/**
 * See Copyright Notice in picrin.h
 */

#include "picrin.h"
#include "picrin/extra.h"
#include "picrin/private/object.h"
#include "picrin/private/state.h"

static pic_value
pic_features(pic_state *pic)
{
  pic_get_args(pic, "");

  return pic->features;
}

static void
pic_init_features(pic_state *pic)
{
  pic_defun(pic, "features", pic_features);

  pic_add_feature(pic, "picrin");

#if __STDC_IEC_559__
  pic_add_feature(pic, "ieee-float");
#endif

#if _POSIX_SOURCE
  pic_add_feature(pic, "posix");
#endif

#if _WIN32
  pic_add_feature(pic, "windows");
#endif

#if __unix__
  pic_add_feature(pic, "unix");
#endif
#if __gnu_linux__
  pic_add_feature(pic, "gnu-linux");
#endif
#if __FreeBSD__
  pic_add_feature(pic, "freebsd");
#endif

#if __i386__
  pic_add_feature(pic, "i386");
#elif __x86_64__
  pic_add_feature(pic, "x86-64");
#elif __ppc__
  pic_add_feature(pic, "ppc");
#elif __sparc__
  pic_add_feature(pic, "sparc");
#endif

#if __ILP32__
  pic_add_feature(pic, "ilp32");
#elif __LP64__
  pic_add_feature(pic, "lp64");
#endif

#if defined(__BYTE_ORDER__)
# if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
  pic_add_feature(pic, "little-endian");
# elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
  pic_add_feature(pic, "big-endian");
# endif
#else
# if __LITTLE_ENDIAN__
  pic_add_feature(pic, "little-endian");
# elif __BIG_ENDIAN__
  pic_add_feature(pic, "big-endian");
# endif
#endif
}

void
pic_add_feature(pic_state *pic, const char *feature)
{
  pic_push(pic, pic_intern_cstr(pic, feature), pic->features);
}

#define import_builtin_syntax(name) do {                \
    pic_value nick, real;                               \
    nick = pic_intern_lit(pic, "builtin:" name);        \
    real = pic_intern_lit(pic, name);                   \
    pic_put_identifier(pic, nick, real, env);           \
  } while (0)

#define declare_vm_procedure(name) do {         \
    pic_value sym;                              \
    sym = pic_intern_lit(pic, name);            \
    pic_put_identifier(pic, sym, sym, env);     \
  } while (0)

void pic_init_bool(pic_state *);
void pic_init_pair(pic_state *);
void pic_init_port(pic_state *);
void pic_init_number(pic_state *);
void pic_init_proc(pic_state *);
void pic_init_symbol(pic_state *);
void pic_init_vector(pic_state *);
void pic_init_blob(pic_state *);
void pic_init_cont(pic_state *);
void pic_init_char(pic_state *);
void pic_init_error(pic_state *);
void pic_init_str(pic_state *);
void pic_init_var(pic_state *);
void pic_init_write(pic_state *);
void pic_init_read(pic_state *);
void pic_init_dict(pic_state *);
void pic_init_record(pic_state *);
void pic_init_eval(pic_state *);
void pic_init_lib(pic_state *);
void pic_init_weak(pic_state *);

extern const char pic_boot[][80];

static void
pic_init_core(pic_state *pic)
{
  size_t ai;
  pic_value env;

  pic_deflibrary(pic, "picrin.base");

  ai = pic_enter(pic);

#define DONE pic_leave(pic, ai);

  env = pic_library_environment(pic, pic->lib);

  import_builtin_syntax("define");
  import_builtin_syntax("set!");
  import_builtin_syntax("quote");
  import_builtin_syntax("lambda");
  import_builtin_syntax("if");
  import_builtin_syntax("begin");
  import_builtin_syntax("define-macro");

  declare_vm_procedure("cons");
  declare_vm_procedure("car");
  declare_vm_procedure("cdr");
  declare_vm_procedure("null?");
  declare_vm_procedure("symbol?");
  declare_vm_procedure("pair?");
  declare_vm_procedure("+");
  declare_vm_procedure("-");
  declare_vm_procedure("*");
  declare_vm_procedure("/");
  declare_vm_procedure("=");
  declare_vm_procedure("<");
  declare_vm_procedure(">");
  declare_vm_procedure("<=");
  declare_vm_procedure(">=");
  declare_vm_procedure("not");

  DONE;

  pic_init_bool(pic); DONE;
  pic_init_pair(pic); DONE;
  pic_init_port(pic); DONE;
  pic_init_number(pic); DONE;
  pic_init_proc(pic); DONE;
  pic_init_symbol(pic); DONE;
  pic_init_vector(pic); DONE;
  pic_init_blob(pic); DONE;
  pic_init_cont(pic); DONE;
  pic_init_char(pic); DONE;
  pic_init_error(pic); DONE;
  pic_init_str(pic); DONE;
  pic_init_var(pic); DONE;
  pic_init_read(pic); DONE;
  pic_init_dict(pic); DONE;
  pic_init_record(pic); DONE;
  pic_init_eval(pic); DONE;
  pic_init_lib(pic); DONE;
  pic_init_weak(pic); DONE;

#if PIC_USE_WRITE
  pic_init_write(pic); DONE;
#endif

  pic_init_features(pic);

  pic_load_cstr(pic, &pic_boot[0][0]);
}

pic_state *
pic_open(pic_allocf allocf, void *userdata)
{
  char t;

  pic_state *pic;

  pic = allocf(userdata, NULL, sizeof(pic_state));

  if (! pic) {
    goto EXIT_PIC;
  }

  /* allocator */
  pic->allocf = allocf;

  /* user data */
  pic->userdata = userdata;

  /* turn off GC */
  pic->gc_enable = false;

  /* continuation chain */
  pic->cc = NULL;

  /* root block */
  pic->cp = NULL;

  /* prepare VM stack */
  pic->stbase = pic->sp = allocf(userdata, NULL, PIC_STACK_SIZE * sizeof(pic_value));
  pic->stend = pic->stbase + PIC_STACK_SIZE;

  if (! pic->sp) {
    goto EXIT_SP;
  }

  /* callinfo */
  pic->cibase = pic->ci = allocf(userdata, NULL, PIC_STACK_SIZE * sizeof(struct callinfo));
  pic->ciend = pic->cibase + PIC_STACK_SIZE;

  if (! pic->ci) {
    goto EXIT_CI;
  }

  /* GC arena */
  pic->arena = allocf(userdata, NULL, PIC_ARENA_SIZE * sizeof(struct object *));
  pic->arena_size = PIC_ARENA_SIZE;
  pic->arena_idx = 0;

  if (! pic->arena) {
    goto EXIT_ARENA;
  }

  /* memory heap */
  pic->heap = pic_heap_open(pic);

  /* symbol table */
  kh_init(oblist, &pic->oblist);

  /* unique symbol count */
  pic->ucnt = 0;

  /* global variables */
  pic->globals = pic_invalid_value(pic);

  /* macros */
  pic->macros = pic_invalid_value(pic);

  /* features */
  pic->features = pic_nil_value(pic);

  /* libraries */
  kh_init(ltable, &pic->ltable);
  pic->lib = NULL;

  /* ireps */
  pic->ireps.next = &pic->ireps;
  pic->ireps.prev = &pic->ireps;

  /* raised error object */
  pic->panicf = NULL;
  pic->err = pic_invalid_value(pic);

  /* file pool */
  memset(pic->files, 0, sizeof pic->files);
#if PIC_USE_STDIO
  xfopen_file(pic, stdin, "r");
  xfopen_file(pic, stdout, "w");
  xfopen_file(pic, stderr, "w");
  pic->files[1].flag |= X_LNBUF;
  pic->files[2].flag |= X_UNBUF;
#else
  xfopen_null(pic, "r");
  xfopen_null(pic, "w");
  xfopen_null(pic, "w");
#endif

  /* native stack marker */
  pic->native_stack_start = &t;

  /* root tables */
  pic->globals = pic_make_weak(pic);
  pic->macros = pic_make_weak(pic);

  /* root block */
  pic->cp = (struct checkpoint *)pic_obj_alloc(pic, sizeof(struct checkpoint), PIC_TYPE_CP);
  pic->cp->prev = NULL;
  pic->cp->depth = 0;
  pic->cp->in = pic->cp->out = NULL;

  /* standard libraries */
  pic_make_library(pic, "picrin.user");
  pic_in_library(pic, "picrin.user");

  /* turn on GC */
  pic->gc_enable = true;

  pic_init_core(pic);

  pic_leave(pic, 0);            /* empty arena */

  return pic;

 EXIT_ARENA:
  allocf(userdata, pic->ci, 0);
 EXIT_CI:
  allocf(userdata, pic->sp, 0);
 EXIT_SP:
  allocf(userdata, pic, 0);
 EXIT_PIC:
  return NULL;
}

void
pic_close(pic_state *pic)
{
  pic_allocf allocf = pic->allocf;

  /* clear out root objects */
  pic->sp = pic->stbase;
  pic->ci = pic->cibase;
  pic->arena_idx = 0;
  pic->err = pic_invalid_value(pic);
  pic->globals = pic_invalid_value(pic);
  pic->macros = pic_invalid_value(pic);
  pic->features = pic_nil_value(pic);

  /* free all libraries */
  kh_clear(ltable, &pic->ltable);

  /* free all heap objects */
  pic_gc(pic);

  /* flush all xfiles */
  xfflush(pic, NULL);

  /* free heaps */
  pic_heap_close(pic, pic->heap);

  /* free runtime context */
  allocf(pic->userdata, pic->stbase, 0);
  allocf(pic->userdata, pic->cibase, 0);

  /* free global stacks */
  kh_destroy(oblist, &pic->oblist);
  kh_destroy(ltable, &pic->ltable);

  /* free GC arena */
  allocf(pic->userdata, pic->arena, 0);

  allocf(pic->userdata, pic, 0);
}