// Copyright © 2017 Project Golan, all rights reserved.
// See COPYING for more information.
#include "m_tokbuf.h"
#include "m_str.h"

#include <Doominati.h>

#include <setjmp.h>
#include <string.h>
#include <stdlib.h>

// Static Functions ----------------------------------------------------------|

_Noreturn static void R_ResDec_throw (struct R_rdcst *st, char const *emsg);
static M_token       *R_ResDec_expect(struct R_rdcst *st, M_toktype t, char const *exp);

// Types ---------------------------------------------------------------------|

typedef struct R_rdcst
{
   __prop throw  {call: R_ResDec_throw (this)}
   __prop expect {call: R_ResDec_expect(this)}

   M_tkbuf tb;
   jmp_buf ejmp;
} R_rdcst;

// Static Functions ----------------------------------------------------------|

//
// R_ResDec_throw
//
_Noreturn static void R_ResDec_throw(R_rdcst *st, char const *emsg)
{
   fprintf(stderr, "ResDec: %s\n", emsg);
   longjmp(st->ejmp, 1);
}

//
// R_ResDec_expect
//
static M_token *R_ResDec_expect(R_rdcst *st, M_toktype t, char const *exp)
{
   M_token *tok;
   if((tok = st->tb.get())->type != t)
      st->throw(M_StrFmt("expected %s", exp));
   return tok;
}

//
// R_ResDec_getFont
//
static void R_ResDec_getFont(R_rdcst *st)
{
   char const *fname;
   __str name;
   int pt;

   name = M_StrCreate(st->expect(tok_string, "alias name")->textV);
   st->expect(tok_eq, "'='");

   fname = st->expect(tok_string, "file name")->textV;
   st->expect(tok_comma, "','");

   pt = strtoi(st->expect(tok_number, "pt size")->textV, NULL, 0);
   DGE_Font_Create(name, fname, pt);
}

//
// R_ResDec_getTexture
//
static void R_ResDec_getTexture(R_rdcst *st)
{
   char const *fname;
   __str name;

   name = M_StrCreate(st->expect(tok_string, "alias name")->textV);
   st->expect(tok_eq, "'='");

   fname = st->expect(tok_string, "file name")->textV;
   DGE_Texture_Create(name, fname);
}

//
// R_ResDec_getShader
//
static void R_ResDec_getShader(R_rdcst *st)
{
   char const *fp, *vp;
   __str name;
   bool data = false;

   name = M_StrCreate(st->expect(tok_string, "alias name")->textV);
   st->expect(tok_eq, "'='");

   if(st->tb.drop(tok_identi) && strcmp(st->tb.reget()->textV, "data") == 0)
      data = true;

   fp = st->expect(tok_string, "fragment shader")->textV;
   st->expect(tok_comma, "','");

   vp = st->expect(tok_string, "vertex shader")->textV;
   if(data) DGE_Shader_CreateData(name, fp, vp);
   else     DGE_Shader_CreateFile(name, fp, vp);
}

// Extern Functions ----------------------------------------------------------|

//
// R_ResDec_Load
//
void R_ResDec_Load(char const *fname)
{
   R_rdcst st = {{.bbeg = 4, .bend = 10, .fp = fopen(fname, "r")}};

   if(!st.tb.fp) {
      fprintf(stderr, "ResDec: couldn't open file '%s'\n", fname);
      goto done;
   }

   st.tb.ctor();

   if(setjmp(st.ejmp) == 1)
      goto done;

   for(M_token *tok; (tok = st.tb.get())->type != tok_eof;)
   {
      if(tok->type != tok_identi)
         st.throw("expected identifier");
      else if(strcmp(tok->textV, "font") == 0)
         R_ResDec_getFont(&st);
      else if(strcmp(tok->textV, "texture") == 0)
         R_ResDec_getTexture(&st);
      else if(strcmp(tok->textV, "shader") == 0)
         R_ResDec_getShader(&st);
      else if(strcmp(tok->textV, "include") == 0)
         R_ResDec_Load(st.expect(tok_string, "file name")->textV);
      else
         st.throw(M_StrFmt("invalid resource type '%s'", tok->textV));
   }

   printf("ResDec: '%s' loaded.\n", fname);

done:
   st.tb.dtor();
   fclose(st.tb.fp);
}

// EOF