/**
 * @file move.c
 * @author Joe Wingbermuehle
 * @date 2004-2006
 *
 * @brief Client window move functions.
 *
 */

#include "jwm.h"
#include "move.h"

#include "border.h"
#include "client.h"
#include "clientlist.h"
#include "cursor.h"
#include "error.h"
#include "event.h"
#include "key.h"
#include "main.h"
#include "outline.h"
#include "pager.h"
#include "screen.h"
#include "status.h"
#include "tray.h"

typedef struct {
   int valid;
   int left, right;
   int top, bottom;
} RectangleType;

static int shouldStopMove;
static SnapModeType snapMode = SNAP_BORDER;
static int snapDistance = DEFAULT_SNAP_DISTANCE;

static MoveModeType moveMode = MOVE_OPAQUE;

static void StopMove(ClientNode *np,
   int doMove, int oldx, int oldy, int hmax, int vmax);
static void MoveController(int wasDestroyed);

static void DoSnap(ClientNode *np);
static void DoSnapScreen(ClientNode *np);
static void DoSnapBorder(ClientNode *np);
static int ShouldSnap(const ClientNode *np);
static void GetClientRectangle(const ClientNode *np, RectangleType *r);

static int CheckOverlapTopBottom(const RectangleType *a,
   const RectangleType *b);
static int CheckOverlapLeftRight(const RectangleType *a,
   const RectangleType *b);

static int CheckLeftValid(const RectangleType *client,
   const RectangleType *other, const RectangleType *left);
static int CheckRightValid(const RectangleType *client,
   const RectangleType *other, const RectangleType *right);
static int CheckTopValid(const RectangleType *client,
   const RectangleType *other, const RectangleType *top);
static int CheckBottomValid(const RectangleType *client,
   const RectangleType *other, const RectangleType *bottom);

/** Set the snap mode to use. */
void SetSnapMode(SnapModeType mode) {
   snapMode = mode;
}

/** Set the move mode to use. */
void SetMoveMode(MoveModeType mode) {
   moveMode = mode;
}

/** Set the snap distance. */
void SetSnapDistance(const char *value) {
   int temp;

   Assert(value);

   temp = atoi(value);
   if(temp > MAX_SNAP_DISTANCE || temp < MIN_SNAP_DISTANCE) {
      snapDistance = DEFAULT_SNAP_DISTANCE;
      Warning("invalid snap distance specified: %d", temp);
   } else {
      snapDistance = temp;
   }

}

/** Restore the default snap distance. */
void SetDefaultSnapDistance() {
   snapDistance = DEFAULT_SNAP_DISTANCE;
}

/** Callback for stopping moves. */
void MoveController(int wasDestroyed) {

   if(moveMode == MOVE_OUTLINE) {
      ClearOutline();
   }

   JXUngrabPointer(display, CurrentTime);
   JXUngrabKeyboard(display, CurrentTime);

   DestroyMoveWindow();
   shouldStopMove = 1;

}

/** Move a client window. */
int MoveClient(ClientNode *np, int startx, int starty) {

   XEvent event;
   int oldx, oldy;
   int doMove;
   int north, south, east, west;
   int height;
   int hmax, vmax;

   Assert(np);

   if(!(np->state.border & BORDER_MOVE)) {
      return 0;
   }

   GrabMouseForMove();

   np->controller = MoveController;
   shouldStopMove = 0;

   oldx = np->x;
   oldy = np->y;
   vmax = 0;
   hmax = 0;

   if(!(GetMouseMask() & (Button1Mask | Button2Mask))) {
      StopMove(np, 0, oldx, oldy, 0, 0);
      return 0;
   }

   GetBorderSize(np, &north, &south, &east, &west);

   startx -= west;
   starty -= north;

   doMove = 0;
   for(;;) {

      WaitForEvent(&event);

      if(shouldStopMove) {
         np->controller = NULL;
         SetDefaultCursor(np->parent);
         return doMove;
      }

      switch(event.type) {
      case ButtonRelease:
         if(event.xbutton.button == Button1
            || event.xbutton.button == Button2) {
            StopMove(np, doMove, oldx, oldy, hmax, vmax);
            return doMove;
         }
         break;
      case MotionNotify:

         DiscardMotionEvents(&event, np->window);

         np->x = event.xmotion.x_root - startx;
         np->y = event.xmotion.y_root - starty;

         DoSnap(np);

         if(!doMove && (abs(np->x - oldx) > MOVE_DELTA
            || abs(np->y - oldy) > MOVE_DELTA)) {

            if(np->state.status & (STAT_HMAX | STAT_VMAX)) {
               if(np->state.status & STAT_HMAX) {
                  hmax = 1;
               }
               if(np->state.status & STAT_VMAX) {
                  vmax = 1;
               }
               MaximizeClient(np, 0, 0);
               startx = np->width / 2;
               starty = -north / 2;
               MoveMouse(np->parent, startx, starty);
            }

            CreateMoveWindow(np);
            doMove = 1;
         }

         if(doMove) {

            if(moveMode == MOVE_OUTLINE) {
               ClearOutline();
               height = north + south;
               if(!(np->state.status & STAT_SHADED)) {
                  height += np->height;
               }
               DrawOutline(np->x - west, np->y - north,
                  np->width + west + east, height);
            } else {
               JXMoveWindow(display, np->parent, np->x - west,
                  np->y - north);
               SendConfigureEvent(np);
            }
            UpdateMoveWindow(np);
            UpdatePager();
         }

         break;
      default:
         break;
      }
   }
}

/** Move a client window (keyboard or menu initiated). */
int MoveClientKeyboard(ClientNode *np) {

   XEvent event;
   int oldx, oldy;
   int moved;
   int height;
   int north, south, east, west;
   int hmax, vmax;

   Assert(np);

   if(!(np->state.border & BORDER_MOVE)) {
      return 0;
   }

   hmax = 0;
   if(np->state.status & STAT_HMAX) {
      hmax = 1;
   }
   vmax = 0;
   if(np->state.status & STAT_VMAX) {
      vmax = 1;
   }
   if(vmax || hmax) {
      MaximizeClient(np, 0, 0);
   }

   GrabMouseForMove();
   if(JXGrabKeyboard(display, np->window, True, GrabModeAsync,
      GrabModeAsync, CurrentTime) != GrabSuccess) {
      Debug("could not grab keyboard for client move");
      return 0;
   }

   GetBorderSize(np, &north, &south, &east, &west);

   oldx = np->x;
   oldy = np->y;

   np->controller = MoveController;
   shouldStopMove = 0;

   CreateMoveWindow(np);
   UpdateMoveWindow(np);

   MoveMouse(rootWindow, np->x, np->y);
   DiscardMotionEvents(&event, np->window);

   if(np->state.status & STAT_SHADED) {
      height = 0;
   } else {
      height = np->height;
   }

   for(;;) {

      WaitForEvent(&event);

      if(shouldStopMove) {
         np->controller = NULL;
         SetDefaultCursor(np->parent);
         return 1;
      }

      moved = 0;

      if(event.type == KeyPress) {

         while(JXCheckTypedWindowEvent(display, np->window, KeyPress, &event));

         switch(GetKey(&event.xkey) & 0xFF) {
         case KEY_UP:
            if(np->y + height > 0) {
               np->y -= 10;
            }
            break;
         case KEY_DOWN:
            if(np->y < rootHeight) {
               np->y += 10;
            }
            break;
         case KEY_RIGHT:
            if(np->x < rootWidth) {
               np->x += 10;
            }
            break;
         case KEY_LEFT:
            if(np->x + np->width > 0) {
               np->x -= 10;
            }
            break;
         default:
            StopMove(np, 1, oldx, oldy, hmax, vmax);
            return 1;
         }

         MoveMouse(rootWindow, np->x, np->y);
         JXCheckTypedWindowEvent(display, np->window, MotionNotify, &event);

         moved = 1;

      } else if(event.type == MotionNotify) {

         while(JXCheckTypedWindowEvent(display, np->window,
            MotionNotify, &event));

         np->x = event.xmotion.x;
         np->y = event.xmotion.y;

         moved = 1;

      } else if(event.type == ButtonRelease) {

         StopMove(np, 1, oldx, oldy, hmax, vmax);
         return 1;

      }

      if(moved) {

         if(moveMode == MOVE_OUTLINE) {
            ClearOutline();
            DrawOutline(np->x - west, np->y - west,
               np->width + west + east, height + north + west);
         } else {
            JXMoveWindow(display, np->parent, np->x - west, np->y - north);
            SendConfigureEvent(np);
         }

         UpdateMoveWindow(np);
         UpdatePager();

      }

   }

}

/** Stop move. */
void StopMove(ClientNode *np, int doMove,
   int oldx, int oldy, int hmax, int vmax) {

   int north, south, east, west;

   Assert(np);
   Assert(np->controller);

   (np->controller)(0);

   np->controller = NULL;

   SetDefaultCursor(np->parent);

   if(!doMove) {

      np->x = oldx;
      np->y = oldy;

      /* Restore maximized status. */
      if(hmax || vmax) {
         MaximizeClient(np, hmax, vmax);
      }

      return;

   }

   GetBorderSize(np, &north, &south, &east, &west);

   JXMoveWindow(display, np->parent, np->x - west, np->y - north);
   SendConfigureEvent(np);

   /* Restore maximized status. */
   if(hmax || vmax) {
      MaximizeClient(np, hmax, vmax);
   }

}

/** Snap to the screen and/or neighboring windows. */
void DoSnap(ClientNode *np) {
   switch(snapMode) {
   case SNAP_BORDER:
      DoSnapBorder(np);
      DoSnapScreen(np);
      break;
   case SNAP_SCREEN:
      DoSnapScreen(np);
      break;
   default:
      break;
   }
}

/** Snap to the screen. */
void DoSnapScreen(ClientNode *np) {

   RectangleType client;
   int screen;
   const ScreenType *sp;
   int screenCount;
   int north, south, east, west;

   GetClientRectangle(np, &client);

   GetBorderSize(np, &north, &south, &east, &west);

   screenCount = GetScreenCount();
   for(screen = 0; screen < screenCount; screen++) {

      sp = GetScreen(screen);

      if(abs(client.right - sp->width - sp->x) <= snapDistance) {
         np->x = sp->x + sp->width - west - np->width;
      }
      if(abs(client.left - sp->x) <= snapDistance) {
         np->x = sp->x + east;
      }
      if(abs(client.bottom - sp->height - sp->y) <= snapDistance) {
         np->y = sp->y + sp->height - south;
         if(!(np->state.status & STAT_SHADED)) {
            np->y -= np->height;
         }
      }
      if(abs(client.top - sp->y) <= snapDistance) {
         np->y = north + sp->y;
      }

   }

}

/** Snap to window borders. */
void DoSnapBorder(ClientNode *np) {

   const ClientNode *tp;
   const TrayType *tray;
   RectangleType client, other;
   RectangleType left = { 0 };
   RectangleType right = { 0 };
   RectangleType top = { 0 };
   RectangleType bottom = { 0 };
   int layer;
   int north, south, east, west;

   GetClientRectangle(np, &client);

   GetBorderSize(np, &north, &south, &east, &west);

   other.valid = 1;

   /* Work from the bottom of the window stack to the top. */
   for(layer = 0; layer < LAYER_COUNT; layer++) {

      /* Check tray windows. */
      for(tray = GetTrays(); tray; tray = tray->next) {

         if(tray->hidden) {
            continue;
         }

         other.left = tray->x;
         other.right = tray->x + tray->width;
         other.top = tray->y;
         other.bottom = tray->y + tray->height;

         left.valid = CheckLeftValid(&client, &other, &left);
         right.valid = CheckRightValid(&client, &other, &right);
         top.valid = CheckTopValid(&client, &other, &top);
         bottom.valid = CheckBottomValid(&client, &other, &bottom);

         if(CheckOverlapTopBottom(&client, &other)) {
            if(abs(client.left - other.right) <= snapDistance) {
               left = other;
            }
            if(abs(client.right - other.left) <= snapDistance) {
               right = other;
            }
         }
         if(CheckOverlapLeftRight(&client, &other)) {
            if(abs(client.top - other.bottom) <= snapDistance) {
               top = other;
            }
            if(abs(client.bottom - other.top) <= snapDistance) {
               bottom = other;
            }
         }

      }

      /* Check client windows. */
      for(tp = nodeTail[layer]; tp; tp = tp->prev) {

         if(tp == np || !ShouldSnap(tp)) {
            continue;
         }

         GetClientRectangle(tp, &other);

         /* Check if this border invalidates any previous value. */
         left.valid = CheckLeftValid(&client, &other, &left);
         right.valid = CheckRightValid(&client, &other, &right);
         top.valid = CheckTopValid(&client, &other, &top);
         bottom.valid = CheckBottomValid(&client, &other, &bottom);

         /* Compute the new snap values. */
         if(CheckOverlapTopBottom(&client, &other)) {
            if(abs(client.left - other.right) <= snapDistance) {
               left = other;
            }
            if(abs(client.right - other.left) <= snapDistance) {
               right = other;
            }
         }
         if(CheckOverlapLeftRight(&client, &other)) {
            if(abs(client.top - other.bottom) <= snapDistance) {
               top = other;
            }
            if(abs(client.bottom - other.top) <= snapDistance) {
               bottom = other;
            }
         }

      }

   }

   if(right.valid) {
      np->x = right.left - np->width - west;
   }
   if(left.valid) {
      np->x = left.right + east;
   }
   if(bottom.valid) {
      np->y = bottom.top - south;
      if(!(np->state.status & STAT_SHADED)) {
         np->y -= np->height;
      }
   }
   if(top.valid) {
      np->y = top.bottom + north;
   }

}

/** Determine if we should snap to the specified client. */
int ShouldSnap(const ClientNode *np) {
   if(np->state.status & STAT_HIDDEN) {
      return 0;
   } else if(np->state.status & STAT_MINIMIZED) {
      return 0;
   } else {
      return 1;
   }
}

/** Get a rectangle to represent a client window. */
void GetClientRectangle(const ClientNode *np, RectangleType *r) {

   int north, south, east, west;

   GetBorderSize(np, &north, &south, &east, &west);

   r->left = np->x - west;
   r->right = np->x + np->width + east;
   r->top = np->y - north;
   if(np->state.status & STAT_SHADED) {
      r->bottom = np->y + south;
   } else {
      r->bottom = np->y + np->height + south;
   }

   r->valid = 1;

}

/** Check for top/bottom overlap. */
int CheckOverlapTopBottom(const RectangleType *a, const RectangleType *b) {
   if(a->top >= b->bottom) {
      return 0;
   } else if(a->bottom <= b->top) {
      return 0;
   } else {
      return 1;
   }
}

/** Check for left/right overlap. */
int CheckOverlapLeftRight(const RectangleType *a, const RectangleType *b) {
   if(a->left >= b->right) {
      return 0;
   } else if(a->right <= b->left) {
      return 0;
   } else {
      return 1;
   }
}

/** Check if the current left snap position is valid.
 * @param client The window being moved.
 * @param other A window higher in stacking order than
 * previously check windows.
 * @param left The top/bottom of the current left snap window.
 * @return 1 if the current left snap position is still valid, otherwise 0.
 */
int CheckLeftValid(const RectangleType *client,
   const RectangleType *other, const RectangleType *left) {

   if(!left->valid) {
      return 0;
   }

   if(left->right > other->right) {
      return 1;
   }

   /* If left and client go higher than other then still valid. */
   if(left->top < other->top && client->top < other->top) {
      return 1;
   }

   /* If left and client go lower than other then still valid. */
   if(left->bottom > other->bottom && client->bottom > other->bottom) {
      return 1;
   }

   if(other->left >= left->right) {
      return 1;
   }

   return 0;

}

/** Check if the current right snap position is valid. */
int CheckRightValid(const RectangleType *client,
   const RectangleType *other, const RectangleType *right) {

   if(!right->valid) {
      return 0;
   }

   if(right->left < other->left) {
      return 1;
   }

   /* If right and client go higher than other then still valid. */
   if(right->top < other->top && client->top < other->top) {
      return 1;
   }

   /* If right and client go lower than other then still valid. */
   if(right->bottom > other->bottom && client->bottom > other->bottom) {
      return 1;
   }

   if(other->right <= right->left) {
      return 1;
   }

   return 0;

}

/** Check if the current top snap position is valid. */
int CheckTopValid(const RectangleType *client,
   const RectangleType *other, const RectangleType *top) {

   if(!top->valid) {
      return 0;
   }

   if(top->bottom > other->bottom) {
      return 1;
   }

   /* If top and client are to the left of other then still valid. */
   if(top->left < other->left && client->left < other->left) {
      return 1;
   }

   /* If top and client are to the right of other then still valid. */
   if(top->right > other->right && client->right > other->right) {
      return 1;
   }

   if(other->top >= top->bottom) {
      return 1;
   }

   return 0;

}

/** Check if the current bottom snap position is valid. */
int CheckBottomValid(const RectangleType *client,
   const RectangleType *other, const RectangleType *bottom) {

   if(!bottom->valid) {
      return 0;
   }

   if(bottom->top < other->top) {
      return 1;
   }

   /* If bottom and client are to the left of other then still valid. */
   if(bottom->left < other->left && client->left < other->left) {
      return 1;
   }

   /* If bottom and client are to the right of other then still valid. */
   if(bottom->right > other->right && client->right > other->right) {
      return 1;
   }

   if(other->bottom <= bottom->top) {
      return 1;
   }

   return 0;

}