/*!@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
#include <unistdio.h> //ulc_fprintf
/* Local */
#include "print.h"
#include "apc.h"
#include "ir.h"
#undef  do_error
#define do_error(...) exit(-1)
#define XXH_PRIVATE_API
#include "../xxHash/xxhash.h"
/* Public */
int      ir_init(void);
void     ir_quit(void);
void     ir_test(void);
int      ir_linker(void);
int      ir_condenser(void);
/* Memory allocation structures */
struct pagenode_t;
struct pagenode_header_t {
  struct pagenode_t* next;
  char*              head;
};
struct pagenode_t {
  struct pagenode_header_t header;
  char                     root[];
};
struct pagelist_t {
  struct pagenode_t* root, * head;
  size_t             pagesize;
};
#define SYS_PAGESIZE     (sys_pagesize)
#define NAME_PAGESIZE    (APC_NAME_MAX * 1024)
#define PL_HEADERSIZE    (sizeof(struct pagenode_header_t))
#define PL_HEADSIZE(_PL) (_PL.head->header.head - _PL.head->root)
#define PL_HEADMEM(_PL)  (_PL.pagesize - PL_HEADERSIZE - PL_HEADSIZE(_PL))
/* Set data mem */
enum dtype { FSDAT, MSDAT, ADAT, LDAT, FBDAT };
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, * namelist_head;
};
struct ir_setld_t
{ struct ir_classld_t*  classld;
  long long             ref;
  struct ir_namelist_t* namelist, * namelist_head;
};
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;
  uint32_t              ref;
  uint8_t*              name;
  struct ir_framebox_t* frameboxes;
  struct ir_simplex_t*  audio;
  struct ir_link_t*     links;
};
/* Functions */
static inline
struct ir_framebox_t* ir_set_add_framebox(struct ir_set_t*,uint8_t*);
static inline
union ir_setdata_t*   ir_framedata (enum dtype,const uint8_t*,apc_facing,int,int);
static inline
int      bytes_identical(const uint8_t*,const uint8_t*);
static inline
int      classnames_identical(const uint8_t*,const uint8_t*);
static
void*    stack_alloc(size_t);
#define  struct_alloc(_T) ((struct _T*) stack_alloc(sizeof(struct _T)))
#define  struct_clear(_S) (memset((_S), 0, sizeof(*(_S))))
static
uint8_t* name_alloc(const uint8_t*);
static
uint8_t* classname_alloc(const uint8_t*);
static inline
void*    pagelist_pop(struct pagelist_t*,size_t);
#define $($)#$
#define  pagelist_alloc(pagelist) do {					\
    pagelist.head->header.next = (struct pagenode_t*) malloc(pagelist.pagesize); \
    if (pagelist.head->header.next == NULL)				\
      eprintf("Memory allocation error\n");				\
    struct_clear(pagelist.head->header.next);				\
    pagelist.head = pagelist.head->header.next;				\
    pagelist.head->header.head = pagelist.head->root;			\
  } while (0)
#define  pagelist_init(pagelist,size) do {			\
    pagelist.pagesize = size;					\
    pagelist.root = (struct pagenode_t*) malloc(size);		\
    if (pagelist.root == NULL)					\
      eprintf("Memory allocation error\n");			\
    struct_clear(pagelist.root);				\
    pagelist.head = pagelist.root;				\
    pagelist.head->header.head = pagelist.head->root;		\
  } while (0)
static
void     pagenode_free(struct pagenode_t*);
#define  REFHASH(ref) (XXH32(&ref, sizeof(uint32_t), 0xCEED) & 0xCFF)

extern //apc.c
long     sys_pagesize;
static
struct pagelist_t datapages, namepages, refhashpages;
static
struct ir_class_t root_class = { .name = (uint8_t*)"." };

/* Init */
int ir_init
( void )
{ pagelist_init(datapages, (size_t)SYS_PAGESIZE);
  pagelist_init(namepages, (size_t)NAME_PAGESIZE);
  pagelist_init(refhashpages, (size_t)SYS_PAGESIZE);
  return 0;
}

/* Quit/Cleanup */
void ir_quit
( void )
{ pagenode_free(datapages.root);
  pagenode_free(namepages.root);
  pagenode_free(refhashpages.root);
}

/* Recursively clean pagenode linked list, freeing last first */
static
void pagenode_free
( struct pagenode_t* pagenode )
{ if (pagenode->header.next != NULL)
    pagenode_free(pagenode->header.next);
  free(pagenode);
}

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

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

/* Return the class's name string */
uint8_t* ir_class_name
( struct ir_class_t* class )
{ return class->name; }

/* 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,
  const uint8_t*     name
)
{ struct ir_class_t* iter;
  if (class->nextchild == NULL)
    { class->nextchild = struct_alloc(ir_class_t);
      struct_clear(class->nextchild);
      class->nextchild->name = classname_alloc(name);
      return class->nextchild;
    }
  iter = class->nextchild;
  if (iter->name == NULL)
    eprintf("Null name pointer in class %p\n", iter);
  if (name == NULL)
    eprintf("Null child added to class %s\n", iter->name);
 check:
  if (classnames_identical(iter->name, name))
    return iter;
  if (iter->nextsib != NULL)
    { iter = iter->nextsib;
      goto check;
    }
  iter->nextsib = struct_alloc(ir_class_t);
  struct_clear(iter->nextsib);
  iter->nextsib->name = classname_alloc(name);
  return iter->nextsib;
}

/* 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,
  const uint8_t*     name
)
{ struct ir_set_t* iter;
  if (class->root_set == NULL)
    { class->root_set = struct_alloc(ir_set_t);
      struct_clear(class->root_set);
      class->root_set->name = name_alloc(name);
      return class->root_set;
    }
  iter = class->root_set;
  if (iter->name == NULL)
    eprintf("Null name pointer in class %p\n", iter);
  if (name == NULL)
    eprintf("Null set added to class %U\n", iter->name);
 check:
  if (bytes_identical(iter->name, name))
    return iter;
  if (iter->nextsib != NULL)
    { iter = iter->nextsib;
      goto check;
    }
  iter->nextsib = struct_alloc(ir_set_t);
  struct_clear(iter->nextsib);
  iter->nextsib->name = name_alloc(name);
  return iter->nextsib;
}

struct ir_set_t* ir_set_from_ref
( uint32_t ref )
{ uint16_t hash;
  struct ir_set_t** iters;
  struct pagenode_t* iterp;
  iterp = refhashpages.root;
  hash = REFHASH(ref);
  do
    iters = ((struct ir_set_t**) iterp->root) + hash;
  while (*iters != NULL && (*iters)->ref != ref && (iterp = iterp->header.next) != NULL);
  return *iters;
}


/* 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,
  const uint8_t*   name
)
{ struct ir_set_t* iter;
  if (set->nextchild == NULL)
    { set->nextchild = struct_alloc(ir_set_t);
      struct_clear(set->nextchild);
      set->nextchild->name = name_alloc(name);
      return set->nextchild;
    }
  iter = set->nextchild;
  if (name == NULL)
    eprintf("Null child added to set %s\n", iter->name);
  if (iter->name == NULL)
    eprintf("Null name pointer in set %p\n", iter);
 check:
  if (bytes_identical(iter->name, name))
    return iter;
  if (iter->nextsib != NULL)
    { iter = iter->nextsib;
      goto check;
    }
  iter->nextsib = struct_alloc(ir_set_t);
  struct_clear(iter->nextsib);
  iter->nextsib->name = name_alloc(name);
  return iter->nextsib;
}

/* Add a framebox to a set
   Attempts to create a new framebox of the specified set, returning
   the framebox if it already exists
   Name is not allocated, but assigned, unlike other "XXX_add" functions where
   name is duplicated into IR's internal array.
*/
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)
    { set->frameboxes = struct_alloc(ir_framebox_t);
      struct_clear(set->frameboxes);
      set->frameboxes->header.data_name = name;
      return set->frameboxes;
    }
  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->header.nextsib = (union ir_setdata_t*) struct_alloc(ir_framebox_t);
  struct_clear(iter->header.nextsib);
  iter->header.nextsib->header.data_name = name;
  return (struct ir_framebox_t*) (iter->header.nextsib);
}

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

static inline
int classnames_identical
( const uint8_t* stra,
  const 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;
	setdata->audio.header.nextsib = (union ir_setdata_t*) set->audio;
        set->audio = (struct ir_simplex_t*) 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,
  uint32_t         ref
)
{ uint16_t hash, oldhash;
  struct ir_set_t** iters;
  struct pagenode_t* iterp;
  uint32_t           oldref;
  oldref = set->ref;
  oldhash = 0;
  hash = REFHASH(ref);
  iterp = refhashpages.root;
 check_depth:
  iters = ((struct ir_set_t**) iterp->root) + hash;
  if (*iters == NULL || *iters == set)
    *iters = set;
  else
    { if (iterp->header.next == NULL)
	pagelist_alloc(refhashpages);
      iterp = iterp->header.next;
      goto check_depth;
    }
  if (oldref != 0)
    { wprintf("Ref override: 0x%x -> 0x%x for set %s\n", oldref, ref, set->name);
      if (oldhash != 0)
	*iters = NULL;
      else
	{ oldhash = hash;
	  hash = REFHASH(oldref);
	  goto check_depth;
	}
    }
  set->ref = ref;
}

void ir_data_assign_path
( union ir_setdata_t* setdata,
  const uint8_t*      path
)
{ if (path == NULL)
    eprintf("Null path in data %s\n", setdata->header.data_name);
  if (setdata->header.src_filename != NULL)
    wprintf("Path override: %s -> %s for setdata %s\n",
	    setdata->header.src_filename, path, setdata->header.data_name);
  setdata->header.src_filename = name_alloc(path);
}

union ir_setdata_t* ir_framesheet
( const uint8_t* name,
  apc_facing     d,
  int            width,
  int            height
)
{ return ir_framedata(FSDAT, name, d, width, height); }

union ir_setdata_t* ir_mapsheet
( const uint8_t* name,
  apc_facing     d,
  int            width,
  int            height
)
{ return ir_framedata(MSDAT, name, d, width, height); }

static inline
union ir_setdata_t* ir_framedata
( enum dtype     type,
  const uint8_t* name,
  apc_facing     d,
  int            width,
  int            height
)
{ struct ir_framedata_t* framedata = struct_alloc(ir_framedata_t);
  struct_clear(framedata);
  if (name == NULL)
    eprintf("Null name in set allocation\n");
  framedata->header.type = type;
  framedata->header.data_name = name_alloc(name);
  framedata->frameinfo.facing = d;
  framedata->frameinfo.w = width;
  framedata->frameinfo.h = height;
  return (union ir_setdata_t*) framedata;
}

union ir_setdata_t* ir_audio
( const uint8_t* name )
{ struct ir_simplex_t* audio = struct_alloc(ir_simplex_t);
  struct_clear(audio);
  if (name == NULL)
    eprintf("Null audio\n");
  audio->header.type = ADAT;
  audio->header.data_name = name_alloc(name);
  return (union ir_setdata_t*) audio;
}


/* Create classld that points to a class */
struct ir_classld_t* ir_classld_from_class
( struct ir_class_t* class )
{ struct ir_classld_t* classld;
  if (class == NULL)
    eprintf("Null class in classld\n");
  classld = struct_alloc(ir_classld_t);
  struct_clear(classld);
  classld->root_class = class;
  return classld;
}

struct ir_setld_t* ir_setld_from_ref
( uint32_t ref )
{ struct ir_setld_t* setld;
  setld = struct_alloc(ir_setld_t);
  struct_clear(setld);
  setld->ref = ref;
  return setld;
}

struct ir_setld_t* ir_setld_from_classld
( struct ir_classld_t* classld,
  const uint8_t*       name
)
{ struct ir_setld_t* setld;
  setld = struct_alloc(ir_setld_t);
  struct_clear(setld);
  setld->namelist = struct_alloc(ir_namelist_t);
  struct_clear(setld->namelist);
  setld->namelist_head = setld->namelist;
  setld->namelist_head->name = name_alloc(name);
  setld->classld = classld;
  return setld; 
}

struct ir_setld_t* ir_setld_addchild
( struct ir_setld_t* setld,
  const uint8_t*     name
)
{ if (setld->namelist == NULL)
    { setld->namelist = struct_alloc(ir_namelist_t);
      struct_clear(setld->namelist);
      setld->namelist_head = setld->namelist;
    }
  else
    { setld->namelist_head->nextsib = struct_alloc(ir_namelist_t);
      struct_clear(setld->namelist_head->nextsib);
      setld->namelist_head = setld->namelist_head->nextsib;
    }
  setld->namelist_head->name = name_alloc(name);
  return setld;
}

union ir_setdata_t* ir_link
( enum ltype         link_type,
  struct ir_setld_t* setld,
  const uint8_t*     name
)
{ struct ir_link_t* link;
  link = struct_alloc(ir_link_t);
  struct_clear(link);
  link->header.type = LDAT;
  link->type = link_type; 
  link->classld = setld->classld;
  link->setld = setld;
  if (link_type != OLINK && name != NULL)
    link->header.data_name = name_alloc(name);
  return (union ir_setdata_t*) link;
}

static inline
void* pagelist_pop
( struct pagelist_t* pagelist,
  size_t             size
)
{ size_t headsize = PL_HEADSIZE((*pagelist));
  if (!headsize)
    { free(pagelist->head);
      pagelist->head = pagelist->root;
      while (pagelist->head->header.next != NULL)
	pagelist->head = pagelist->head->header.next;
    }
  if (headsize < size)
    eprintf("Attempted to pop unaligned value from pagelist\n");
  pagelist->head->header.head -= size;
  return pagelist->head->header.head;
}

static
void* stack_alloc
( size_t bytes )
{ void* p;
  if (PL_HEADMEM(datapages) < bytes) 
    pagelist_alloc(datapages);
  p = datapages.head->header.head;
  datapages.head->header.head += bytes;
  return p;
}

static
uint8_t* name_alloc
( const uint8_t* name_src )
{ const uint8_t* iter;
  uint8_t*       name;
  int            head_mem;
 copy:
  name = (uint8_t*)namepages.head->header.head;
  iter = name_src;
  for (head_mem = PL_HEADMEM(namepages); *iter && *iter != '_' && *iter != '.' && head_mem; head_mem--)
    *(namepages.head->header.head)++ = *iter++;
  if (head_mem < 1) //not enough room
    { pagelist_alloc(namepages);
      goto copy;
    }
  *(namepages.head->header.head)++ = '\0';
  return name;
}

static
uint8_t* classname_alloc
( const uint8_t* name_src )
{ const uint8_t* iter;
  uint8_t*       name;
  int            head_mem;
 copy:
  name = (uint8_t*)namepages.head->header.head;
  iter = name_src;
  for (head_mem = PL_HEADMEM(namepages); *iter && head_mem; head_mem--)
    *(namepages.head->header.head)++ = *iter++;
  if (head_mem < 1) //not enough room
    { pagelist_alloc(namepages);
      goto copy;
    }
  *(namepages.head->header.head)++ = '\0';
  return name;
}

static void crawl_class(struct ir_class_t*);
static void crawl_set(struct ir_set_t*,int);
void     ir_test(void)
{ uprintf("IR From Directory: %s\n",getcwd(NULL,255));
  crawl_class(&root_class);
  if (root_class.root_set != NULL)
    crawl_set(root_class.root_set, 0);
}

static
void crawl_class
( struct ir_class_t* class )
{ struct ir_class_t* iter;
  for (iter = class->nextchild; iter != NULL; iter = iter->nextsib)
    { wprintf("%U/\n", iter->name);
      if(chdir((char*)iter->name))
	eprintf("CHDIR %U from %s\n",iter->name,getcwd(NULL,255));
      crawl_class(iter);
      if (iter->root_set != NULL)
        crawl_set(iter->root_set, 0);
      uprintf("%U\\\n",iter->name);
      if (chdir(".."))
	eprintf("CHDIR ..\n");
    }
}

static
void crawl_set
( struct ir_set_t* set,
  int depth
)
{ struct ir_set_t* setlist[64], ** slp, * iter;
  int i = depth * 12;
  while (i--)
    putchar('.');
  i = depth;
  slp = setlist;
  for(iter = set; iter != NULL; iter = iter->nextchild)
    { uprintf("[%10U]", iter->name);
      *slp++ = iter;
      i++;
    }
  --i;
  putchar('\n');
  for(iter = *--slp; slp >= setlist; iter = *--slp, --i)
    if (iter->nextsib != NULL)
      crawl_set(iter->nextsib,i);
}