// Confirmation Tests
//
// `secret rm`, `secret version rm`, `secret vault remove` and
// `secret unlocker remove` ask the user to confirm on a terminal, naming
// what they are about to remove, and remove it only on y or yes. --force
// skips the question. Without --force, a command whose stdin is not a
// terminal fails at once, since nobody is there to answer.
//
// The tests answer through Instance.terminal, which stands in for a
// terminal. Without it, whether stdin is a terminal decides; the tests in
// integration_test.go that run `secret rm` on a pseudo-terminal cover that.

//nolint:testpackage // sets the unexported terminal field of Instance
package cli

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

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

const (
	// confirmTestSecret is the secret the tests remove, or remove a
	// version of, in the vault "work".
	confirmTestSecret = "test/secret"

	// lastUnlockerRemoval names the case that removes the only unlocker.
	lastUnlockerRemoval = "unlocker rm, the last one"
)

// removal is one removal command, set up on its own state directory.
type removal struct {
	fs  afero.Fs
	run func(cli *Instance, cmd *cobra.Command, force bool) error
	// removed is the directory the command removes.
	removed string
	// question is the question the command asks.
	question string
}

// newConfirmTestVaults returns an in-memory state directory with the
// vaults "other" and "work", the current one. "work" holds two versions of
// confirmTestSecret and the given number of PGP unlockers. It returns the
// directory of "work" and the older version.
func newConfirmTestVaults(
	t *testing.T, unlockers int,
) (*afero.MemMapFs, string, string) {
	t.Helper()

	fs := &afero.MemMapFs{}
	mnemonic := testMnemonicBuffer(t)

	_, err := vault.CreateVault(fs, testStateDir, "other", mnemonic)
	require.NoError(t, err)

	vlt, err := vault.CreateVault(fs, testStateDir, "work", mnemonic)
	require.NoError(t, err)

	addTestSecret(t, vlt, []byte("older"), false)
	addTestSecret(t, vlt, []byte("newer"), true)

	vaultDir, err := vlt.GetDirectory()
	require.NoError(t, err)

	versions, err := secret.ListVersions(fs,
		filepath.Join(vaultDir, "secrets.d", "test%secret"))
	require.NoError(t, err)
	require.Len(t, versions, 2)

	for i := range unlockers {
		writePGPUnlocker(t, fs, filepath.Join(vaultDir, "unlockers.d"),
			fmt.Sprintf("pgp-%d", i),
			time.Date(2026, time.October, 4, 12, i, 0, 0, time.UTC),
			listTestGPGKeyID+string(rune('A'+i)))
	}

	// ListVersions lists the newest version first.
	return fs, vaultDir, versions[1]
}

// newRemoval sets up the removal the command names.
func newRemoval(t *testing.T, command string) removal {
	t.Helper()

	unlockers := 2
	if command == lastUnlockerRemoval {
		unlockers = 1
	}

	fs, workDir, older := newConfirmTestVaults(t, unlockers)
	unlockerID := "pgp-" + listTestGPGKeyID + "A"

	removeFirstUnlocker := func(cli *Instance, cmd *cobra.Command, force bool) error {
		return cli.UnlockersRemove(unlockerID, force, cmd)
	}

	switch command {
	case "rm":
		return removal{
			fs: fs,
			run: func(cli *Instance, cmd *cobra.Command, force bool) error {
				return cli.RemoveSecret(cmd, confirmTestSecret, force)
			},
			removed: filepath.Join(workDir, "secrets.d", "test%secret"),
			question: "Permanently remove secret 'test/secret' and its 2 " +
				"version(s) from vault 'work'?",
		}
	case "version rm":
		return removal{
			fs: fs,
			run: func(cli *Instance, cmd *cobra.Command, force bool) error {
				return cli.RemoveVersion(cmd, confirmTestSecret, older, force)
			},
			removed: filepath.Join(
				workDir, "secrets.d", "test%secret", "versions", older),
			question: "Permanently remove version " + older +
				" of secret 'test/secret' from vault 'work'?",
		}
	case "vault rm":
		return removal{
			fs: fs,
			run: func(cli *Instance, cmd *cobra.Command, force bool) error {
				return cli.RemoveVault(cmd, "work", force)
			},
			removed:  workDir,
			question: "Permanently remove vault 'work' and its 1 secret(s)?",
		}
	case "unlocker rm":
		return removal{
			fs:      fs,
			run:     removeFirstUnlocker,
			removed: filepath.Join(workDir, "unlockers.d", "pgp-0"),
			question: "Permanently remove unlocker '" + unlockerID +
				"' from vault 'work'? It is not the vault's last unlocker.",
		}
	case lastUnlockerRemoval:
		return removal{
			fs:      fs,
			run:     removeFirstUnlocker,
			removed: filepath.Join(workDir, "unlockers.d", "pgp-0"),
			question: "Permanently remove unlocker '" + unlockerID +
				"', the last unlocker of vault 'work', which holds 1 " +
				"secret(s)? Without an unlocker the vault opens only " +
				"with its mnemonic.",
		}
	}

	t.Fatalf("no removal %q", command)

	return removal{}
}

// removalCommands lists the commands newRemoval sets up.
func removalCommands() []string {
	return []string{
		"rm", "version rm", "vault rm", "unlocker rm", lastUnlockerRemoval,
	}
}

// newConfirmTestCommand returns a command whose output is discarded and
// whose stderr, where the question goes, is the returned buffer.
func newConfirmTestCommand() (*cobra.Command, *bytes.Buffer) {
	var stderr bytes.Buffer

	cmd := &cobra.Command{}
	cmd.SetOut(io.Discard)
	cmd.SetErr(&stderr)

	return cmd, &stderr
}

// requireExists asserts whether the directory dir exists.
func requireExists(t *testing.T, fs afero.Fs, dir string, want bool) {
	t.Helper()

	exists, err := afero.DirExists(fs, dir)
	require.NoError(t, err)
	require.Equal(t, want, exists, dir)
}

// TestConfirmAnswers checks which answers confirm accepts: y or yes, in
// any case, around which spaces do not matter.
func TestConfirmAnswers(t *testing.T) {
	t.Parallel()

	for answer, want := range map[string]error{
		"y\n":       nil,
		"Y\n":       nil,
		"yes\n":     nil,
		"  YES  \n": nil,
		"y":         nil,
		"\n":        errNotConfirmed,
		"":          errNotConfirmed,
		"n\n":       errNotConfirmed,
		"yy\n":      errNotConfirmed,
		"no\ny\n":   errNotConfirmed,
	} {
		t.Run(fmt.Sprintf("%q", answer), func(t *testing.T) {
			t.Parallel()

			cli := &Instance{terminal: strings.NewReader(answer)}
			cmd, stderr := newConfirmTestCommand()

			err := cli.confirm(cmd, "Remove it?")

			require.ErrorIs(t, err, want)
			assert.Equal(t, "Remove it? [y/N] ", stderr.String())
		})
	}
}

// TestRemovalAnsweredYesRemoves checks that each removal asks its question
// and removes what it names when the user answers y.
func TestRemovalAnsweredYesRemoves(t *testing.T) {
	t.Parallel()

	for _, command := range removalCommands() {
		t.Run(command, func(t *testing.T) {
			t.Parallel()

			r := newRemoval(t, command)
			requireExists(t, r.fs, r.removed, true)

			cli := NewCLIInstanceWithStateDir(r.fs, testStateDir)
			cli.terminal = strings.NewReader("y\n")
			cmd, stderr := newConfirmTestCommand()

			require.NoError(t, r.run(cli, cmd, false))

			assert.Equal(t, r.question+" [y/N] ", stderr.String())
			requireExists(t, r.fs, r.removed, false)
		})
	}
}

// TestRemovalDeclinedLeavesEverything checks that each removal changes
// nothing when the user answers anything but y or yes, a bare Enter
// included.
func TestRemovalDeclinedLeavesEverything(t *testing.T) {
	t.Parallel()

	for _, command := range removalCommands() {
		for _, answer := range []string{"\n", "n\n", ""} {
			t.Run(fmt.Sprintf("%s %q", command, answer), func(t *testing.T) {
				t.Parallel()

				r := newRemoval(t, command)
				before := stateDirModTimes(t, r.fs)

				cli := NewCLIInstanceWithStateDir(r.fs, testStateDir)
				cli.terminal = strings.NewReader(answer)
				cmd, stderr := newConfirmTestCommand()

				err := r.run(cli, cmd, false)

				require.ErrorIs(t, err, errNotConfirmed)
				assert.Equal(t, r.question+" [y/N] ", stderr.String())
				assert.Equal(t, before, stateDirModTimes(t, r.fs))
			})
		}
	}
}

// TestRemovalForcedAsksNothing checks that each removal with --force
// removes what it would have named without asking, and without reading
// its input, which is not a terminal.
func TestRemovalForcedAsksNothing(t *testing.T) {
	t.Parallel()

	for _, command := range removalCommands() {
		t.Run(command, func(t *testing.T) {
			t.Parallel()

			r := newRemoval(t, command)

			input := strings.NewReader("n\n")
			cli := NewCLIInstanceWithStateDir(r.fs, testStateDir)
			cmd, stderr := newConfirmTestCommand()
			cmd.SetIn(input)

			require.NoError(t, r.run(cli, cmd, true))

			assert.Empty(t, stderr.String(), "asked with --force")
			assert.Equal(t, 2, input.Len(), "read its input with --force")
			requireExists(t, r.fs, r.removed, false)
		})
	}
}

// TestRemovalWithoutTerminalFailsAtOnce checks that each removal without
// --force, whose input is not a terminal, fails at once telling the user
// to pass --force, and changes nothing. The input is a pipe that nobody
// writes to or closes, so reading it would block for good.
func TestRemovalWithoutTerminalFailsAtOnce(t *testing.T) {
	t.Parallel()

	for _, command := range removalCommands() {
		t.Run(command, func(t *testing.T) {
			t.Parallel()

			r := newRemoval(t, command)
			before := stateDirModTimes(t, r.fs)

			input, inputWriter, err := os.Pipe()
			require.NoError(t, err)

			t.Cleanup(func() {
				_ = inputWriter.Close()
				_ = input.Close()
			})

			cli := NewCLIInstanceWithStateDir(r.fs, testStateDir)
			cmd, stderr := newConfirmTestCommand()
			cmd.SetIn(input)

			done := make(chan error, 1)

			go func() { done <- r.run(cli, cmd, false) }()

			select {
			case err := <-done:
				require.ErrorIs(t, err, errNoTerminal)
				assert.Contains(t, err.Error(), "pass --force")
			case <-time.After(lockWait):
				// Closing the pipe ends the read, and frees the lock if
				// the command holds it.
				_ = inputWriter.Close()

				t.Fatal("waited for an answer on input that is not a terminal")
			}

			assert.Empty(t, stderr.String(), "asked without a terminal")
			assert.Equal(t, before, stateDirModTimes(t, r.fs))
		})
	}
}

// TestRemovalAsksWithoutHoldingLock checks that while `secret rm` waits
// for its answer, another command can take the state directory lock and
// change the secret, and that the removal then removes nothing, since the
// secret is no longer what the question named.
func TestRemovalAsksWithoutHoldingLock(t *testing.T) {
	t.Parallel()

	r := newRemoval(t, "rm")

	answers, answerWriter := io.Pipe()
	questions, questionWriter := io.Pipe()

	// Closing the answers ends the read if the test fails while the
	// command waits for one.
	t.Cleanup(func() { _ = answerWriter.Close() })

	rm := NewCLIInstanceWithStateDir(r.fs, testStateDir)
	rm.terminal = answers
	cmd := &cobra.Command{}
	cmd.SetOut(io.Discard)
	cmd.SetErr(questionWriter)

	done := make(chan error, 1)

	go func() { done <- r.run(rm, cmd, false) }()

	question, err := bufio.NewReader(questions).ReadString(']')
	require.NoError(t, err)
	require.Equal(t, r.question+" [y/N]", question)

	// Adds a third version while rm waits for its answer.
	add := NewCLIInstanceWithStateDir(r.fs, testStateDir)
	add.Mnemonic = testMnemonicBuffer(t)
	add.cmd = &cobra.Command{}
	add.cmd.SetIn(strings.NewReader("newest"))
	add.cmd.SetOut(io.Discard)

	added := make(chan error, 1)

	go func() { added <- add.AddSecret(confirmTestSecret, true) }()

	select {
	case err := <-added:
		require.NoError(t, err)
	case <-time.After(lockWait):
		t.Fatal("secret add waited for the lock while secret rm asked")
	}

	_, err = answerWriter.Write([]byte("y\n"))
	require.NoError(t, err)

	select {
	case err := <-done:
		require.ErrorIs(t, err, errChangedWhileAsking)
	case <-time.After(lockWait):
		t.Fatal("secret rm did not finish once answered")
	}

	requireExists(t, r.fs, r.removed, true)
}