/**
# Copyright (c) NVIDIA CORPORATION.  All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
**/

package nvcdi

import (
	"github.com/NVIDIA/nvidia-container-toolkit/pkg/nvcdi/spec"
	"github.com/sirupsen/logrus"
	"gitlab.com/nvidia/cloud-native/go-nvlib/pkg/nvlib/device"
	"gitlab.com/nvidia/cloud-native/go-nvlib/pkg/nvlib/info"
	"gitlab.com/nvidia/cloud-native/go-nvlib/pkg/nvml"
)

type wrapper struct {
	Interface

	vendor string
	class  string
}

type nvcdilib struct {
	logger        *logrus.Logger
	nvmllib       nvml.Interface
	mode          string
	devicelib     device.Interface
	deviceNamer   DeviceNamer
	driverRoot    string
	nvidiaCTKPath string

	vendor string
	class  string

	infolib info.Interface
}

// New creates a new nvcdi library
func New(opts ...Option) Interface {
	l := &nvcdilib{}
	for _, opt := range opts {
		opt(l)
	}
	if l.mode == "" {
		l.mode = ModeAuto
	}
	if l.logger == nil {
		l.logger = logrus.StandardLogger()
	}
	if l.deviceNamer == nil {
		l.deviceNamer, _ = NewDeviceNamer(DeviceNameStrategyIndex)
	}
	if l.driverRoot == "" {
		l.driverRoot = "/"
	}
	if l.nvidiaCTKPath == "" {
		l.nvidiaCTKPath = "/usr/bin/nvidia-ctk"
	}
	if l.infolib == nil {
		l.infolib = info.New()
	}

	var lib Interface
	switch l.resolveMode() {
	case ModeNvml:
		if l.nvmllib == nil {
			l.nvmllib = nvml.New()
		}
		if l.devicelib == nil {
			l.devicelib = device.New(device.WithNvml(l.nvmllib))
		}

		lib = (*nvmllib)(l)
	case ModeWsl:
		lib = (*wsllib)(l)
	default:
		// TODO: We would like to return an error here instead of panicking
		panic("Unknown mode")
	}

	w := wrapper{
		Interface: lib,
		vendor:    l.vendor,
		class:     l.class,
	}
	return &w
}

// GetSpec combines the device specs and common edits from the wrapped Interface to a single spec.Interface.
func (l *wrapper) GetSpec() (spec.Interface, error) {
	deviceSpecs, err := l.GetAllDeviceSpecs()
	if err != nil {
		return nil, err
	}

	edits, err := l.GetCommonEdits()
	if err != nil {
		return nil, err
	}

	return spec.New(
		spec.WithDeviceSpecs(deviceSpecs),
		spec.WithEdits(*edits.ContainerEdits),
		spec.WithVendor(l.vendor),
		spec.WithClass(l.class),
	)

}

// resolveMode resolves the mode for CDI spec generation based on the current system.
func (l *nvcdilib) resolveMode() (rmode string) {
	if l.mode != ModeAuto {
		return l.mode
	}
	defer func() {
		l.logger.Infof("Auto-detected mode as %q", rmode)
	}()

	isWSL, reason := l.infolib.HasDXCore()
	l.logger.Debugf("Is WSL-based system? %v: %v", isWSL, reason)

	if isWSL {
		return ModeWsl
	}

	return ModeNvml
}