"golang.org/x/mod/semver"
)

// IsToolchain reports whether the module path corresponds to the
// virtual, non-downloadable module tracking go or toolchain directives in the go.mod file.
//
// Note that IsToolchain only matches "go" and "toolchain", not the
// real, downloadable module "golang.org/toolchain" containing toolchain files.
//
//	IsToolchain("go") = true
//	IsToolchain("toolchain") = true

package gover

import (
	"slices"
	"strings"
	"testing"

	"golang.org/x/mod/module"
)

func TestIsToolchain(t *testing.T) { test1(t, isToolchainTests, "IsToolchain", IsToolchain) }

var isToolchainTests = []testCase1[string, bool]{
	{"go", true},
	{"toolchain", true},
	{"anything", false},
	{"golang.org/toolchain", false},
}

	if err != nil {
		return "", err
	}
	return filepath.Join(cfg.GOMODCACHE, "cache/download", enc, "/@v"), nil
}

func CachePath(ctx context.Context, m module.Version, suffix string) (string, error) {
	if gover.IsToolchain(m.Path) {
		return "", ErrToolchain
	}
	dir, err := cacheDir(ctx, m.Path)
	if err != nil {
		return "", err
	}
	if !gover.ModIsValid(m.Path, m.Version) {

		}

		// Module path or pattern.
		var match func(string) bool
		if arg == "all" {
			match = func(p string) bool { return !gover.IsToolchain(p) }
		} else if strings.Contains(arg, "...") {
			mp := pkgpattern.MatchPattern(arg)
			match = func(p string) bool { return mp(p) && !gover.IsToolchain(p) }
		} else {
			var v string
			if mg == nil {
				var ok bool
				v, ok = rs.rootSelected(arg)
				if !ok {

			base.Errorf("%s", err)
			ok = false
		}
	}
	if ok {
		fmt.Printf("all modules verified\n")
	}
}

func verifyMod(ctx context.Context, mod module.Version) []error {
	if gover.IsToolchain(mod.Path) {
		// "go" and "toolchain" have no disk footprint; nothing to verify.
		return nil
	}
	if modload.MainModules.Contains(mod.Path) {
		return nil
	}
	var errs []error

func (q *query) matchesPath(path string) bool {
	if q.matchWildcard != nil && !gover.IsToolchain(path) {
		return q.matchWildcard(path)
	}
	return path == q.pattern
}

// canMatchInModule reports whether the given module path can potentially
// contain q.pattern.
func (q *query) canMatchInModule(mPath string) bool {
	if gover.IsToolchain(mPath) {
		return false
	}
	if q.canMatchWildcardInModule != nil {

			}
		}
		if HasModRoot() {
			walkPkgs(VendorDir(), "", pruneVendor)
		}
		return
	}

	for _, mod := range modules {
		if gover.IsToolchain(mod.Path) || !treeCanMatch(mod.Path) {
			continue
		}

		var (
			root, modPrefix string
			isLocal         bool
		)
		if MainModules.Contains(mod.Path) {
			if MainModules.ModRoot(mod) == "" {

func goModSummary(m module.Version) (*modFileSummary, error) {
	if m.Version == "" && !inWorkspaceMode() && MainModules.Contains(m.Path) {
		panic("internal error: goModSummary called on a main module")
	}
	if gover.IsToolchain(m.Path) {
		return rawGoModSummary(m)
	}

	if cfg.BuildMod == "vendor" {
		summary := &modFileSummary{
			module: module.Version{Path: m.Path},
		}

		readVendorList(VendorDir())

		info.GoVersion = v.(string)
	}

	// completeFromModCache fills in the extra fields in m using the module cache.
	completeFromModCache := func(m *modinfo.ModulePublic) {
		if gover.IsToolchain(m.Path) {
			return
		}

		checksumOk := func(suffix string) bool {
			return rs == nil || m.Version == "" || !mustHaveSums() ||
				modfetch.HaveSum(module.Version{Path: m.Path, Version: m.Version + suffix})

// AllowedFunc of qm.
func (qm *queryMatcher) allowsVersion(ctx context.Context, v string) bool {
	if qm.prefix != "" && !strings.HasPrefix(v, qm.prefix) {
		if gover.IsToolchain(qm.path) && strings.TrimSuffix(qm.prefix, ".") == v {
			// Allow 1.21 to match "1.21." prefix.
		} else {
			return false
		}
	}
	if qm.filter != nil && !qm.filter(v) {
		return false
	}