from django.shortcuts import render, redirect
from django.contrib.auth import authenticate, login, logout
from django.contrib.auth.decorators import login_required, permission_required
from django.contrib import messages
from django.http import HttpResponse
from .models import User, Role, Permission, RolePermission, UserRole


def login_view(request):
    """User login view"""
    if request.method == 'POST':
        username = request.POST['username']
        password = request.POST['password']
        user = authenticate(request, username=username, password=password)
        if user is not None:
            login(request, user)
            return redirect('inventory:dashboard')
        else:
            messages.error(request, 'Invalid username or password')
    
    context = {
        'module_title': 'Login',
    }
    return render(request, 'accounts/login.html', context)


def logout_view(request):
    """User logout view"""
    logout(request)
    messages.info(request, 'You have been logged out')
    return redirect('accounts:login')


def register_view(request):
    """User registration view"""
    # In a real app, this would contain registration logic
    return HttpResponse("Registration page")


@login_required
def profile_view(request):
    """User profile view"""
    context = {
        'module_title': 'User Profile',
    }
    return render(request, 'accounts/profile.html', context)


@login_required
def edit_profile_view(request):
    """Edit user profile view"""
    # In a real app, this would contain profile editing logic
    return HttpResponse("Edit profile page")


# User Management Views
@login_required
@permission_required('accounts.view_user', raise_exception=True)
def user_list_view(request):
    """List all users"""
    users = User.objects.all()
    context = {
        'module_title': 'User Management',
        'users': users,
    }
    return render(request, 'accounts/user_list.html', context)


@login_required
@permission_required('accounts.add_user', raise_exception=True)
def create_user_view(request):
    """Create a new user"""
    if request.method == 'POST':
        from django.contrib import messages

        username = request.POST.get('username')
        first_name = request.POST.get('first_name')
        last_name = request.POST.get('last_name')
        email = request.POST.get('email')
        password = request.POST.get('password')
        phone = request.POST.get('phone')
        department = request.POST.get('department')
        position = request.POST.get('position')
        is_active = request.POST.get('is_active') == 'on'
        roles = request.POST.getlist('roles')

        try:
            # Create the user
            user = User.objects.create_user(
                username=username,
                email=email,
                password=password,
                first_name=first_name,
                last_name=last_name
            )
            user.phone = phone
            user.department = department
            user.position = position
            user.is_active = is_active
            user.save()

            # Assign roles
            for role_id in roles:
                try:
                    role = Role.objects.get(id=role_id)
                    UserRole.objects.get_or_create(user=user, role=role)
                except Role.DoesNotExist:
                    pass

            messages.success(request, f'User {username} created successfully!')
            return redirect('accounts:user_detail', user_id=user.id)

        except Exception as e:
            messages.error(request, f'Error creating user: {str(e)}')

    # GET request - show form
    roles = Role.objects.all()
    context = {
        'module_title': 'Create User',
        'roles': roles,
    }
    return render(request, 'accounts/create_user.html', context)


@login_required
@permission_required('accounts.view_user', raise_exception=True)
def user_detail_view(request, user_id):
    """View user details"""
    try:
        user = User.objects.get(id=user_id)
        context = {
            'module_title': 'User Details',
            'user': user,
        }
        return render(request, 'accounts/user_detail.html', context)
    except User.DoesNotExist:
        messages.error(request, 'User not found')
        return redirect('accounts:user_list')


@login_required
@permission_required('accounts.change_user', raise_exception=True)
def edit_user_view(request, user_id):
    """Edit user details"""
    try:
        user = User.objects.get(id=user_id)
    except User.DoesNotExist:
        messages.error(request, 'User not found')
        return redirect('accounts:user_list')

    if request.method == 'POST':
        from django.contrib import messages

        # Update basic information
        user.first_name = request.POST.get('first_name')
        user.last_name = request.POST.get('last_name')
        user.email = request.POST.get('email')
        user.phone = request.POST.get('phone')
        user.department = request.POST.get('department')
        user.position = request.POST.get('position')
        user.is_active = request.POST.get('is_active') == 'on'

        # Update password if provided
        password = request.POST.get('password')
        if password:
            user.set_password(password)

        user.save()

        # Update roles
        user.userrole_set.all().delete()  # Remove existing roles
        roles = request.POST.getlist('roles')
        for role_id in roles:
            try:
                role = Role.objects.get(id=role_id)
                UserRole.objects.get_or_create(user=user, role=role)
            except Role.DoesNotExist:
                pass

        messages.success(request, f'User {user.username} updated successfully!')
        return redirect('accounts:user_detail', user_id=user.id)

    # GET request - show form
    roles = Role.objects.all()
    user_roles = user.userrole_set.values_list('role_id', flat=True)

    context = {
        'module_title': 'Edit User',
        'user': user,
        'roles': roles,
        'user_roles': user_roles,
    }
    return render(request, 'accounts/edit_user.html', context)


@login_required
@permission_required('accounts.delete_user', raise_exception=True)
def delete_user_view(request, user_id):
    """Delete a user"""
    try:
        user = User.objects.get(id=user_id)
    except User.DoesNotExist:
        messages.error(request, 'User not found')
        return redirect('accounts:user_list')

    if request.method == 'POST':
        username = user.username
        user.delete()
        messages.success(request, f'User {username} deleted successfully!')
        return redirect('accounts:user_list')

    context = {
        'module_title': 'Delete User',
        'user': user,
    }
    return render(request, 'accounts/delete_user.html', context)


# Role Management Views
@login_required
@permission_required('accounts.view_role', raise_exception=True)
def role_list_view(request):
    """List all roles"""
    roles = Role.objects.all()
    context = {
        'module_title': 'Role Management',
        'roles': roles,
    }
    return render(request, 'accounts/role_list.html', context)


@login_required
@permission_required('accounts.add_role', raise_exception=True)
def create_role_view(request):
    """Create a new role"""
    if request.method == 'POST':
        name = request.POST.get('name')
        description = request.POST.get('description')
        permissions = request.POST.getlist('permissions')

        try:
            role = Role.objects.create(
                name=name,
                description=description
            )

            # Assign permissions
            for perm_id in permissions:
                try:
                    permission = Permission.objects.get(id=perm_id)
                    RolePermission.objects.get_or_create(role=role, permission=permission)
                except Permission.DoesNotExist:
                    pass

            messages.success(request, f'Role {name} created successfully!')
            return redirect('accounts:role_detail', role_id=role.id)

        except Exception as e:
            messages.error(request, f'Error creating role: {str(e)}')

    # GET request - show form
    permissions = Permission.objects.all()
    context = {
        'module_title': 'Create Role',
        'permissions': permissions,
    }
    return render(request, 'accounts/create_role.html', context)


@login_required
@permission_required('accounts.view_role', raise_exception=True)
def role_detail_view(request, role_id):
    """View role details"""
    try:
        role = Role.objects.get(id=role_id)
        context = {
            'module_title': 'Role Details',
            'role': role,
        }
        return render(request, 'accounts/role_detail.html', context)
    except Role.DoesNotExist:
        messages.error(request, 'Role not found')
        return redirect('accounts:role_list')


@login_required
@permission_required('accounts.change_role', raise_exception=True)
def edit_role_view(request, role_id):
    """Edit role details"""
    try:
        role = Role.objects.get(id=role_id)
    except Role.DoesNotExist:
        messages.error(request, 'Role not found')
        return redirect('accounts:role_list')

    if request.method == 'POST':
        name = request.POST.get('name')
        description = request.POST.get('description')
        permissions = request.POST.getlist('permissions')

        try:
            role.name = name
            role.description = description
            role.save()

            # Update permissions
            role.rolepermission_set.all().delete()  # Remove existing permissions
            for perm_id in permissions:
                try:
                    permission = Permission.objects.get(id=perm_id)
                    RolePermission.objects.get_or_create(role=role, permission=permission)
                except Permission.DoesNotExist:
                    pass

            messages.success(request, f'Role {name} updated successfully!')
            return redirect('accounts:role_detail', role_id=role.id)

        except Exception as e:
            messages.error(request, f'Error updating role: {str(e)}')

    # GET request - show form
    permissions = Permission.objects.all()
    role_permissions = role.rolepermission_set.values_list('permission_id', flat=True)

    context = {
        'module_title': 'Edit Role',
        'role': role,
        'permissions': permissions,
        'role_permissions': role_permissions,
    }
    return render(request, 'accounts/edit_role.html', context)


@login_required
@permission_required('accounts.delete_role', raise_exception=True)
def delete_role_view(request, role_id):
    """Delete a role"""
    try:
        role = Role.objects.get(id=role_id)
    except Role.DoesNotExist:
        messages.error(request, 'Role not found')
        return redirect('accounts:role_list')

    if request.method == 'POST':
        role_name = role.name
        role.delete()
        messages.success(request, f'Role {role_name} deleted successfully!')
        return redirect('accounts:role_list')

    context = {
        'module_title': 'Delete Role',
        'role': role,
    }
    return render(request, 'accounts/delete_role.html', context)


# Permission Management Views
@login_required
@permission_required('accounts.view_permission', raise_exception=True)
def permission_list_view(request):
    """List all permissions"""
    permissions = Permission.objects.all()
    context = {
        'module_title': 'Permission Management',
        'permissions': permissions,
    }
    return render(request, 'accounts/permission_list.html', context)


@login_required
@permission_required('accounts.change_role', raise_exception=True)
def assign_permissions_view(request, role_id):
    """Assign permissions to a role"""
    try:
        role = Role.objects.get(id=role_id)
    except Role.DoesNotExist:
        messages.error(request, 'Role not found')
        return redirect('accounts:role_list')

    if request.method == 'POST':
        permissions = request.POST.getlist('permissions')

        try:
            # Remove existing permissions
            role.rolepermission_set.all().delete()

            # Add new permissions
            for perm_id in permissions:
                try:
                    permission = Permission.objects.get(id=perm_id)
                    RolePermission.objects.get_or_create(role=role, permission=permission)
                except Permission.DoesNotExist:
                    pass

            messages.success(request, f'Permissions updated for role {role.name}!')
            return redirect('accounts:role_detail', role_id=role.id)

        except Exception as e:
            messages.error(request, f'Error updating permissions: {str(e)}')

    # GET request - show form
    permissions = Permission.objects.all()
    role_permissions = role.rolepermission_set.values_list('permission_id', flat=True)

    context = {
        'module_title': f'Assign Permissions to {role.name}',
        'role': role,
        'permissions': permissions,
        'role_permissions': role_permissions,
    }
    return render(request, 'accounts/assign_permissions.html', context)