package game

// Closure regressions for the casino RNG hardening: the entropy-seeded
// constructor must be the one PRODUCTION wires, not merely available.

import (
	"io/fs"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

// TestProductionCasinoSeedIsEntropy pins the production wiring: game.New must
// build its casino manager with casino.NewManagerEntropy, and no production
// file may call casino.NewManager(seed). That constructor exists only as the
// deterministic test seam, because a wall-clock seed makes every shoe, reel,
// and spin stream reconstructible from the startup nanosecond.
//
// The manager's seed is unexported and deliberately not observable through the
// casino API (NewManagerEntropy and NewManager are otherwise
// indistinguishable), so this is a source-level guard: it is the only place
// the choice of constructor can be pinned. It fails on a revert to
// NewManager(time.Now().UnixNano()).
func TestProductionCasinoSeedIsEntropy(t *testing.T) {
	root := filepath.Join("..", "..")
	sawEntropyCall := false
	err := filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
		if err != nil {
			return err
		}
		if d.IsDir() {
			name := d.Name()
			// Skip VCS internals, generated/test data, and the persisted
			// game data (which is not Go source at all).
			if path != root && (strings.HasPrefix(name, ".") || name == "testdata" || name == "vendor") {
				return fs.SkipDir
			}
			return nil
		}
		if !strings.HasSuffix(d.Name(), ".go") || strings.HasSuffix(d.Name(), "_test.go") {
			return nil
		}
		data, readErr := os.ReadFile(path)
		if readErr != nil {
			return readErr
		}
		rel, relErr := filepath.Rel(root, path)
		if relErr != nil {
			rel = path
		}
		for i, line := range strings.Split(string(data), "\n") {
			trimmed := strings.TrimSpace(line)
			if strings.HasPrefix(trimmed, "//") || strings.HasPrefix(trimmed, "*") {
				continue // prose about the seam, not a call
			}
			if strings.Contains(trimmed, "casino.NewManager(") {
				t.Errorf("%s:%d calls the deterministic casino.NewManager(seed) outside tests: %s", rel, i+1, trimmed)
			}
			if strings.Contains(trimmed, "casino.NewManagerEntropy()") {
				sawEntropyCall = true
			}
		}
		return nil
	})
	if err != nil {
		t.Fatalf("walk module: %v", err)
	}
	if !sawEntropyCall {
		t.Fatal("no production call to casino.NewManagerEntropy() found: the casino RNG entropy fix is not wired")
	}
}