#include <string.h>

#include "base.h"
#include "../game.h"

// =========== [ impl ] ===========
#include "../util/input.h"
#include "../render/gl_2d.h"
#include "../render/gl_2d_font.h"
// ================================

__gui_internal _gui;

void gui_load_font( GL_DATA* gl, __gui_internal::__font* fnt, const char* name ) {
  // todo: this probably crashes when fonts r re-created
  GL_FONT** fptr = gl->fonts.where( fn( GL_FONT** ptr ) {
    GL_FONT* f = *ptr;
    return strstr( f->name, name ) != 0;
  } );

  if( !fptr ) {
    dlog( "gui_load_font() : error loading font %s\n", name );
    return;
  }

  fnt->glfnt = *fptr;
}

void gui_init( GAME_DATA* game ) {
  GL_DATA* gl = game->gl;
  gui_load_font( gl, &_gui.fonts.jpn12, "jpn12" );
  gui_load_font( gl, &_gui.fonts.jpn16, "jpn16" );
}

void gui_end() {
  _gui.cur_window = 0;
}

void gui_draw( GAME_DATA* game ) {
  _gui.batch = game->render.batch_2d;
  gl_batch_empty( _gui.batch );

  _gui.windows.each( fn( GUI_WINDOW** w ) {
    GUI_WINDOW* wnd = *w;
    if( !wnd->enabled ) return;

    wnd->draw_fn( wnd );
  } );

  gl_batch_draw( _gui.batch );
}

void gui_input( GAME_DATA* game ) {
  for( I32 i = (I32)_gui.windows.size - 1; i >= 0; --i ) {
    GUI_WINDOW* wnd = _gui.windows[i];
    if( !wnd->enabled ) continue;

    wnd->input_fn( wnd );
    break;
  }
}

void gui_onframe( GAME_DATA* game ) { _profiled
  gui_input( game );
  gui_draw( game );

  gui_run_callbacks();
}

void gui_free( GUI_BASE* node ) {
  node->children.each( fn( GUI_BASE** ptr ) {
    GUI_BASE* child = *ptr;
    gui_free( child );
  } );

  node->children.clear();

  if( !node->parent ) {
    I32 idx = _gui.windows.idx_of( (GUI_WINDOW*)node );
    if( idx != -1 )
      _gui.windows.erase( idx );

    if( _gui.cur_window == node ) {
      if( _gui.windows.size > 0 ) {
        idx = idx > _gui.windows.size - 1 ? _gui.windows.size - 1 : 0;
        _gui.cur_window = _gui.windows[idx];
      }
    }
  }
  else if( _gui.cur_view == node ) {
    _gui.cur_view = 0;
    for( U32 i = 0; i < node->parent->children.size; ++i ) {
      GUI_BASE* n = node->parent->children.data[i];
      if( n == node )
        continue;

      if( !strcmp( n->name, "BASE_VIEW" ) ) {
        _gui.cur_view = (GUI_VIEW*)n;
        break;
      }

      n = gui_find_node( n, "BASE_VIEW" );
      if( n != node ) {
        _gui.cur_view = (GUI_VIEW*)n;
        break;
      }
    }
  }

  delete node;
}

I32 gui_relx( GUI_BASE* node ) {
  I32 x = node->x;
  for( GUI_BASE* p = node->parent; !!p; p = p->parent ) {
    x += p->x;
  }
  return x;
}

I32 gui_rely( GUI_BASE* node ) {
  I32 y = node->y;
  for( GUI_BASE* p = node->parent; !!p; p = p->parent ) {
    y += p->y;
  }
  return y;
}

GUI_BASE* gui_find_node( GUI_BASE* root, const char* name ) {
  if( !root )
    return 0;

  if( !strcmp( root->name, name ) )
    return root;

  for( U32 i = 0; i < root->children.size; ++i ) {
    GUI_BASE* child = root->children.data[i];
    GUI_BASE* node = gui_find_node( child, name );
    if( node )
      return node;
  }

  return 0;
}

GUI_WINDOW* gui_get_parent_wnd( GUI_BASE* node ) {
  if( !node->parent )
    return (GUI_WINDOW*)node;

  for( GUI_BASE* b = node; !!b; b = b->parent ) {
    if( !b->parent )
      return (GUI_WINDOW*)b;
  }

  return (GUI_WINDOW*)node;
}

void gui_empty_children( GUI_BASE* node ) {
  node->children.each( fn( GUI_BASE** ptr ) {
    gui_free( *ptr );
  } );

  node->children.clear();
}

GUI_VIEW* gui_get_view() {
  return _gui.cur_view;
}

void gui_set_view( struct GUI_VIEW* view ) {
  _gui.cur_view = view;
}

GUI_WINDOW* gui_get_window() {
  return _gui.cur_window;
}

void gui_set_window( GUI_WINDOW* window ) {
  _gui.cur_window = window;
}

void gui_bring_to_top( GUI_WINDOW* window ) {
  for( U32 i = 0; i < _gui.windows.size; ++i ) {
    if( _gui.windows[i] == window ) {
      _gui.windows.erase( i );
      break;
    }
  }

  _gui.windows.push( window );
}

U8 gui_is_fg_window( GUI_BASE* node ) {
  GUI_WINDOW* top_wnd;
  for( I32 i = _gui.windows.size - 1; i >= 0; --i ) {
    GUI_WINDOW* wnd = _gui.windows[i];
    if( !wnd->enabled )
      continue;

    top_wnd = wnd;
    break;
  }

  if( !node->parent ) {
    return top_wnd == node;
  }

  return gui_get_parent_wnd( node ) == top_wnd;
}

U8 gui_check_target() {
  if( !_gui.cur_view ) {
    dlog( "gui_check_target() : no view" );
    return 0;
  }

  return 1;
}

void gui_run_callbacks() {
  LIST<__gui_internal::callback_entry> cb_copy = _gui.callbacks;
  _gui.callbacks.clear();

  for( I32 i = cb_copy.size - 1; i >= 0; --i ) {
    __gui_internal::callback_entry* e = &cb_copy[i];
    if( e->callback )
      e->callback( e->data );
  }
}

void gui_push_callback( GUI_CALLBACK cb ) {
  __gui_internal::callback_entry e;
  e.data = 0;
  e.callback = cb;

  _gui.callbacks.push( e );
}

void gui_push_callback( void* data, GUI_CALLBACK cb ) {
  __gui_internal::callback_entry e;
  e.data = data;
  e.callback = cb;

  _gui.callbacks.push( e );
}

void gui_base_input_fn( void* ptr ) {
  GUI_BASE* e = (GUI_BASE*)ptr;
  if( !e ) return;

  e->children.each( fn( GUI_BASE** ptr ) {
    GUI_BASE* child = *ptr;
    if( child->enabled && child->input_fn )
      child->input_fn( child );
  } );
}

void gui_draw_frect( I32 x, I32 y, I32 w, I32 h, CLR col ) {
  gl_2d_frect( _gui.batch, { (F32)x, (F32)y }, { (F32)w, (F32)h }, col );
}

void gui_draw_rect( I32 x, I32 y, I32 w, I32 h, CLR col ) {
  gl_2d_rect( _gui.batch, { (F32)x, (F32)y }, { (F32)w, (F32)h }, col );
}

void gui_draw_line( I32 x0, I32 y0, I32 x1, I32 y1, CLR col ) {
  gl_2d_line( _gui.batch, { (F32)x0, (F32)y0 }, { (F32)x1, (F32)y1 }, col );
}

GL_FONT* gui_font_from_idx( U32 fnt ) {
  if( fnt > FNT_LAST ) {
    dlog( "gui_font_from_idx() : invalid font index %d", fnt );
    return 0;
  }

  __gui_internal::__font* pfnt;
  switch( fnt ) {
    case FNT_JPN12: pfnt = &_gui.fonts.jpn12; break;
    case FNT_JPN16: pfnt = &_gui.fonts.jpn16; break;
    default: return 0;
  };

  return pfnt->glfnt;
}

void gui_draw_str_internal( I32 x, I32 y, U8 align, U32 fnt, CLR col, const char* str ) {
  GL_FONT* pfnt = gui_font_from_idx( fnt );
  if( !pfnt ) return;

  I32 w;
  gui_draw_get_str_bounds( &w, 0, fnt, str );
  switch( align ) {
    case ALIGN_R: x -= w; break;
    case ALIGN_C: x -= (I32)( w * 0.5f ); break;
  }

  gl_font_draw( pfnt, _gui.batch, { (F32)x, (F32)y }, str, col );
}

void gui_draw_str( I32 x, I32 y, U8 align, U32 fnt, CLR col, const char* fmt, ... ) {
  va_list args;
  va_start( args, fmt );
  char buf[GUI_STR_BUF_MAX];
  vsprintf( buf, fmt, args );
  va_end( args );

  gui_draw_str_internal( x, y, align, fnt, col, buf );
}

void gui_draw_get_str_bounds_internal( I32* w, I32* h, U32 fnt, const char* buf ) {
  GL_FONT* pfnt = gui_font_from_idx( fnt );
  if( !pfnt ) return;

  VEC2 dim = gl_font_dim( pfnt, buf );
  if( w ) *w = dim.x;
  if( h ) *h = dim.y;
}

void gui_draw_get_str_bounds( I32* w, I32* h, U32 fnt, const char *fmt, ... ) {
  va_list args;
  va_start( args, fmt );
  char buf[GUI_STR_BUF_MAX];
  vsprintf( buf, fmt, args );
  va_end( args );

  gui_draw_get_str_bounds_internal( w, h, fnt, buf );
}

void gui_draw_get_clip( I32 *x, I32 *y, I32 *w, I32 *h ) {
  VEC2 start, dim;
  gl_get_clip( _gui.batch->gl, &start, &dim );

  if( x ) *x = (I32)start.x;
  if( y ) *y = (I32)start.y;
  if( w ) *w = (I32)dim.x;
  if( h ) *h = (I32)dim.y;
}

void gui_draw_set_clip( I32 x, I32 y, I32 w, I32 h ) {
  VEC2 start, dim;
  start.x = (F32)x;
  start.y = (F32)y;
  dim.x = (F32)w;
  dim.y = (F32)h;

  gl_set_clip( _gui.batch->gl, start, dim );
}

void gui_draw_reset_clip() {
  gl_reset_clip( _gui.batch->gl );
}

void gui_draw_push_clip( I32 x, I32 y, I32 w, I32 h ) {
  I32 cx,cy,cw,ch;
  gui_draw_get_clip( &cx, &cy, &cw, &ch );

  __gui_internal::clip_rect rect{ cx, cy, cw, ch };
  _gui.clip_rects.push( rect );

  gui_draw_set_clip( x, y, w, h );
}

void gui_draw_pop_clip() {
  if( !_gui.clip_rects.size ) {
    dlog( "gui_draw_pop_clip() : clip stack empty\n" );
    return gui_draw_reset_clip();
  }

  __gui_internal::clip_rect rect = _gui.clip_rects.pop();
  gui_draw_set_clip( rect.x, rect.y, rect.w, rect.h );
}

void gui_cursor_pos( I32 *x, I32 *y ) {
  if( x ) *x = input.mouse.pos.x;
  if( y ) *y = input.mouse.pos.y;
}

U8 gui_mbutton_down( U8 button ) {
  switch( button ) {
    case GUI_MBTNLEFT:
      return input.mouse.left;
    case GUI_MBTNRIGHT:
      return input.mouse.right;
    case GUI_MBTNMIDDLE:
      return input.mouse.middle;
    case GUI_MBTNSCROLL:
      return input.mouse.wheel;
  };

  return 0;
}

void gui_capture_scroll() {
  input.mouse.wheel = 0;
}

U8 gui_key_down( U8 key ) {
  return input.keys[key];
}

F32 gui_frametime() {
  return _gui.batch->gl->frametime;
}

F32 gui_time() {
  return u_time();
}