package cli_test

import (
	"fmt"
	"maps"
	"os"
	"slices"
	"strings"
	"sync"
	"testing"

	"git.eeqj.de/sneak/secret/internal/cli"
	"git.eeqj.de/sneak/secret/internal/secret"
	"git.eeqj.de/sneak/secret/internal/vault"
	"github.com/awnumar/memguard"
	"github.com/spf13/afero"
	"github.com/spf13/cobra"
	"github.com/stretchr/testify/require"
)

const (
	// testStateDir is the in-memory state directory of the test vaults.
	testStateDir = "/test/state"

	// testPassphrase protects the passphrase unlocker of each test vault.
	testPassphrase = "test-passphrase"

	// testVersion is a version name in the format the vault uses.
	testVersion = "20260101.001"

	// missingFile is an import source that does not exist, so an import
	// that opened it before checking the name would fail with another error.
	missingFile = "/no/such/file"
)

// testMnemonicBuffer returns testMnemonic in a locked buffer that is
// destroyed when the test ends.
func testMnemonicBuffer(t *testing.T) *memguard.LockedBuffer {
	t.Helper()

	mnemonic := memguard.NewBufferFromBytes([]byte(testMnemonic))
	t.Cleanup(mnemonic.Destroy)

	return mnemonic
}

// The state directory newTwoVaultFs copies, recorded by snapshotStateDir.
// Creating a passphrase unlocker is slow by design, so the vaults are made
// once, by the first test that needs them.
//
//nolint:gochecknoglobals // shared by the tests that use newTwoVaultFs
var (
	twoVaultsOnce sync.Once
	twoVaults     map[string]string
)

// newTwoVaultFs returns an in-memory filesystem holding the vaults "work"
// and "default", the current one. Each holds the secret "x" and a
// passphrase unlocker, so both secrets.d and unlockers.d have contents.
// Every call returns a new copy of the same vaults.
//
//nolint:ireturn // afero.Fs is the filesystem abstraction used throughout
func newTwoVaultFs(t *testing.T) afero.Fs {
	t.Helper()

	twoVaultsOnce.Do(func() {
		fs := afero.NewMemMapFs()
		mnemonic := testMnemonicBuffer(t)

		for _, name := range []string{"work", "default"} {
			vlt, err := vault.CreateVault(fs, testStateDir, name, mnemonic)
			require.NoError(t, err)

			err = vlt.AddSecret("x", memguard.NewBufferFromBytes([]byte("value")), false)
			require.NoError(t, err)

			_, err = vlt.CreatePassphraseUnlocker(
				memguard.NewBufferFromBytes([]byte(testPassphrase)))
			require.NoError(t, err)
		}

		twoVaults = snapshotStateDir(t, fs)
	})

	require.NotNil(t, twoVaults, "making the vaults failed in an earlier test")

	return newFsFromSnapshot(t, twoVaults)
}

// snapshotStateDir maps every file under the state directory to its
// contents, and every directory, written with a trailing "/", to "". Two
// snapshots are equal only if nothing in it was added, removed or changed.
func snapshotStateDir(t *testing.T, fs afero.Fs) map[string]string {
	t.Helper()

	tree := map[string]string{}

	err := afero.Walk(fs, testStateDir, func(
		path string, info os.FileInfo, err error,
	) error {
		if err != nil {
			return err
		}

		if info.IsDir() {
			tree[path+"/"] = ""

			return nil
		}

		content, err := afero.ReadFile(fs, path)
		if err != nil {
			return err
		}

		tree[path] = string(content)

		return nil
	})
	require.NoError(t, err)

	return tree
}

// newFsFromSnapshot returns a new in-memory filesystem holding exactly the
// directories and files recorded by snapshotStateDir.
//
//nolint:ireturn // afero.Fs is the filesystem abstraction used throughout
func newFsFromSnapshot(t *testing.T, tree map[string]string) afero.Fs {
	t.Helper()

	fs := afero.NewMemMapFs()

	// In sorted order every directory comes before its contents.
	for _, path := range slices.Sorted(maps.Keys(tree)) {
		dir, isDir := strings.CutSuffix(path, "/")
		if isDir {
			require.NoError(t, fs.MkdirAll(dir, secret.DirPerms))

			continue
		}

		err := afero.WriteFile(fs, path, []byte(tree[path]), secret.FilePerms)
		require.NoError(t, err)
	}

	return fs
}

// requireRejectedAndUnchanged runs a command on a copy of the state
// directory recorded in before. It requires an error with exactly the
// message of want, so that a later check rejecting the argument does not
// count, and everything under the state directory as it was: the error
// alone proves nothing, since it could come after the vault had already
// been deleted.
func requireRejectedAndUnchanged(
	t *testing.T, before map[string]string, want error,
	run func(c *cli.Instance) error,
) {
	t.Helper()

	fs := newFsFromSnapshot(t, before)

	err := run(cli.NewCLIInstanceWithStateDir(fs, testStateDir))

	require.Equal(t, before, snapshotStateDir(t, fs))
	require.EqualError(t, err, want.Error())
}

// TestInvalidSecretNameLeavesVaultsUnchanged is a regression test for
// https://git.eeqj.de/sneak/secret/issues/33, where `secret rm ..` deleted
// the whole vault, and `secret rm .` or `secret rm ""` every secret in it.
// Moves and imports use --force, so that only the name check stands in
// the way.
//
//nolint:paralleltest // the cases share cmd
func TestInvalidSecretNameLeavesVaultsUnchanged(t *testing.T) {
	// Creating a passphrase unlocker is slow by design, so the vaults are
	// created once and each case runs on its own copy of them.
	before := snapshotStateDir(t, newTwoVaultFs(t))

	vaultDir := testStateDir + "/vaults.d/default"
	require.Contains(t, before, vaultDir+"/secrets.d/x/")
	require.Contains(t, before, vaultDir+"/unlockers.d/passphrase/")
	require.Equal(t, "default", before[testStateDir+"/currentvault"])

	cmd := &cobra.Command{}

	tests := []struct {
		command  string
		rejected string // the secret name the command must reject
		run      func(c *cli.Instance) error
	}{
		{"rm ..", "..", func(c *cli.Instance) error {
			return c.RemoveSecret(cmd, "..", false)
		}},
		{"rm .", ".", func(c *cli.Instance) error {
			return c.RemoveSecret(cmd, ".", false)
		}},
		{`rm ""`, "", func(c *cli.Instance) error {
			return c.RemoveSecret(cmd, "", false)
		}},
		{"rm ../../etc", "../../etc", func(c *cli.Instance) error {
			return c.RemoveSecret(cmd, "../../etc", false)
		}},
		{"mv --force .. x", "..", func(c *cli.Instance) error {
			return c.MoveSecret(cmd, "..", "x", true)
		}},
		{"mv --force x ..", "..", func(c *cli.Instance) error {
			return c.MoveSecret(cmd, "x", "..", true)
		}},
		{`mv --force x ""`, "", func(c *cli.Instance) error {
			return c.MoveSecret(cmd, "x", "", true)
		}},
		// "work" is not the current vault: a move within it must not
		// select it when a name is rejected.
		{"mv --force work:.. work:x", "..", func(c *cli.Instance) error {
			return c.MoveSecret(cmd, "work:..", "work:x", true)
		}},
		{"mv --force work:x work:..", "..", func(c *cli.Instance) error {
			return c.MoveSecret(cmd, "work:x", "work:..", true)
		}},
		{"mv --force default:.. work", "..", func(c *cli.Instance) error {
			return c.MoveSecret(cmd, "default:..", "work", true)
		}},
		{"mv --force default:.. work:y", "..", func(c *cli.Instance) error {
			return c.MoveSecret(cmd, "default:..", "work:y", true)
		}},
		{"mv --force default:x work:..", "..", func(c *cli.Instance) error {
			return c.MoveSecret(cmd, "default:x", "work:..", true)
		}},
		{"import --force ..", "..", func(c *cli.Instance) error {
			return c.ImportSecret(cmd, "..", missingFile, true)
		}},
		{"import --force .", ".", func(c *cli.Instance) error {
			return c.ImportSecret(cmd, ".", missingFile, true)
		}},
		{"import --force ../../etc", "../../etc", func(c *cli.Instance) error {
			return c.ImportSecret(cmd, "../../etc", missingFile, true)
		}},
		{"version list ..", "..", func(c *cli.Instance) error {
			return c.ListVersions(cmd, "..")
		}},
		{"version promote ..", "..", func(c *cli.Instance) error {
			return c.PromoteVersion(cmd, "..", testVersion)
		}},
		{"version rm ..", "..", func(c *cli.Instance) error {
			return c.RemoveVersion(cmd, "..", testVersion)
		}},
		{"encrypt ..", "..", func(c *cli.Instance) error {
			return c.Encrypt("..", "", "")
		}},
		{"decrypt ..", "..", func(c *cli.Instance) error {
			return c.Decrypt("..", "", "")
		}},
	}

	for _, tt := range tests {
		t.Run(tt.command, func(t *testing.T) {
			requireRejectedAndUnchanged(t, before, vault.ValidateSecretName(tt.rejected), tt.run)
		})
	}
}

// TestInvalidVersionLeavesVaultsUnchanged is a regression test for
// https://git.eeqj.de/sneak/secret/issues/67, where
// `secret version rm x ../../..` deleted the whole vault,
// `secret version rm x ..` the secret x, and `secret version rm x .` or
// `secret version rm x ""` every version of x. A version argument is
// accepted only if it is one of the versions `secret version list` lists.
//
//nolint:paralleltest // the cases share cmd
func TestInvalidVersionLeavesVaultsUnchanged(t *testing.T) {
	before := snapshotStateDir(t, newTwoVaultFs(t))

	cmd := &cobra.Command{}

	commands := []struct {
		command string
		run     func(c *cli.Instance, version string) error
	}{
		{"version rm x", func(c *cli.Instance, version string) error {
			return c.RemoveVersion(cmd, "x", version)
		}},
		{"version promote x", func(c *cli.Instance, version string) error {
			return c.PromoteVersion(cmd, "x", version)
		}},
		{"get x --version", func(c *cli.Instance, version string) error {
			return c.GetSecretWithVersion(cmd, "x", version)
		}},
	}

	for _, tt := range commands {
		for _, version := range []string{"", ".", "..", "../../..", "a/b"} {
			t.Run(fmt.Sprintf("%s %q", tt.command, version), func(t *testing.T) {
				want := fmt.Errorf("version '%s' %w '%s'",
					version, vault.ErrVersionNotFound, "x")
				requireRejectedAndUnchanged(t, before, want,
					func(c *cli.Instance) error { return tt.run(c, version) })
			})
		}
	}
}

// TestInvalidVaultNameLeavesStateUnchanged is a regression test for
// https://git.eeqj.de/sneak/secret/issues/68, where
// `secret vault import ..` wrote a long-term key and an unlocker into the
// state directory itself, and `secret vault select ..` made it the current
// vault. Each command that takes a vault name must reject an invalid one
// before building a path from it. The instance is given the mnemonic and
// the passphrase, and moves and removals use --force, so that only the name
// check stands in the way.
//
//nolint:paralleltest // the cases share cmd
func TestInvalidVaultNameLeavesStateUnchanged(t *testing.T) {
	before := snapshotStateDir(t, newTwoVaultFs(t))

	mnemonic := testMnemonicBuffer(t)
	passphrase := memguard.NewBufferFromBytes([]byte(testPassphrase))
	t.Cleanup(passphrase.Destroy)

	cmd := &cobra.Command{}

	// Each command is a format with %q where the vault name goes.
	commands := []struct {
		command string
		run     func(c *cli.Instance, name string) error
	}{
		{"vault create %q", func(c *cli.Instance, name string) error {
			return c.CreateVault(cmd, name)
		}},
		{"vault import %q", func(c *cli.Instance, name string) error {
			return c.VaultImport(cmd, name)
		}},
		{"vault select %q", func(c *cli.Instance, name string) error {
			return c.SelectVault(cmd, name)
		}},
		{"vault remove --force %q", func(c *cli.Instance, name string) error {
			return c.RemoveVault(cmd, name, true)
		}},
		{"mv --force %q:x work:x", func(c *cli.Instance, name string) error {
			return c.MoveSecret(cmd, name+":x", "work:x", true)
		}},
		{"mv --force default:x %q:x", func(c *cli.Instance, name string) error {
			return c.MoveSecret(cmd, "default:x", name+":x", true)
		}},
	}

	for _, tt := range commands {
		for _, name := range []string{"", ".", "..", "a/b"} {
			t.Run(fmt.Sprintf(tt.command, name), func(t *testing.T) {
				requireRejectedAndUnchanged(t, before, vault.ValidateVaultName(name),
					func(c *cli.Instance) error {
						c.Mnemonic = mnemonic
						c.UnlockPassphrase = passphrase

						return tt.run(c, name)
					})
			})
		}
	}
}

// TestRemoveVersionRemovesOnlyThatVersion checks that `secret version rm`
// with a version that is not the current one removes that version and
// changes nothing else.
func TestRemoveVersionRemovesOnlyThatVersion(t *testing.T) {
	t.Parallel()

	fs := newTwoVaultFs(t)

	vlt, err := vault.GetCurrentVault(fs, testStateDir)
	require.NoError(t, err)

	vlt.Mnemonic = testMnemonicBuffer(t)

	// A second version of "x" becomes the current one.
	err = vlt.AddSecret("x", memguard.NewBufferFromBytes([]byte("new")), true)
	require.NoError(t, err)

	secretDir := testStateDir + "/vaults.d/default/secrets.d/x"
	versions, err := secret.ListVersions(fs, secretDir)
	require.NoError(t, err)
	require.Len(t, versions, 2)

	// ListVersions lists the newest version first.
	oldDir := secretDir + "/versions/" + versions[1] + "/"
	before := snapshotStateDir(t, fs)
	require.Contains(t, before, oldDir)

	c := cli.NewCLIInstanceWithStateDir(fs, testStateDir)
	err = c.RemoveVersion(&cobra.Command{}, "x", versions[1])
	require.NoError(t, err)

	// Expected: the state as before without everything under oldDir.
	want := map[string]string{}

	for path, content := range before {
		if !strings.HasPrefix(path, oldDir) {
			want[path] = content
		}
	}

	require.Equal(t, want, snapshotStateDir(t, fs))
}

// TestMoveToVaultNameRenamesInCurrentVault checks that `secret mv x work`,
// where "work" is also the name of a vault, renames the secret "x" to "work"
// in the current vault and changes nothing else.
func TestMoveToVaultNameRenamesInCurrentVault(t *testing.T) {
	t.Parallel()

	before := snapshotStateDir(t, newTwoVaultFs(t))
	fs := newFsFromSnapshot(t, before)

	c := cli.NewCLIInstanceWithStateDir(fs, testStateDir)
	err := c.MoveSecret(&cobra.Command{}, "x", "work", false)
	require.NoError(t, err)

	// Expected: the state as before, with everything under the current
	// vault's secrets.d/x/ now under secrets.d/work/.
	oldDir := testStateDir + "/vaults.d/default/secrets.d/x/"
	newDir := testStateDir + "/vaults.d/default/secrets.d/work/"
	want := map[string]string{}

	for path, content := range before {
		rest, found := strings.CutPrefix(path, oldDir)
		if found {
			path = newDir + rest
		}

		want[path] = content
	}

	require.Contains(t, want, newDir)
	require.Equal(t, want, snapshotStateDir(t, fs))
}