#include "base.h"
#include "../util/input.h"

#include <SDL_keycode.h>

const U32 TEXTBOX_TITLE_OFFSET = 15;

U8 is_printable_char( U8 key ) {
  return key >= 32 && key < 127;
}

void gui_textbox_draw_newline_str( GUI_TEXTBOX* tb, I32 x, I32 y, CLR clr, I32* endposx, I32* endposy ) {
  char linebuf[GUI_TEXTBOX_MAX];
  char* start = tb->value;
  I32 tw, th;

  for( char* c = start; !!*c; ++c ) {
    if( *c == '\n' ) {
      U32 len = (U32)( c - start );
      memcpy( linebuf, start, len );
      linebuf[len] = 0;

      gui_draw_str( x, y, ALIGN_L, FNT_JPN12, clr, linebuf );
      gui_draw_get_str_bounds( &tw, &th, FNT_JPN12, linebuf );
      y += th + 1;

      *endposx = x + tw;
      *endposy = y + th;

      if( *(c+1) == 0 )
        break;

      start = ++c;
    }
    else if( (*c+1) == 0 ) {
      U32 len = (U32)( c - start );
      memcpy( linebuf, start, len );
      linebuf[len] = 0;

      gui_draw_str( x, y, ALIGN_L, FNT_JPN12, clr, linebuf );
      gui_draw_get_str_bounds( &tw, &th, FNT_JPN12, linebuf );
      y += th + 1;
      *endposx = x + tw;
      *endposy = y + th;

      break;
    }
  }
}

void gui_textbox_draw_blinker( GUI_TEXTBOX* tb, I32 x, I32 y, CLR clr ) {
  if( !tb->active )
    return;
  if( gui_time() - tb->blinktime > 1.0f ) {
    tb->blink = !tb->blink;
    tb->blinktime = gui_time();
  }

  if( tb->blink )
    gui_draw_str( x, y, ALIGN_L, FNT_JPN12, clr, "|" );
}

void gui_textbox_draw_fn( void* ptr ) {
  GUI_TEXTBOX* tb = (GUI_TEXTBOX*)ptr;

  I32 x = gui_relx( tb );
  I32 y = gui_rely( tb );

  gui_draw_str( x, y, ALIGN_L, FNT_JPN12, ui_clr.txt, tb->name );
  y += TEXTBOX_TITLE_OFFSET;

  CLR col = gui_is_fg_window( tb )? ui_clr.border : ui_clr.border_inactive;

  gui_draw_frect( x, y, tb->w, tb->h, col );
  gui_draw_frect( x+1, y+1, tb->w-2, tb->h-2, ui_clr.bg_sec );

  CLR clr = tb->active? ui_clr.txt : ui_clr.txt_inactive;
  I32 ypos = y + 3;
  I32 xpos = x + 2;

  I32 endposx, endposy;

  if( tb->allow_newl ) {
    gui_textbox_draw_newline_str( tb, xpos, ypos, clr, &endposx, &endposy );
  } else {
    gui_draw_str( xpos, ypos, ALIGN_L, FNT_JPN12, clr, tb->value );

    I32 tw, th;
    gui_draw_get_str_bounds( &tw, &th, FNT_JPN12, tb->value );
    endposx = xpos + tw;
    endposy = ypos;
  }

  gui_textbox_draw_blinker( tb, endposx, endposy, clr );
}

void gui_textbox_handle_mouse( GUI_TEXTBOX* tb ) {
  I32 x = gui_relx( tb );
  I32 y = gui_rely( tb ) + TEXTBOX_TITLE_OFFSET;
  I32 w = tb->w;
  I32 h = tb->h;

  U8 m1 = gui_mbutton_down( 0 );
  I32 mx, my;
  gui_cursor_pos( &mx, &my );

  U8 inbounds = mx >= x && mx <= x + w && my >= y && my <= y + h;

  if( m1 ) {
    if( inbounds )
      tb->m1held = 1;
    else
     tb->active = 0;
  } else {
    if( inbounds && tb->m1held ) {
      tb->active = 1;
      tb->blink = 1;
      tb->blinktime = gui_time();
    }
    tb->m1held = 0;
  }
}

void gui_textbox_loop_keys( GUI_TEXTBOX* tb ) {
  U32 len = strlen( tb->value );

  for( U32 i = 0; i < 0xff; ++i ) {
    U8 key  = tb->keys[i];
    U8 prev = tb->prevkeys[i];

    if( !key && prev && i == tb->heldkey )
      tb->heldkey = 0;
    else if( key && !prev ) {
      if( is_printable_char( i ) && len < tb->maxlen - 1 ) {
        if( tb->keys[SDLK_LSHIFT & 0xff] || tb->keys[SDLK_RSHIFT & 0xff] )
          tb->value[len] = (char)i + ('a' - 'A');
        else
          tb->value[len] = (char)i;
        tb->value[++len] = 0;
      }
      else if( i == '\b' ) {
        if( len > 0 ) {
          tb->value[--len] = 0;
        }
      }
      else if( i == '\r' ) {
        if( tb->allow_newl ) {
          tb->value[len] = '\n';
          tb->value[++len] = 0;
        }
        else {
          tb->active = 0;
        }
      } else {
        if( i == '\x1b' )
          tb->active = 0;
        if( tb->cb )
          tb->cb( tb );
        continue;
      }

      tb->heldkey = i;
      tb->heldtime = gui_time();
      if( tb->cb )
        tb->cb( tb );
    }
  }
}

void gui_textbox_handle_repeat( GUI_TEXTBOX* tb ) {
  if( !tb->heldkey )
    return;

  F32 delta = gui_time() - tb->heldtime;
  if( delta <= 0.75f )
    return;

  if( gui_time() - tb->repeattime > 0.05f ) {
    U32 len = strlen( tb->value );
    if( is_printable_char( tb->heldkey ) && len < (tb->maxlen - 1) ) {
      if( tb->keys[SDLK_LSHIFT & 0xff] || tb->keys[SDLK_RSHIFT & 0xff] )
        tb->value[len] = tb->heldkey + ('a' - 'A');
      else
        tb->value[len] = tb->heldkey;
      tb->value[++len] = 0;
      if( tb->cb )
        tb->cb( tb );
    }
    else if( tb->heldkey == '\b' && len > 0 ) {
      tb->value[--len] = 0;
      if( tb->cb )
        tb->cb( tb );
    }

    tb->repeattime = gui_time();
  }
}

void gui_textbox_handle_keyboard( GUI_TEXTBOX* tb ) {
  if( !tb->active )
    return;

  memcpy( tb->prevkeys, tb->keys, 0xff );
  memcpy( tb->keys, input.keys, 0xff );

  gui_textbox_loop_keys( tb );
  gui_textbox_handle_repeat( tb );
}

void gui_textbox_input_fn( void* ptr ) {
  GUI_TEXTBOX* tb = (GUI_TEXTBOX*)ptr;

  gui_textbox_handle_mouse( tb );
  gui_textbox_handle_keyboard( tb );
}

GUI_TEXTBOX* gui_textbox( I32 x, I32 y, I32 w, I32 h, const char* title, U32 maxlen, U8 allow_newl ) {
  GUI_TEXTBOX* tb = new GUI_TEXTBOX;

  tb->x = x;
  tb->y = y;
  tb->w = w;
  tb->h = h;
  tb->xbound = tb->w;
  tb->ybound = tb->h + TEXTBOX_TITLE_OFFSET;
  tb->parent = _gui.cur_view;
  tb->draw_fn = gui_textbox_draw_fn;
  tb->input_fn = gui_textbox_input_fn;
  strcpy( tb->name, title );

  tb->cb = 0;
  tb->active = 0;
  tb->m1held = 0;
  tb->heldkey = 0;
  tb->heldtime = 0;
  tb->repeattime = 0;
  tb->maxlen = maxlen;
  tb->allow_newl = allow_newl;
  memset( tb->value, 0, GUI_TEXTBOX_MAX );
  memset( tb->keys, 0, 0xff );
  memset( tb->prevkeys, 0, 0xff );

  gui_get_view()->children.push( tb );

  return tb;
}