vaultik/internal/cli/app.go

package cli

import (
	"context"
	"errors"
	"fmt"
	"io"
	"os"
	"os/signal"
	"path/filepath"
	"strings"
	"syscall"
	"time"

	"github.com/adrg/xdg"
	"go.uber.org/fx"
	"sneak.berlin/go/vaultik/internal/config"
	"sneak.berlin/go/vaultik/internal/database"
	"sneak.berlin/go/vaultik/internal/globals"
	"sneak.berlin/go/vaultik/internal/log"
	"sneak.berlin/go/vaultik/internal/pidlock"
	"sneak.berlin/go/vaultik/internal/snapshot"
	"sneak.berlin/go/vaultik/internal/storage"
	"sneak.berlin/go/vaultik/internal/ui"
	"sneak.berlin/go/vaultik/internal/vaultik"
)

// AppOptions contains common options for creating the fx application.
// It includes the configuration file path, logging options, and additional
// fx modules and invocations that should be included in the application.
type AppOptions struct {
	ConfigPath string
	LogOptions log.LogOptions
	Modules    []fx.Option
	Invokes    []fx.Option
}

// setupGlobals records the startup time and prints the startup banner.
// In --cron mode the banner is suppressed (LogOptions.Cron == true).
func setupGlobals(lc fx.Lifecycle, g *globals.Globals, v *vaultik.Vaultik, opts log.LogOptions) {
	lc.Append(fx.Hook{
		OnStart: func(ctx context.Context) error {
			g.StartTime = time.Now().UTC()
			if opts.Cron || opts.Quiet {
				// Replace UI writer with a discarding one so all
				// user-facing output is suppressed.
				v.UI = ui.NewWithColor(io.Discard, false)
			} else {
				v.UI.Banner("%s %s (commit %s, %s) invoked at %s by %s",
					g.Appname, g.Version, g.ShortCommit(), g.CommitDate,
					g.StartTime.Format(time.RFC3339), globals.Author)
			}
			return nil
		},
	})
}

// NewApp creates a new fx application with common modules.
// It sets up the base modules (config, database, logging, globals) and
// combines them with any additional modules specified in the options.
// The returned fx.App is ready to be started with RunApp.
func NewApp(opts AppOptions) *fx.App {
	baseModules := []fx.Option{
		fx.Supply(config.ConfigPath(opts.ConfigPath)),
		fx.Supply(opts.LogOptions),
		fx.Provide(globals.New),
		fx.Provide(log.New),
		config.Module,
		database.Module,
		log.Module,
		storage.Module,
		snapshot.Module,
		fx.Provide(vaultik.New),
		fx.Invoke(setupGlobals),
		fx.NopLogger,
	}

	allOptions := append(baseModules, opts.Modules...)
	allOptions = append(allOptions, opts.Invokes...)

	return fx.New(allOptions...)
}

// cleanStartupError strips fx's dependency-injection call-chain noise from
// startup errors. fx wraps the underlying error with messages like
//
//	could not build arguments for function "X" (file:line): failed to build T:
//	could not build arguments for function "Y" (file:line): failed to build U:
//	received non-nil error from function "Z" (file:line): <real error>
//
// Users care about the real error, not the DI plumbing. We strip everything
// up through the last "): " (which is always the close-paren of an fx
// function-location annotation followed by the wrapped error).
func cleanStartupError(err error) error {
	msg := err.Error()
	if idx := strings.LastIndex(msg, "): "); idx >= 0 {
		msg = msg[idx+3:]
	}
	return errors.New(msg)
}

// RunApp starts and stops the fx application within the given context.
// It handles graceful shutdown on interrupt signals (SIGINT, SIGTERM) and
// ensures the application stops cleanly. The function blocks until the
// application completes or is interrupted. Returns an error if startup fails.
func RunApp(ctx context.Context, app *fx.App) error {
	// Set up signal handling for graceful shutdown
	sigChan := make(chan os.Signal, 1)
	signal.Notify(sigChan, os.Interrupt, syscall.SIGTERM)

	// Create a context that will be cancelled on signal
	ctx, cancel := context.WithCancel(ctx)
	defer cancel()

	// Start the app
	if err := app.Start(ctx); err != nil {
		return cleanStartupError(err)
	}

	// Handle shutdown
	shutdownComplete := make(chan struct{})
	go func() {
		defer close(shutdownComplete)
		<-sigChan
		log.Notice("Received interrupt signal, shutting down gracefully...")

		// Create a timeout context for shutdown
		shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 30*time.Second)
		defer shutdownCancel()

		if err := app.Stop(shutdownCtx); err != nil {
			log.Error("Error during shutdown", "error", err)
		}
	}()

	// Wait for either the signal handler to complete shutdown or the app to request shutdown
	select {
	case <-shutdownComplete:
		// Shutdown completed via signal
		return nil
	case <-ctx.Done():
		// Context cancelled (shouldn't happen in normal operation)
		if err := app.Stop(context.Background()); err != nil {
			log.Error("Error stopping app", "error", err)
		}
		return ctx.Err()
	case <-app.Done():
		// App finished running (e.g., backup completed)
		return nil
	}
}

// RunWithApp is a helper that creates and runs an fx app with the given options.
// It combines NewApp and RunApp into a single convenient function. This is the
// preferred way to run CLI commands that need the full application context.
// It acquires a PID lock before starting to prevent concurrent instances.
func RunWithApp(ctx context.Context, opts AppOptions) error {
	// Acquire PID lock to prevent concurrent instances
	lockDir := filepath.Join(xdg.DataHome, "vaultik")
	lock, err := pidlock.Acquire(lockDir)
	if err != nil {
		if errors.Is(err, pidlock.ErrAlreadyRunning) {
			return fmt.Errorf("cannot start: %w", err)
		}
		return fmt.Errorf("failed to acquire lock: %w", err)
	}
	defer func() {
		if err := lock.Release(); err != nil {
			log.Warn("Failed to release PID lock", "error", err)
		}
	}()

	app := NewApp(opts)
	return RunApp(ctx, app)
}