/*!@file
  \brief   IR Memory Implementation
  \details Intermediary memory management
  \author  Jordan Lavatai
  \date    Aug 2016
  ----------------------------------------------------------------------------*/
/* Standard */
#include <stdlib.h> //exit, malloc
#include <stdio.h>  //print
#include <stdarg.h> //va_args
#include <stdint.h> //uint64_t
#include <string.h> //memset, str*
/* Unicode */
#include <unistd.h>   //u8_* functions
#include <unitypes.h> //uint8_t as a char
#include <unistr.h>   //u32_cpy
/* Local */
#include "apc.h"
#include "ir.h"
/* Public */
int      ir_init(void);
void     ir_quit(void);
int      ir_linker(void);
int      ir_condenser(void);
/* Private */
struct pagenode_t;
extern //apc.c
long sys_pagesize;
static inline
struct ir_framebox_t* ir_set_add_framebox(struct ir_set_t*, uint8_t*);
static
void                  ir_free_pages(struct pagenode_t*);
static inline
int                   bytes_identical(uint8_t*,uint8_t*);
static
void*                 stack_alloc(size_t);
/* Memory allocator */
struct pagenode_t {
  struct pagenode_t* next;
  char*              head;
  char               root[];
}* pagenode_root, * pagenode_head;
#define PN_ALLOCSIZE    (sys_pagesize)
#define PN_HEADERSIZE() (sizeof(struct pagenode_t*) + sizeof(char*))
#define PN_MEMSIZE()    (PN_ALLOCSIZE - PN_HEADERSIZE())
#define PN_HEADSIZE()   (pagenode_head->head - pagenode_head->root)
#define PN_HEADSPACE()  (PN_MEMSIZE() - PN_HEADSIZE())
/* Enumerated types */
enum dtype { FSDAT, MSDAT, ADAT, LDAT, FBDAT };
enum ltype { OLINK, MLINK, VLINK, ALINK };
/* Set link data */
struct ir_namelist_t;
struct ir_namelist_t
{ struct ir_namelist_t* nextsib;
  uint8_t*              name;
};
struct ir_classld_t
{ struct ir_class_t*    root_class;
  struct ir_namelist_t* namelist;
};
struct ir_setld_t
{ struct classld_t*     classld;
  long long             ref;
  struct ir_namelist_t* namelist;
};
/* Set data mem */
struct ir_setdata_header_t
{ enum dtype          type;
  uint8_t*            src_filename, * data_name;
  union ir_setdata_t* nextsib;
};
struct ir_frameinfo_t
{ int facing, w, h; };
struct ir_framedata_t
{ struct ir_setdata_header_t header;
  struct ir_frameinfo_t      frameinfo;
};
struct ir_framebox_t
{ struct ir_setdata_header_t header;
  struct ir_framedata_t      framesheets[FACING_MAX];
  struct ir_framedata_t      mapsheets[FACING_MAX];
};
struct ir_simplex_t
{ struct ir_setdata_header_t header; };
struct ir_link_t
{ struct ir_setdata_header_t header;
  struct ir_classld_t*       classld;
  struct ir_setld_t*         setld;
  enum ltype                 type;
};
union ir_setdata_t
{ struct ir_setdata_header_t  header;
  struct ir_framebox_t        framebox;
  struct ir_framedata_t       framesheet;
  struct ir_framedata_t       mapsheet;
  struct ir_simplex_t         audio;
  struct ir_link_t            link;
};
struct ir_class_t
{ struct ir_class_t* nextchild, * nextsib;
  struct ir_set_t*   root_set;
  uint8_t*           name;
};
struct ir_set_t
{ struct ir_set_t*      nextchild, * nextsib;
  struct ir_class_t*    class;
  long long             ref;
  uint8_t*              name;
  struct ir_framebox_t* frameboxes;
  struct ir_simplex_t*  audio;
  struct ir_link_t*     links;
};
/* Function-Like Macros */
#define do_warn() do {				\
  } while (0)
#define wprint(str) do {			\
    fprintf(stderr, str);			\
    do_warn();					\
  } while (0)
#define wprintf(fmt,...) do {			\
    fprintf(stderr, fmt, __VA_ARGS__);		\
    do_warn();					\
  } while (0)
#define do_error() do {				\
    exit(-1);					\
  } while (0)
#define eprint(str) do {			\
    fprintf(stderr, str);			\
    do_error();					\
  } while (0)
#define eprintf(fmt,...) do {			\
    fprintf(stderr, fmt, __VA_ARGS__);		\
    do_error();					\
  } while (0)
#define struct_alloc(_T) ((struct _T*) stack_alloc(sizeof(struct _T)))

static
struct ir_class_t root_class = { .name = (uint8_t*)"." };

/* Init */
int ir_init
( void )
{ pagenode_root = (struct pagenode_t*) calloc((size_t)PN_ALLOCSIZE,1);
  if (pagenode_root == NULL)
    return -1;
  pagenode_root->head = pagenode_root->root;
  pagenode_head = pagenode_root;
  return 0;
} 

/* Quit/Cleanup
   Recursively clean pagenode linked list
*/
void ir_quit
( void )
{ ir_free_pages(pagenode_root); }

static
void ir_free_pages
( struct pagenode_t* pagenode )
{ if (pagenode->next != NULL)
    ir_free_pages(pagenode->next);
  free(pagenode);
}

/* Link
*/
int ir_linker
( void )
{ return 0; }

/* Condense
*/
int ir_condenser
( void )
{ return 0; }

/* Return a pointer to the root class */
struct ir_class_t* ir_class_root
( void )
{ return &root_class; }

/* Add a subclass to a class
   Attempts to create a new subclass in the provided class, returning
   the class if it already exists
*/
struct ir_class_t* ir_class_addchild
( struct ir_class_t* class,
  uint8_t*           name
)
{ struct ir_class_t* iter;
  if (class->nextchild == NULL)
    return class->nextchild = struct_alloc(ir_class_t);
  iter = class->nextchild;
 check:
  if (bytes_identical(iter->name, name))
    return iter;
  if (iter->nextsib != NULL)
    { iter = iter->nextsib;
      goto check;
    }
  iter = struct_alloc(ir_class_t);
  iter->nextsib = class->nextchild;
  return class->nextchild = iter;
}

/* Add a set to a class
   Attempts to create a new root set in the specified class, returning
   the set if it already exists
*/
struct ir_set_t* ir_class_addset
( struct ir_class_t* class,
  uint8_t*           name
)
{ struct ir_set_t* iter;
  if (class->root_set == NULL)
    return class->root_set = struct_alloc(ir_set_t);
  iter = class->root_set;
 check:
  if (bytes_identical(iter->name, name))
    return iter;
  if (iter->nextsib != NULL)
    { iter = iter->nextsib;
      goto check;
    }
  iter = struct_alloc(ir_set_t);
  iter->nextsib = class->root_set;
  return class->root_set = iter;
}

/* Add a set to a set
   Attempts to create a new subset of the specified set, returning the
   child if it already exists
*/
struct ir_set_t* ir_set_addchild
( struct ir_set_t* set,
  uint8_t*         name
)
{ struct ir_set_t* iter;
  if (set->nextchild == NULL)
    return set->nextchild = struct_alloc(ir_set_t);
  iter = set->nextchild;
 check:
  if (bytes_identical(iter->name, name))
    return iter;
  if (iter->nextsib != NULL)
    { iter = iter->nextsib;
      goto check;
    }
  iter = struct_alloc(ir_set_t);
  iter->nextsib = set->nextchild;
  return set->nextchild = iter;
}

/* Add a framebox to a set
   Attempts to create a new framebox of the specified set, returning
   the framebox if it already exists
*/
static inline
struct ir_framebox_t* ir_set_add_framebox
( struct ir_set_t* set,
  uint8_t*         name
)
{ struct ir_framebox_t* iter;
  if (set->frameboxes == NULL)
    return set->frameboxes = struct_alloc(ir_framebox_t);
  iter = set->frameboxes;
 check:
  if (bytes_identical(iter->header.data_name, name))
    return iter;
  if (iter->header.nextsib != NULL)
    { iter = (struct ir_framebox_t*) iter->header.nextsib;
      goto check;
    }
  iter = struct_alloc(ir_framebox_t);
  iter->header.nextsib = (union ir_setdata_t*) set->frameboxes;
  return set->frameboxes = iter;
}

/* Match two null-terminated bytestrings
   Return 1 if the two bytestrings are identical, else 0
*/
static inline
int bytes_identical
( uint8_t* stra,
  uint8_t* strb
)
{ int ca, cb;
  do {
    ca = *stra++;
    cb = *strb++;
  } while (ca && ca == cb);
  return (ca == cb);
}

/* Assign Setdata to Set

 */
void ir_set_assign_data
( struct ir_set_t*      set,
  union  ir_setdata_t*  setdata
)
{ struct ir_framebox_t* framebox;
  struct ir_simplex_t*  simplex;
  switch (setdata->header.type)
    { case FSDAT:
	framebox = ir_set_add_framebox(set, setdata->header.data_name);
	if (framebox->framesheets[setdata->framesheet.frameinfo.facing].header.data_name != NULL)
	  wprintf("Duplicate framesheet [%i] %s\n",
		  setdata->framesheet.frameinfo.facing, setdata->header.data_name);
	framebox->framesheets[setdata->framesheet.frameinfo.facing] = setdata->framesheet;
	break;
      case MSDAT:
	framebox = ir_set_add_framebox(set, setdata->header.data_name);
	if (framebox->mapsheets[setdata->mapsheet.frameinfo.facing].header.data_name != NULL)
	  wprintf("Duplicate mapsheet [%i] %s\n",
		  setdata->mapsheet.frameinfo.facing, setdata->header.data_name);
	framebox->mapsheets[setdata->mapsheet.frameinfo.facing] = setdata->mapsheet;
	break;
      case ADAT:
	if (set->audio == NULL)
	  { set->audio = (struct ir_simplex_t*) setdata;
	    return;
	  }
	simplex = set->audio;
	while (simplex->header.nextsib != NULL)
	  if (bytes_identical(simplex->header.data_name, setdata->header.data_name))
	    { wprintf("Duplicate audio %s\n", setdata->header.data_name);
	      *simplex = setdata->audio;
	      //setdata is now a pointer to redundant, unused memory.
	      return;
	    }
	  else
	    simplex = (struct ir_simplex_t*) simplex->header.nextsib;
	simplex->header.nextsib = setdata;
	break;
      case LDAT:
	setdata->link.header.nextsib = (union ir_setdata_t*) set->links;
	set->links = (struct ir_link_t*) setdata;
	break;
      default:
	fprintf(stderr, "Unknown setdata type %x\n", setdata->header.type);
	exit(-1);
    }
}

void ir_set_assign_ref
( struct ir_set_t* set,
  long long        ref
)
{ if (set->ref != 0)
    wprintf("Ref override: 0x%lx -> 0x%lx for set %s\n",
	    (long unsigned) set->ref, (long unsigned) ref, set->name);
  set->ref = ref;
  //TODO: reflist_add(set);
}

void ir_data_assign_path
( union ir_setdata_t* setdata,
  uint8_t*            path
)
{ setdata->header.src_filename = path;
  //TODO: internal strdup, not assign (= path;)
}


//TODO: Macro ir_framsheet and mapsheet?
union ir_setdata_t* ir_framesheet
( uint8_t* name,
  apc_facing d,
  int width,
  int height
)
{ struct ir_framedata_t* framesheet = struct_alloc(ir_framedata_t);
  framesheet->header.type = FSDAT;
  framesheet->header.data_name = name;
  framesheet->frameinfo.facing = d;
  framesheet->frameinfo.w = width;
  framesheet->frameinfo.h = height;
  return (union ir_setdata_t*) framesheet; 
}

union ir_setdata_t* ir_mapsheet
( uint8_t* name,
  apc_facing d,
  int width,
  int height
)
{ struct ir_framedata_t* mapsheet = struct_alloc(ir_framedata_t);
  mapsheet->header.type = MSDAT;
  mapsheet->header.data_name = name;
  mapsheet->frameinfo.facing = d;
  mapsheet->frameinfo.w = width;
  mapsheet->frameinfo.h = height;
  return (union ir_setdata_t*) mapsheet;
}

union ir_setdata_t* ir_audio
( uint8_t* name )
{ struct ir_simplex_t* audio = struct_alloc(ir_simplex_t);
  audio->header.type = ADAT;
  audio->header.data_name = name;
  return (union ir_setdata_t*) audio;
}

static
void* stack_alloc(size_t bytes)
{ if (!bytes)
    { wprint("Attempting to allocate 0 bytes in stack_alloc");
      return pagenode_head->head;
    }
  if (PN_HEADSPACE() < bytes) 
    { pagenode_head->next = (struct pagenode_t*) calloc(PN_ALLOCSIZE,1);
      pagenode_head = pagenode_head->next;
      pagenode_head->head = pagenode_head->root;
    }
  pagenode_head->head += bytes;
  return (void*) pagenode_head->head - bytes;
}