/* gfx.c - (almost) all stuff related to drawing
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 */
#include <gtk/gtk.h>
#include <sys/types.h>
#include <sys/time.h>

#include "gtkballs.h"
#include "scoreboard.h" /* read_score */
#include "prefs.h" /* pref_get_*() */
#include "path.h"
#include "theme.h"
#include "gfx.h"
#include "mainmenu.h" /* menu_set_sensitive_undo */
#include "mainwin.h"
#include "game.h"

GdkPixmap *_pixmap = NULL;

/* x and y of cell "under pointer" */
gint _pointer_x = 0, _pointer_y = 0;

/* Balls that shows what colors will appear on next turn */
GtkWidget **_small_balls = NULL;

/* Number of node and color of the jumping ball */
gint _jumping_ball = 0;

gint _animation_in_progress = FALSE;

/* jumping animation phase */
volatile gint _phase = 0;

/* jumping animation timer tag */
guint _timer_tag = 0;

gboolean have_path(gint source_ball, gint target_ball);
void move_ball(gint source_ball, gint target_ball);

gint xy_to_cell_number(gint x, gint y) {
   return find_node_of_x_y(x, y, rules_get_width());
}


gint get_jump_phase(gint x, gint y) {
   if (!_animation_in_progress || xy_to_cell_number(x, y) != _jumping_ball) {
      return 0;
   }
   return _phase;
}

void set_jump_phase(gint p) {
   if (!_animation_in_progress) {
      return;
   }
   _phase = p;
}

gint get_destroy_phase(gint x, gint y) {
   return board_get_destroy_at_xy(x, y);
}

void update_rectangle(gint x, gint y, gint w, gint h) {
   GtkWidget *widget = mw_get_da();

   if (!widget || !_pixmap) {
      return;
   }
   gdk_draw_drawable (gtk_widget_get_window (widget),
   widget->style->fg_gc[gtk_widget_get_state(widget)],
   _pixmap, x, y, x, y, w, h);
}

void draw_ball_no_update(gint ballcolor, gint x, gint y, gint jumpnum, gint destroynum)
{
   GtkWidget *widget = mw_get_da();
   GdkGC *gc = widget->style->fg_gc[gtk_widget_get_state(widget)];
   gint cxs = gtkbTheme->emptycell.xsize;
   gint cys = gtkbTheme->emptycell.ysize;
   GtkbPixmap *obj;
   gint xr, yr;

   if (!widget || !_pixmap) {
      return;
   }

   if (pref_get_show_highlight() && x == _pointer_x && y == _pointer_y) {
      obj = &gtkbTheme->hemptycell;
   } else {
      obj = &gtkbTheme->emptycell;
   }
   gdk_draw_pixbuf (_pixmap,
                    gc,
                    obj->pixbuf,
                    0, 0,
                    x * cxs, y * cys,
                    cxs, cys,
                    GDK_RGB_DITHER_NONE, 0, 0);

   if (ballcolor > 0) { /* ball */
      if (!jumpnum && !destroynum) { /* still ball */
         obj = &gtkbTheme->balls[ballcolor - 1].ball;
      } else if (jumpnum) { /* jumping ball */
         obj = &gtkbTheme->balls[ballcolor - 1].jump[jumpnum - 1];
      } else { /* disappearing ball */
         obj = &gtkbTheme->balls[ballcolor - 1].destroy[destroynum - 1];
      }
   } else if (ballcolor < 0) { /* paw */
      obj = &gtkbTheme->paws[-1 - ballcolor];
   } else { /* empty cell */
      return;
   }

   xr = x * cxs + (cxs - obj->xsize) / 2;
   yr = y * cys + (cys - obj->ysize) / 2;
   gdk_draw_pixbuf (_pixmap,
                    gc,
                    obj->pixbuf,
                    0, 0,
                    xr, yr,
                    obj->xsize, obj->ysize,
                    GDK_RGB_DITHER_NONE, 0, 0);
}

void draw_ball(gint ballcolor, gint x, gint y, gint jumpnum, gint destroynum) {
   gint cxs = gtkbTheme->emptycell.xsize;
   gint cys = gtkbTheme->emptycell.ysize;

   draw_ball_no_update(ballcolor, x, y, jumpnum, destroynum);
   update_rectangle(x * cxs, y * cys, cxs, cys);
}

void redraw_ball(gint x, gint y) {
   draw_ball(board_get_at_xy(x, y), x, y, get_jump_phase(x, y), get_destroy_phase(x, y));
}

void redraw_pointer(void) {
   draw_ball(board_get_at_xy(_pointer_x, _pointer_y),
             _pointer_x, _pointer_y,
              get_jump_phase(_pointer_x, _pointer_y),
              get_destroy_phase(_pointer_x, _pointer_y));
}

void draw_board(void) {
   gint i, j;

   if (!mw_get_da()) {
      return;
   }
   for (j = 0; j < rules_get_height(); j++) {
      for (i = 0; i < rules_get_width(); i++) {
         if (!_animation_in_progress || ((xy_to_cell_number(i, j)) != _jumping_ball)) {
            draw_ball_no_update(board_get_at_xy(i, j), i, j, 0, 0);
         }
      }
   }
   update_rectangle(0, 0, -1, -1);
}

gint inc_with_limit(gint val, gint lim) {
   if (val < lim) {
      return val + 1;
   }
   return lim;
}

gint dec_with_limit(gint val, gint lim) {
   if (val > lim) {
      return val - 1;
   }
   return lim;
}

gboolean animate_ball(gpointer data) {
   GtkWidget *widget = GTK_WIDGET(data);
   int x, y, bc = board_get_at_node(_jumping_ball);

   find_x_y_of_the_node(&x, &y, _jumping_ball, rules_get_width(), rules_get_height());
   if (widget != NULL) {
      draw_ball(bc, x, y, _phase + 1, 0);
   }

   ++_phase;
   if (_phase >= gtkbTheme->balls[bc - 1].jumpphases) {
      _phase = 0;
   }
   _timer_tag = g_timeout_add (gtkbTheme->balls[bc - 1].jumpdelays[_phase], animate_ball, widget);

   return FALSE;
}

void stop_jumping_animation(void) {
   if (_animation_in_progress) {
      g_source_remove (_timer_tag);
      _animation_in_progress = FALSE;
   }
}

void move_pointer_to(gint x, gint y)
{
   gint i, jp, dp, xc = _pointer_x, yc = _pointer_y;

   if (x >= rules_get_width() || y >= rules_get_height() || x < 0 || y < 0) {
      /* "boundary check" */
      return;
   }
   if (_pointer_x == x && _pointer_y == y) {
      return;
   }
   _pointer_x = x;
   _pointer_y = y;
   for (i = 0; i < 2; i++) {
      if (i) {
         xc = _pointer_x;
         yc = _pointer_y;
      }
      jp = get_jump_phase(xc, yc);
      dp = get_destroy_phase(xc, yc);
      draw_ball(board_get_at_xy(xc, yc), xc, yc, jp, dp);
   }
}

void move_pointer(Direction dir) {
   gint xn = _pointer_x, yn = _pointer_y;

   if (dir == DIR_LEFT || dir == DIR_UP_LEFT || dir == DIR_DOWN_LEFT) {
      xn = dec_with_limit(_pointer_x, 0);
   }
   if (dir == DIR_RIGHT || dir == DIR_UP_RIGHT || dir == DIR_DOWN_RIGHT) {
      xn = inc_with_limit(_pointer_x, rules_get_width() - 1);
   }
   if (dir == DIR_UP || dir == DIR_UP_LEFT || dir == DIR_UP_RIGHT) {
      yn = dec_with_limit(_pointer_y, 0);
   }
   if (dir == DIR_DOWN || dir == DIR_DOWN_LEFT || dir == DIR_DOWN_RIGHT) {
      yn = inc_with_limit(_pointer_y, rules_get_height() - 1);
   }
   if (xn == _pointer_x && yn == _pointer_y) {
      return;
   }

   move_pointer_to(xn, yn);
}

void pointer_pressed(gint x, gint y) {
   gint xn, yn, node, bc;

   if (x == -1 || y == -1) {
      x = _pointer_x;
      y = _pointer_y;
   }
   node = xy_to_cell_number(x, y);

   if (_animation_in_progress && node == _jumping_ball) {
      /* already selected ball clicked */
      return;
   }

   if (board_get_at_node(node) > 0) {
      /* cell with ball pressed */
      if (_animation_in_progress) {
         /* another ball already jumping, stop him */
         stop_jumping_animation();
         find_x_y_of_the_node(&xn, &yn, _jumping_ball, rules_get_width(), rules_get_height());
         draw_ball(board_get_at_node(_jumping_ball), xn, yn, 0, 0);
      }
      /* select ball at x,y and start it jumping */
      _jumping_ball = node;
      bc = board_get_at_node(node);
      _animation_in_progress = TRUE;
      _phase = 0;
      _timer_tag = g_timeout_add(gtkbTheme->balls[bc - 1].jumpdelays[_phase], animate_ball, mw_get_da());
   } else if (_animation_in_progress && have_path(_jumping_ball, node)) {
      /* cell without ball pressed while ball selected */
      game_save_state_for_undo();
      menu_set_sensitive_undo(TRUE);
      stop_jumping_animation();
      move_ball(_jumping_ball, node);
      if (!destroy_lines(TRUE)) {
         new_turn(rules_get_next(), FALSE);
      }
      timer_start();
   }
}

void reinit_board(gint *newboard, gint *newnext, gint score, gint oldnext) {
   struct score_board sb[10];
   gint cells = rules_get_width() * rules_get_height() - 1;

   stop_jumping_animation();
   if (_pointer_x >= rules_get_width()) {
      _pointer_x = rules_get_width() - 1;
   }
   if (_pointer_y >= rules_get_height()) {
      _pointer_y = rules_get_height() - 1;
   }
   if (rules_get_destroy() > cells) {
      rules_set_destroy(cells);
   }
   if (rules_get_next() > cells) {
      rules_set_next(cells);
   }
   game_init_game(newboard, newnext);
   read_score(sb, NULL, NULL);
   mw_set_hi_score(score > sb[0].score ? score : sb[0].score);
   mw_set_user_score(score);
   remake_board(oldnext, newnext ? 1 : 0);
   if (!newboard) {
      new_game();
   } else {
      menu_set_sensitive_undo(FALSE);
      draw_next_balls();
   }
}

void remake_board(gint numoldchilds, gboolean isnextvalid) {
   gint  cxs, cys, i;

   if (numoldchilds && numoldchilds != rules_get_next())
   {
      if (_small_balls) {
         for (i = 0; i < numoldchilds; i++) {
            gtk_widget_destroy(_small_balls[i]);
         }
      }
      _small_balls = g_realloc(_small_balls, rules_get_next() * sizeof(GtkWidget *));
      for (i = 0; i < rules_get_next(); i++) {
         if (isnextvalid) {
            _small_balls[i] = gtk_image_new_from_pixbuf(gtkbTheme->balls[next_get(i) - 1].small.pixbuf);
         } else {
            _small_balls[i] = gtk_image_new_from_pixbuf(gtkbTheme->balls[0].small.pixbuf);
         }
         mw_small_balls_add(_small_balls[i]);
      }
      mw_show_hide_next_balls(pref_get_show_next_colors());
   }

   cxs = gtkbTheme->emptycell.xsize;
   cys = gtkbTheme->emptycell.ysize;
   gtk_widget_set_size_request(mw_get_da(), rules_get_width() * cxs, rules_get_height() * cys);
   if (_pixmap) {
      g_object_unref(_pixmap);
   }
   _pixmap = gdk_pixmap_new(mw_get_da()->window, rules_get_width() * cxs, rules_get_height() * cys, -1);
   draw_board();
}

void draw_next_balls(void) {
   gint i;

   for (i = 0; i < rules_get_next(); i++) {
      gtk_image_set_from_pixbuf(GTK_IMAGE(_small_balls[i]), gtkbTheme->balls[next_get(i) - 1].small.pixbuf);
   }
}

/* Refill the screen from the backing pixmap */
gint expose_event(GtkWidget *widget, GdkEventExpose *event) {
   GdkRectangle *rects;
   int n_rects;
   int i;

   gdk_region_get_rectangles(event->region, &rects, &n_rects);

   for (i = 0; i < n_rects; i++) {
      gdk_draw_drawable (gtk_widget_get_window (widget),
                         widget->style->fg_gc[gtk_widget_get_state(widget)],
                         _pixmap, rects[i].x, rects[i].y, rects[i].x, rects[i].y,
                         rects[i].width, rects[i].height);
   }

   g_free (rects);

   return FALSE;
}

void find_pawnum_and_direction(gint pawx, gint pawy, gint x, gint y, gint *pawnum, gint *direction)
{
   if (pawy < y) {
      *pawnum = 2;
      if (*direction == 1) *pawnum = 6;
      if (*direction == 3) *pawnum = 7;
      *direction = 2; /* up */
   } else if (pawy > y) {
      *pawnum = 0;
      if (*direction == 1) *pawnum = 4;
      if (*direction == 3) *pawnum = 5;
      *direction = 0; /* down */
   } else if (pawx < x) {
      *pawnum = 1;
      if (*direction == 0) *pawnum = 4;
      if (*direction == 2) *pawnum = 6;
      *direction = 1; /* left */
   } else if (pawx > x) {
      *pawnum = 3;
      if (*direction == 0) *pawnum = 5;
      if (*direction == 2) *pawnum = 7;
      *direction = 3; /* right */
   }
}

gint find_direction(gint pawx, gint pawy, gint x, gint y) {
   if (pawy < y) return 2; /* up */
   if (pawy > y) return 0; /* down */
   if (pawx < x) return 1; /* left */
   if (pawx > x) return 3; /* right */
   return -1; /* should never happens */
}

/* FIXME: remake it properly =/ */
gboolean have_path(gint source_ball, gint target_ball) {
   gint nodes[rules_get_width() * rules_get_height()];
   gint path[rules_get_width() * rules_get_height()];
   gint *np = nodes;
   gint i;

   for (i = 0; i < rules_get_height() * rules_get_width(); i++) {
      *np++ = board_get_at_node(i) > 0 ? -1 : 0;
   }
   nodes[source_ball] = nodes[target_ball] = 0;
   if (!find_path(nodes, source_ball, target_ball, path, rules_get_width(), rules_get_height())) {
      return 0;
   }
   return 1;
}

void move_ball(gint source_ball, gint target_ball)
{
   gint nodes[rules_get_width() * rules_get_height()];
   gint path[rules_get_width() * rules_get_height()];
   gint pawx = -1, pawy = -1;
   gint i, j, k, phase, blah;
   gint x, y, color, tbx, tby, bc = board_get_at_node(_jumping_ball);
   gint direction, pawnum;
   gint *np = nodes;
   struct timeval tvs, tve;

   g_assert(board_get_at_node(target_ball) == 0);
   find_x_y_of_the_node(&tbx, &tby, target_ball, rules_get_width(), rules_get_height());

   for (blah = 0; blah < rules_get_height() * rules_get_width(); blah++) {
      *np++ = board_get_at_node(blah) > 0 ? -1 : 0;
   }

   nodes[source_ball] = nodes[target_ball] = 0;
   g_assert(find_path(nodes, source_ball, target_ball, path, rules_get_width(), rules_get_height()) == 1);

   find_x_y_of_the_node(&x, &y, source_ball, rules_get_width(), rules_get_height());
   color = board_get_at_node(source_ball);
   board_set_at_node(source_ball, 0);
   phase = 0;

   draw_ball(0, x, y, 0, 0);
   if (pref_get_show_path())
   {
      lock_actions(1);
      for (k = path[0] - 1; k; k--)
      {
         gettimeofday(&tvs, NULL);
         find_x_y_of_the_node(&i, &j, path[k], rules_get_width(), rules_get_height());
         if (k == path[0] - 1) {
            /* x and y are the coordinates of starting position */
            pawx = x;
            pawy = y;
         } else {
            find_x_y_of_the_node(&pawx, &pawy, path[k + 1], rules_get_width(), rules_get_height());
         }
         if (k != path[0] - 1) {
            find_pawnum_and_direction(pawx, pawy, i, j, &pawnum, &direction);
         } else {
            pawnum = direction = find_direction(pawx, pawy, i, j);
         }
         if (pref_get_show_footprints()) {
            board_set_at_xy(pawx, pawy, -1 - pawnum);
            draw_ball(-1 - pawnum, pawx, pawy, 0, 0);
         }
         board_set_at_xy(i, j, bc);
         draw_ball(bc, i, j, 0, 0);
         do {
            gtk_main_iteration_do(0);
            gettimeofday(&tve, NULL);
         } while ((tve.tv_sec  - tvs.tv_sec) * 1000000 + tve.tv_usec - tvs.tv_usec < 100000);
         board_set_at_xy(i, j, 0);
         draw_ball(0, i, j, 0, 0);
      }
      lock_actions(0);
      if (k == path[0] - 1) {
         /* x and y are the coordinates of starting position */
         pawx = x;
         pawy = y;
      } else {
         find_x_y_of_the_node(&pawx, &pawy, path[k + 1], rules_get_width(), rules_get_height());
      }
      if (pref_get_show_footprints()) {
         find_pawnum_and_direction(pawx, pawy, tbx, tby, &pawnum, &direction);
         board_set_at_xy(pawx, pawy, -1 - pawnum);
         draw_ball(-1 - pawnum, pawx, pawy, 0, 0);
      }
   }
   if (pref_get_show_path() && pref_get_show_footprints()) {
      board_set_at_node(source_ball, 0);
      for (k = path[0] - 1; k; k--) {
         board_set_at_node(path[k], 0);
      }
   }
   board_set_at_node(target_ball, color);
   draw_ball(color, tbx, tby, 0, 0);
}