package kdbx

import (
	"bytes"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"
)

// These tests prove the only thing that finally matters about a KDBX
// implementation: that a real KeePass reads what this package writes, and
// that this package reads what a real KeePass writes. They are skipped
// where keepassxc-cli is not installed.
func keepassxc(t *testing.T) string {
	t.Helper()
	path, err := exec.LookPath("keepassxc-cli")
	if err != nil {
		t.Skip("keepassxc-cli is not installed; skipping the interoperability test")
	}
	return path
}

// run feeds stdin lines to keepassxc-cli and returns its stdout.
func run(t *testing.T, stdin string, args ...string) string {
	t.Helper()
	cmd := exec.Command(keepassxc(t), args...)
	cmd.Stdin = strings.NewReader(stdin)
	var out, errb bytes.Buffer
	cmd.Stdout, cmd.Stderr = &out, &errb
	if err := cmd.Run(); err != nil {
		t.Fatalf("keepassxc-cli %s: %v\nstdout: %s\nstderr: %s",
			strings.Join(args, " "), err, out.String(), errb.String())
	}
	return out.String()
}

const vaultPassword = "interop-password-1"

// writeVault creates a vault with this package and returns its path.
func writeVault(t *testing.T, db *Database) string {
	t.Helper()
	data, err := db.Marshal(vaultPassword)
	if err != nil {
		t.Fatal(err)
	}
	path := filepath.Join(t.TempDir(), "vault.kdbx")
	if err := os.WriteFile(path, data, 0o600); err != nil {
		t.Fatal(err)
	}
	return path
}

func TestKeePassXCReadsWhatWeWrite(t *testing.T) {
	keepassxc(t)
	db := New("Interop Vault", fastKDF)
	db.RootGroup().Nodes = append(db.RootGroup().Nodes,
		NewEntry("Router", "admin", "s3cret-pw", "https://router.lan", "a note"))
	group := NewGroup("Servers")
	group.Nodes = append(group.Nodes, NewEntry("Backup", "root", "other-pw", "", ""))
	db.RootGroup().Nodes = append(db.RootGroup().Nodes, group)
	path := writeVault(t, db)

	listing := run(t, vaultPassword+"\n", "ls", "-q", "-R", "-f", path)
	for _, want := range []string{"Router", "Servers/Backup"} {
		if !strings.Contains(listing, want) {
			t.Errorf("KeePassXC listing lacks %q:\n%s", want, listing)
		}
	}

	// The protected value must decrypt to exactly what we stored.
	got := run(t, vaultPassword+"\n", "show", "-q", "-s", "-a", "Password", path, "Router")
	if strings.TrimSpace(got) != "s3cret-pw" {
		t.Errorf("KeePassXC read the password as %q", strings.TrimSpace(got))
	}
	got = run(t, vaultPassword+"\n", "show", "-q", "-a", "Notes", path, "Router")
	if strings.TrimSpace(got) != "a note" {
		t.Errorf("KeePassXC read the notes as %q", strings.TrimSpace(got))
	}
}

func TestWeReadWhatKeePassXCWrites(t *testing.T) {
	keepassxc(t)
	db := New("Interop Vault", fastKDF)
	db.RootGroup().Nodes = append(db.RootGroup().Nodes,
		NewEntry("Router", "admin", "s3cret-pw", "", ""))
	path := writeVault(t, db)

	// KeePassXC opens our file, adds an entry and saves it back. The saved
	// file is now KeePassXC's own output, in the format it chose to keep.
	run(t, vaultPassword+"\nkeepassxc-made-this\n", "add", "-q", "-u", "someone",
		"--url", "https://added.example", "-p", path, "Added By KeePassXC")

	data, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	back, err := Open(data, vaultPassword)
	if err != nil {
		t.Fatalf("reading KeePassXC's output: %v", err)
	}
	if back.Version>>16 != 4 {
		t.Fatalf("KeePassXC rewrote the file as version %d.%d",
			back.Version>>16, back.Version&0xFFFF)
	}

	titles := map[string]string{}
	back.Root.walk(func(n *Node) {
		if n.Name == "Entry" {
			titles[entryValue(n, "Title")] = entryValue(n, "Password")
		}
	})
	if titles["Router"] != "s3cret-pw" {
		t.Errorf("our own entry came back as %q", titles["Router"])
	}
	if titles["Added By KeePassXC"] != "keepassxc-made-this" {
		t.Errorf("KeePassXC's entry read as %q", titles["Added By KeePassXC"])
	}
}

// A vault created with the production work factor must also interoperate:
// the KDF is part of the file, and Argon2d is what this package writes.
func TestKeePassXCOpensArgon2dVaultAtDefaultCost(t *testing.T) {
	keepassxc(t)
	db := New("Argon2 Vault", DefaultKDF)
	path := writeVault(t, db)
	out := run(t, vaultPassword+"\n", "db-info", "-q", path)
	if !strings.Contains(out, "Argon2") {
		t.Errorf("KeePassXC does not report Argon2:\n%s", out)
	}
}