package vault_test

import (
	"os"
	"path/filepath"
	"slices"
	"testing"

	"filippo.io/age"
	"git.eeqj.de/sneak/secret/internal/secret"
	"git.eeqj.de/sneak/secret/internal/vault"
	"git.eeqj.de/sneak/secret/pkg/agehd"
	"github.com/awnumar/memguard"
	"github.com/spf13/afero"
)

// deriveVaultIdentity derives the long-term identity for the given vault
// from testMnemonic using the derivation index stored in its metadata.
func deriveVaultIdentity(
	t *testing.T, fs afero.Fs, vlt *vault.Vault,
) *age.X25519Identity {
	t.Helper()

	vaultDir, err := vlt.GetDirectory()
	if err != nil {
		t.Fatalf("Failed to get vault directory: %v", err)
	}

	vaultMetadata, err := vault.LoadVaultMetadata(fs, vaultDir)
	if err != nil {
		t.Fatalf("Failed to load vault metadata: %v", err)
	}

	ltIdentity, err := agehd.DeriveIdentity(testMnemonic,
		vaultMetadata.DerivationIndex)
	if err != nil {
		t.Fatalf("Failed to derive long-term key: %v", err)
	}

	return ltIdentity
}

//nolint:paralleltest // t.Setenv forbids parallel subtests
func TestVaultWithRealFilesystem(t *testing.T) {
	// Create a temporary directory for our tests
	tempDir := t.TempDir()

	// Use the real filesystem
	fs := afero.NewOsFs()

	// Set test environment variables
	t.Setenv(secret.EnvMnemonic, testMnemonic)
	t.Setenv(secret.EnvUnlockPassphrase, testPassphrase)

	// Test currentvault file handling (plain file with relative path)
	t.Run("CurrentVaultFileHandling", func(t *testing.T) {
		testCurrentVaultFileHandling(t, fs, tempDir)
	})

	// Test secret operations with deeply nested paths
	t.Run("DeepPathSecrets", func(t *testing.T) {
		testDeepPathSecrets(t, fs, tempDir)
	})

	// Test key caching in GetOrDeriveLongTermKey
	t.Run("KeyCaching", func(t *testing.T) {
		testKeyCaching(t, fs, tempDir)
	})

	// Test vault name validation
	t.Run("VaultNameValidation", func(t *testing.T) {
		testVaultNameValidation(t, fs, tempDir)
	})

	// Test multiple vaults and switching between them
	t.Run("MultipleVaults", func(t *testing.T) {
		testMultipleVaults(t, fs, tempDir)
	})

	// Test adding a secret in one vault and verifying it's not visible in
	// another
	t.Run("VaultIsolation", func(t *testing.T) {
		testVaultIsolation(t, fs, tempDir)
	})
}

func testCurrentVaultFileHandling(t *testing.T, fs afero.Fs, tempDir string) {
	t.Helper()

	stateDir := filepath.Join(tempDir, "currentvault-test")

	err := os.MkdirAll(stateDir, 0o700)
	if err != nil {
		t.Fatalf("Failed to create state dir: %v", err)
	}

	// Create a test vault
	vlt, err := vault.CreateVault(fs, stateDir, testVaultName)
	if err != nil {
		t.Fatalf("Failed to create vault: %v", err)
	}

	// Get the vault directory
	vaultDir, err := vlt.GetDirectory()
	if err != nil {
		t.Fatalf("Failed to get vault directory: %v", err)
	}

	// Verify the currentvault file exists and contains just the vault name
	currentVaultPath := filepath.Join(stateDir, "currentvault")

	currentVaultContents, err := os.ReadFile(filepath.Clean(currentVaultPath))
	if err != nil {
		t.Fatalf("Failed to read currentvault file: %v", err)
	}

	if string(currentVaultContents) != testVaultName {
		t.Errorf("Expected currentvault to contain %q, got %q",
			testVaultName, string(currentVaultContents))
	}

	// Test that ResolveVaultSymlink correctly resolves the path
	resolvedPath, err := vault.ResolveVaultSymlink(fs, currentVaultPath)
	if err != nil {
		t.Fatalf("Failed to resolve currentvault path: %v", err)
	}

	if resolvedPath != vaultDir {
		t.Errorf("Expected resolved path to be %s, got %s", vaultDir, resolvedPath)
	}
}

func testDeepPathSecrets(t *testing.T, fs afero.Fs, tempDir string) {
	t.Helper()

	stateDir := filepath.Join(tempDir, "deep-path-test")

	err := os.MkdirAll(stateDir, 0o700)
	if err != nil {
		t.Fatalf("Failed to create state dir: %v", err)
	}

	// Create a test vault - CreateVault now handles public key when
	// mnemonic is in env
	vlt, err := vault.CreateVault(fs, stateDir, testVaultName)
	if err != nil {
		t.Fatalf("Failed to create vault: %v", err)
	}

	// Load vault metadata to get its derivation index
	vaultDir, err := vlt.GetDirectory()
	if err != nil {
		t.Fatalf("Failed to get vault directory: %v", err)
	}

	vaultMetadata, err := vault.LoadVaultMetadata(fs, vaultDir)
	if err != nil {
		t.Fatalf("Failed to load vault metadata: %v", err)
	}

	// Derive long-term key from mnemonic using the vault's derivation index
	ltIdentity, err := agehd.DeriveIdentity(testMnemonic,
		vaultMetadata.DerivationIndex)
	if err != nil {
		t.Fatalf("Failed to derive long-term key: %v", err)
	}

	// Unlock the vault
	vlt.Unlock(ltIdentity)

	// Create a secret with a deeply nested path
	deepPath := "api/credentials/production/database/primary"
	secretValue := []byte("supersecretdbpassword")
	expectedValue := make([]byte, len(secretValue))
	copy(expectedValue, secretValue)

	secretBuffer := memguard.NewBufferFromBytes(secretValue)
	defer secretBuffer.Destroy()

	err = vlt.AddSecret(deepPath, secretBuffer, false)
	if err != nil {
		t.Fatalf("Failed to add secret with deep path: %v", err)
	}

	// List secrets and verify our deep path secret is there
	secrets, err := vlt.ListSecrets()
	if err != nil {
		t.Fatalf("Failed to list secrets: %v", err)
	}

	if !slices.Contains(secrets, deepPath) {
		t.Errorf("Deep path secret not found in listed secrets")
	}

	// Retrieve the secret and verify its value
	retrievedValue, err := vlt.GetSecret(deepPath)
	if err != nil {
		t.Fatalf("Failed to retrieve deep path secret: %v", err)
	}

	if string(retrievedValue) != string(expectedValue) {
		t.Errorf("Retrieved value doesn't match. Expected %q, got %q",
			string(expectedValue), string(retrievedValue))
	}
}

func testKeyCaching(t *testing.T, fs afero.Fs, tempDir string) {
	t.Helper()

	stateDir := filepath.Join(tempDir, "key-cache-test")

	err := os.MkdirAll(stateDir, 0o700)
	if err != nil {
		t.Fatalf("Failed to create state dir: %v", err)
	}

	// Create a test vault - CreateVault now handles public key when
	// mnemonic is in env
	vlt, err := vault.CreateVault(fs, stateDir, testVaultName)
	if err != nil {
		t.Fatalf("Failed to create vault: %v", err)
	}

	// Load vault metadata to get its derivation index
	vaultDir, err := vlt.GetDirectory()
	if err != nil {
		t.Fatalf("Failed to get vault directory: %v", err)
	}

	vaultMetadata, err := vault.LoadVaultMetadata(fs, vaultDir)
	if err != nil {
		t.Fatalf("Failed to load vault metadata: %v", err)
	}

	// Derive long-term key from mnemonic for verification using the
	// vault's derivation index
	ltIdentity, err := agehd.DeriveIdentity(testMnemonic,
		vaultMetadata.DerivationIndex)
	if err != nil {
		t.Fatalf("Failed to derive long-term key: %v", err)
	}

	// Verify the vault is locked initially
	if !vlt.Locked() {
		t.Errorf("Vault should be locked initially")
	}

	// First call to GetOrDeriveLongTermKey should derive and cache the key
	firstKey, err := vlt.GetOrDeriveLongTermKey()
	if err != nil {
		t.Fatalf("Failed to get long-term key: %v", err)
	}

	// Verify the vault is now unlocked
	if vlt.Locked() {
		t.Errorf("Vault should be unlocked after GetOrDeriveLongTermKey")
	}

	// Second call should return the cached key without re-deriving
	secondKey, err := vlt.GetOrDeriveLongTermKey()
	if err != nil {
		t.Fatalf("Failed to get cached long-term key: %v", err)
	}

	// Verify both keys are the same instance
	if firstKey != secondKey {
		t.Errorf("Second key call should return same instance as first call")
	}

	// Verify the public key matches what we expect
	expectedPubKey := ltIdentity.Recipient().String()

	actualPubKey := firstKey.Recipient().String()
	if actualPubKey != expectedPubKey {
		t.Errorf("Public key mismatch. Expected %s, got %s",
			expectedPubKey, actualPubKey)
	}

	// Now clear the key and verify it's locked again
	vlt.ClearLongTermKey()

	if !vlt.Locked() {
		t.Errorf("Vault should be locked after clearing key")
	}

	// Get the key again and verify it works
	thirdKey, err := vlt.GetOrDeriveLongTermKey()
	if err != nil {
		t.Fatalf("Failed to re-derive long-term key: %v", err)
	}

	// Verify the public key still matches
	actualPubKey = thirdKey.Recipient().String()
	if actualPubKey != expectedPubKey {
		t.Errorf("Re-derived public key mismatch. Expected %s, got %s",
			expectedPubKey, actualPubKey)
	}
}

func testVaultNameValidation(t *testing.T, fs afero.Fs, tempDir string) {
	t.Helper()

	stateDir := filepath.Join(tempDir, "name-validation-test")

	err := os.MkdirAll(stateDir, 0o700)
	if err != nil {
		t.Fatalf("Failed to create state dir: %v", err)
	}

	// Test valid vault names
	validNames := []string{
		"default",
		"test-vault",
		"production.vault",
		"vault_123",
		"a-very-long-vault-name-with-dashes",
	}

	for _, name := range validNames {
		_, err := vault.CreateVault(fs, stateDir, name)
		if err != nil {
			t.Errorf("Failed to create vault with valid name %q: %v", name, err)
		}
	}

	// Test invalid vault names
	invalidNames := []string{
		"",             // Empty
		"UPPERCASE",    // Uppercase not allowed
		"invalid/name", // Slashes not allowed in vault names
		"invalid name", // Spaces not allowed
		"invalid@name", // Special chars not allowed
	}

	for _, name := range invalidNames {
		_, err := vault.CreateVault(fs, stateDir, name)
		if err == nil {
			t.Errorf("Expected error creating vault with invalid name %q, "+
				"but got none", name)
		}
	}
}

func testMultipleVaults(t *testing.T, fs afero.Fs, tempDir string) {
	t.Helper()

	stateDir := filepath.Join(tempDir, "multi-vault-test")

	err := os.MkdirAll(stateDir, 0o700)
	if err != nil {
		t.Fatalf("Failed to create state dir: %v", err)
	}

	// Create three vaults
	vaultNames := []string{"vault1", "vault2", "vault3"}
	for _, name := range vaultNames {
		_, err := vault.CreateVault(fs, stateDir, name)
		if err != nil {
			t.Fatalf("Failed to create vault %s: %v", name, err)
		}
	}

	// List vaults and verify all three are there
	vaults, err := vault.ListVaults(fs, stateDir)
	if err != nil {
		t.Fatalf("Failed to list vaults: %v", err)
	}

	if len(vaults) != 3 {
		t.Errorf("Expected 3 vaults, got %d", len(vaults))
	}

	// Test switching between vaults
	for _, name := range vaultNames {
		// Select the vault
		err := vault.SelectVault(fs, stateDir, name)
		if err != nil {
			t.Fatalf("Failed to select vault %s: %v", name, err)
		}

		// Get current vault and verify it's the one we selected
		currentVault, err := vault.GetCurrentVault(fs, stateDir)
		if err != nil {
			t.Fatalf("Failed to get current vault after selecting %s: %v",
				name, err)
		}

		if currentVault.GetName() != name {
			t.Errorf("Expected current vault to be %s, got %s",
				name, currentVault.GetName())
		}
	}
}

func testVaultIsolation(t *testing.T, fs afero.Fs, tempDir string) {
	t.Helper()

	stateDir := filepath.Join(tempDir, "isolation-test")

	err := os.MkdirAll(stateDir, 0o700)
	if err != nil {
		t.Fatalf("Failed to create state dir: %v", err)
	}

	// Create two vaults - CreateVault now handles public key when mnemonic
	// is in env
	vault1, err := vault.CreateVault(fs, stateDir, "vault1")
	if err != nil {
		t.Fatalf("Failed to create vault1: %v", err)
	}

	vault2, err := vault.CreateVault(fs, stateDir, "vault2")
	if err != nil {
		t.Fatalf("Failed to create vault2: %v", err)
	}

	// Derive long-term keys from mnemonic
	// Note: Both vaults will have different derivation indexes due to
	// GetNextDerivationIndex
	ltIdentity1 := deriveVaultIdentity(t, fs, vault1)
	ltIdentity2 := deriveVaultIdentity(t, fs, vault2)

	// Unlock the vaults with their respective keys
	vault1.Unlock(ltIdentity1)
	vault2.Unlock(ltIdentity2)

	// Add a secret to vault1
	secretValue := []byte("secret in vault1")

	secretBuffer := memguard.NewBufferFromBytes(secretValue)
	defer secretBuffer.Destroy()

	err = vault1.AddSecret(testSecretName, secretBuffer, false)
	if err != nil {
		t.Fatalf("Failed to add secret to vault1: %v", err)
	}

	// Verify the secret exists in vault1
	vault1Secrets, err := vault1.ListSecrets()
	if err != nil {
		t.Fatalf("Failed to list secrets in vault1: %v", err)
	}

	if !slices.Contains(vault1Secrets, testSecretName) {
		t.Errorf("Secret not found in vault1")
	}

	// Verify the secret does NOT exist in vault2
	vault2Secrets, err := vault2.ListSecrets()
	if err != nil {
		t.Fatalf("Failed to list secrets in vault2: %v", err)
	}

	if slices.Contains(vault2Secrets, testSecretName) {
		t.Errorf("Secret from vault1 should not be visible in vault2")
	}
}