package photon

import (
	"time"

	version "github.com/knqyf263/go-rpm-version"
	"golang.org/x/xerrors"
	"k8s.io/utils/clock"

	"github.com/aquasecurity/trivy-db/pkg/vulnsrc/photon"
	ftypes "github.com/aquasecurity/trivy/pkg/fanal/types"
	"github.com/aquasecurity/trivy/pkg/log"
	"github.com/aquasecurity/trivy/pkg/scanner/utils"
	"github.com/aquasecurity/trivy/pkg/types"
)

var (
	eolDates = map[string]time.Time{
		"1.0": time.Date(2022, 2, 28, 23, 59, 59, 0, time.UTC),
		"2.0": time.Date(2022, 12, 31, 23, 59, 59, 0, time.UTC),
		// The following versions don't have the EOL dates yet.
		// See https://blogs.vmware.com/vsphere/2022/01/photon-1-x-end-of-support-announcement.html
		"3.0": time.Date(2024, 6, 30, 23, 59, 59, 0, time.UTC),
		"4.0": time.Date(2025, 12, 31, 23, 59, 59, 0, time.UTC),
	}
)

type options struct {
	clock clock.Clock
}

type option func(*options)

func WithClock(clock clock.Clock) option {
	return func(opts *options) {
		opts.clock = clock
	}
}

// Scanner implements the Photon scanner
type Scanner struct {
	vs photon.VulnSrc
	*options
}

// NewScanner is the factory method for Scanner
func NewScanner(opts ...option) *Scanner {
	o := &options{
		clock: clock.RealClock{},
	}

	for _, opt := range opts {
		opt(o)
	}
	return &Scanner{
		vs:      photon.NewVulnSrc(),
		options: o,
	}
}

// Detect scans and returns vulnerabilities using photon scanner
func (s *Scanner) Detect(osVer string, _ *ftypes.Repository, pkgs []ftypes.Package) ([]types.DetectedVulnerability, error) {
	log.Logger.Info("Detecting Photon Linux vulnerabilities...")
	log.Logger.Debugf("Photon Linux: os version: %s", osVer)
	log.Logger.Debugf("Photon Linux: the number of packages: %d", len(pkgs))

	var vulns []types.DetectedVulnerability
	for _, pkg := range pkgs {
		advisories, err := s.vs.Get(osVer, pkg.SrcName)
		if err != nil {
			return nil, xerrors.Errorf("failed to get Photon Linux advisory: %w", err)
		}

		installed := utils.FormatVersion(pkg)
		installedVersion := version.NewVersion(installed)
		for _, adv := range advisories {
			fixedVersion := version.NewVersion(adv.FixedVersion)
			vuln := types.DetectedVulnerability{
				VulnerabilityID:  adv.VulnerabilityID,
				PkgID:            pkg.ID,
				PkgName:          pkg.Name,
				InstalledVersion: installed,
				Ref:              pkg.Ref,
				Layer:            pkg.Layer,
				Custom:           adv.Custom,
				DataSource:       adv.DataSource,
			}
			if installedVersion.LessThan(fixedVersion) {
				vuln.FixedVersion = adv.FixedVersion
				vulns = append(vulns, vuln)
			}
		}
	}
	return vulns, nil
}

// IsSupportedVersion checks if the OS version reached end-of-support.
func (s *Scanner) IsSupportedVersion(osFamily, osVer string) bool {
	eol, ok := eolDates[osVer]
	if !ok {
		log.Logger.Warnf("This OS version is not on the EOL list: %s %s", osFamily, osVer)
		return false
	}
	return s.clock.Now().Before(eol)
}
