#include <string.h>
#include "mir.h"
#include "mir-gen.h"

#ifdef CTAB_INCLUDE_STRING
#include CTAB_INCLUDE_STRING
#else
#include "mir-ctab"
#endif

static size_t curr_input_byte_num;

static int read_byte (MIR_context_t ctx) {
  if (curr_input_byte_num >= sizeof (mir_code)) return EOF;
  return mir_code[curr_input_byte_num++];
}

#include <dlfcn.h>
#if defined(__unix__) || defined(__APPLE__)
#include <sys/stat.h>
#endif

static struct lib {
  char *name;
  void *handler;
} libs[] = {
#if !defined(__APPLE__)
  {"/lib64/libc.so.6", NULL}, {"/lib64/libm.so.6", NULL}, {"/lib64/libpthread.so.0", NULL}
#else
  {"/usr/lib/libc.dylib", NULL}, {"/usr/lib/libm.dylib", NULL}
#endif
};

static void close_libs (void) {
  for (int i = 0; i < sizeof (libs) / sizeof (struct lib); i++)
    if (libs[i].handler != NULL) dlclose (libs[i].handler);
}

static void open_libs (void) {
  for (int i = 0; i < sizeof (libs) / sizeof (struct lib); i++)
    if ((libs[i].handler = dlopen (libs[i].name, RTLD_LAZY)) == NULL) {
      fprintf (stderr, "can not open lib %s\n", libs[i].name);
      close_libs ();
      exit (1);
    }
}

static void *import_resolver (const char *name) {
  void *sym = NULL;

  if (strcmp (name, "dlopen") == 0) return dlopen;
  if (strcmp (name, "dlsym") == 0) return dlsym;
  if (strcmp (name, "dlclose") == 0) return dlclose;
#if defined(__unix__) || defined(__APPLE__)
  if (strcmp (name, "stat") == 0) return stat;
#if defined(__APPLE__) && defined(__aarch64__)
  if (strcmp (name, "_MIR_set_code") == 0) return _MIR_set_code;
#endif
#endif
  for (int i = 0; i < sizeof (libs) / sizeof (struct lib); i++) {
    if ((sym = dlsym (libs[i].handler, name)) != NULL) break;
  }
  if (sym == NULL) {
    fprintf (stderr, "can not load symbol %s\n", name);
    close_libs ();
    exit (1);
  }
  return sym;
}

#ifndef MIR_BIN_DEBUG
#define MIR_BIN_DEBUG 0
#endif

#if MIR_BIN_DEBUG
#include "real-time.h"
#endif

#ifndef MIR_USE_INTERP
#define MIR_USE_INTERP 0
#endif

#ifndef MIR_USE_GEN
#define MIR_USE_GEN 0
#endif

#ifndef MIR_USE_LAZY_GEN
#define MIR_USE_LAZY_GEN 1
#endif

int main (int argc, char *argv[], char *env[]) {
  int exit_code;
  MIR_val_t val;
  MIR_module_t module;
  MIR_item_t func, main_func = NULL;
  uint64_t (*fun_addr) (int, char *argv[], char *env[]);
  MIR_context_t ctx = MIR_init ();
  unsigned funcs_num = 0;
#if MIR_BIN_DEBUG
  double start_time = real_usec_time ();
#endif

  assert (MIR_USE_INTERP || MIR_USE_GEN || MIR_USE_LAZY_GEN);
  curr_input_byte_num = 0;
  MIR_read_with_func (ctx, read_byte);
#if MIR_BIN_DEBUG
  fprintf (stderr, "Finish of MIR reading from memory -- curr_time %.0f usec\n",
           real_usec_time () - start_time);
#endif
  for (module = DLIST_HEAD (MIR_module_t, *MIR_get_module_list (ctx)); module != NULL;
       module = DLIST_NEXT (MIR_module_t, module)) {
    for (func = DLIST_HEAD (MIR_item_t, module->items); func != NULL;
         func = DLIST_NEXT (MIR_item_t, func)) {
      if (func->item_type != MIR_func_item) continue;
      funcs_num++;
      if (strcmp (func->u.func->name, "main") == 0) main_func = func;
    }
    MIR_load_module (ctx, module);
  }
  if (main_func == NULL) {
    fprintf (stderr, "cannot execute program w/o main function\n");
    return 1;
  }
  open_libs ();
  if (MIR_USE_INTERP) {
    MIR_link (ctx, MIR_set_interp_interface, import_resolver);
#if MIR_BIN_DEBUG
    fprintf (stderr, "Finish of loading/linking (%d funcs) -- curr_time %.0f usec\n", funcs_num,
             real_usec_time () - start_time);
    start_time = real_usec_time ();
#endif
    MIR_interp (ctx, main_func, &val, 3, (MIR_val_t){.i = argc}, (MIR_val_t){.a = (void *) argv},
                (MIR_val_t){.a = (void *) env});
#if MIR_BIN_DEBUG
    fprintf (stderr, "Finish of execution -- overall execution time %.0f usec\n",
             real_usec_time () - start_time);
#endif
    exit_code = val.i;
  } else {
    MIR_gen_init (ctx, 1);
    MIR_link (ctx, MIR_USE_GEN ? MIR_set_gen_interface : MIR_set_lazy_gen_interface,
              import_resolver);
#if MIR_BIN_DEBUG
    fprintf (stderr,
             (!MIR_USE_GEN
                ? "Finish of MIR loading/linking (%d funcs) -- curr_time %.0f usec\n"
                : "Finish of MIR loading/linking/generation (%d funcs) -- curr_time %.0f usec\n"),
             funcs_num, real_usec_time () - start_time);
#endif
    fun_addr = MIR_gen (ctx, 0, main_func);
#if MIR_BIN_DEBUG
    start_time = real_usec_time ();
#endif
    exit_code = fun_addr (argc, argv, env);
#if MIR_BIN_DEBUG
    fprintf (stderr,
             (MIR_USE_GEN
                ? "Finish of execution -- overall execution time %.0f usec\n"
                : "Finish of generation and execution -- overall execution time %.0f usec\n"),
             real_usec_time () - start_time);
#endif
    MIR_gen_finish (ctx);
  }
  MIR_finish (ctx);
  close_libs ();
  return exit_code;
}