package cli

import (
	"context"
	"errors"
	"fmt"
	"os"
	"strings"

	"banger/internal/config"
	"banger/internal/installmeta"
	"banger/internal/model"
	"banger/internal/paths"
)

var (
	loadInstallMetadata = func() (installmeta.Metadata, error) {
		return installmeta.Load(installmeta.DefaultPath)
	}
	currentUID = os.Getuid
)

// ensureDaemon validates that the current CLI user matches the
// installed banger owner, then pings the system socket. Every CLI
// command that needs to talk to the daemon routes through here.
func (d *deps) ensureDaemon(ctx context.Context) (paths.Layout, model.DaemonConfig, error) {
	meta, metaErr := loadInstallMetadata()
	if metaErr == nil && currentUID() != meta.OwnerUID {
		return paths.Layout{}, model.DaemonConfig{}, fmt.Errorf("banger is installed for %s; switch to that user or reinstall with `sudo banger system install --owner %s`", meta.OwnerUser, userHint())
	}
	if metaErr != nil && !errors.Is(metaErr, os.ErrNotExist) {
		return paths.Layout{}, model.DaemonConfig{}, fmt.Errorf("load %s: %w", installmeta.DefaultPath, metaErr)
	}

	userLayout, err := paths.Resolve()
	if err != nil {
		return paths.Layout{}, model.DaemonConfig{}, err
	}
	cfg, err := config.Load(userLayout)
	if err != nil {
		return paths.Layout{}, model.DaemonConfig{}, err
	}
	layout := paths.ResolveSystem()
	if _, err := d.daemonPing(ctx, layout.SocketPath); err == nil {
		return layout, cfg, nil
	}
	if metaErr == nil {
		return paths.Layout{}, model.DaemonConfig{}, fmt.Errorf("banger service not reachable at %s; run `sudo banger system restart`", layout.SocketPath)
	}
	return paths.Layout{}, model.DaemonConfig{}, fmt.Errorf("banger service not running at %s; run `sudo banger system install`", layout.SocketPath)
}

func userHint() string {
	if sudoUser := strings.TrimSpace(os.Getenv("SUDO_USER")); sudoUser != "" {
		return sudoUser
	}
	if user := strings.TrimSpace(os.Getenv("USER")); user != "" {
		return user
	}
	return "<user>"
}