"""
Role-based access control decorators for PX360.

Provides decorators to restrict views based on user roles:
- PX Admin
- Hospital Admin  
- Department Manager
- PX Coordinator
- Source User
"""
from functools import wraps
from django.core.exceptions import PermissionDenied
from django.contrib.auth.decorators import login_required
from django.shortcuts import redirect
from django.contrib import messages
from django.utils.translation import gettext_lazy as _


def px_admin_required(view_func):
    """
    Decorator to restrict access to PX Admins only.
    
    Example:
        @px_admin_required
        def system_settings(request):
            # Only PX Admins can access this
    """
    @wraps(view_func)
    @login_required
    def _wrapped_view(request, *args, **kwargs):
        if not request.user.is_px_admin():
            messages.error(
                request,
                _("Access denied. PX Admin privileges required.")
            )
            return redirect('analytics:command_center')
        
        return view_func(request, *args, **kwargs)
    
    return _wrapped_view


def hospital_admin_required(view_func):
    """
    Decorator to restrict access to Hospital Admins and PX Admins.
    
    Example:
        @hospital_admin_required
        def hospital_settings(request):
            # Only Hospital Admins and PX Admins can access this
    """
    @wraps(view_func)
    @login_required
    def _wrapped_view(request, *args, **kwargs):
        if not (request.user.is_px_admin() or request.user.is_hospital_admin()):
            messages.error(
                request,
                _("Access denied. Hospital Admin privileges required.")
            )
            return redirect('analytics:command_center')
        
        return view_func(request, *args, **kwargs)
    
    return _wrapped_view


def admin_required(view_func):
    """
    Decorator to restrict access to any Admin (PX, Hospital, or Dept Manager).
    
    Example:
        @admin_required
        def management_view(request):
            # Any admin can access this
    """
    @wraps(view_func)
    @login_required
    def _wrapped_view(request, *args, **kwargs):
        if not (request.user.is_px_admin() or 
                request.user.is_hospital_admin() or 
                request.user.is_department_manager()):
            messages.error(
                request,
                _("Access denied. Admin privileges required.")
            )
            return redirect('analytics:command_center')
        
        return view_func(request, *args, **kwargs)
    
    return _wrapped_view


def px_coordinator_required(view_func):
    """
    Decorator to restrict access to PX Coordinators and above.
    
    Allows: PX Admin, Hospital Admin, Department Manager, PX Coordinator
    
    Example:
        @px_coordinator_required
        def complaint_management(request):
            # Coordinators and admins can access this
    """
    @wraps(view_func)
    @login_required
    def _wrapped_view(request, *args, **kwargs):
        user = request.user
        if not (user.is_px_admin() or 
                user.is_hospital_admin() or 
                user.is_department_manager() or
                user.has_role('PX Coordinator')):
            messages.error(
                request,
                _("Access denied. PX Coordinator privileges required.")
            )
            return redirect('analytics:command_center')
        
        return view_func(request, *args, **kwargs)
    
    return _wrapped_view


def staff_required(view_func):
    """
    Decorator to restrict access to Hospital Staff (not Source Users).
    
    Allows all authenticated users except Source Users.
    
    Example:
        @staff_required
        def internal_tool(request):
            # Any hospital staff can access, but not source users
    """
    @wraps(view_func)
    @login_required
    def _wrapped_view(request, *args, **kwargs):
        if request.user.is_source_user():
            messages.error(
                request,
                _("Access denied. This page is not available for source users.")
            )
            return redirect('px_sources:source_user_dashboard')
        
        return view_func(request, *args, **kwargs)
    
    return _wrapped_view


def source_user_required(view_func):
    """
    Decorator to restrict access to Source Users only.
    
    Example:
        @source_user_required
        def source_user_dashboard(request):
            # Only source users can access this
    """
    @wraps(view_func)
    @login_required
    def _wrapped_view(request, *args, **kwargs):
        if not request.user.is_source_user():
            raise PermissionDenied(
                _("Access denied. Source user privileges required.")
            )
        
        # Get source user profile
        profile = request.user.get_source_user_profile_active()
        if not profile:
            messages.error(
                request,
                _("Your source user account is inactive. Please contact your administrator.")
            )
            return redirect('accounts:login')
        
        # Store in request for easy access
        request.source_user = profile
        request.source = profile.source
        
        return view_func(request, *args, **kwargs)
    
    return _wrapped_view


def block_source_user(view_func):
    """
    Decorator to BLOCK source users from accessing admin/staff pages.
    Redirects source users to their dashboard instead.
    
    Example:
        @block_source_user
        def staff_management(request):
            # Source users CANNOT access this
    """
    @wraps(view_func)
    @login_required
    def _wrapped_view(request, *args, **kwargs):
        if request.user.is_source_user():
            # Silently redirect to source user dashboard
            return redirect('px_sources:source_user_dashboard')
        
        return view_func(request, *args, **kwargs)
    
    return _wrapped_view


def source_user_or_admin(view_func):
    """
    Decorator that allows both source users AND admins.
    
    Example:
        @source_user_or_admin
        def complaint_detail(request, pk):
            # Both source users and admins can view
    """
    @wraps(view_func)
    @login_required
    def _wrapped_view(request, *args, **kwargs):
        user = request.user
        
        # Allow admins
        if (user.is_px_admin() or 
            user.is_hospital_admin() or 
            user.is_department_manager()):
            return view_func(request, *args, **kwargs)
        
        # Allow active source users
        if user.is_source_user():
            profile = user.get_source_user_profile_active()
            if profile:
                request.source_user = profile
                request.source = profile.source
                return view_func(request, *args, **kwargs)
        
        raise PermissionDenied(_("Access denied."))
    
    return _wrapped_view