/**
# Copyright 2024 NVIDIA CORPORATION
#
# 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 discover

import (
	"fmt"
	"path/filepath"
	"strings"

	"github.com/NVIDIA/nvidia-container-toolkit/internal/logger"
	"github.com/NVIDIA/nvidia-container-toolkit/internal/lookup"
)

// mountsToContainerPath defines a Discoverer for a required set of mounts.
// When these are discovered by a locator the specified container root is used
// to construct the container path for the mount returned.
type mountsToContainerPath struct {
	None
	logger        logger.Interface
	locator       lookup.Locator
	required      []string
	containerRoot string
}

func (d *mountsToContainerPath) Mounts() ([]Mount, error) {
	seen := make(map[string]bool)
	var mounts []Mount
	for _, target := range d.required {
		if strings.Contains(target, "*") {
			// TODO: We could relax this condition.
			return nil, fmt.Errorf("wildcard patterns are not supported: %s", target)
		}
		candidates, err := d.locator.Locate(target)
		if err != nil {
			d.logger.Warningf("Could not locate %v: %v", target, err)
			continue
		}
		if len(candidates) == 0 {
			d.logger.Warningf("Missing %v", target)
			continue
		}
		hostPath := candidates[0]
		if seen[hostPath] {
			d.logger.Debugf("Skipping duplicate mount %v", hostPath)
			continue
		}
		seen[hostPath] = true
		d.logger.Debugf("Located %v as %v", target, hostPath)

		containerPath := filepath.Join(d.containerRoot, target)
		d.logger.Infof("Selecting %v as %v", hostPath, containerPath)

		mount := Mount{
			HostPath: hostPath,
			Path:     containerPath,
			Options: []string{
				"ro",
				"nosuid",
				"nodev",
				"bind",
			},
		}
		mounts = append(mounts, mount)
	}

	return mounts, nil
}