// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
// SPDX-License-Identifier: BSD-3-Clause

package verify

import (
	"testing"
)

func TestGroundTruthBasic(t *testing.T) {
	// Use the simple test kernel — it assembles with go tool asm.
	gt, err := GroundTruth("../testdata/verify/basic_amd64.s")
	if err != nil {
		t.Fatalf("GroundTruth: %v", err)
	}
	if len(gt) == 0 {
		t.Fatal("no functions extracted from ground truth")
	}
	// The "add" function should be present and non-empty.
	code, ok := gt["add"]
	if !ok {
		t.Fatalf("function 'add' not found in ground truth; got: %v", keys(gt))
	}
	if len(code) == 0 {
		t.Fatal("add: zero-length code")
	}
	t.Logf("ground truth functions: %v", keys(gt))
}

func TestGroundTruthComparison(t *testing.T) {
	// Assemble with gasm and compare against go tool asm.
	k, err := Load("../testdata/verify/basic_amd64.s")
	if err != nil {
		t.Fatalf("Load: %v", err)
	}
	defer k.Close()

	gt, err := GroundTruth("../testdata/verify/basic_amd64.s")
	if err != nil {
		t.Fatalf("GroundTruth: %v", err)
	}

	for _, name := range k.FuncNames() {
		fl, _ := k.Func(name)
		gasmCode := k.Image().Code[fl.Offset : fl.Offset+fl.Size]
		goCode, ok := gt[name]
		if !ok {
			t.Errorf("%s: not in ground truth", name)
			continue
		}
		if len(gasmCode) != len(goCode) {
			t.Errorf("%s: size mismatch: gasm=%d go=%d", name, len(gasmCode), len(goCode))
			continue
		}
		for i := range gasmCode {
			if gasmCode[i] != goCode[i] {
				t.Errorf("%s: byte %d differs: gasm=%02x go=%02x", name, i, gasmCode[i], goCode[i])
				break
			}
		}
	}
}

func TestGroundTruthBadFile(t *testing.T) {
	_, err := GroundTruth("/nonexistent/file_amd64.s")
	if err == nil {
		t.Fatal("expected error for nonexistent file")
	}
}

func keys(m map[string][]byte) []string {
	out := make([]string, 0, len(m))
	for k := range m {
		out = append(out, k)
	}
	return out
}