/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2015 - Andre Leiradella
 *
 *  RetroArch 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 Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  RetroArch 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 RetroArch.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#include <string.h>
#include <ctype.h>

#include <formats/jsonsax.h>
#include <rhash.h>
#include <retro_log.h>
#include <rthreads/async_job.h>

#include "cheevos.h"
#include "dynamic.h"
#include "net_http_special.h"

#include "configuration.h"
#include "performance.h"
#include "runloop.h"

enum
{
   CHEEVOS_VAR_SIZE_BIT_0,
   CHEEVOS_VAR_SIZE_BIT_1,
   CHEEVOS_VAR_SIZE_BIT_2,
   CHEEVOS_VAR_SIZE_BIT_3,
   CHEEVOS_VAR_SIZE_BIT_4,
   CHEEVOS_VAR_SIZE_BIT_5,
   CHEEVOS_VAR_SIZE_BIT_6,
   CHEEVOS_VAR_SIZE_BIT_7,
   CHEEVOS_VAR_SIZE_NIBBLE_LOWER,
   CHEEVOS_VAR_SIZE_NIBBLE_UPPER,
   /* Byte, */
   CHEEVOS_VAR_SIZE_EIGHT_BITS, /* =Byte, */
   CHEEVOS_VAR_SIZE_SIXTEEN_BITS,
   CHEEVOS_VAR_SIZE_THIRTYTWO_BITS,

   CHEEVOS_VAR_SIZE_LAST
}; /* cheevos_var_t.size */

enum
{
   CHEEVOS_VAR_TYPE_ADDRESS,     /* compare to the value of a live address in RAM */
   CHEEVOS_VAR_TYPE_VALUE_COMP,  /* a number. assume 32 bit */
   CHEEVOS_VAR_TYPE_DELTA_MEM,   /* the value last known at this address. */
   CHEEVOS_VAR_TYPE_DYNAMIC_VAR, /* a custom user-set variable */

   CHEEVOS_VAR_TYPE_LAST
}; /* cheevos_var_t.type */

enum
{
   CHEEVOS_COND_OP_EQUALS,
   CHEEVOS_COND_OP_LESS_THAN,
   CHEEVOS_COND_OP_LESS_THAN_OR_EQUAL,
   CHEEVOS_COND_OP_GREATER_THAN,
   CHEEVOS_COND_OP_GREATER_THAN_OR_EQUAL,
   CHEEVOS_COND_OP_NOT_EQUAL_TO,

   CHEEVOS_COND_OP_LAST
}; /* cheevos_cond_t.op */

enum
{
   CHEEVOS_COND_TYPE_STANDARD,
   CHEEVOS_COND_TYPE_PAUSE_IF,
   CHEEVOS_COND_TYPE_RESET_IF,

   CHEEVOS_COND_TYPE_LAST
}; /* cheevos_cond_t.type */

enum
{
   CHEEVOS_DIRTY_TITLE       = 1 << 0,
   CHEEVOS_DIRTY_DESC        = 1 << 1,
   CHEEVOS_DIRTY_POINTS      = 1 << 2,
   CHEEVOS_DIRTY_AUTHOR      = 1 << 3,
   CHEEVOS_DIRTY_ID          = 1 << 4,
   CHEEVOS_DIRTY_BADGE       = 1 << 5,
   CHEEVOS_DIRTY_CONDITIONS  = 1 << 6,
   CHEEVOS_DIRTY_VOTES       = 1 << 7,
   CHEEVOS_DIRTY_DESCRIPTION = 1 << 8,

   CHEEVOS_DIRTY_ALL         = (1 << 9) - 1
};

typedef struct
{
   unsigned size;
   unsigned type;
   unsigned bank_id;
   unsigned value;
   unsigned previous;
} cheevos_var_t;

typedef struct
{
   unsigned type;
   unsigned req_hits;
   unsigned curr_hits;

   cheevos_var_t source;
   unsigned      op;
   cheevos_var_t target;
} cheevos_cond_t;

typedef struct
{
   cheevos_cond_t *conds;
   unsigned        count;

   const char* expression;
} cheevos_condset_t;

typedef struct
{
   unsigned    id;
   const char *title;
   const char *description;
   const char *author;
   const char *badge;
   unsigned    points;
   unsigned    dirty;
   int         active;
   int         modified;

   cheevos_condset_t *condsets;
   unsigned count;
} cheevo_t;

typedef struct
{
   cheevo_t *cheevos;
   unsigned  count;
} cheevoset_t;

typedef struct
{
   int loaded;
   
   cheevoset_t core;
   cheevoset_t unofficial;

   char token[32];

   async_job_t *jobs;
} cheevos_locals_t;

cheevos_locals_t cheevos_locals =
{
   0,
   {NULL, 0},
   {NULL, 0},
   {0},
   NULL
};

cheevos_globals_t cheevos_globals =
{
   0,
   0
};

/*****************************************************************************
Supporting functions.
*****************************************************************************/

static uint32_t cheevos_djb2(const char* str, size_t length)
{
   const unsigned char *aux = (const unsigned char*)str;
   const unsigned char *end = aux + length;
   uint32_t hash = 5381;

   while (aux < end)
      hash = (hash << 5) + hash + *aux++;

   return hash;
}

#ifdef NDEBUG

#define http_get net_http_get

#else

static int http_get(const char **result, size_t *size, const char *url, retro_time_t *timeout)
{
   int ret = net_http_get(result, size, url, timeout);
   const char *msg;
   
   switch (ret)
   {
      case NET_HTTP_GET_OK:
         return ret;
         
      case NET_HTTP_GET_MALFORMED_URL:
         msg = "malformed url";
         break;
         
      case NET_HTTP_GET_CONNECT_ERROR:
         msg = "connect error";
         break;
         
      case NET_HTTP_GET_TIMEOUT:
         msg = "timeout";
         break;
         
      default:
         msg = "?";
         break;
   }
   
   RARCH_LOG("CHEEVOS error getting %s: %s\n", url, msg);
   RARCH_LOG("CHEEVOS http result was %s\n", *result ? *result : "(null)");
   return ret;
}

#endif

typedef struct
{
   unsigned    key_hash;
   int         is_key;
   const char *value;
   size_t      length;
}
cheevo_getvalueud_t;

static int getvalue__json_key(void *userdata, const char *name, size_t length)
{
   cheevo_getvalueud_t* ud = (cheevo_getvalueud_t*)userdata;

   ud->is_key = cheevos_djb2(name, length) == ud->key_hash;
   return 0;
}

static int getvalue__json_string(void *userdata, const char *string, size_t length)
{
   cheevo_getvalueud_t* ud = (cheevo_getvalueud_t*)userdata;

   if (ud->is_key)
   {
      ud->value = string;
      ud->length = length;
      ud->is_key = 0;
   }

   return 0;
}

static int getvalue__json_boolean(void *userdata, int istrue)
{
   cheevo_getvalueud_t* ud = (cheevo_getvalueud_t*)userdata;

   if ( ud->is_key )
   {
      ud->value = istrue ? "true" : "false";
      ud->length = istrue ? 4 : 5;
      ud->is_key = 0;
   }

   return 0;
}

static int getvalue__json_null(void *userdata)
{
   cheevo_getvalueud_t* ud = (cheevo_getvalueud_t*)userdata;

   if ( ud->is_key )
   {
      ud->value = "null";
      ud->length = 4;
      ud->is_key = 0;
   }

   return 0;
}

static int cheevos_get_value(const char *json, unsigned key_hash, char *value, size_t length)
{
   static const jsonsax_handlers_t handlers =
   {
      NULL,
      NULL,
      NULL,
      NULL,
      NULL,
      NULL,
      getvalue__json_key,
      NULL,
      getvalue__json_string,
      getvalue__json_string, /* number */
      getvalue__json_boolean,
      getvalue__json_null
   };

   cheevo_getvalueud_t ud;

   ud.key_hash = key_hash;
   ud.is_key = 0;
   ud.length = 0;
   *value = 0;

   if (jsonsax_parse(json, &handlers, (void*)&ud) == JSONSAX_OK && ud.length < length)
   {
      strncpy(value, ud.value, length);
      value[ud.length] = 0;
      return 0;
   }

   return -1;
}

/*****************************************************************************
Count number of achievements in a JSON file.
*****************************************************************************/

typedef struct
{
   int      in_cheevos;
   uint32_t field_hash;
   unsigned core_count;
   unsigned unofficial_count;
}
cheevos_countud_t;

static int count__json_end_array(void *userdata)
{
  cheevos_countud_t* ud = (cheevos_countud_t*)userdata;
  ud->in_cheevos = 0;
  return 0;
}

static int count__json_key(void *userdata, const char *name, size_t length)
{
   cheevos_countud_t* ud = (cheevos_countud_t*)userdata;
   ud->field_hash = cheevos_djb2(name, length);

   if (ud->field_hash == 0x69749ae1U /* Achievements */)
      ud->in_cheevos = 1;

   return 0;
}

static int count__json_number(void *userdata, const char *number, size_t length)
{
   cheevos_countud_t* ud = (cheevos_countud_t*)userdata;
   long flags;

   if (ud->in_cheevos && ud->field_hash == 0x0d2e96b2U /* Flags */)
   {
      flags = strtol(number, NULL, 10);

      if (flags == 3) /* core achievements */
         ud->core_count++;
      else if (flags == 5) /* unofficial achievements */
         ud->unofficial_count++;
   }

   return 0;
}

static int count_cheevos(const char *json, unsigned *core_count, unsigned *unofficial_count)
{
   static const jsonsax_handlers_t handlers =
   {
      NULL,
      NULL,
      NULL,
      NULL,
      NULL,
      count__json_end_array,
      count__json_key,
      NULL,
      NULL,
      count__json_number,
      NULL,
      NULL
   };

   int res;
   cheevos_countud_t ud;
   ud.in_cheevos = 0;
   ud.core_count = 0;
   ud.unofficial_count = 0;

   res = jsonsax_parse(json, &handlers, (void*)&ud);

   *core_count = ud.core_count;
   *unofficial_count = ud.unofficial_count;

   return res;
}

/*****************************************************************************
Parse the MemAddr field.
*****************************************************************************/

static unsigned prefix_to_comp_size(char prefix)
{
   /* Careful not to use ABCDEF here, this denotes part of an actual variable! */

   switch( toupper( prefix ) )
   {
      case 'M': return CHEEVOS_VAR_SIZE_BIT_0;
      case 'N': return CHEEVOS_VAR_SIZE_BIT_1;
      case 'O': return CHEEVOS_VAR_SIZE_BIT_2;
      case 'P': return CHEEVOS_VAR_SIZE_BIT_3;
      case 'Q': return CHEEVOS_VAR_SIZE_BIT_4;
      case 'R': return CHEEVOS_VAR_SIZE_BIT_5;
      case 'S': return CHEEVOS_VAR_SIZE_BIT_6;
      case 'T': return CHEEVOS_VAR_SIZE_BIT_7;
      case 'L': return CHEEVOS_VAR_SIZE_NIBBLE_LOWER;
      case 'U': return CHEEVOS_VAR_SIZE_NIBBLE_UPPER;
      case 'H': return CHEEVOS_VAR_SIZE_EIGHT_BITS;
      case 'X': return CHEEVOS_VAR_SIZE_THIRTYTWO_BITS;
      default:
      case ' ': return CHEEVOS_VAR_SIZE_SIXTEEN_BITS;
   }
}

static unsigned read_hits(const char **memaddr)
{
   const char *str = *memaddr;
   unsigned num_hits = 0;
   char *end;

   if (*str == '(' || *str == '.')
   {
      num_hits = strtol(str + 1, &end, 10);
      str = end + 1;
   }

   *memaddr = str;
   return num_hits;
}

static unsigned parse_operator(const char **memaddr)
{
   const char *str = *memaddr;
   unsigned char op;

   if (*str == '=' && str[1] == '=')
   {
      op = CHEEVOS_COND_OP_EQUALS;
      str += 2;
   }
   else if (*str == '=')
   {
      op = CHEEVOS_COND_OP_EQUALS;
      str++;
   }
   else if (*str == '!' && str[1] == '=')
   {
      op = CHEEVOS_COND_OP_NOT_EQUAL_TO;
      str += 2;
   }
   else if (*str == '<' && str[1] == '=')
   {
      op = CHEEVOS_COND_OP_LESS_THAN_OR_EQUAL;
      str += 2;
   }
   else if (*str == '<')
   {
      op = CHEEVOS_COND_OP_LESS_THAN;
      str++;
   }
   else if (*str == '>' && str[1] == '=')
   {
      op = CHEEVOS_COND_OP_GREATER_THAN_OR_EQUAL;
      str += 2;
   }
   else if (*str == '>')
   {
      op = CHEEVOS_COND_OP_GREATER_THAN;
      str++;
   }
   else
   {
      /* TODO log the exception */
      op = CHEEVOS_COND_OP_EQUALS;
   }

   *memaddr = str;
   return op;
}

static void parse_var(cheevos_var_t *var, const char **memaddr)
{
   const char *str = *memaddr;
   unsigned base = 16;
   char *end;

   if (toupper(*str) == 'D' && str[1] == '0' && toupper(str[2]) == 'X')
   {
      /* d0x + 4 hex digits */
      str += 3;
      var->type = CHEEVOS_VAR_TYPE_DELTA_MEM;
   }
   else if (*str == '0' && toupper(str[1]) == 'X')
   {
      /* 0x + 4 hex digits */
      str += 2;
      var->type = CHEEVOS_VAR_TYPE_ADDRESS;
   }
   else
   {
      var->type = CHEEVOS_VAR_TYPE_VALUE_COMP;

      if (toupper(*str) == 'H')
         str++;
      else
         base = 10;
   }

   if (var->type != CHEEVOS_VAR_TYPE_VALUE_COMP)
   {
      var->size = prefix_to_comp_size(*str);

      if (var->size != CHEEVOS_VAR_SIZE_SIXTEEN_BITS)
         str++;
   }

   var->value = strtol(str, &end, base);
   *memaddr = end;
}

static void parse_cond(cheevos_cond_t *cond, const char **memaddr)
{
   const char* str = *memaddr;

   if (*str == 'R' && str[1] == ':')
   {
      cond->type = CHEEVOS_COND_TYPE_RESET_IF;
      str += 2;
   }
   else if (*str == 'P' && str[1] == ':')
   {
      cond->type = CHEEVOS_COND_TYPE_PAUSE_IF;
      str += 2;
   }
   else
      cond->type = CHEEVOS_COND_TYPE_STANDARD;

   parse_var(&cond->source, &str);
   cond->op = parse_operator(&str);
   parse_var(&cond->target, &str);
   cond->curr_hits = 0;
   cond->req_hits = read_hits(&str);

   *memaddr = str;
}

static unsigned count_cond_sets(const char *memaddr)
{
   unsigned count = 0;
   cheevos_cond_t cond;

   do
   {
      do
      {
         while (*memaddr == ' ' || *memaddr == '_' || *memaddr == '|' || *memaddr == 'S')
            memaddr++; /* Skip any chars up til the start of the achievement condition */

         parse_cond(&cond, &memaddr);
      }
      while (*memaddr == '_' || *memaddr == 'R' || *memaddr == 'P'); /* AND, ResetIf, PauseIf */

      count++;
   }
   while (*memaddr == 'S'); /* Repeat for all subconditions if they exist */

   return count;
}

static unsigned count_conds_in_set(const char *memaddr, unsigned set)
{
   unsigned index = 0;
   unsigned count = 0;
   cheevos_cond_t cond;

   do
   {
      do
      {
         while (*memaddr == ' ' || *memaddr == '_' || *memaddr == '|' || *memaddr == 'S')
            memaddr++; /* Skip any chars up til the start of the achievement condition */

         parse_cond(&cond, &memaddr);

         if (index == set)
            count++;
      }
      while (*memaddr == '_' || *memaddr == 'R' || *memaddr == 'P'); /* AND, ResetIf, PauseIf */
   }
   while (*memaddr == 'S'); /* Repeat for all subconditions if they exist */

   return count;
}

static void parse_memaddr(cheevos_cond_t *cond, const char *memaddr)
{
   do
   {
      do
      {
         while (*memaddr == ' ' || *memaddr == '_' || *memaddr == '|' || *memaddr == 'S')
            memaddr++; /* Skip any chars up til the start of the achievement condition */

         parse_cond(cond++, &memaddr);
      }
      while (*memaddr == '_' || *memaddr == 'R' || *memaddr == 'P'); /* AND, ResetIf, PauseIf */
   }
   while (*memaddr == 'S'); /* Repeat for all subconditions if they exist */
}

/*****************************************************************************
Load achievements from a JSON string.
*****************************************************************************/

typedef struct
{
   const char *string;
   size_t      length;
}
cheevos_field_t;

typedef struct
{
   int      in_cheevos;
   unsigned core_count;
   unsigned unofficial_count;

   cheevos_field_t *field;
   cheevos_field_t  id, memaddr, title, desc, points, author;
   cheevos_field_t  modified, created, badge, flags;
}
cheevos_readud_t;

static INLINE const char *dupstr(const cheevos_field_t *field)
{
   char *string = (char*)malloc(field->length + 1);

   if (string)
   {
      memcpy ((void*)string, (void*)field->string, field->length);
      string[field->length] = 0;
   }

   return string;
}

static int new_cheevo(cheevos_readud_t *ud)
{
   int flags = strtol(ud->flags.string, NULL, 10);
   const cheevos_condset_t *end;
   unsigned set;
   cheevos_condset_t *condset;
   cheevo_t *cheevo;

   if (flags == 3)
      cheevo = cheevos_locals.core.cheevos + ud->core_count++;
   else
      cheevo = cheevos_locals.unofficial.cheevos + ud->unofficial_count++;

   cheevo->id = strtol(ud->id.string, NULL, 10);
   cheevo->title = dupstr(&ud->title);
   cheevo->description = dupstr(&ud->desc);
   cheevo->author = dupstr(&ud->author);
   cheevo->badge = dupstr(&ud->badge);
   cheevo->points = strtol(ud->points.string, NULL, 10);
   cheevo->dirty = 0;
   cheevo->active = 1; /* flags == 3; */
   cheevo->modified = 0;

   if (!cheevo->title || !cheevo->description || !cheevo->author || !cheevo->badge)
   {
      free((void*)cheevo->title);
      free((void*)cheevo->description);
      free((void*)cheevo->author);
      free((void*)cheevo->badge);
      return -1;
   }

   cheevo->count = count_cond_sets(ud->memaddr.string);

   if (cheevo->count)
   {
      cheevo->condsets = (cheevos_condset_t*)malloc(cheevo->count * sizeof(cheevos_condset_t));

      if (!cheevo->condsets)
         return -1;

      memset((void*)cheevo->condsets, 0, cheevo->count * sizeof(cheevos_condset_t));
      end = cheevo->condsets + cheevo->count;
      set = 0;

      for (condset = cheevo->condsets; condset < end; condset++)
      {
         condset->count = count_conds_in_set(ud->memaddr.string, set++);

         if (condset->count)
         {
            condset->conds = (cheevos_cond_t*)malloc(condset->count * sizeof(cheevos_cond_t));

            if (!condset->conds)
               return -1;

            memset((void*)condset->conds, 0, condset->count * sizeof(cheevos_cond_t));
            condset->expression = dupstr(&ud->memaddr);
            parse_memaddr(condset->conds, ud->memaddr.string);
         }
         else
            condset->conds = NULL;
      }
   }

   return 0;
}

static int read__json_key( void *userdata, const char *name, size_t length)
{
   cheevos_readud_t *ud = (cheevos_readud_t*)userdata;
   uint32_t hash = cheevos_djb2(name, length);

   ud->field = NULL;

   if (hash == 0x69749ae1U /* Achievements */)
      ud->in_cheevos = 1;
   else if (ud->in_cheevos)
   {
      switch ( hash )
      {
         case 0x005973f2U: /* ID          */ ud->field = &ud->id;       break;
         case 0x1e76b53fU: /* MemAddr     */ ud->field = &ud->memaddr;  break;
         case 0x0e2a9a07U: /* Title       */ ud->field = &ud->title;    break;
         case 0xe61a1f69U: /* Description */ ud->field = &ud->desc;     break;
         case 0xca8fce22U: /* Points      */ ud->field = &ud->points;   break;
         case 0xa804edb8U: /* Author      */ ud->field = &ud->author;   break;
         case 0xdcea4fe6U: /* Modified    */ ud->field = &ud->modified; break;
         case 0x3a84721dU: /* Created     */ ud->field = &ud->created;  break;
         case 0x887685d9U: /* BadgeName   */ ud->field = &ud->badge;    break;
         case 0x0d2e96b2U: /* Flags       */ ud->field = &ud->flags;    break;
      }
   }

   return 0;
}

static int read__json_string(void *userdata, const char *string, size_t length)
{
   cheevos_readud_t *ud = (cheevos_readud_t*)userdata;

   if (ud->field)
   {
      ud->field->string = string;
      ud->field->length = length;
   }

   return 0;
}

static int read__json_number(void *userdata, const char *number, size_t length)
{
   cheevos_readud_t *ud = (cheevos_readud_t*)userdata;

   if (ud->field)
   {
      ud->field->string = number;
      ud->field->length = length;
   }

   return 0;
}

static int read__json_end_object(void *userdata)
{
   cheevos_readud_t *ud = (cheevos_readud_t*)userdata;

   if (ud->in_cheevos)
      return new_cheevo(ud);

   return 0;
}

static int read__json_end_array(void *userdata)
{
   cheevos_readud_t *ud = (cheevos_readud_t*)userdata;
   ud->in_cheevos = 0;
   return 0;
}

static int cheevos_parse(const char *json)
{
   static const jsonsax_handlers_t handlers =
   {
      NULL,
      NULL,
      NULL,
      read__json_end_object,
      NULL,
      read__json_end_array,
      read__json_key,
      NULL,
      read__json_string,
      read__json_number,
      NULL,
      NULL
   };

   static int initialize = 1;

   unsigned core_count, unofficial_count;
   cheevos_readud_t ud;

   /* Just return OK if cheevos are disabled. */
   if (!config_get_ptr()->cheevos.enable)
      return 0;

   /* Count the number of achievements in the JSON file. */

   if (count_cheevos(json, &core_count, &unofficial_count) != JSONSAX_OK)
      return -1;

   /* Allocate the achievements. */

   cheevos_locals.core.cheevos = (cheevo_t*)malloc(core_count * sizeof(cheevo_t));
   cheevos_locals.core.count = core_count;

   cheevos_locals.unofficial.cheevos = (cheevo_t*)malloc(unofficial_count * sizeof(cheevo_t));
   cheevos_locals.unofficial.count = unofficial_count;

   if (!cheevos_locals.core.cheevos || !cheevos_locals.unofficial.cheevos)
   {
      free((void*)cheevos_locals.core.cheevos);
      free((void*)cheevos_locals.unofficial.cheevos);
      cheevos_locals.core.count = cheevos_locals.unofficial.count = 0;

      return -1;
   }

   memset((void*)cheevos_locals.core.cheevos, 0, core_count * sizeof(cheevo_t));
   memset((void*)cheevos_locals.unofficial.cheevos, 0, unofficial_count * sizeof(cheevo_t));

   /* Load the achievements. */

   ud.in_cheevos = 0;
   ud.field = NULL;
   ud.core_count = 0;
   ud.unofficial_count = 0;

   if (!jsonsax_parse(json, &handlers, (void*)&ud) == JSONSAX_OK)
   {
      cheevos_unload();
      return -1;
   }
   
   if (initialize)
   {
      initialize = 0;
      cheevos_locals.jobs = async_job_new();
   }

   return -(cheevos_locals.jobs == NULL);
}

/*****************************************************************************
Test all the achievements (call once per frame).
*****************************************************************************/

static const uint8_t *get_memory(unsigned offset)
{
   size_t size = core.retro_get_memory_size( RETRO_MEMORY_SYSTEM_RAM );
   uint8_t *memory;

   if (offset < size)
   {
      memory = (uint8_t*)core.retro_get_memory_data(RETRO_MEMORY_SYSTEM_RAM);
      return memory + offset;
   }

   offset -= size;
   size = core.retro_get_memory_size(RETRO_MEMORY_SAVE_RAM);

   if (offset < size)
   {
      memory = (uint8_t*)core.retro_get_memory_data(RETRO_MEMORY_SAVE_RAM);
      return memory + offset;
   }

   offset -= size;
   size = core.retro_get_memory_size(RETRO_MEMORY_VIDEO_RAM);

   if (offset < size)
   {
      memory = (uint8_t*)core.retro_get_memory_data(RETRO_MEMORY_VIDEO_RAM);
      return memory + offset;
   }

   offset -= size;
   size = core.retro_get_memory_size(RETRO_MEMORY_RTC);

   if (offset < size)
   {
      memory = (uint8_t*)core.retro_get_memory_data(RETRO_MEMORY_RTC);
      return memory + offset;
   }

   return NULL;
}

static unsigned get_var_value(cheevos_var_t *var)
{
   unsigned previous = var->previous;
   unsigned live_val = 0;
   const uint8_t *memory;

   if (var->type == CHEEVOS_VAR_TYPE_VALUE_COMP)
      return var->value;

   if (var->type == CHEEVOS_VAR_TYPE_ADDRESS || var->type == CHEEVOS_VAR_TYPE_DELTA_MEM)
   {
      /* TODO Check with Scott if the bank id is needed */
      memory = get_memory(var->value);
      live_val = memory[0];

      if (var->size >= CHEEVOS_VAR_SIZE_BIT_0 && var->size <= CHEEVOS_VAR_SIZE_BIT_7)
         live_val = (live_val & (1 << (var->size - CHEEVOS_VAR_SIZE_BIT_0))) != 0;
      else if (var->size == CHEEVOS_VAR_SIZE_NIBBLE_LOWER)
         live_val &= 0x0f;
      else if (var->size == CHEEVOS_VAR_SIZE_NIBBLE_UPPER)
         live_val = (live_val >> 4) & 0x0f;
      else if (var->size == CHEEVOS_VAR_SIZE_EIGHT_BITS)
         ; /* nothing */
      else if (var->size == CHEEVOS_VAR_SIZE_SIXTEEN_BITS)
         live_val |= memory[1] << 8;
      else if (var->size == CHEEVOS_VAR_SIZE_THIRTYTWO_BITS)
      {
         live_val |= memory[1] << 8;
         live_val |= memory[2] << 16;
         live_val |= memory[3] << 24;
      }

      if (var->type == CHEEVOS_VAR_TYPE_DELTA_MEM)
      {
         var->previous = live_val;
         return previous;
      }

      return live_val;
   }

   /* We shouldn't get here... */
   return 0;
}

static int test_condition(cheevos_cond_t *cond)
{
   unsigned sval = get_var_value(&cond->source);
   unsigned tval = get_var_value(&cond->target);

   switch (cond->op)
   {
      case CHEEVOS_COND_OP_EQUALS:
         return sval == tval;

      case CHEEVOS_COND_OP_LESS_THAN:
         return sval < tval;

      case CHEEVOS_COND_OP_LESS_THAN_OR_EQUAL:
         return sval <= tval;

      case CHEEVOS_COND_OP_GREATER_THAN:
         return sval > tval;

      case CHEEVOS_COND_OP_GREATER_THAN_OR_EQUAL:
         return sval >= tval;

      case CHEEVOS_COND_OP_NOT_EQUAL_TO:
         return sval != tval;

      default:
         return 1;
   }
}

static int test_cond_set(const cheevos_condset_t *condset, int *dirty_conds, int *reset_conds, int match_any)
{
   int cond_valid = 0;
   int set_valid = 1;
   const cheevos_cond_t *end = condset->conds + condset->count;
   cheevos_cond_t *cond;

   /* Now, read all Pause conditions, and if any are true, do not process further (retain old state) */
   for (cond = condset->conds; cond < end; cond++)
   {
      if (cond->type == CHEEVOS_COND_TYPE_PAUSE_IF)
      {
         /* Reset by default, set to 1 if hit! */
         cond->curr_hits = 0;

         if (test_condition(cond))
         {
            cond->curr_hits = 1;
            *dirty_conds = 1;

            /* Early out: this achievement is paused, do not process any further! */
            return 0;
         }
      }
   }

   /* Read all standard conditions, and process as normal: */
   for (cond = condset->conds; cond < end; cond++)
   {
      if (cond->type == CHEEVOS_COND_TYPE_PAUSE_IF || cond->type == CHEEVOS_COND_TYPE_RESET_IF)
         continue;

      if (cond->req_hits != 0 && cond->curr_hits >= cond->req_hits)
         continue;

      cond_valid = test_condition(cond);

      if (cond_valid)
      {
         cond->curr_hits++;
         *dirty_conds = 1;

         /* Process this logic, if this condition is true: */
         if (cond->req_hits == 0)
            ; /* Not a hit-based requirement: ignore any additional logic! */
         else if (cond->curr_hits < cond->req_hits)
            cond_valid = 0; /* Not entirely valid yet! */

         if (match_any)
            break;
      }

      /* Sequential or non-sequential? */
      set_valid &= cond_valid;
   }

   /* Now, ONLY read reset conditions! */
   for (cond = condset->conds; cond < end; cond++)
   {
      if (cond->type == CHEEVOS_COND_TYPE_RESET_IF)
      {
         cond_valid = test_condition(cond);

         if (cond_valid)
         {
            *reset_conds = 1; /* Resets all hits found so far */
            set_valid = 0;    /* Cannot be valid if we've hit a reset condition. */
            break;            /* No point processing any further reset conditions. */
         }
      }
   }

   return set_valid;
}

static int reset_cond_set(cheevos_condset_t *condset, int deltas)
{
   int dirty = 0;
   const cheevos_cond_t *end = condset->conds + condset->count;
   cheevos_cond_t *cond;

   if (deltas)
   {
      for (cond = condset->conds; cond < end; cond++)
      {
         dirty |= cond->curr_hits != 0;
         cond->curr_hits = 0;

         cond->source.previous = cond->source.value;
         cond->target.previous = cond->target.value;
      }
   }
   else
   {
      for (cond = condset->conds; cond < end; cond++)
      {
         dirty |= cond->curr_hits != 0;
         cond->curr_hits = 0;
      }
   }

   return dirty;
}

static int test_cheevo(cheevo_t *cheevo)
{
   int dirty_conds = 0;
   int reset_conds = 0;
   int ret_val = 0;
   int ret_val_sub_cond = cheevo->count == 1;
   cheevos_condset_t *condset = cheevo->condsets;
   const cheevos_condset_t *end = condset + cheevo->count;
   int dirty;

   if (condset < end)
   {
      ret_val = test_cond_set(condset, &dirty_conds, &reset_conds, 0);
      condset++;
   }

   while (condset < end)
   {
      int res = test_cond_set(condset, &dirty_conds, &reset_conds, 0);
      ret_val_sub_cond |= res;
      condset++;
   }

   if (dirty_conds)
      cheevo->dirty |= CHEEVOS_DIRTY_CONDITIONS;

   if (reset_conds)
   {
      dirty = 0;

      for (condset = cheevo->condsets; condset < end; condset++)
         dirty |= reset_cond_set(condset, 0);

      if (dirty)
         cheevo->dirty |= CHEEVOS_DIRTY_CONDITIONS;
   }

   return ret_val && ret_val_sub_cond;
}

static int cheevos_login(retro_time_t *timeout)
{
   const char *username;
   const char *password;
   char request[256];
   const char *json;
   int res;

   if (cheevos_locals.token[0])
      return 0;
   
   username = config_get_ptr()->cheevos.username;
   password = config_get_ptr()->cheevos.password;
   
   if (!username || !*username || !password || !*password)
   {
      rarch_main_msg_queue_push("Missing Retro Achievements account information", 0, 5 * 60, false);
      rarch_main_msg_queue_push("Please fill in your account information in Settings", 0, 5 * 60, false);
      RARCH_LOG("CHEEVOS username and/or password not informed\n");
      return -1;
   }

   snprintf(
      request, sizeof(request),
      "http://retroachievements.org/dorequest.php?r=login&u=%s&p=%s",
      username, password
   );

   request[sizeof(request) - 1] = 0;

   if (!http_get(&json, NULL, request, timeout))
   {
      res = cheevos_get_value(json, 0x0e2dbd26U /* Token */, cheevos_locals.token, sizeof(cheevos_locals.token));
      free((void*)json);

      if (!res)
      {
         RARCH_LOG("CHEEVOS user token is '%s'\n", cheevos_locals.token);
         return 0;
      }
   }

   rarch_main_msg_queue_push("Retro Achievements login error", 0, 5 * 60, false);
   rarch_main_msg_queue_push("Please make sure your account information is correct", 0, 5 * 60, false);
   RARCH_LOG("CHEEVOS error getting user token\n");
   return -1;
}

static void cheevo_unlocker(void *payload)
{
   cheevo_t *cheevo = (cheevo_t*)payload;
   char request[256];
   const char *result;

   if (!cheevos_login(NULL))
   {
      snprintf(
         request, sizeof(request),
         "http://retroachievements.org/dorequest.php?r=awardachievement&u=%s&t=%s&a=%u&h=%d",
         config_get_ptr()->cheevos.username, cheevos_locals.token, cheevo->id, 0
      );

      request[sizeof(request) - 1] = 0;
      RARCH_LOG("CHEEVOS awarding achievement %u: %s\n", cheevo->id, request);

      if (!http_get(&result, NULL, request, NULL))
      {
         RARCH_LOG("CHEEVOS awarded achievement %u: %s\n", cheevo->id, result);
         free((void*)result);
      }
      else
         RARCH_LOG("CHEEVOS error awarding achievement %u\n", cheevo->id);
   }
}

static void test_cheevo_set(const cheevoset_t *set)
{
   const cheevo_t *end = set->cheevos + set->count;
   cheevo_t *cheevo;

   for (cheevo = set->cheevos; cheevo < end; cheevo++)
   {
      if (cheevo->active && test_cheevo(cheevo))
      {
         RARCH_LOG("CHEEVOS %s\n", cheevo->title);
         RARCH_LOG("CHEEVOS %s\n", cheevo->description);

         rarch_main_msg_queue_push(cheevo->title, 0, 3 * 60, false);
         rarch_main_msg_queue_push(cheevo->description, 0, 5 * 60, false);

         async_job_add(cheevos_locals.jobs, cheevo_unlocker, (void*)cheevo);

         cheevo->active = 0;
      }
   }
}

void cheevos_test(void)
{
   if (config_get_ptr()->cheevos.enable && !cheevos_globals.cheats_are_enabled && !cheevos_globals.cheats_were_enabled)
   {
      test_cheevo_set(&cheevos_locals.core);

      if (config_get_ptr()->cheevos.test_unofficial)
         test_cheevo_set(&cheevos_locals.unofficial);
   }
}

/*****************************************************************************
Free the loaded achievements.
*****************************************************************************/

static void free_condset(const cheevos_condset_t *set)
{
   free((void*)set->conds);
}

static void free_cheevo(const cheevo_t *cheevo)
{
   free((void*)cheevo->title);
   free((void*)cheevo->description);
   free((void*)cheevo->author);
   free((void*)cheevo->badge);
   free_condset(cheevo->condsets);
}

static void free_cheevo_set(const cheevoset_t *set)
{
   const cheevo_t *cheevo = set->cheevos;
   const cheevo_t *end = cheevo + set->count;

   while (cheevo < end)
   {
      free_cheevo(cheevo++);
   }

   free((void*)set->cheevos);
}

void cheevos_unload(void)
{
   if (cheevos_locals.loaded)
   {
      free_cheevo_set(&cheevos_locals.core);
      free_cheevo_set(&cheevos_locals.unofficial);
      
      cheevos_locals.loaded = 0;
   }
}

/*****************************************************************************
Load achievements from retroachievements.org.
*****************************************************************************/

static int cheevos_get_by_game_id(const char **json, unsigned game_id, retro_time_t *timeout)
{
   char request[256];

   /* Just return OK if cheevos are disabled. */
   if (!config_get_ptr()->cheevos.enable)
      return 0;

   if (!cheevos_login(timeout))
   {
      snprintf(
         request, sizeof(request),
         "http://retroachievements.org/dorequest.php?r=patch&u=%s&g=%u&f=3&l=1&t=%s",
         config_get_ptr()->cheevos.username, game_id, cheevos_locals.token
      );

      request[sizeof(request) - 1] = 0;

      if (!http_get(json, NULL, request, timeout))
      {
         RARCH_LOG("CHEEVOS got achievements for game id %u\n", game_id);
         return 0;
      }

      RARCH_LOG("CHEEVOS error getting achievements for game id %u\n", game_id);
   }

   return -1;
}

static unsigned cheevos_get_game_id(unsigned char *hash, retro_time_t *timeout)
{
   char request[256];
   const char* json;
   char game_id[16];
   int res;
   
   RARCH_LOG(
      "CHEEVOS getting game id for hash %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n",
      hash[ 0], hash[ 1], hash[ 2], hash[ 3],
      hash[ 4], hash[ 5], hash[ 6], hash[ 7],
      hash[ 8], hash[ 9], hash[10], hash[11],
      hash[12], hash[13], hash[14], hash[15]
   );

   snprintf(
      request, sizeof(request),
      "http://retroachievements.org/dorequest.php?r=gameid&u=%s&m=%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
      config_get_ptr()->cheevos.username,
      hash[ 0], hash[ 1], hash[ 2], hash[ 3],
      hash[ 4], hash[ 5], hash[ 6], hash[ 7],
      hash[ 8], hash[ 9], hash[10], hash[11],
      hash[12], hash[13], hash[14], hash[15]
   );

   request[sizeof(request) - 1] = 0;

   if (!http_get(&json, NULL, request, timeout))
   {
      res = cheevos_get_value(json, 0xb4960eecU /* GameID */, game_id, sizeof(game_id));
      free((void*)json);

      if (!res)
      {
         RARCH_LOG("CHEEVOS got game id %s\n", game_id);
         return strtoul(game_id, NULL, 10);
      }
   }

   RARCH_LOG("CHEEVOS error getting game_id\n");
   return 0;
}

static int cheevos_playing_activity(unsigned game_id, retro_time_t *timeout)
{
   char request[256];
   const char* json;
   
   if (!cheevos_login(timeout))
   {
      snprintf(
         request, sizeof(request),
         "http://retroachievements.org/dorequest.php?r=postactivity&u=%s&t=%s&a=3&m=%u",
         config_get_ptr()->cheevos.username, cheevos_locals.token, game_id
      );

      request[sizeof(request) - 1] = 0;

      if (!http_get(&json, NULL, request, timeout))
      {
         free((void*)json);
         RARCH_LOG("CHEEVOS posted playing game %u activity\n", game_id);
         return 0;
      }
      else
         RARCH_LOG("CHEEVOS error posting playing game %u activity\n", game_id);
   }
   
   return -1;
}

typedef struct
{
   int is_element;
} cheevos_deactivate_t;

static int deactivate__json_index(void *userdata, unsigned int index)
{
   cheevos_deactivate_t *ud = (cheevos_deactivate_t*)userdata;
   ud->is_element = 1;
   return 0;
}

static int deactivate__json_number(void *userdata, const char *number, size_t length)
{
   cheevos_deactivate_t *ud = (cheevos_deactivate_t*)userdata;
   cheevo_t* cheevo;
   const cheevo_t* end;
   long id;
   int found;
   
   if (ud->is_element)
   {
      ud->is_element = 0;
      id = strtol(number, NULL, 10);
      found = 0;
      
      for (cheevo = cheevos_locals.core.cheevos, end = cheevo + cheevos_locals.core.count; cheevo < end; cheevo++)
      {
         if (cheevo->id == id)
         {
            cheevo->active = 0;
            found = 1;
            break;
         }
      }
      
      if (!found)
      {
         for (cheevo = cheevos_locals.unofficial.cheevos, end = cheevo + cheevos_locals.unofficial.count; cheevo < end; cheevo++)
         {
            if (cheevo->id == id)
            {
               cheevo->active = 0;
               break;
            }
         }
      }
   }
   
   return 0;
}

static int cheevos_deactivate_unlocks(unsigned game_id, retro_time_t *timeout)
{
   /* Only call this function after the cheevos have been loaded. */
   
   static const jsonsax_handlers_t handlers =
   {
      NULL,
      NULL,
      NULL,
      NULL,
      NULL,
      NULL,
      NULL,
      deactivate__json_index,
      NULL,
      deactivate__json_number,
      NULL,
      NULL
   };
   
   char request[256];
   const char* json;
   cheevos_deactivate_t ud;
   int res;
   
   if (!cheevos_login(timeout))
   {
      snprintf(
         request, sizeof(request),
         "http://retroachievements.org/dorequest.php?r=unlocks&u=%s&t=%s&g=%u&h=0",
         config_get_ptr()->cheevos.username, cheevos_locals.token, game_id
      );

      request[sizeof(request) - 1] = 0;

      if (!http_get(&json, NULL, request, timeout))
      {
         ud.is_element = 0;
         res = jsonsax_parse(json, &handlers, (void*)&ud);
         free((void*)json);
         
         if (res == JSONSAX_OK)
         {
            RARCH_LOG("CHEEVOS deactivated unlocked achievements\n");
            return 0;
         }
      }
   }
   
   RARCH_LOG("CHEEVOS error deactivating unlocked achievements\n");
   return -1;
}

#define CHEEVOS_EIGHT_MB (8 * 1024 * 1024)

int cheevos_load(const void *data, size_t size)
{
   const char *json;
   MD5_CTX ctx, saved_ctx;
   retro_time_t timeout;
   char buffer[4096];
   size_t len;
   unsigned char hash[16];
   unsigned game_id;

   /* Just return OK if cheevos are disabled. */
   if (!config_get_ptr()->cheevos.enable)
      return 0;

   MD5_Init(&ctx);
   MD5_Update(&ctx, data, size);
   saved_ctx = ctx;
   MD5_Final(hash, &ctx);

   timeout = 15000000;
   game_id = cheevos_get_game_id(hash, &timeout);

   if (!game_id && size < CHEEVOS_EIGHT_MB)
   {
      /* Maybe the content is a SNES game, continue MD5 with zeroes up to 8 MB. */
      size = CHEEVOS_EIGHT_MB - size;
      memset((void*)buffer, 0, sizeof(buffer));

      do
      {
         len = sizeof(buffer);

         if (len > size)
            len = size;

         MD5_Update(&saved_ctx, (void*)buffer, len);
         size -= len;
      }
      while (size);

      MD5_Final(hash, &saved_ctx);

      game_id = cheevos_get_game_id(hash, &timeout);
   }

   if (game_id)
   {
      cheevos_playing_activity(game_id, &timeout);
      
      if (!cheevos_get_by_game_id(&json, game_id, &timeout))
      {
         if (!cheevos_parse(json))
         {
            cheevos_deactivate_unlocks(game_id, &timeout);
            free((void*)json);
            cheevos_locals.loaded = 1;
            
            return 0;
         }
         
         free((void*)json);
      }
      
      rarch_main_msg_queue_push("Error loading achievements", 0, 5 * 60, false);
   }
   else
      rarch_main_msg_queue_push("This game doesn't feature achievements", 0, 5 * 60, false);
   
   cheevos_locals.loaded = 0;
   return -1;
}