package sandbox

import (
	"context"
	"io"
	"time"

	"github.com/yaoapp/yao/tai/workspace"
)

// ---------------------------------------------------------------------------
// Computer — unified interface for execution environments
// ---------------------------------------------------------------------------

// Computer is the unified interface for remote execution environments.
// Both Box (container) and Host (bare metal) implement it.
type Computer interface {
	ComputerInfo() ComputerInfo
	Exec(ctx context.Context, cmd []string, opts ...ExecOption) (*ExecResult, error)
	Stream(ctx context.Context, cmd []string, opts ...ExecOption) (*ExecStream, error)
	VNC(ctx context.Context) (string, error)
	Proxy(ctx context.Context, port int, path string) (string, error)
	BindWorkplace(workspaceID string)
	Workplace() workspace.FS
}

// ComputerInfo holds identity and registry information for a Computer.
type ComputerInfo struct {
	Kind         string // "box" | "host"
	NodeID       string
	TaiID        string
	MachineID    string
	Version      string
	System       SystemInfo
	Mode         string // "direct" | "tunnel"
	Capabilities map[string]bool
	Status       string

	// Box-specific fields (zero values for Host)
	BoxID       string
	ContainerID string
	Owner       string
	Image       string
	Policy      LifecyclePolicy
	Labels      map[string]string
}

// SystemInfo describes the hardware and environment of a Tai node.
type SystemInfo struct {
	OS       string
	Arch     string
	Hostname string
	NumCPU   int
	TotalMem int64
	Shell    string // preferred shell: "sh", "pwsh", "powershell", "cmd.exe"
	TempDir  string // system temp directory
}

// ---------------------------------------------------------------------------
// Lifecycle
// ---------------------------------------------------------------------------

type LifecyclePolicy string

const (
	OneShot     LifecyclePolicy = "oneshot"
	Session     LifecyclePolicy = "session"
	LongRunning LifecyclePolicy = "longrunning"
	Persistent  LifecyclePolicy = "persistent"
)

const DefaultStopTimeout = 2 * time.Second

// ---------------------------------------------------------------------------
// Create / List options
// ---------------------------------------------------------------------------

type PortMapping struct {
	ContainerPort int
	HostPort      int
	HostIP        string
	Protocol      string
}

type CreateOptions struct {
	ID          string
	Owner       string
	Labels      map[string]string
	NodeID      string
	Image       string
	WorkDir     string
	User        string
	Env         map[string]string
	Memory      int64
	CPUs        float64
	VNC         bool
	Ports       []PortMapping
	Policy      LifecyclePolicy
	IdleTimeout time.Duration
	MaxLifetime time.Duration
	StopTimeout time.Duration

	WorkspaceID string
	MountMode   string
	MountPath   string
}

type ListOptions struct {
	Owner  string
	NodeID string
	Labels map[string]string
}

// ---------------------------------------------------------------------------
// Unified ExecOption / ExecResult / ExecStream
// ---------------------------------------------------------------------------

type execConfig struct {
	WorkDir        string
	Env            map[string]string
	Timeout        time.Duration
	Stdin          []byte
	MaxOutputBytes int64
}

// ExecOption configures an Exec or Stream call on any Computer.
type ExecOption func(*execConfig)

func WithWorkDir(dir string) ExecOption {
	return func(c *execConfig) { c.WorkDir = dir }
}

func WithEnv(env map[string]string) ExecOption {
	return func(c *execConfig) { c.Env = env }
}

func WithTimeout(timeout time.Duration) ExecOption {
	return func(c *execConfig) { c.Timeout = timeout }
}

func WithStdin(data []byte) ExecOption {
	return func(c *execConfig) { c.Stdin = data }
}

func WithMaxOutput(bytes int64) ExecOption {
	return func(c *execConfig) { c.MaxOutputBytes = bytes }
}

// ExecResult holds the outcome of a command executed on any Computer.
type ExecResult struct {
	ExitCode   int
	Stdout     string
	Stderr     string
	DurationMs int64
	Error      string
	Truncated  bool
}

// ExecStream provides real-time streaming I/O for a running command.
type ExecStream struct {
	Stdout io.ReadCloser
	Stderr io.ReadCloser
	Stdin  io.WriteCloser
	Wait   func() (int, error)
	Cancel func()
}

// ---------------------------------------------------------------------------
// Attach (Box-specific, not part of Computer interface)
// ---------------------------------------------------------------------------

type attachConfig struct {
	Protocol string
	Path     string
	Headers  map[string]string
}

type AttachOption func(*attachConfig)

func WithProtocol(protocol string) AttachOption {
	return func(c *attachConfig) { c.Protocol = protocol }
}

func WithPath(path string) AttachOption {
	return func(c *attachConfig) { c.Path = path }
}

func WithHeaders(headers map[string]string) AttachOption {
	return func(c *attachConfig) { c.Headers = headers }
}

// ImagePullOptions configures an image pull operation.
type ImagePullOptions struct {
	Auth *RegistryAuth
}

// RegistryAuth holds credentials for a private container registry.
type RegistryAuth struct {
	Username string
	Password string
	Server   string
}

type ServiceConn struct {
	Read   func() ([]byte, error)
	Write  func(data []byte) error
	Events <-chan []byte
	URL    string
	Close  func() error
}

// BoxInfo is a snapshot of a Box's runtime state (used by Manager.List).
type BoxInfo struct {
	ID           string
	ContainerID  string
	NodeID       string
	Owner        string
	Status       string
	Policy       LifecyclePolicy
	Labels       map[string]string
	Image        string
	CreatedAt    time.Time
	LastActive   time.Time
	ProcessCount int
	VNC          bool
}