// SPICE protocol capture for QEMU/KVM virtual machines.
package backends

import (
	"fmt"
	"image"
	"net"
	"time"

	"git.cloonar.com/openclawd/iso-bot/pkg/engine/capture"
)

// SpiceConfig holds configuration for SPICE capture.
type SpiceConfig struct {
	// Host is the SPICE server hostname or IP address.
	Host string `yaml:"host"`

	// Port is the SPICE server port (default 5900).
	Port int `yaml:"port"`

	// Password for SPICE authentication (optional).
	Password string `yaml:"password"`

	// TLSPort is the secure SPICE port (if using TLS).
	TLSPort int `yaml:"tls_port"`

	// UseTLS enables encrypted connection.
	UseTLS bool `yaml:"use_tls"`

	// CACertFile path to CA certificate for TLS verification.
	CACertFile string `yaml:"ca_cert_file"`

	// Channels specifies which SPICE channels to use (display, inputs, etc.).
	Channels []string `yaml:"channels"`

	// ConnectTimeout is the timeout for initial connection.
	ConnectTimeoutMs int `yaml:"connect_timeout_ms"`

	// ImageCompression sets the preferred image compression type.
	ImageCompression string `yaml:"image_compression"` // "auto", "quic", "glz", "lz"
}

// SpiceSource captures frames from a QEMU/KVM VM via SPICE protocol.
type SpiceSource struct {
	config      SpiceConfig
	conn        net.Conn
	sessionID   uint32
	channels    map[string]*SpiceChannel
	displays    []*SpiceDisplay
	width       int
	height      int
	connected   bool
}

// SpiceChannel represents a SPICE protocol channel.
type SpiceChannel struct {
	Type     string
	ID       int
	Conn     net.Conn
	Sequence uint64
}

// SpiceDisplay represents a display surface in SPICE.
type SpiceDisplay struct {
	ID     uint32
	Width  int
	Height int
	Format SpicePixelFormat
	Data   []byte
}

// SpicePixelFormat describes pixel format used by SPICE.
type SpicePixelFormat struct {
	BitsPerPixel int
	BytesPerPixel int
	RedShift     int
	GreenShift   int
	BlueShift    int
	RedMask      uint32
	GreenMask    uint32
	BlueMask     uint32
}

// NewSpiceSource creates a SPICE capture source.
func NewSpiceSource(configMap map[string]interface{}) (capture.Source, error) {
	var config SpiceConfig

	// Extract config from map
	if host, ok := configMap["host"].(string); ok {
		config.Host = host
	} else {
		return nil, fmt.Errorf("spice host is required")
	}

	if port, ok := configMap["port"].(int); ok {
		config.Port = port
	} else {
		config.Port = 5900 // Default SPICE port
	}

	if password, ok := configMap["password"].(string); ok {
		config.Password = password
	}

	if tlsPort, ok := configMap["tls_port"].(int); ok {
		config.TLSPort = tlsPort
	} else {
		config.TLSPort = 5901 // Default TLS port
	}

	if useTLS, ok := configMap["use_tls"].(bool); ok {
		config.UseTLS = useTLS
	}

	if caCert, ok := configMap["ca_cert_file"].(string); ok {
		config.CACertFile = caCert
	}

	if channels, ok := configMap["channels"].([]string); ok {
		config.Channels = channels
	} else {
		config.Channels = []string{"display", "inputs"} // Default channels
	}

	if connectTimeout, ok := configMap["connect_timeout_ms"].(int); ok {
		config.ConnectTimeoutMs = connectTimeout
	} else {
		config.ConnectTimeoutMs = 10000 // 10 seconds
	}

	if compression, ok := configMap["image_compression"].(string); ok {
		config.ImageCompression = compression
	} else {
		config.ImageCompression = "auto"
	}

	return &SpiceSource{
		config:   config,
		channels: make(map[string]*SpiceChannel),
		displays: make([]*SpiceDisplay, 0),
	}, nil
}

// Name returns a description of this capture source.
func (s *SpiceSource) Name() string {
	return fmt.Sprintf("SPICE: %s:%d", s.config.Host, s.config.Port)
}

// Capture grabs a single frame from the SPICE display.
func (s *SpiceSource) Capture() (image.Image, error) {
	if !s.connected {
		if err := s.connect(); err != nil {
			return nil, fmt.Errorf("failed to connect to SPICE server: %w", err)
		}
	}

	// TODO: Implement SPICE frame capture
	// 1. Check for display updates on the display channel
	// 2. Process SPICE display commands (draw operations)
	// 3. Update local framebuffer with received display data
	// 4. Convert framebuffer to Go image.Image
	return nil, fmt.Errorf("SPICE capture not implemented yet")
}

// CaptureRegion grabs a sub-region of the SPICE display.
func (s *SpiceSource) CaptureRegion(r capture.Region) (image.Image, error) {
	// TODO: Implement region capture
	// SPICE may support partial updates, otherwise crop full frame
	fullFrame, err := s.Capture()
	if err != nil {
		return nil, err
	}

	// Crop the image to the specified region
	bounds := image.Rect(r.X, r.Y, r.X+r.Width, r.Y+r.Height)
	return fullFrame.(interface{
		SubImage(r image.Rectangle) image.Image
	}).SubImage(bounds), nil
}

// Size returns the SPICE display dimensions.
func (s *SpiceSource) Size() (width, height int) {
	return s.width, s.height
}

// Close disconnects from the SPICE server.
func (s *SpiceSource) Close() error {
	s.connected = false
	
	// Close all channels
	for _, channel := range s.channels {
		if channel.Conn != nil {
			channel.Conn.Close()
		}
	}
	
	if s.conn != nil {
		return s.conn.Close()
	}
	return nil
}

// connect establishes connection to SPICE server and performs handshake.
func (s *SpiceSource) connect() error {
	// TODO: Implement SPICE connection and protocol handshake
	// 1. Connect to main channel (host:port)
	// 2. Exchange SPICE link messages
	// 3. Authenticate (if password required)
	// 4. Establish display and input channels
	// 5. Get display configuration
	
	port := s.config.Port
	if s.config.UseTLS {
		port = s.config.TLSPort
	}

	addr := fmt.Sprintf("%s:%d", s.config.Host, port)
	conn, err := net.DialTimeout("tcp", addr, time.Duration(s.config.ConnectTimeoutMs)*time.Millisecond)
	if err != nil {
		return fmt.Errorf("failed to connect to %s: %w", addr, err)
	}

	s.conn = conn
	s.connected = true

	return fmt.Errorf("SPICE handshake not implemented")
}

// performHandshake handles SPICE protocol negotiation.
func (s *SpiceSource) performHandshake() error {
	// TODO: Implement SPICE handshake
	// 1. Send SpiceLinkMess with supported channels and capabilities
	// 2. Receive SpiceLinkReply
	// 3. Authenticate with password (if required)
	// 4. Establish channels based on configuration
	return fmt.Errorf("SPICE handshake not implemented")
}

// connectChannel establishes a specific SPICE channel.
func (s *SpiceSource) connectChannel(channelType string, channelID int) (*SpiceChannel, error) {
	// TODO: Connect to specific SPICE channel
	// 1. Open new connection for channel
	// 2. Send channel link messages
	// 3. Complete channel-specific handshake
	// 4. Setup message processing for channel type
	return nil, fmt.Errorf("SPICE channel connection not implemented")
}

// processDisplayMessages handles messages on the display channel.
func (s *SpiceSource) processDisplayMessages() error {
	// TODO: Process SPICE display messages
	// Handle messages like:
	// - SPICE_MSG_DISPLAY_MODE (display mode change)
	// - SPICE_MSG_DISPLAY_MARK (display updates)
	// - SPICE_MSG_DISPLAY_RESET (display reset)
	// - SPICE_MSG_DISPLAY_COPY_BITS (copy operation)
	// - SPICE_MSG_DISPLAY_INVAL_ALL_PIXMAPS (invalidate caches)
	// - Various draw operations (draw_alpha, draw_copy, etc.)
	return fmt.Errorf("SPICE display message processing not implemented")
}

// updateDisplay processes a display update command.
func (s *SpiceSource) updateDisplay(displayID uint32, x, y, width, height int, data []byte) error {
	// TODO: Update local framebuffer with received display data
	// 1. Find or create display surface
	// 2. Decompress image data (if compressed)
	// 3. Update framebuffer region
	return fmt.Errorf("SPICE display update not implemented")
}

// decompressImage decompresses SPICE image data based on format.
func (s *SpiceSource) decompressImage(data []byte, compression string) ([]byte, error) {
	// TODO: Implement SPICE image decompression
	// Support formats: QUIC, GLZ, LZ, JPEG
	switch compression {
	case "quic":
		return s.decompressQUIC(data)
	case "glz":
		return s.decompressGLZ(data)
	case "lz":
		return s.decompressLZ(data)
	default:
		return data, nil // Uncompressed
	}
}

// decompressQUIC decompresses QUIC-compressed image data.
func (s *SpiceSource) decompressQUIC(data []byte) ([]byte, error) {
	// TODO: Implement QUIC decompression
	return nil, fmt.Errorf("QUIC decompression not implemented")
}

// decompressGLZ decompresses GLZ-compressed image data.
func (s *SpiceSource) decompressGLZ(data []byte) ([]byte, error) {
	// TODO: Implement GLZ decompression
	return nil, fmt.Errorf("GLZ decompression not implemented")
}

// decompressLZ decompresses LZ-compressed image data.
func (s *SpiceSource) decompressLZ(data []byte) ([]byte, error) {
	// TODO: Implement LZ decompression
	return nil, fmt.Errorf("LZ decompression not implemented")
}