/**
 * coopgammad -- Cooperative gamma server
 * Copyright (C) 2016  Mattias Andrée (maandree@kth.se)
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include "state.h"
#include "util.h"

#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>



/**
 * The name of the process
 */
char* restrict argv0; /* do not marshal */

/**
 * The real pathname of the process's binary,
 * `NULL` if `argv0` is satisfactory
 */
char* restrict argv0_real = NULL;

/**
 * Array of all outputs
 */
struct output* restrict outputs = NULL;

/**
 * The nubmer of elements in `outputs`
 */
size_t outputs_n = 0;

/**
 * The server socket's file descriptor
 */
int socketfd = -1;

/**
 * Has the process receive a signal
 * telling it to re-execute?
 */
volatile sig_atomic_t reexec = 0; /* do not marshal */

/**
 * Has the process receive a signal
 * telling it to terminate?
 */
volatile sig_atomic_t terminate = 0; /* do not marshal */

/**
 * Has the process receive a to
 * disconnect from or reconnect to
 * the site? 1 if disconnect, 2 if
 * reconnect, 0 otherwise.
 */
volatile sig_atomic_t connection = 0;

/**
 * List of all client's file descriptors
 * 
 * Unused slots, with index less than `connections_used`,
 * should have the value -1 (negative)
 */
int* restrict connections = NULL;

/**
 * The number of elements allocated for `connections`
 */
size_t connections_alloc = 0;

/**
 * The index of the first unused slot in `connections`
 */
size_t connections_ptr = 0;

/**
 * The index of the last used slot in `connections`, plus 1
 */
size_t connections_used = 0;

/**
 * The clients' connections' inbound-message buffers
 */
struct message* restrict inbound = NULL;

/**
 * The clients' connections' outbound-message buffers
 */
struct ring* restrict outbound = NULL;

/**
 * Is the server connect to the display?
 * 
 * Set to true before the initial connection
 */
int connected = 1;

/**
 * The adjustment method, -1 for automatic
 */
int method = -1;

/**
 * The site's name, may be `NULL`
 */
char* restrict sitename = NULL;

/**
 * The libgamma site state
 */
libgamma_site_state_t site; /* do not marshal */

/**
 * The libgamma partition states
 */
libgamma_partition_state_t* restrict partitions = NULL; /* do not marshal */

/**
 * The libgamma CRTC states
 */
libgamma_crtc_state_t* restrict crtcs = NULL; /* do not marshal */

/**
 * Preserve gamma ramps at priority 0?
 */
int preserve = 0;



/**
 * As part of a state dump, dump one or two gamma ramp-trios
 * 
 * @param  left        The left ramps
 * @param  right       The right ramps
 * @param  depth       The gamma ramp type/depth
 * @param  have_right  Print right ramps?
 * @param  indent      Print indent
 */
static void ramps_dump(union gamma_ramps* left, union gamma_ramps* right,
		       signed depth, int have_right, const char* indent)
{
#define STRINGISE(SIDE, CH, N, BUF)							\
  do											\
    if ((SIDE == NULL) || (SIDE->u8.CH == NULL))					\
      strcpy(BUF, "null");								\
    else if (i < N)									\
      switch (depth)									\
	{										\
	case -2:  snprintf(BUF, sizeof(BUF), "%lf",        SIDE->d.CH[i]);    break;	\
	case -1:  snprintf(BUF, sizeof(BUF), "%f", (double)(SIDE->f.CH[i]));  break;	\
	case  8:  snprintf(BUF, sizeof(BUF), "%02" PRIx8,  SIDE->u8.CH[i]);   break;	\
	case 16:  snprintf(BUF, sizeof(BUF), "%04" PRIx16, SIDE->u16.CH[i]);  break;	\
	case 32:  snprintf(BUF, sizeof(BUF), "%08" PRIx32, SIDE->u32.CH[i]);  break;	\
	case 64:  snprintf(BUF, sizeof(BUF), "%16" PRIx64, SIDE->u64.CH[i]);  break;	\
	default:									\
	  strcpy(BUF, "corrupt state");							\
	  break;									\
	}										\
  while (0)
  
  char lr[100], lg[100], lb[100], rr[100], rg[100], rb[100];
  size_t rn = left ? left->u8.red_size   : right ? right->u8.red_size   : 0;
  size_t gn = left ? left->u8.green_size : right ? right->u8.green_size : 0;
  size_t bn = left ? left->u8.blue_size  : right ? right->u8.blue_size  : 0;
  size_t i, n = rn > gn ? rn : gn;
  n = n > bn ? n : bn;
  
  for (i = 0; i < n; i++)
    {
      *lr = *lg = *lb = *rr = *rg = *rb = '\0';
      
      STRINGISE(left, red,   rn, lr);
      STRINGISE(left, green, gn, lg);
      STRINGISE(left, blue,  bn, lb);
      
      if (have_right)
	{
	  STRINGISE(right, red,   rn, rr);
	  STRINGISE(right, green, gn, rg);
	  STRINGISE(right, blue,  bn, rb);
	}
      
      if (have_right)
	fprintf(stderr, "%s%zu: %s, %s, %s :: %s, %s, %s\n", indent, i, lr, lg, lb, rr, rg, rb);
      else
	fprintf(stderr, "%s%zu: %s, %s, %s\n", indent, i, lr, lg, lb);
    }
}


/**
 * Dump the state to stderr
 */
void state_dump(void)
{
  size_t i, j;
  fprintf(stderr, "argv0: %s\n", argv0 ? argv0 : "(null)");
  fprintf(stderr, "Realpath of argv0: %s\n", argv0_real ? argv0_real : "(null)");
  fprintf(stderr, "Calibrations preserved: %s\n", preserve ? "yes" : "no");
  fprintf(stderr, "Connected: %s\n", connected ? "yes" : "no");
  fprintf(stderr, "Socket FD: %i\n", socketfd);
  fprintf(stderr, "Re-execution pending: %s\n", reexec ? "yes" : "no");
  fprintf(stderr, "Termination pending: %s\n", terminate ? "yes" : "no");
  if ((0 <= connection) && (connection <= 2))
    fprintf(stderr, "Pending connection change: %s\n",
	    connection == 0 ? "none" : connection == 1 ? "disconnect" : "reconnect");
  else
    fprintf(stderr, "Pending connection change: %i (CORRUPT STATE)\n", connection);
  fprintf(stderr, "Adjustment method: %i\n", method);
  fprintf(stderr, "Site name: %s\n", sitename ? sitename : "(automatic)");
  fprintf(stderr, "Clients:\n");
  fprintf(stderr, "  Next empty slot: %zu\n", connections_ptr);
  fprintf(stderr, "  Initialised slots: %zu\n", connections_used);
  fprintf(stderr, "  Allocated slots: %zu\n", connections_alloc);
  if (connections == NULL)
    fprintf(stderr, "  File descriptor array is null\n");
  else
    for (i = 0; i < connections_used; i++)
      {
	if (connections[i] < 0)
	  {
	    fprintf(stderr, "  Slot %zu: empty\n", i);
	    continue;
	  }
	fprintf(stderr, "  Slot %zu:\n", i);
	fprintf(stderr, "    File descriptor: %i\n", connections[i]);
	if (inbound == NULL)
	  fprintf(stderr, "    Inbound message array is null\n");
	else
	  {
	    fprintf(stderr, "    Inbound message:\n");
	    fprintf(stderr, "      Header array: %s\n", inbound[i].headers ? "non-null" : "null");
	    fprintf(stderr, "      Headers: %zu\n", inbound[i].header_count);
	    fprintf(stderr, "      Payload buffer: %s\n", inbound[i].payload ? "non-null" : "null");
	    fprintf(stderr, "      Payload size: %zu\n", inbound[i].payload_size);
	    fprintf(stderr, "      Payload write pointer: %zu\n", inbound[i].payload_ptr);
	    fprintf(stderr, "      Message buffer: %s\n", inbound[i].buffer ? "non-null" : "null");
	    fprintf(stderr, "      Message buffer size: %zu\n", inbound[i].buffer_size);
	    fprintf(stderr, "      Message buffer write pointer: %zu\n", inbound[i].buffer_ptr);
	    fprintf(stderr, "      Read stage: %i\n", inbound[i].stage);
	  }
	if (outbound == NULL)
	  fprintf(stderr, "    Outbound message array is null\n");
	else
	  {
	    fprintf(stderr, "      Ring buffer: %s\n", outbound[i].buffer ? "non-null" : "null");
	    fprintf(stderr, "      Head: %zu\n", outbound[i].end);
	    fprintf(stderr, "      Tail: %zu\n", outbound[i].start);
	    fprintf(stderr, "      Size: %zu\n", outbound[i].size);
	  }
      }
  fprintf(stderr, "Partition array: %s\n", partitions ? "non-null" : "null");
  fprintf(stderr, "CRTC array: %s\n", crtcs ? "non-null" : "null");
  fprintf(stderr, "Output:\n");
  fprintf(stderr, "  Output count: %zu\n", outputs_n);
  if (outputs == NULL)
    fprintf(stderr, "  Output array is null\n");
  else
    for (i = 0; i < outputs_n; i++)
      {
	struct output* restrict out = outputs + i;
	const char* str;
	fprintf(stderr, "  Output %zu:\n", i);
	fprintf(stderr, "    Depth: %i (%s)\n", out->depth,
		out->depth == -1 ? "float" :
		out->depth == -2 ? "double" :
		out->depth ==  8 ? "uint8_t" :
		out->depth == 16 ? "uint16_t" :
		out->depth == 32 ? "uint32_t" :
		out->depth == 64 ? "uint64_t" : "CORRUPT STATE");
	fprintf(stderr, "    Gamma supported: %s (%i)\n",
		out->supported == LIBGAMMA_YES ? "yes" :
		out->supported == LIBGAMMA_NO ? "no" :
		out->supported == LIBGAMMA_MAYBE ? "maybe" :
		"CORRUPT STATE", out->supported);
	fprintf(stderr, "    Name is EDID: %s\n", out->name_is_edid ? "yes" : "no");
	switch (out->colourspace)
	  {
	  case COLOURSPACE_UNKNOWN:          str = "unknown";                                      break;
	  case COLOURSPACE_SRGB:             str = "sRGB with explicit gamut";                     break;
	  case COLOURSPACE_SRGB_SANS_GAMUT:  str = "sRGB with implicit gamut (actually illegal)";  break;
	  case COLOURSPACE_RGB:              str = "RGB other than sRGB, with unknown gamut";      break;
	  case COLOURSPACE_RGB_SANS_GAMUT:   str = "RGB other than sRGB, with listed gamut";       break;
	  case COLOURSPACE_NON_RGB:          str = "Non-RGB multicolour";                          break;
	  case COLOURSPACE_GREY:             str = "Monochrome or singlecolour scale";             break;
	  default:                           str = "CORRUPT STATE";                                break;
	  }
	fprintf(stderr, "    Colourspace: %s (%i)\n", str, out->colourspace);
	if ((out->colourspace == COLOURSPACE_SRGB) || (out->colourspace == COLOURSPACE_RGB))
	  {
	    fprintf(stderr, "      Red (x, y): (%u / 1024, %u / 1024)\n", out->red_x, out->red_y);
	    fprintf(stderr, "      Green (x, y): (%u / 1024, %u / 1024)\n", out->green_x, out->green_y);
	    fprintf(stderr, "      Blue (x, y): (%u / 1024, %u / 1024)\n", out->blue_x, out->blue_y);
	    fprintf(stderr, "      White (x, y): (%u / 1024, %u / 1024)\n", out->white_x, out->white_y);
	    if (out->colourspace == COLOURSPACE_SRGB)
	      {
		fprintf(stderr, "      Expected red (x, y): (655 / 1024, 338 / 1024)\n");
		fprintf(stderr, "      Expected green (x, y): (307 / 1024, 614 / 1024)\n");
		fprintf(stderr, "      Expected blue (x, y): (154 / 1024, 61 / 1024)\n");
		fprintf(stderr, "      Expected white (x, y): (320 / 1024, 337 / 1024)\n");
	      }
	  }
	if (out->supported)
	  {
	    fprintf(stderr, "    Gamma ramp size:\n");
	    fprintf(stderr, "      Red: %zu stops\n", out->red_size);
	    fprintf(stderr, "      Green: %zu stops\n", out->green_size);
	    fprintf(stderr, "      Blue: %zu stops\n", out->blue_size);
	    fprintf(stderr, "      Total: %zu bytes\n", out->ramps_size);
	    fprintf(stderr, "    Name: %s\n", out->name ? out->name : "(null)");
	    fprintf(stderr, "    CRTC state: %s\n", out->crtc ? "non-null" : "null");
	    fprintf(stderr, "    Saved gamma ramps (stop: red, green, blue):\n");
	    ramps_dump(&(out->saved_ramps), NULL, out->depth, 0, "      ");
	    fprintf(stderr, "    Filter table:\n");
	    fprintf(stderr, "      Filter count: %zu\n", out->table_size);
	    fprintf(stderr, "      Slots allocated: %zu\n", out->table_alloc);
	    if (out->table_size > 0)
	      {
		if (out->table_filters == NULL)
		  fprintf(stderr, "      Filter table is null\n");
		if (out->table_sums == NULL)
		  fprintf(stderr, "      Result table is null\n");
	      }
	    for (j = 0; j < out->table_size; j++)
	      {
		struct filter* restrict filter = out->table_filters ? out->table_filters + j : NULL;
		fprintf(stderr, "      Filter %zu:\n", j);
		if (filter != NULL)
		  {
		    if (filter->lifespan == LIFESPAN_UNTIL_DEATH)
		      fprintf(stderr, "        Client FD: %i\n", filter->client);
		    switch (filter->lifespan)
		      {
		      case LIFESPAN_REMOVE:         str = "remove (ILLEGAL STATE)";  break;
		      case LIFESPAN_UNTIL_REMOVAL:  str = "until-removal";           break;
		      case LIFESPAN_UNTIL_DEATH:    str = "until-death";             break;
		      default:                      str = "CORRUPT STATE";           break;
		      }
		    fprintf(stderr, "        Lifespan: %s (%i)\n", str, filter->lifespan);
		    fprintf(stderr, "        Priority: %"PRIi64"\n", filter->priority);
		    fprintf(stderr, "        Class: %s\n", filter->class ? filter->class : "(null)");
		    str = "yes";
		    if (filter->class == NULL)
		      str = "no, is NULL";
		    else if (strchr(filter->class, '\n'))
		      str = "no, contains LF";
		    else if (strstr(filter->class, "::") == NULL)
		      str = "no, does not contain \"::\"";
		    else if (strstr(strstr(filter->class, "::") + 2, "::") == NULL)
		      str = "no, contains only one \"::\"";
		    else if (verify_utf8(filter->class) < 0)
		      str = "no, not UTF-8";
		    fprintf(stderr, "        Class legal: %s\n", str);
		    if ((filter->ramps == NULL) && (filter->lifespan != LIFESPAN_REMOVE))
		      fprintf(stderr, "        Ramps are NULL\n");
		  }
		if (filter != NULL ? (filter->lifespan != LIFESPAN_REMOVE) : (out->table_sums != NULL))
		  {
		    union gamma_ramps left;
		    size_t depth;
		    switch (out->depth)
		      {
		      case -2:  depth = sizeof(double);  break;
		      case -1:  depth = sizeof(float);   break;
		      case 8: case 16: case 32: case 64:
			depth = (size_t)(out->depth) / 8;
			break;
		      default:
			goto corrupt_depth;
		      }
		    if (filter && filter->ramps)
		      {
			left.u8.red_size   = out->red_size;
			left.u8.green_size = out->green_size;
			left.u8.blue_size  = out->blue_size;
			left.u8.red   = filter->ramps;
			left.u8.green = left.u8.red + out->red_size * depth;
			left.u8.blue  = left.u8.green + out->green_size * depth;
		      }
		    fprintf(stderr,"        Ramps (stop: filter red, green, blue :: "
			    "composite red, geen, blue):\n");
		    ramps_dump((filter && filter->ramps) ? &left : NULL,
			       out->table_sums ? out->table_sums + j : NULL,
			       out->depth, 1, "          ");
		  corrupt_depth:;
		  }
	      }
	  }
      }
}


/**
 * Destroy the state
 */
void state_destroy(void)
{
  size_t i;
  
  for (i = 0; i < connections_used; i++)
    if (connections[i] >= 0)
      {
	message_destroy(inbound + i);
	ring_destroy(outbound + i);
      }
  free(inbound);
  free(outbound);
  free(connections);
  
  if (outputs != NULL)
    for (i = 0; i < outputs_n; i++)
      output_destroy(outputs + i);
  free(outputs);
  if (crtcs != NULL)
    for (i = 0; i < outputs_n; i++)
      libgamma_crtc_destroy(crtcs + i);
  free(crtcs);
  if (partitions != NULL)
    for (i = 0; i < site.partitions_available; i++)
      libgamma_partition_destroy(partitions + i);
  free(partitions);
  libgamma_site_destroy(&site);
  
  free(sitename);
}


#if defined(__clang__)
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wcast-align"
#endif


/**
 * Marshal the state
 * 
 * @param   buf  Output buffer for the marshalled data,
 *               `NULL` to only measure how many bytes
 *               this buffer needs
 * @return       The number of marshalled bytes
 */
size_t state_marshal(void* restrict buf)
{
  size_t off = 0, i, n;
  char* restrict bs = buf;
  
  if (argv0_real == NULL)
    {
      if (bs != NULL)
	*(bs + off) = '\0';
      off += 1;
    }
  else
    {
      n = strlen(argv0_real) + 1;
      if (bs != NULL)
	memcpy(bs + off, argv0_real, n);
      off += n;
    }
  
  if (bs != NULL)
    *(size_t*)(bs + off) = outputs_n;
  off += sizeof(size_t);
  
  for (i = 0; i < outputs_n; i++)
    off += output_marshal(outputs + i, bs ? bs + off : NULL);
  
  if (bs != NULL)
    *(int*)(bs + off) = socketfd;
  off += sizeof(int);
  
  if (bs != NULL)
    *(sig_atomic_t*)(bs + off) = connection;
  off += sizeof(sig_atomic_t);
  
  if (bs != NULL)
    *(int*)(bs + off) = connected;
  off += sizeof(int);
  
  if (bs != NULL)
    *(size_t*)(bs + off) = connections_ptr;
  off += sizeof(size_t);
  
  if (bs != NULL)
    *(size_t*)(bs + off) = connections_used;
  off += sizeof(size_t);
  
  if (bs != NULL)
    memcpy(bs + off, connections, connections_used * sizeof(*connections));
  off += connections_used * sizeof(*connections);
  
  for (i = 0; i < connections_used; i++)
    if (connections[i] >= 0)
      {
	off += message_marshal(inbound + i, bs ? bs + off : NULL);
	off += ring_marshal(outbound + i, bs ? bs + off : NULL);
      }
  
  if (bs != NULL)
    *(int*)(bs + off) = method;
  off += sizeof(int);
  
  if (bs != NULL)
    *(int*)(bs + off) = sitename != NULL;
  off += sizeof(int);
  if (sitename != NULL)
    {
      n = strlen(sitename) + 1;
      if (bs != NULL)
	memcpy(bs + off, sitename, n);
      off += n;
    }
  
  if (bs != NULL)
    *(int*)(bs + off) = preserve;
  off += sizeof(int);
  
  return off;
}


/**
 * Unmarshal the state
 * 
 * @param   buf  Buffer for the marshalled data
 * @return       The number of unmarshalled bytes, 0 on error
 */
size_t state_unmarshal(const void* restrict buf)
{
  size_t off = 0, i, n;
  const char* restrict bs = buf;
  
  connections = NULL;
  inbound = NULL;
  
  if (*(bs + off))
    {
      n = strlen(bs + off) + 1;
      if (!(argv0_real = memdup(bs + off, n)))
	return 0;
      off += n;
    }
  else
    off += 1;
  
  outputs_n = *(const size_t*)(bs + off);
  off += sizeof(size_t);
  
  outputs = calloc(outputs_n, sizeof(*outputs));
  if (outputs == NULL)
    return 0;
  
  for (i = 0; i < outputs_n; i++)
    {
      off += n = output_unmarshal(outputs + i, bs + off);
      if (n == 0)
	return 0;
    }
  
  socketfd = *(const int*)(bs + off);
  off += sizeof(int);
  
  connection = *(const sig_atomic_t*)(bs + off);
  off += sizeof(sig_atomic_t);
  
  connected = *(const int*)(bs + off);
  off += sizeof(int);
  
  connections_ptr = *(const size_t*)(bs + off);
  off += sizeof(size_t);
  
  connections_alloc = connections_used = *(const size_t*)(bs + off);
  off += sizeof(size_t);
  
  if (connections_alloc > 0)
    {
      connections = memdup(bs + off, connections_alloc * sizeof(*connections));
      if (connections == NULL)
	return 0;
      off += connections_used * sizeof(*connections);
      
      inbound = malloc(connections_alloc * sizeof(*inbound));
      if (inbound == NULL)
	return 0;
    }
  
  for (i = 0; i < connections_used; i++)
    if (connections[i] >= 0)
      {
	off += n = message_unmarshal(inbound + i, bs + off);
	if (n == 0)
	  return 0;
	off += n = ring_unmarshal(outbound + i, bs + off);
	if (n == 0)
	  return 0;
      }
  
  method = *(const int*)(bs + off);
  off += sizeof(int);
  
  if (*(const int*)(bs + off))
    {
      off += sizeof(int);
      n = strlen(bs + off) + 1;
      if (!(sitename = memdup(bs + off, n)))
	return 0;
      off += n;
    }
  else
    off += sizeof(int);
  
  preserve = *(const int*)(bs + off);
  off += sizeof(int);
  
  return off;
}


#if defined(__clang__)
# pragma GCC diagnostic pop
#endif