// Copyright 2025 The gVisor Authors.
//
// 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 nvconf

import (
	"fmt"
	"strconv"
	"strings"
)

// DriverVersion represents a NVIDIA driver version patch release.
//
// +stateify savable
type DriverVersion struct {
	major int
	minor int
	patch int
}

// NewDriverVersion returns a new driver version.
func NewDriverVersion(major, minor, patch int) DriverVersion {
	return DriverVersion{major, minor, patch}
}

// DriverVersionFrom returns a DriverVersion from a string.
func DriverVersionFrom(version string) (DriverVersion, error) {
	parts := strings.Split(version, ".")
	if len(parts) < 2 || len(parts) > 3 {
		return DriverVersion{}, fmt.Errorf("invalid format of version string %q", version)
	}
	var (
		res DriverVersion
		err error
	)
	res.major, err = strconv.Atoi(parts[0])
	if err != nil {
		return DriverVersion{}, fmt.Errorf("invalid format for major version %q: %v", version, err)
	}
	res.minor, err = strconv.Atoi(parts[1])
	if err != nil {
		return DriverVersion{}, fmt.Errorf("invalid format for minor version %q: %v", version, err)
	}
	if len(parts) == 3 {
		res.patch, err = strconv.Atoi(parts[2])
		if err != nil {
			return DriverVersion{}, fmt.Errorf("invalid format for patch version %q: %v", version, err)
		}
	} else {
		res.patch = 0
	}
	return res, nil
}

func (v DriverVersion) String() string {
	return fmt.Sprintf("%02d.%02d.%02d", v.major, v.minor, v.patch)
}

// Equals returns true if the two driver versions are equal.
func (v DriverVersion) Equals(other DriverVersion) bool {
	return v.major == other.major && v.minor == other.minor && v.patch == other.patch
}

// IsGreaterThan returns true if v is greater than other.
// isGreaterThan returns true if v is more recent than other, assuming v and other are on the same
// dev branch.
func (v DriverVersion) IsGreaterThan(other DriverVersion) bool {
	switch {
	case v.major > other.major:
		return true
	case other.major > v.major:
		return false
	case v.minor > other.minor:
		return true
	case other.minor > v.minor:
		return false
	case v.patch > other.patch:
		return true
	case other.patch > v.patch:
		return false
	default:
		return true
	}
}

// Major returns the major version number.
func (v DriverVersion) Major() int {
	return v.major
}
