip_address": str(log.ip_address) if log.ip_address else None,
            "user_agent": log.user_agent,
            "correlation_id": log.correlation_id,
            "old_values": log.old_values,
            "new_values": log.new_values,
            "metadata": log.extra_metadata,
            "created_at": log.created_at,
            "action_display": log.action_display,
            "user_email": None,
            "user_name": None
        }
        
        # Agregar info del usuario si existe
        if log.user:
            log_dict["user_email"] = log.user.email
            log_dict["user_name"] = log.user.full_name
            log_dict["user_role"] = log.user.role.value if hasattr(log.user.role, 'value') else str(log.user.role)
        
        logs_response.append(AuditLogResponse(**log_dict))
    
    return AuditLogListResponse(
        logs=logs_response,
        total=total,
        page=page,
        per_page=per_page,
        total_pages=total_pages
    )


@router.get("/stats", response_model=AuditLogStats)
async def get_audit_stats(
    current_user: User = Depends(require_auditor_role),
    current_tenant: Tenant = Depends(get_current_tenant),
    db: AsyncSession = Depends(get_db)
):
    """
    Obtener estadísticas de auditoría del tenant.
    
    **Permisos**: ADMIN, SUPPORT_MANAGER, AUDITOR
    
    **Retorna**: Estadísticas de actividad
    """
    logger.info(
        "Fetching audit stats",
        user_id=str(current_user.id),
        tenant_id=str(current_tenant.id)
    )
    
    now = datetime.utcnow()
    
    # Total de acciones
    total_query = select(func.count()).select_from(AuditLog).where(
        AuditLog.tenant_id == current_tenant.id
    )
    total_result = await db.execute(total_query)
    total_actions = total_result.scalar() or 0
    
    # Acciones hoy (├║ltimas 24 horas)
    today_start = now - timedelta(days=1)
    today_query = select(func.count()).select_from(AuditLog).where(
        and_(
            AuditLog.tenant_id == current_tenant.id,
            AuditLog.created_at >= today_start
        )
    )
    today_result = await db.execute(today_query)
    actions_today = today_result.scalar() or 0
    
    # Acciones esta semana (últimos 7 días)
    week_start = now - timedelta(days=7)
    week_query = select(func.count()).select_from(AuditLog).where(
        and_(
            AuditLog.tenant_id == current_tenant.id,
            AuditLog.created_at >= week_start
        )
    )
    week_result = await db.execute(week_query)
    actions_this_week = week_result.scalar() or 0
    
    # Top 5 acciones más frecuentes
    top_actions_query = select(
        AuditLog.action,
        func.count(AuditLog.id).label('count')
    ).where(
        AuditLog.tenant_id == current_tenant.id
    ).group_by(
        AuditLog.action
    ).order_by(
        desc('count')
    ).limit(5)
    
    top_actions_result = await db.execute(top_actions_query)
    top_actions = {row.action: row.count for row in top_actions_result}
    
    # Acciones por tipo de recurso
    by_resource_query = select(
        AuditLog.resource_type,
        func.count(AuditLog.id).label('count')
    ).where(
        AuditLog.tenant_id == current_tenant.id
    ).group_by(
        AuditLog.resource_type
    ).order_by(
        desc('count')
    )
    
    by_resource_result = await db.execute(by_resource_query)
    by_resource_type = {row.resource_type: row.count for row in by_resource_result}
    
    # Top usuarios (con join a users para obtener nombres)
    top_users_query = select(
        User.email,
        func.count(AuditLog.id).label('count')
    ).join(
        User, AuditLog.user_id == User.id
    ).where(
        AuditLog.tenant_id == current_tenant.id
    ).group_by(
        User.email
    ).order_by(
        desc('count')
    ).limit(5)
    
    top_users_result = await db.execute(top_users_query)
    top_users = {row.email: row.count for row in top_users_result}
    
    # Acciones críticas hoy (delete, update sensibles, etc.)
    critical_actions_query = select(func.count()).select_from(AuditLog).where(
        and_(
            AuditLog.tenant_id == current_tenant.id,
            AuditLog.created_at >= today_start,
            or_(
                AuditLog.action.like('%.delete'),
                AuditLog.action.like('user.update'),
                AuditLog.action.like('%.assign'),
                AuditLog.action.in_(['user.login_failed', 'user.logout'])
            )
        )
    )
    critical_result = await db.execute(critical_actions_query)
    critical_actions_today = critical_result.scalar() or 0
    
    return AuditLogStats(
        total_actions=total_actions,
        actions_today=actions_today,
        actions_this_week=actions_this_week,
        critical_actions_today=critical_actions_today,
        top_actions=top_actions,
        top_users=top_users,
        by_resource_type=by_resource_type
    )


@router.get("/{log_id}", response_model=AuditLogResponse)
async def get_audit_log_detail(
    log_id: uuid.UUID,
    current_user: User = Depends(require_auditor_role),
    current_tenant: Tenant = Depends(get_current_tenant),
    db: AsyncSession = Depends(get_db)
):
    """
    Obtener detalle de un audit log específico.
    
    **Permisos**: ADMIN, SUPPORT_MANAGER, AUDITOR
    
    **Retorna**: Detalle completo del audit log
    """
    # Buscar el log
    query = select(AuditLog).where(
        and_(
            AuditLog.id == log_id,
            AuditLog.tenant_id == current_tenant.id
        )
    )
    
    result = await db.execute(query)
    log = result.scalar_one_or_none()
    
    if not log:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Audit log {log_id} no encontrado"
        )
    
    # Convertir a response
    log_dict = {
        "id": log.id,
        "tenant_id": log.tenant_id,
        "user_id": log.user_id,
        "action": log.action,
        "resource_type": log.resource_type,
        "resource_id": log.resource_id,
        "ip_address": str(log.ip_address) if log.ip_address else None,
        "user_agent": log.user_agent,
        "correlation_id": log.correlation_id,
        "old_values": log.old_values,
        "new_values": log.new_values,
        "metadata": log.extra_metadata,
        "created_at": log.created_at,
        "action_display": log.action_display,
        "user_email": None,
        "user_name": None
    }
    
    if log.user:
        log_dict["user_email"] = log.user.email
        log_dict["user_name"] = log.user.full_name
    
    return AuditLogResponse(**log_dict)