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

#include "picrin.h"
#include "picrin/gc.h"
#include "picrin/read.h"
#include "picrin/proc.h"
#include "picrin/macro.h"
#include "picrin/cont.h"
#include "picrin/port.h"
#include "picrin/error.h"
#include "picrin/dict.h"

void pic_init_core(pic_state *);

pic_state *
pic_open(int argc, char *argv[], char **envp)
{
  struct pic_port *pic_make_standard_port(pic_state *, xFILE *, short);
  char t;

  pic_state *pic;
  size_t ai;

  pic = malloc(sizeof(pic_state));

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

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

  /* command line */
  pic->argc = argc;
  pic->argv = argv;
  pic->envp = envp;

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

  /* callinfo */
  pic->cibase = pic->ci = calloc(PIC_STACK_SIZE, sizeof(pic_callinfo));
  pic->ciend = pic->cibase + PIC_STACK_SIZE;

  /* exception handler */
  pic->xpbase = pic->xp = calloc(PIC_RESCUE_SIZE, sizeof(struct pic_proc *));
  pic->xpend = pic->xpbase + PIC_RESCUE_SIZE;

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

  /* symbol table */
  xh_init_str(&pic->syms, sizeof(pic_sym));

  /* global variables */
  pic->globals = NULL;

  /* macros */
  pic->macros = NULL;

  /* attributes */
  xh_init_ptr(&pic->attrs, sizeof(struct pic_dict *));

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

  /* libraries */
  pic->libs = pic_nil_value();
  pic->lib = NULL;

  /* GC arena */
  pic->arena = calloc(PIC_ARENA_SIZE, sizeof(struct pic_object **));
  pic->arena_size = PIC_ARENA_SIZE;
  pic->arena_idx = 0;

  /* raised error object */
  pic->err = pic_undef_value();

  /* standard ports */
  pic->xSTDIN = NULL;
  pic->xSTDOUT = NULL;
  pic->xSTDERR = NULL;

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

  ai = pic_gc_arena_preserve(pic);

#define S(slot,name) pic->slot = pic_intern_cstr(pic, name);

  S(sDEFINE, "define");
  S(sLAMBDA, "lambda");
  S(sIF, "if");
  S(sBEGIN, "begin");
  S(sSETBANG, "set!");
  S(sQUOTE, "quote");
  S(sQUASIQUOTE, "quasiquote");
  S(sUNQUOTE, "unquote");
  S(sUNQUOTE_SPLICING, "unquote-splicing");
  S(sDEFINE_SYNTAX, "define-syntax");
  S(sIMPORT, "import");
  S(sEXPORT, "export");
  S(sDEFINE_LIBRARY, "define-library");
  S(sIN_LIBRARY, "in-library");
  S(sCOND_EXPAND, "cond-expand");
  S(sAND, "and");
  S(sOR, "or");
  S(sELSE, "else");
  S(sLIBRARY, "library");
  S(sONLY, "only");
  S(sRENAME, "rename");
  S(sPREFIX, "prefix");
  S(sEXCEPT, "except");
  S(sCONS, "cons");
  S(sCAR, "car");
  S(sCDR, "cdr");
  S(sNILP, "null?");
  S(sSYMBOLP, "symbol?");
  S(sPAIRP, "pair?");
  S(sADD, "+");
  S(sSUB, "-");
  S(sMUL, "*");
  S(sDIV, "/");
  S(sMINUS, "minus");
  S(sEQ, "=");
  S(sLT, "<");
  S(sLE, "<=");
  S(sGT, ">");
  S(sGE, ">=");
  S(sNOT, "not");
  S(sREAD, "read");
  S(sFILE, "file");
  pic_gc_arena_restore(pic, ai);

#define R(slot,name) pic->slot = pic_gensym(pic, pic_intern_cstr(pic, name));

  R(rDEFINE, "define");
  R(rLAMBDA, "lambda");
  R(rIF, "if");
  R(rBEGIN, "begin");
  R(rSETBANG, "set!");
  R(rQUOTE, "quote");
  R(rDEFINE_SYNTAX, "define-syntax");
  R(rIMPORT, "import");
  R(rEXPORT, "export");
  R(rDEFINE_LIBRARY, "define-library");
  R(rIN_LIBRARY, "in-library");
  R(rCOND_EXPAND, "cond-expand");
  pic_gc_arena_restore(pic, ai);

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

  /* root block */
  pic->wind = pic_alloc(pic, sizeof(struct pic_winder));
  pic->wind->prev = NULL;
  pic->wind->depth = 0;
  pic->wind->in = pic->wind->out = NULL;

  /* reader */
  pic->reader = malloc(sizeof(struct pic_reader));
  pic->reader->typecase = PIC_CASE_DEFAULT;
  pic->reader->trie = pic_make_trie(pic);
  xh_init_int(&pic->reader->labels, sizeof(pic_value));

  /* init readers */
  pic_init_reader(pic);

  /* standard libraries */
  pic->PICRIN_BASE = pic_open_library(pic, pic_read_cstr(pic, "(picrin base)"));
  pic->PICRIN_USER = pic_open_library(pic, pic_read_cstr(pic, "(picrin user)"));
  pic->lib = pic->PICRIN_USER;

  /* standard I/O */
  pic->xSTDIN = pic_make_standard_port(pic, xstdin, PIC_PORT_IN);
  pic->xSTDOUT = pic_make_standard_port(pic, xstdout, PIC_PORT_OUT);
  pic->xSTDERR = pic_make_standard_port(pic, xstderr, PIC_PORT_OUT);

  pic_gc_arena_restore(pic, ai);

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

  pic_init_core(pic);

  return pic;
}

void
pic_close(pic_state *pic)
{
  xh_entry *it;

  /* invoke exit handlers */
  while (pic->wind) {
    if (pic->wind->out) {
      pic_apply0(pic, pic->wind->out);
    }
    pic->wind = pic->wind->prev;
  }

  /* free symbol names */
  for (it = xh_begin(&pic->syms); it != NULL; it = xh_next(it)) {
    free(xh_key(it, char *));
  }

  /* clear out root objects */
  pic->sp = pic->stbase;
  pic->ci = pic->cibase;
  pic->xp = pic->xpbase;
  pic->arena_idx = 0;
  pic->err = pic_undef_value();
  pic->globals = NULL;
  pic->macros = NULL;
  xh_clear(&pic->syms);
  xh_clear(&pic->attrs);
  pic->features = pic_nil_value();
  pic->libs = pic_nil_value();

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

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

  /* free runtime context */
  free(pic->stbase);
  free(pic->cibase);
  free(pic->xpbase);

  /* free reader struct */
  xh_destroy(&pic->reader->labels);
  pic_trie_delete(pic, pic->reader->trie);
  free(pic->reader);

  /* free global stacks */
  xh_destroy(&pic->syms);
  xh_destroy(&pic->attrs);

  /* free GC arena */
  free(pic->arena);

  free(pic);
}