package main

import (
	"crypto/ed25519"
	"crypto/sha256"
	"encoding/base64"
	"encoding/hex"
	"strings"
	"testing"
)

func TestSignFirmwareProducesVerifiableManifest(t *testing.T) {
	content := []byte("deterministic firmware fixture")
	result, err := signFirmware("terminal-a", "rev-b", "1.2.3", content)
	if err != nil {
		t.Fatal(err)
	}
	digest := sha256.Sum256(content)
	if result.SHA256 != hex.EncodeToString(digest[:]) || result.Size != len(content) {
		t.Fatalf("digest=%s size=%d", result.SHA256, result.Size)
	}
	for _, fragment := range []string{"model=terminal-a", "hardware_revision=rev-b", "version=1.2.3", "sha256=" + result.SHA256} {
		if !strings.Contains(result.Manifest, fragment) {
			t.Fatalf("manifest missing %q: %s", fragment, result.Manifest)
		}
	}
	publicKey, err := base64.StdEncoding.DecodeString(result.PublicKeyBase64)
	if err != nil {
		t.Fatal(err)
	}
	signature, err := base64.StdEncoding.DecodeString(result.SignatureBase64)
	if err != nil {
		t.Fatal(err)
	}
	if !ed25519.Verify(ed25519.PublicKey(publicKey), []byte(result.Manifest), signature) {
		t.Fatal("firmware signature did not verify")
	}
	if ed25519.Verify(ed25519.PublicKey(publicKey), []byte(result.Manifest+"tampered"), signature) {
		t.Fatal("tampered manifest unexpectedly verified")
	}
}