package cli

import (
	"errors"
	"fmt"
	"io"
	"log"
	"path/filepath"
	"strings"
	"text/tabwriter"
	"time"

	"filippo.io/age"
	"git.eeqj.de/sneak/secret/internal/secret"
	"git.eeqj.de/sneak/secret/internal/vault"
	"github.com/spf13/afero"
	"github.com/spf13/cobra"
)

const (
	tabWriterPadding = 2
)

// Sentinel errors for version operations
var (
	errVersionNotFound            = errors.New("not found for secret")
	errCannotRemoveCurrentVersion = errors.New("promote another version first")
)

// newVersionCmd returns the version management command
func newVersionCmd() *cobra.Command {
	cli, err := NewCLIInstance()
	if err != nil {
		log.Fatalf("failed to initialize CLI: %v", err)
	}

	return VersionCommands(cli)
}

// VersionCommands returns the version management commands
func VersionCommands(cli *Instance) *cobra.Command {
	versionCmd := &cobra.Command{
		Use:   "version",
		Short: "Manage secret versions",
		Long: "Commands for managing secret versions including listing, " +
			"promoting, and retrieving specific versions",
	}

	// List versions command
	listCmd := &cobra.Command{
		Use:               "list <secret-name>",
		Aliases:           []string{"ls"},
		Short:             "List all versions of a secret",
		Args:              cobra.ExactArgs(1),
		ValidArgsFunction: getSecretNamesCompletionFunc(cli.fs, cli.stateDir),
		RunE: func(cmd *cobra.Command, args []string) error {
			return cli.ListVersions(cmd, args[0])
		},
	}

	// Promote version command
	promoteCmd := &cobra.Command{
		Use:   "promote <secret-name> <version>",
		Short: "Promote a specific version to current",
		Long: "Updates the current symlink to point to the specified " +
			"version without modifying timestamps",
		Args: cobra.ExactArgs(2), //nolint:mnd // secret-name and version args
		ValidArgsFunction: func(
			cmd *cobra.Command, args []string, toComplete string,
		) ([]string, cobra.ShellCompDirective) {
			// Complete secret name for first arg
			if len(args) == 0 {
				return getSecretNamesCompletionFunc(cli.fs, cli.stateDir)(cmd, args, toComplete)
			}
			// Version number completion for the second arg is not implemented
			return nil, cobra.ShellCompDirectiveNoFileComp
		},
		RunE: func(cmd *cobra.Command, args []string) error {
			return cli.PromoteVersion(cmd, args[0], args[1])
		},
	}

	// Remove version command
	removeCmd := &cobra.Command{
		Use:     "remove <secret-name> <version>",
		Aliases: []string{"rm"},
		Short:   "Remove a specific version of a secret",
		Long: "Remove a specific version of a secret. Cannot remove the " +
			"current version.",
		Args: cobra.ExactArgs(2), //nolint:mnd // secret-name and version args
		ValidArgsFunction: func(
			cmd *cobra.Command, args []string, toComplete string,
		) ([]string, cobra.ShellCompDirective) {
			// Complete secret name for first arg
			if len(args) == 0 {
				return getSecretNamesCompletionFunc(cli.fs, cli.stateDir)(cmd, args, toComplete)
			}
			// Version number completion for the second arg is not implemented
			return nil, cobra.ShellCompDirectiveNoFileComp
		},
		RunE: func(cmd *cobra.Command, args []string) error {
			return cli.RemoveVersion(cmd, args[0], args[1])
		},
	}

	versionCmd.AddCommand(listCmd, promoteCmd, removeCmd)

	return versionCmd
}

// ListVersions lists all versions of a secret
func (cli *Instance) ListVersions(cmd *cobra.Command, secretName string) error {
	secret.Debug("ListVersions called", "secret_name", secretName)

	// Get current vault
	vlt, err := vault.GetCurrentVault(cli.fs, cli.stateDir)
	if err != nil {
		secret.Debug("Failed to get current vault", "error", err)

		return err
	}

	vaultDir, err := vlt.GetDirectory()
	if err != nil {
		secret.Debug("Failed to get vault directory", "error", err)

		return err
	}

	// Get the encoded secret name
	encodedName := strings.ReplaceAll(secretName, "/", "%")
	secretDir := filepath.Join(vaultDir, "secrets.d", encodedName)

	// Check if secret exists
	exists, err := afero.DirExists(cli.fs, secretDir)
	if err != nil {
		secret.Debug("Failed to check if secret exists", "error", err)

		return fmt.Errorf("failed to check if secret exists: %w", err)
	}

	if !exists {
		secret.Debug("Secret not found", "secret_name", secretName)

		return fmt.Errorf("secret '%s' %w", secretName, errSecretNotFound)
	}

	// List all versions
	versions, err := secret.ListVersions(cli.fs, secretDir)
	if err != nil {
		secret.Debug("Failed to list versions", "error", err)

		return fmt.Errorf("failed to list versions: %w", err)
	}

	if len(versions) == 0 {
		cmd.Println("No versions found")

		return nil
	}

	// Get current version
	currentVersion, err := secret.GetCurrentVersion(cli.fs, secretDir)
	if err != nil {
		secret.Debug("Failed to get current version", "error", err)

		currentVersion = ""
	}

	// Get long-term key for decrypting metadata
	ltIdentity, err := vlt.GetOrDeriveLongTermKey()
	if err != nil {
		return fmt.Errorf("failed to get long-term key: %w", err)
	}

	// Create table writer
	w := tabwriter.NewWriter(cmd.OutOrStdout(), 0, 0, tabWriterPadding, ' ', 0)
	_, _ = fmt.Fprintln(w, "VERSION\tCREATED\tSTATUS\tNOT_BEFORE\tNOT_AFTER")

	// Load and display each version's metadata
	for _, version := range versions {
		printVersionRow(w, vlt, secretName, version, currentVersion, ltIdentity)
	}

	_ = w.Flush()

	return nil
}

// printVersionRow loads one version's metadata and writes its table row
func printVersionRow(
	w io.Writer, vlt *vault.Vault,
	secretName, version, currentVersion string,
	ltIdentity *age.X25519Identity,
) {
	sv := secret.NewVersion(vlt, secretName, version)

	// Load metadata
	err := sv.LoadMetadata(ltIdentity)
	if err != nil {
		secret.Warn("Failed to load version metadata",
			"version", version, "error", err)
		// Display version with error
		status := "error"
		if version == currentVersion {
			status = "current (error)"
		}

		_, _ = fmt.Fprintf(w, "%s\t%s\t%s\t%s\t%s\n", version, "-", status, "-", "-")

		return
	}

	// Determine status
	status := "expired"
	if version == currentVersion {
		status = "current"
	}

	// Format timestamps
	createdAt := formatVersionTime(sv.Metadata.CreatedAt)
	notBefore := formatVersionTime(sv.Metadata.NotBefore)
	notAfter := formatVersionTime(sv.Metadata.NotAfter)

	_, _ = fmt.Fprintf(w, "%s\t%s\t%s\t%s\t%s\n",
		version, createdAt, status, notBefore, notAfter)
}

// formatVersionTime formats an optional version timestamp, "-" when unset
func formatVersionTime(t *time.Time) string {
	if t == nil {
		return "-"
	}

	return t.Format("2006-01-02 15:04:05")
}

// PromoteVersion promotes a specific version to current
func (cli *Instance) PromoteVersion(
	cmd *cobra.Command, secretName string, version string,
) error {
	// Get current vault
	vlt, err := vault.GetCurrentVault(cli.fs, cli.stateDir)
	if err != nil {
		return err
	}

	vaultDir, err := vlt.GetDirectory()
	if err != nil {
		return err
	}

	// Get the encoded secret name
	encodedName := strings.ReplaceAll(secretName, "/", "%")
	secretDir := filepath.Join(vaultDir, "secrets.d", encodedName)

	// Check if version exists
	versionDir := filepath.Join(secretDir, "versions", version)

	exists, err := afero.DirExists(cli.fs, versionDir)
	if err != nil {
		return fmt.Errorf("failed to check if version exists: %w", err)
	}

	if !exists {
		return fmt.Errorf("version '%s' %w '%s'",
			version, errVersionNotFound, secretName)
	}

	// Update the current symlink using the proper function
	err = secret.SetCurrentVersion(cli.fs, secretDir, version)
	if err != nil {
		return fmt.Errorf("failed to update current version: %w", err)
	}

	cmd.Printf("Promoted version %s to current for secret '%s'\n", version, secretName)

	return nil
}

// RemoveVersion removes a specific version of a secret
func (cli *Instance) RemoveVersion(
	cmd *cobra.Command, secretName string, version string,
) error {
	// Get current vault
	vlt, err := vault.GetCurrentVault(cli.fs, cli.stateDir)
	if err != nil {
		return err
	}

	vaultDir, err := vlt.GetDirectory()
	if err != nil {
		return err
	}

	// Get the encoded secret name
	encodedName := strings.ReplaceAll(secretName, "/", "%")
	secretDir := filepath.Join(vaultDir, "secrets.d", encodedName)

	// Check if secret exists
	exists, err := afero.DirExists(cli.fs, secretDir)
	if err != nil {
		return fmt.Errorf("failed to check if secret exists: %w", err)
	}

	if !exists {
		return fmt.Errorf("secret '%s' %w", secretName, errSecretNotFound)
	}

	// Check if version exists
	versionDir := filepath.Join(secretDir, "versions", version)

	exists, err = afero.DirExists(cli.fs, versionDir)
	if err != nil {
		return fmt.Errorf("failed to check if version exists: %w", err)
	}

	if !exists {
		return fmt.Errorf("version '%s' %w '%s'",
			version, errVersionNotFound, secretName)
	}

	// Get current version
	currentVersion, err := secret.GetCurrentVersion(cli.fs, secretDir)
	if err != nil {
		return fmt.Errorf("failed to get current version: %w", err)
	}

	// Don't allow removing the current version
	if version == currentVersion {
		return fmt.Errorf("cannot remove the current version '%s'; %w",
			version, errCannotRemoveCurrentVersion)
	}

	// Remove the version directory
	err = cli.fs.RemoveAll(versionDir)
	if err != nil {
		return fmt.Errorf("failed to remove version: %w", err)
	}

	cmd.Printf("Removed version %s of secret '%s'\n", version, secretName)

	return nil
}