#include "eruta.h"
#include "image.h"
#include "rh.h"
#include "fifi.h"
#include "zori.h"
#include "str.h"
#include "mem.h"
#include "state.h"
#include "monolog.h"

#include <string.h>

#include <stdarg.h>
#include <mruby.h>
#include <mruby/error.h>

/* Debugging level for console output. */ 
#define LOG_CONSOLE(FORMAT, ...) LOG_LEVEL("CONSOLE", FORMAT, __VA_ARGS__)
#define LOG_ENABLE_CONSOLE()     LOG_ENABLE(CONSOLE)
#define LOG_DISABLE_CONSOLE()    LOG_DISABLE(CONSOLE)

/* Amount of parameters a mruby function can be called with using _va functions */
#define RH_ARGS_MAX 64

/*
* RH contains helper functions for the mruby ruby interpreter.
*/

/*
 * Converts C like arguments to an array of mruby mrb_values.
 * Returns amount of arguments parsed, negative on failure.
 * 
 * Format specifier characters for the format argument: 
 *
 * z: String from null terminated C string      [char*]
 * s: String                                    [char*, int] 
 * Y: sYmbol from null terminated C string      [char*]
 * y: symbol                                    [char*, int] 
 * 
 * f: Float                                     [double]
 * i: Integer                                   [int]
 * b: Boolean                                   [int] 
 * 0: nil
 * Other characters: Error. Will return -(index or erroneous character) .
 */ 
int rh_args_va(Ruby * ruby, mrb_value * values,  int size,  char * format, va_list list) {
  int ch; int index;
  int i; double d; const char * str;
  index = 0; 
  
  for (ch = (*format) ; (ch) && (index < size) ; format++ , ch = (*format)) {
    mrb_value val;
    int error = FALSE;
    switch(ch) {
      case 's':
        str = va_arg(list, const char*);
        i   = va_arg(list, int);
        val = mrb_str_new(ruby, str, i);
        break;
        
      case 'z':
        str = va_arg(list, const char*);
        val = mrb_str_new_cstr(ruby, str);
        break;
        
      case 'y':
        str = va_arg(list, const char*);
        i   = va_arg(list, int);
        val = mrb_symbol_value(mrb_intern(ruby, str, (size_t)i));
        break;
        
      case 'Y':
        str = va_arg(list, const char*);
        val = mrb_symbol_value(mrb_intern_cstr(ruby, str));
        break; 
        
      case 'i':
        i   = va_arg(list, int);
        val = mrb_fixnum_value(i);
        break;
        
      case 'f':
        d   = va_arg(list, double);
        val = mrb_float_value(ruby, d);
        break;
        
      case 'b': 
        i   = va_arg(list, int);
        val = ( i ? mrb_true_value() : mrb_false_value());
        break;
      
      case '0':
        val = mrb_nil_value();
        break;
        
      default:
        error = TRUE;
        break;
    }
    if (error) { 
      return -index;
    }
    values[index] = val;
    index ++;
  }
  return index;
}


/* strdup isn't ANSI C, just posix... :p so we need our own version.*/
char *rh_strdup(const char *str) {
    char * res = malloc(strlen(str) + 1);
    if(res) { strcpy(res, str); }
    return res;
}

/* Helps convert C values to mruby values in an array. */
int rh_args(Ruby * ruby, mrb_value * values,  int size,  char * format, ...) {
  int res;
  va_list list;
  va_start(list, format);
  res = rh_args_va(ruby, values, size, format, list);
  va_end(list);
  return res;
}


/** Calulates the execption string. Result only tempoarily available..
XXX: check if this doesn't leak memory... you must free the results manually.
*/
char * rh_exceptionstring(Ruby * self) {
  char      * result;
  mrb_value   value;
  mrb_value   backtrace;
  mrb_value   backtrace_str;
  
  if (!self->exc) return NULL; 
  //
  /* XXX: Too bad, the backtrace doesn't seem to be filled in for some reason...
   * Should figure out how to fix this.
   */
  mrb_print_backtrace(self);
  backtrace = // mrb_get_backtrace(self);
  mrb_funcall(self, mrb_obj_value(self->exc), "backtrace", 0);

  backtrace_str  = mrb_funcall(self, backtrace, "join", 1, mrb_str_new_lit(self, "\n"));
  LOG_ERROR("backtrace: %s\n", mrb_string_value_cstr(self, &backtrace_str));
  value  = mrb_funcall(self, mrb_obj_value(self->exc), "inspect", 0);
  
  
  
  // reset exception since we have it's string value.
  // Does this leak memory or not???
  self->exc = NULL;
  return rh_strdup(mrb_string_value_cstr(self, &value));
}


/** Allocates and initialzes a new ruby state. */
Ruby * rh_new() {
   Ruby * self = mrb_open();
   /*mrb_define_method(self, self->kernel_module, 
                     "path", tr_Path, ARGS_REQ(1));*/
   return self;
}

/** Frees a ruby state. */
Ruby * rh_free(Ruby * self) {
  mrb_close(self);
  return NULL;
}

/** Returns an mrb_value that contains the value of object.inspect. 
*/
mrb_value rh_inspect(mrb_state *mrb, mrb_value obj) {
  return mrb_inspect(mrb, obj);
}

char * rh_inspect_cstr(mrb_state *mrb, mrb_value value) {
  mrb_value res = rh_inspect(mrb, value);
  /* XXX: check that it's not modified anywere or export the const? */
  return (char *) mrb_string_value_cstr(mrb, &res);
}


/* Does the actual reporting depending on the current state of 
 ruby and the returned value. */
int rh_make_report(Ruby * self, mrb_value v) { 
  int res = 0;
  char * str;
 
  /* Report exceptions */
  str = rh_exceptionstring(self);
  if(str) {
    LOG_WARNING("mruby exception: %s", str);
    free(str);
    return 0;
  }
  
  /* Report result value if it's not nil on debug and console levels.
   */
  if (!mrb_nil_p(v)) {
    str = rh_inspect_cstr(self, v);
    LOG_DEBUG("mruby result: %s", str);
    LOG_CONSOLE("-> %s", str);
    return 0;
  }
  return 0;
}


/* Runs a file and reports any errors over the monolog logging system. */
int rh_run_file(Ruby * self, const char * filename, FILE * file) {
  int res;
  char * str;
  mrbc_context * c ; 
  mrb_value v;
  int ai;
  ai = mrb_gc_arena_save(self);
  c = mrbc_context_new(self);  
  mrbc_filename(self, c, filename);
  v = mrb_load_file_cxt(self, file, c);
  mrbc_context_free(self, c);  
  /* Report exceptions */
  res = rh_make_report(self, v);  
  mrb_gc_arena_restore(self, ai);
  return res;
}

int rh_run_filename(Ruby * self, const char * filename) {
  FILE * file = fopen(filename, "rt");
  int res;
  if (!file) {
    LOG_ERROR("No such ruby file: %s\n", filename);
    return -1;
  }
  res = rh_run_file(self, filename, file);
  fclose(file);
  return 0;
}


/**
* Executes a ruby file in Eruta's data/script directory with reporting.
* Returns -2 if the file was not found.
* Returns -3 if the path wasn't found.
*/
int rh_run_script(Ruby * self, const char * filename) {
  char * buf;
  int runres;
  buf = malloc(strlen(filename) + 256);   
  if(!buf) return -3;
  strcpy(buf, "script/");
  strncat(buf, filename, strlen(filename));      
  ALLEGRO_PATH * path = fifi_data_vpath(buf);
  if(!path) { 
    free(buf);
    return -3;
  }
  runres = rh_run_filename(self, PATH_CSTR(path));
  al_destroy_path(path);
  free(buf);
  return runres;
}


/* Executes a ruby command string. 
Errors are reported to the reporter callback if it isn't NULL. */
int rh_dostring(Ruby * self, const char * command) {
  int res = 0;
  char * str;
  mrb_value v;
  int ai;
  ai = mrb_gc_arena_save(self);  
  #ifdef RH_USE_CONTEXT
  mrbc_context      * c  = mrbc_context_new(self);
  mrbc_filename(self, c, "command");
  v = mrb_load_string_cxt(self, command, c);
  mrbc_context_free(self, c); 
  #else
  v = mrb_load_string(self, command);
  #endif
  /* Report exceptions */
  res = rh_make_report(self, v);
  /* mrb GC area seems to be an area for 1024 "new" objects for the generational 
   * GC. It can overflow if a lot of new objects are generated 
   * (say exceptions, etc) on the C side. To prevent this the area must be saved 
   * and restored anywhere many ruby objects may have been generated.
   * It seems that here too this is needed.
   */
  mrb_gc_arena_restore(self, ai);
  return res;
}


/* Executes a ruby function with parameters. 
Errors are reported to the reporter callback if it isn't NULL. */
mrb_value rh_run_function_args(Ruby * self, mrb_value rubyself, char * funcname,    
                        int argc, mrb_value * argv) {
  int res = 0;
  char * str;
  mrb_value v;
  mrb_sym symname = mrb_intern_cstr(self, funcname);
  int ai;
  if(!mrb_respond_to(self, rubyself, symname)) {
    return mrb_nil_value();
  }  
  
  ai = mrb_gc_arena_save(self);
  v = mrb_funcall_argv(self, rubyself, symname, argc, argv);
  res = rh_make_report(self, v);
  mrb_gc_arena_restore(self, ai);
  return v;
}


/** Runs a function in the ruby interpreter, with C arguments according to the 
 * given format string, logging results and errors back to
 * the reporter. The limit is RH_ARGS_MAX arguments.
 */
mrb_value 
rh_run_function_va(Ruby * self, mrb_value rubyself, char * funcname,
                        char * format, va_list list) {
  mrb_value argv[RH_ARGS_MAX];
  int argc;
  argc = rh_args_va(self, argv, RH_ARGS_MAX, format, list);
  if (argc < 0) return mrb_nil_value();
  return rh_run_function_args(self, rubyself, funcname, argc, argv);
}


/** Runs a function in the ruby interpreter, under the toplevel self. 
 * This logs results and errors using monolog.h interfaces.
 */
mrb_value rh_run_toplevel_args(Ruby * ruby, char * name, int argc, mrb_value * argv) {
  return rh_run_function_args(ruby, mrb_top_self(ruby), name, argc, argv);
} 


/** Runs a function in the ruby interpreter, under the toplevel self. 
 * This logs results and errors using monolog.h interfaces.
 */
mrb_value rh_run_toplevel_va(Ruby * ruby, char * name, char * format, va_list list) {
  return rh_run_function_va(ruby, mrb_top_self(ruby), name, format, list);
} 


/** Runs a function in the ruby interpreter, logging results and errors
 * using monolog.h interfaces.
 */
mrb_value rh_run_function(Ruby * ruby, mrb_value rubyself, 
                          char * name, char * format, ...) {
  mrb_value res; 
  va_list list;
  va_start(list, format);
  res = rh_run_function_va(ruby, rubyself, name, format, list);
  va_end(list);
  return res;
}

/** Runs a function in the ruby interpreter, under the toplevel self. 
 * This logs results and errors using monolog.h interfaces.
 */
mrb_value rh_run_toplevel(Ruby * ruby, char * name, char * format, ...) {
  mrb_value res; 
  va_list list;
  va_start(list, format);
  res = rh_run_function_va(ruby, mrb_top_self(ruby), name, format, list);
  va_end(list);
  return res;
}


/* Calls a function, doesn't log anything. */
mrb_value rh_simple_funcall(Ruby * ruby, char * name) {
  int ai;  
  Ruby * mrb = (Ruby *) ruby;  
  mrb_value args[16];
  ai = mrb_gc_arena_save(mrb);
  LOG("GC Area: %d\n", ai);
  // if(ai> 99) exit(0);
  mrb_value v = mrb_funcall_argv(mrb, mrb_top_self(mrb), mrb_intern_cstr(mrb, name), 
                    0, args);
  
  if (mrb->exc) {
    if (!mrb_undef_p(v)) {        
      mrb_p(mrb, mrb_obj_value(mrb->exc));
    }
    return mrb_nil_value();
  }
  mrb_gc_arena_restore(mrb, 0);
  return v;
}

/* Maybe wrap this too? 
mrb_value mrb_funcall_argv(mrb_state*, mrb_value, mrb_sym, int, mrb_value*);
*/

/* Converts and mrb_value to a C boolean as per the ruby interpretation. */
int rh_tobool(mrb_value v) {
  if (mrb_nil_p(v))             return FALSE;
  return mrb_bool(v);
}

/* Documentation for mrb_get_args
  retrieve arguments from mrb_state.

  mrb_get_args(mrb, format, ...)
  
  returns number of arguments parsed.

  format specifiers:

   o: Object [mrb_value]
   S: String [mrb_value]
   A: Array [mrb_value]
   H: Hash [mrb_value]
   s: String [char*,int]
   z: String [char*]
   a: Array [mrb_value*,int]
   f: Float [mrb_float]
   i: Integer [mrb_int]
   n: Symbol [mrb_sym]
   &: Block [mrb_value]
   *: rest argument [mrb_value*,int]
   |: optional
*/

#define RH_EVARGS_MAX 32


/* Returns the current number of the joystick, that is it's index in the allegro 
 * JS list. Too bad but this number may change. Returns -1 if not found; */
static int joystick_nr(ALLEGRO_JOYSTICK * stick) {
  int index;
  ALLEGRO_JOYSTICK * aid;
  for(index = 0 ; index < al_get_num_joysticks(); index ++) {
    aid = al_get_joystick(index);
    if (aid == stick) return index;
  }
  return -1;
}

/* Send the even to the ruby  main "on_poll"   */
int rh_poll_event(mrb_state * mrb, ALLEGRO_EVENT * event) {
  State * state = state_get();
  mrb_value event_args[RH_EVARGS_MAX];
  int nargs = 0;
  
  if (!event) return FALSE;
  switch (event->type) {
    case ALLEGRO_EVENT_JOYSTICK_AXIS:
      nargs = 
      rh_args(mrb, event_args, RH_EVARGS_MAX, "Yfiiif", "joystick_axis",
              event->any.timestamp,
              joystick_nr(event->joystick.id), event->joystick.stick, event->joystick.axis, event->joystick.pos);
    break;
    case ALLEGRO_EVENT_JOYSTICK_BUTTON_DOWN:
      nargs = 
      rh_args(mrb, event_args, RH_EVARGS_MAX, "Yfiiif", "joystick_button_down", 
              event->any.timestamp,
              joystick_nr(event->joystick.id), event->joystick.button);
    break;
    case ALLEGRO_EVENT_JOYSTICK_BUTTON_UP:
      nargs = 
      rh_args(mrb, event_args, RH_EVARGS_MAX, "Yfiiif", "joystick_button_up", 
              event->any.timestamp,
              joystick_nr(event->joystick.id), event->joystick.button);
    break;
    case ALLEGRO_EVENT_JOYSTICK_CONFIGURATION:
      nargs = 
      rh_args(mrb, event_args, RH_EVARGS_MAX, "Yfiiif", "joystick_configuration", 
              event->any.timestamp);
    break;
    case ALLEGRO_EVENT_KEY_DOWN:
      nargs = 
      rh_args(mrb, event_args, RH_EVARGS_MAX, "Yfi", "key_down",
              event->any.timestamp,
              event->keyboard.keycode   );
    break;
    case ALLEGRO_EVENT_KEY_UP:
      nargs = 
      rh_args(mrb, event_args, RH_EVARGS_MAX, "Yfi", "key_up",
              event->any.timestamp,
              event->keyboard.keycode   );
    break;
    case ALLEGRO_EVENT_KEY_CHAR:
      nargs = 
      rh_args(mrb, event_args, RH_EVARGS_MAX, "Yfiiib", "key_char",
              event->any.timestamp,
              event->keyboard.keycode, event->keyboard.unichar,
              event->keyboard.modifiers, event->keyboard.repeat
             );
    break;
    
    case ALLEGRO_EVENT_MOUSE_AXES:
      nargs = 
      rh_args(mrb, event_args, RH_EVARGS_MAX, "Yfiiiiiiii", "mouse_axes",
              event->any.timestamp,
              event->mouse.x, event->mouse.y, event->mouse.z, event->mouse.w,
              event->mouse.dx, event->mouse.dy, event->mouse.dz, event->mouse.dw
             );
    break;

    case ALLEGRO_EVENT_MOUSE_WARPED:
      nargs = 
      rh_args(mrb, event_args, RH_EVARGS_MAX, "Yfiiiiiiii", "mouse_warped",
              event->any.timestamp,
              event->mouse.x, event->mouse.y, event->mouse.z, event->mouse.w,
              event->mouse.dx, event->mouse.dy, event->mouse.dz, event->mouse.dw
             );
    break;
    
    case ALLEGRO_EVENT_MOUSE_BUTTON_DOWN:
      nargs = 
      rh_args(mrb, event_args, RH_EVARGS_MAX, "Yfiiiii", "mouse_button_down",
              event->any.timestamp,
              event->mouse.x, event->mouse.y, event->mouse.z, event->mouse.w,
              event->mouse.button
             );
    break;
    
    case ALLEGRO_EVENT_MOUSE_BUTTON_UP:
      nargs = 
      rh_args(mrb, event_args, RH_EVARGS_MAX, "Yfiiiii", "mouse_button_up",
              event->any.timestamp,
              event->mouse.x, event->mouse.y, event->mouse.z, event->mouse.w,
              event->mouse.button
             );
    break;
    
    case ALLEGRO_EVENT_MOUSE_ENTER_DISPLAY:
      nargs = 
      rh_args(mrb, event_args, RH_EVARGS_MAX, "Yfiiii", "mouse_enter_display",
              event->any.timestamp,
              event->mouse.x, event->mouse.y, event->mouse.z, event->mouse.w
             );
    break;
    
    case ALLEGRO_EVENT_MOUSE_LEAVE_DISPLAY:
      nargs = 
      rh_args(mrb, event_args, RH_EVARGS_MAX, "Yfiiii", "mouse_leave_display",
              event->any.timestamp,
              event->mouse.x, event->mouse.y, event->mouse.z, event->mouse.w
             );
    break;
       
    
    default:
      nargs = rh_args(mrb, event_args, RH_EVARGS_MAX, "Yf", "unknown",
        event->any.timestamp
      );
    break;
  }
  rh_run_toplevel_args(state_ruby(state), "eruta_on_poll", nargs, event_args);
  return TRUE;
}

/* Polls the event queue and while events are available, send them to the ruby 
 main "eruta_on_poll"   */
int rh_poll_events(mrb_state * mrb, ALLEGRO_EVENT_QUEUE * queue) {
  ALLEGRO_EVENT event;
  while(al_get_next_event(queue, &event)) { 
    rh_poll_event(mrb, &event);
  }
  return TRUE;
}


/* Tries to (re-)load the main ruby file, output to console. */
int rh_load_main() { 
  State * state = state_get();
  // Try to load the main ruby file.
  return rh_run_script(state_ruby(state), "main.rb");
}
  

/** For execution of ruby strings by the console */
int rh_run_console_command(struct zori_console * console, const char * command, void * extra)
{
  int res;
  LOG_ENABLE_CONSOLE();
  res = rh_dostring(state_ruby(state_get()), command);
  LOG_DISABLE_CONSOLE();
  (void) console;
  (void) extra;
  return res;
}