// Unlocker List Tests
//
// Tests for `secret unlocker list` behavior when the unlockers.d directory,
// or an unlocker's metadata in it, cannot be read while the listing is
// being rendered:
//
//   - TestUnlockersListSkipsUnreadableUnlockersDir: an unreadable
//     unlockers.d yields no rows rather than rows bearing synthesized IDs.
//   - TestUnlockersListSkipsOnlyUnreadableEntries: a readable entry is
//     still listed, with its real ID and its current-unlocker marker,
//     when a later entry's scan fails.
//   - TestUnlockersListToleratesCorruptMetadata: one unlocker's corrupt
//     metadata does not stop the others from being listed.
//   - TestUnlockersListSkipsUnreadableMetadata: an unlocker whose metadata
//     file cannot be read is left out, and the other is still listed.
//
// The listing resolves each unlocker's real ID by rescanning unlockers.d
// after the vault has already enumerated it. If that rescan fails the ID
// is unknowable, so the entry must be skipped: a synthesized ID matches
// no `unlocker remove` or `unlocker select` argument and would also
// suppress the current-unlocker marker.

//nolint:testpackage // white-box test of unexported internals
package cli

import (
	"bytes"
	"encoding/json"
	"errors"
	"path/filepath"
	"testing"
	"time"

	"git.eeqj.de/sneak/secret/internal/secret"
	"github.com/spf13/afero"
	"github.com/spf13/cobra"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

const (
	// listTestStateDir is the state directory of the synthetic vault used
	// by the unlocker listing tests.
	listTestStateDir = "/state"

	// listTestVaultName is the name of that synthetic vault.
	listTestVaultName = "default"

	// listTestGPGKeyID is the GPG key ID recorded in the readable PGP
	// unlocker's metadata. The unlocker's real ID is derived from it, and
	// differs from the timestamp-derived fallback ID.
	listTestGPGKeyID = "DEADBEEFDEADBEEF"

	// listTestUnlockerDirOne and listTestUnlockerDirTwo are the unlocker
	// directory names under unlockers.d.
	listTestUnlockerDirOne = "host-pgp-2026-08-09"
	listTestUnlockerDirTwo = "host-pgp-2026-08-10"

	// listTestUnlockersDirName is the directory the listing rescans to
	// resolve unlocker IDs.
	listTestUnlockersDirName = "unlockers.d"

	// listTestMetadataFileName is the per-unlocker metadata file name.
	listTestMetadataFileName = "unlocker-metadata.json"

	// listTestDirPerm and listTestFilePerm are the fixture permissions.
	listTestDirPerm  = 0o700
	listTestFilePerm = 0o600
)

// errUnlockersDirUnreadable is returned by the test filesystem in place of
// a successful open of unlockers.d.
var errUnlockersDirUnreadable = errors.New("permission denied")

// unlockersDirFailFs makes unlockers.d unreadable once it has been opened
// successfully openBudget times. This reproduces the directory becoming
// unreadable (permission change, partially restored backup, EIO) between
// the vault's own enumeration and the per-entry rescan that resolves
// unlocker IDs.
type unlockersDirFailFs struct {
	afero.Fs

	openBudget int
	opens      int
}

//nolint:ireturn // afero.File is the interface required by afero.Fs
func (f *unlockersDirFailFs) Open(name string) (afero.File, error) {
	if filepath.Base(name) == listTestUnlockersDirName {
		f.opens++
		if f.opens > f.openBudget {
			return nil, errUnlockersDirUnreadable
		}
	}

	//nolint:wrapcheck // test double must return the wrapped Fs error as-is
	return f.Fs.Open(name)
}

// errMetadataUnreadable is returned by the test filesystem in place of a
// successful open of one unlocker's metadata file.
var errMetadataUnreadable = errors.New("input/output error")

// metadataReadFailFs fails every open of the file at unreadablePath. The
// file still exists, so checking for it succeeds and only reading it fails.
type metadataReadFailFs struct {
	afero.Fs

	unreadablePath string
}

//nolint:ireturn // afero.File is the interface required by afero.Fs
func (f *metadataReadFailFs) Open(name string) (afero.File, error) {
	if name == f.unreadablePath {
		return nil, errMetadataUnreadable
	}

	//nolint:wrapcheck // test double must return the wrapped Fs error as-is
	return f.Fs.Open(name)
}

// writePGPUnlocker writes a PGP unlocker directory with metadata that
// yields the real ID "pgp-<keyID>".
func writePGPUnlocker(
	t *testing.T, fs afero.Fs, unlockersDir, dirName string,
	createdAt time.Time, keyID string,
) {
	t.Helper()

	metadata := secret.PGPUnlockerMetadata{
		UnlockerMetadata: secret.UnlockerMetadata{
			Type:      unlockerTypePGP,
			CreatedAt: createdAt,
		},
		GPGKeyID: keyID,
	}

	encoded, err := json.Marshal(metadata)
	require.NoError(t, err)

	dir := filepath.Join(unlockersDir, dirName)
	require.NoError(t, fs.MkdirAll(dir, listTestDirPerm))
	require.NoError(t, afero.WriteFile(
		fs, filepath.Join(dir, listTestMetadataFileName), encoded,
		listTestFilePerm,
	))
}

// newListTestVault builds a synthetic vault on a MemMapFs containing the
// given number of PGP unlockers, with the first one selected as current.
func newListTestVault(t *testing.T, unlockerCount int) *afero.MemMapFs {
	t.Helper()

	base := &afero.MemMapFs{}
	vaultDir := filepath.Join(listTestStateDir, "vaults.d", listTestVaultName)
	unlockersDir := filepath.Join(vaultDir, listTestUnlockersDirName)

	require.NoError(t, afero.WriteFile(
		base, filepath.Join(listTestStateDir, "currentvault"),
		[]byte(listTestVaultName), listTestFilePerm,
	))

	names := []string{listTestUnlockerDirOne, listTestUnlockerDirTwo}
	names = names[:unlockerCount]

	for i, name := range names {
		writePGPUnlocker(t, base, unlockersDir, name,
			time.Date(2026, time.August, 9+i, 12, 30, 0, 0, time.UTC),
			listTestGPGKeyID+string(rune('A'+i)),
		)
	}

	require.NoError(t, afero.WriteFile(
		base, filepath.Join(vaultDir, "current-unlocker"),
		[]byte(names[0]), listTestFilePerm,
	))

	return base
}

// listUnlockersJSON runs UnlockersList in JSON mode against the given
// filesystem and decodes the emitted unlocker rows.
func listUnlockersJSON(t *testing.T, fs afero.Fs) []UnlockerInfo {
	t.Helper()

	var buf bytes.Buffer

	cmd := &cobra.Command{}
	cmd.SetOut(&buf)
	cmd.SetErr(&buf)

	instance := &Instance{fs: fs, stateDir: listTestStateDir, cmd: cmd}
	require.NoError(t, instance.UnlockersList(true))

	var decoded struct {
		Unlockers []UnlockerInfo `json:"unlockers"`
	}

	require.NoError(t, json.Unmarshal(buf.Bytes(), &decoded))

	return decoded.Unlockers
}

// TestUnlockersListSkipsUnreadableUnlockersDir asserts that an unlockers.d
// which becomes unreadable after the vault enumerated it produces no rows,
// rather than rows carrying fabricated fallback IDs.
func TestUnlockersListSkipsUnreadableUnlockersDir(t *testing.T) {
	t.Parallel()

	base := newListTestVault(t, 1)
	// Budget of one: the vault's own ListUnlockers scan succeeds, the
	// per-entry rescan that resolves the ID fails.
	fs := &unlockersDirFailFs{Fs: base, openBudget: 1}

	unlockers := listUnlockersJSON(t, fs)

	assert.Empty(t, unlockers,
		"an unreadable unlockers.d must yield no rows, not fabricated IDs")
}

// TestUnlockersListSkipsOnlyUnreadableEntries asserts that a readable
// entry survives with its real ID and current-unlocker marker when a later
// entry's rescan fails.
func TestUnlockersListSkipsOnlyUnreadableEntries(t *testing.T) {
	t.Parallel()

	base := newListTestVault(t, 2)
	// Budget of two: ListUnlockers plus the first entry's rescan succeed,
	// the second entry's rescan fails.
	fs := &unlockersDirFailFs{Fs: base, openBudget: 2}

	unlockers := listUnlockersJSON(t, fs)

	require.Len(t, unlockers, 1,
		"only the entry whose directory was readable may be listed")
	assert.Equal(t, "pgp-"+listTestGPGKeyID+"A", unlockers[0].ID,
		"the surviving row must carry the real unlocker ID")
	assert.True(t, unlockers[0].IsCurrent,
		"the current-unlocker marker must survive the skip")
}

// TestUnlockersListReadableEntriesAreListed is the control case: with a
// fully readable unlockers.d every entry is listed with its real ID.
func TestUnlockersListReadableEntriesAreListed(t *testing.T) {
	t.Parallel()

	base := newListTestVault(t, 2)

	unlockers := listUnlockersJSON(t, base)

	require.Len(t, unlockers, 2)
	assert.Equal(t, "pgp-"+listTestGPGKeyID+"A", unlockers[0].ID)
	assert.Equal(t, "pgp-"+listTestGPGKeyID+"B", unlockers[1].ID)
	assert.True(t, unlockers[0].IsCurrent)
	assert.False(t, unlockers[1].IsCurrent)
}

// TestUnlockersListToleratesCorruptMetadata asserts that one unlocker with
// corrupt metadata does not stop the listing. Metadata that is not JSON
// leaves that unlocker out; PGP metadata without a usable GPG key ID lists
// it as "pgp-unknown". The healthy unlocker is listed with its real ID.
func TestUnlockersListToleratesCorruptMetadata(t *testing.T) {
	t.Parallel()

	healthyID := "pgp-" + listTestGPGKeyID + "A"

	tests := []struct {
		name     string
		metadata string
		wantIDs  []string
	}{
		{
			name:     "not JSON",
			metadata: "not json",
			wantIDs:  []string{healthyID},
		},
		{
			name:     "GPG key ID of the wrong type",
			metadata: `{"type": "pgp", "gpgKeyId": 42}`,
			wantIDs:  []string{healthyID, "pgp-unknown"},
		},
		{
			name:     "GPG key ID missing",
			metadata: `{"type": "pgp"}`,
			wantIDs:  []string{healthyID, "pgp-unknown"},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()

			fs := newListTestVault(t, 2)
			metadataPath := filepath.Join(listTestStateDir, "vaults.d",
				listTestVaultName, listTestUnlockersDirName,
				listTestUnlockerDirTwo, listTestMetadataFileName)
			require.NoError(t, afero.WriteFile(
				fs, metadataPath, []byte(tt.metadata), listTestFilePerm,
			))

			unlockers := listUnlockersJSON(t, fs)
			require.Len(t, unlockers, len(tt.wantIDs))

			for i, wantID := range tt.wantIDs {
				assert.Equal(t, wantID, unlockers[i].ID)
			}
		})
	}
}

// TestUnlockersListSkipsUnreadableMetadata asserts that an unlocker whose
// metadata file exists but cannot be read is left out of the listing, and
// the other unlocker is still listed with its real ID. The unreadable one
// sorts first, so finding the other's ID has to step past it as well.
func TestUnlockersListSkipsUnreadableMetadata(t *testing.T) {
	t.Parallel()

	base := newListTestVault(t, 2)
	fs := &metadataReadFailFs{
		Fs: base,
		unreadablePath: filepath.Join(listTestStateDir, "vaults.d",
			listTestVaultName, listTestUnlockersDirName,
			listTestUnlockerDirOne, listTestMetadataFileName),
	}

	unlockers := listUnlockersJSON(t, fs)

	require.Len(t, unlockers, 1,
		"only the unlocker with readable metadata may be listed")
	assert.Equal(t, "pgp-"+listTestGPGKeyID+"B", unlockers[0].ID,
		"the listed row must carry the real unlocker ID")
}