from typing import List, Optional 
from fastapi import APIRouter, Depends, Query
from sqlalchemy.orm import Session
from sqlalchemy import asc, desc, or_, cast, String
 
from app.config.database import get_db
from app.middleware.auth_middleware import get_current_user, User
from app.models.system.audit_log import AuditLog
from app.schemas.auth.audit_schema import AuditLogListResponse
 
router = APIRouter()
  
@router.get("/", response_model=AuditLogListResponse)
def get_audit_logs(
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
    module_name: Optional[str] = Query(None, description="Filter by module name"),
    action_type: Optional[str] = Query(None, description="CREATE | UPDATE | DELETE"),
    performed_by_email: Optional[str] = Query(None, description="Filter by actor email"),
    search: Optional[str] = Query(None, description="Search audit logs"),
    module_names: Optional[List[str]] = Query(None, description="Filter by module names"),
    action_types: Optional[List[str]] = Query(None, description="Filter by action types"),
    performed_by_emails: Optional[List[str]] = Query(None, description="Filter by actor emails"),
    sort_by: Optional[str] = Query("created_at", description="Sort by created_at, module_name, action_type, or performed_by_email"),
    sort_order: Optional[str] = Query("desc", description="Sort order: asc or desc"),
    limit: int = Query(50, ge=1, le=500),
    offset: int = Query(0, ge=0),
):
    """
    Fetch audit logs with optional filters.
    Only accessible to authenticated users (super-admin in practice).
    """
    query = db.query(AuditLog)
 
    if module_name:
        query = query.filter(AuditLog.module_name == module_name)
    if module_names:
        query = query.filter(AuditLog.module_name.in_(module_names))
    if action_type:
        query = query.filter(AuditLog.action_type == action_type.upper())
    if action_types:
        normalized_action_types = [item.upper() for item in action_types]
        query = query.filter(AuditLog.action_type.in_(normalized_action_types))
    if performed_by_email:
        query = query.filter(
            AuditLog.performed_by_email.ilike(f"%{performed_by_email}%")
        )
    if performed_by_emails:
        query = query.filter(AuditLog.performed_by_email.in_(performed_by_emails))
    if search:
        search_term = search.strip()
        query = query.filter(
            or_(
                AuditLog.module_name.ilike(f"%{search_term}%"),
                AuditLog.action_type.ilike(f"%{search_term}%"),
                AuditLog.entity_name.ilike(f"%{search_term}%"),
                AuditLog.description.ilike(f"%{search_term}%"),
                AuditLog.performed_by_email.ilike(f"%{search_term}%"),
                AuditLog.ip_address.ilike(f"%{search_term}%"),
                cast(AuditLog.entity_id, String).ilike(f"%{search_term}%"),
            )
        )
 
    total = query.count()
    sort_column_map = {
        "created_at": AuditLog.created_at,
        "module_name": AuditLog.module_name,
        "action_type": AuditLog.action_type,
        "performed_by_email": AuditLog.performed_by_email,
    }
    sort_column = sort_column_map.get(sort_by or "created_at", AuditLog.created_at)
    order_fn = asc if (sort_order or "").lower() == "asc" else desc
    items = (
        query.order_by(order_fn(sort_column))
        .offset(offset)
        .limit(limit)
        .all()
    )
 
    return AuditLogListResponse(
        items=items,
        total=total,
        limit=limit,
        offset=offset,
    )