package localapi

import (
	"crypto/sha256"
	"encoding/hex"
	"path/filepath"
	"testing"
)

// The leaf is generated once and its fingerprint stays STABLE across "restarts" (re-loads from
// disk) — a fresh cert each boot would invalidate every already-baked bootstrap pin.
func TestEnsureLeaf_StableFingerprintAcrossReload(t *testing.T) {
	dir := t.TempDir()
	certPath := filepath.Join(dir, "leaf.crt")
	keyPath := filepath.Join(dir, "leaf.key")

	cert1, fp1, gen1, err := EnsureLeaf(certPath, keyPath, "192.168.0.162")
	if err != nil {
		t.Fatalf("first ensure: %v", err)
	}
	// B.1/B.3: first call GENERATES; second call LOADS (generated=false) with the SAME fingerprint —
	// persistence keeps the pin stable. A regression that regenerated would flip gen2 true AND change
	// the fp, failing both asserts (the prevention this change exists for).
	if !gen1 {
		t.Fatal("first EnsureLeaf must report generated=true")
	}
	cert2, fp2, gen2, err := EnsureLeaf(certPath, keyPath, "192.168.0.162")
	if err != nil {
		t.Fatalf("second ensure: %v", err)
	}
	if gen2 {
		t.Fatal("second EnsureLeaf must report generated=false (LOADED, not regenerated)")
	}
	if fp1 != fp2 {
		t.Fatalf("fingerprint changed across reload: %s != %s", fp1, fp2)
	}
	// The reported fingerprint must equal the SHA-256 of the served leaf DER (the pin the
	// controller checks against).
	got := sha256.Sum256(cert2.Certificate[0])
	if hex.EncodeToString(got[:]) != fp2 {
		t.Fatal("reported fingerprint does not match the served leaf DER")
	}
	if len(fp1) != 64 {
		t.Fatalf("fingerprint is not a 64-hex SHA-256: %q", fp1)
	}
	_ = cert1
}

// The generated leaf is a usable TLS server cert whose presented leaf matches the pin.
func TestEnsureLeaf_ServesPinnableLeaf(t *testing.T) {
	dir := t.TempDir()
	cert, fp, _, err := EnsureLeaf(filepath.Join(dir, "c"), filepath.Join(dir, "k"), "10.0.0.1")
	if err != nil {
		t.Fatalf("ensure: %v", err)
	}
	if len(cert.Certificate) == 0 {
		t.Fatal("no leaf in cert chain")
	}
	if cert.PrivateKey == nil {
		t.Fatal("generated cert has no private key")
	}
	sum := sha256.Sum256(cert.Certificate[0])
	if hex.EncodeToString(sum[:]) != fp {
		t.Fatal("pin mismatch against served leaf")
	}
}