#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <errno.h>
#include <cairo.h>

#include "broadway-output.h"

/************************************************************************
 *                Basic I/O primitives                                  *
 ************************************************************************/

struct BroadwayOutput {
  GOutputStream *out;
  GString *buf;
  int error;
  guint32 serial;
};

static void
broadway_output_send_cmd (BroadwayOutput *output,
			  gboolean fin, BroadwayWSOpCode code,
			  const void *buf, gsize count)
{
  gboolean mask = FALSE;
  guchar header[16];
  size_t p;

  gboolean mid_header = count > 125 && count <= 65535;
  gboolean long_header = count > 65535;

  /* NB. big-endian spec => bit 0 == MSB */
  header[0] = ( (fin ? 0x80 : 0) | (code & 0x0f) );
  header[1] = ( (mask ? 0x80 : 0) |
                (mid_header ? 126 : long_header ? 127 : count) );
  p = 2;
  if (mid_header)
    {
      *(guint16 *)(header + p) = GUINT16_TO_BE( (guint16)count );
      p += 2;
    }
  else if (long_header)
    {
      *(guint64 *)(header + p) = GUINT64_TO_BE( count );
      p += 8;
    }
  // FIXME: if we are paranoid we should 'mask' the data
  // FIXME: we should really emit these as a single write
  g_output_stream_write_all (output->out, header, p, NULL, NULL, NULL);
  g_output_stream_write_all (output->out, buf, count, NULL, NULL, NULL);
}

void broadway_output_pong (BroadwayOutput *output)
{
  broadway_output_send_cmd (output, TRUE, BROADWAY_WS_CNX_PONG, NULL, 0);
}

int
broadway_output_flush (BroadwayOutput *output)
{
  if (output->buf->len == 0)
    return TRUE;

  broadway_output_send_cmd (output, TRUE, BROADWAY_WS_BINARY,
                            output->buf->str, output->buf->len);

  g_string_set_size (output->buf, 0);

  return !output->error;

}

BroadwayOutput *
broadway_output_new (GOutputStream *out, guint32 serial)
{
  BroadwayOutput *output;

  output = g_new0 (BroadwayOutput, 1);

  output->out = g_object_ref (out);
  output->buf = g_string_new ("");
  output->serial = serial;

  return output;
}

void
broadway_output_free (BroadwayOutput *output)
{
  g_object_unref (output->out);
  free (output);
}

guint32
broadway_output_get_next_serial (BroadwayOutput *output)
{
  return output->serial;
}

void
broadway_output_set_next_serial (BroadwayOutput *output,
				 guint32 serial)
{
  output->serial = serial;
}


/************************************************************************
 *                     Core rendering operations                        *
 ************************************************************************/

static void
append_char (BroadwayOutput *output, char c)
{
  g_string_append_c (output->buf, c);
}

static void
append_bool (BroadwayOutput *output, gboolean val)
{
  g_string_append_c (output->buf, val ? 1: 0);
}

static void
append_flags (BroadwayOutput *output, guint32 val)
{
  g_string_append_c (output->buf, val);
}

static void
append_uint16 (BroadwayOutput *output, guint32 v)
{
  gsize old_len = output->buf->len;
  guint8 *buf;

  g_string_set_size (output->buf, old_len + 2);
  buf = (guint8 *)output->buf->str + old_len;
  buf[0] = (v >> 0) & 0xff;
  buf[1] = (v >> 8) & 0xff;
}

static void
append_uint32 (BroadwayOutput *output, guint32 v)
{
  gsize old_len = output->buf->len;
  guint8 *buf;

  g_string_set_size (output->buf, old_len + 4);
  buf = (guint8 *)output->buf->str + old_len;
  buf[0] = (v >> 0) & 0xff;
  buf[1] = (v >> 8) & 0xff;
  buf[2] = (v >> 16) & 0xff;
  buf[3] = (v >> 24) & 0xff;
}

static void
write_header(BroadwayOutput *output, char op)
{
  append_char (output, op);
  append_uint32 (output, output->serial++);
}

void
broadway_output_grab_pointer (BroadwayOutput *output,
			      int id,
			      gboolean owner_event)
{
  write_header (output, BROADWAY_OP_GRAB_POINTER);
  append_uint16 (output, id);
  append_bool (output, owner_event);
}

guint32
broadway_output_ungrab_pointer (BroadwayOutput *output)
{
  guint32 serial;

  serial = output->serial;
  write_header (output, BROADWAY_OP_UNGRAB_POINTER);

  return serial;
}

void
broadway_output_new_surface(BroadwayOutput *output,
			    int id, int x, int y, int w, int h,
			    gboolean is_temp)
{
  write_header (output, BROADWAY_OP_NEW_SURFACE);
  append_uint16 (output, id);
  append_uint16 (output, x);
  append_uint16 (output, y);
  append_uint16 (output, w);
  append_uint16 (output, h);
  append_bool (output, is_temp);
}

void
broadway_output_disconnected (BroadwayOutput *output)
{
  write_header (output, BROADWAY_OP_DISCONNECTED);
}

void
broadway_output_show_surface(BroadwayOutput *output,  int id)
{
  write_header (output, BROADWAY_OP_SHOW_SURFACE);
  append_uint16 (output, id);
}

void
broadway_output_hide_surface(BroadwayOutput *output,  int id)
{
  write_header (output, BROADWAY_OP_HIDE_SURFACE);
  append_uint16 (output, id);
}

void
broadway_output_destroy_surface(BroadwayOutput *output,  int id)
{
  write_header (output, BROADWAY_OP_DESTROY_SURFACE);
  append_uint16 (output, id);
}


void
broadway_output_move_resize_surface (BroadwayOutput *output,
				     int             id,
				     gboolean        has_pos,
				     int             x,
				     int             y,
				     gboolean        has_size,
				     int             w,
				     int             h)
{
  int val;

  if (!has_pos && !has_size)
    return;

  write_header (output, BROADWAY_OP_MOVE_RESIZE);
  val = (!!has_pos) | ((!!has_size) << 1);
  append_uint16 (output, id);
  append_flags (output, val);
  if (has_pos)
    {
      append_uint16 (output, x);
      append_uint16 (output, y);
    }
  if (has_size)
    {
      append_uint16 (output, w);
      append_uint16 (output, h);
    }
}

void
broadway_output_set_transient_for (BroadwayOutput *output,
				   int             id,
				   int             parent_id)
{
  write_header (output, BROADWAY_OP_SET_TRANSIENT_FOR);
  append_uint16 (output, id);
  append_uint16 (output, parent_id);
}

void
broadway_output_put_buffer (BroadwayOutput *output,
                            int             id,
                            BroadwayBuffer *prev_buffer,
                            BroadwayBuffer *buffer)
{
  gsize len;
  int w, h;
  GZlibCompressor *compressor;
  GOutputStream *out, *out_mem;
  GString *encoded;

  write_header (output, BROADWAY_OP_PUT_BUFFER);

  w = broadway_buffer_get_width (buffer);
  h = broadway_buffer_get_height (buffer);

  append_uint16 (output, id);
  append_uint16 (output, w);
  append_uint16 (output, h);

  encoded = g_string_new ("");
  broadway_buffer_encode (buffer, prev_buffer, encoded);

  compressor = g_zlib_compressor_new (G_ZLIB_COMPRESSOR_FORMAT_RAW, -1);
  out_mem = g_memory_output_stream_new_resizable ();
  out = g_converter_output_stream_new (out_mem, G_CONVERTER (compressor));
  g_object_unref (compressor);

  if (!g_output_stream_write_all (out, encoded->str, encoded->len,
                                  NULL, NULL, NULL) ||
      !g_output_stream_close (out, NULL, NULL))
    g_warning ("compression failed\n");


  len = g_memory_output_stream_get_data_size (G_MEMORY_OUTPUT_STREAM (out_mem));
  append_uint32 (output, len);

  g_string_append_len (output->buf, g_memory_output_stream_get_data (G_MEMORY_OUTPUT_STREAM (out_mem)), len);

  g_string_free (encoded, TRUE);
  g_object_unref (out);
  g_object_unref (out_mem);
}