package runtime

import (
	"path/filepath"
	"strings"
)

// Compose labels set by podman-compose on every container it creates.
const (
	LabelPodmanComposeProject = "io.podman.compose.project"
	LabelComposeWorkingDir    = "com.docker.compose.project.working_dir"
	LabelComposeConfigFiles   = "com.docker.compose.project.config_files"
)

// Container represents a discovered running container.
type Container struct {
	Name    string
	Image   string
	Command string
	Runtime string // "podman" or "docker"
	User    string // empty = root/system scope
	Labels  map[string]string
}

// Project returns the podman-compose project the container belongs to, or "".
func (c Container) Project() string {
	return c.Labels[LabelPodmanComposeProject]
}

// WorkingDir returns the compose project working directory, or "".
func (c Container) WorkingDir() string {
	return c.Labels[LabelComposeWorkingDir]
}

// ComposeFiles returns the compose files used to create the container.
// Relative paths are relative to WorkingDir.
func (c Container) ComposeFiles() []string {
	raw := c.Labels[LabelComposeConfigFiles]
	if raw == "" {
		return nil
	}
	var files []string
	for _, f := range strings.Split(raw, ",") {
		if f = strings.TrimSpace(f); f != "" {
			files = append(files, filepath.Clean(f))
		}
	}
	return files
}

// Runtime is the interface all container runtimes must implement.
// user selects the scope: "" = root/system, otherwise a rootless user.
type Runtime interface {
	Name() string
	ListRunning(user string) ([]Container, error)
	Exists(user, name string) (bool, error)
}

// Available returns all supported runtimes in priority order: podman first,
// docker as fallback (callers skip those with no binary).
func Available() []Runtime {
	return []Runtime{&Podman{}, &Docker{}}
}

// Get returns a runtime by name ("podman" or "docker").
func Get(name string) Runtime {
	switch name {
	case "podman":
		return &Podman{}
	case "docker":
		return &Docker{}
	default:
		return nil
	}
}