/**
 * Functions related to EGLDisplay.
 */

#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "eglcontext.h"
#include "eglsurface.h"
#include "egldisplay.h"
#include "egldriver.h"
#include "eglglobals.h"
#include "eglhash.h"
#include "eglstring.h"
#include "eglmutex.h"
#include "egllog.h"


/**
 * Finish display management.
 */
void
_eglFiniDisplay(void)
{
   _EGLDisplay *dpyList, *dpy;

   /* atexit function is called with global mutex locked */
   dpyList = _eglGlobal.DisplayList;
   while (dpyList) {
      /* pop list head */
      dpy = dpyList;
      dpyList = dpyList->Next;

      if (dpy->ContextList || dpy->SurfaceList)
         _eglLog(_EGL_DEBUG, "Display %p is destroyed with resources", dpy);

      free(dpy);
   }
   _eglGlobal.DisplayList = NULL;
}


/**
 * Allocate a new _EGLDisplay object for the given nativeDisplay handle.
 * We'll also try to determine the device driver name at this time.
 *
 * Note that nativeDisplay may be an X Display ptr, or a string.
 */
_EGLDisplay *
_eglNewDisplay(NativeDisplayType nativeDisplay)
{
   _EGLDisplay *dpy = (_EGLDisplay *) calloc(1, sizeof(_EGLDisplay));
   if (dpy) {
      dpy->NativeDisplay = nativeDisplay;
#if defined(_EGL_PLATFORM_X)
      dpy->Xdpy = (Display *) nativeDisplay;
#endif

      dpy->DriverName = _eglPreloadDriver(dpy);
      if (!dpy->DriverName) {
         free(dpy);
         return NULL;
      }
   }
   return dpy;
}


/**
 * Link a display to itself and return the handle of the link.
 * The handle can be passed to client directly.
 */
EGLDisplay
_eglLinkDisplay(_EGLDisplay *dpy)
{
   _eglLockMutex(_eglGlobal.Mutex);

   dpy->Next = _eglGlobal.DisplayList;
   _eglGlobal.DisplayList = dpy;

   _eglUnlockMutex(_eglGlobal.Mutex);

   return (EGLDisplay) dpy;
}


/**
 * Unlink a linked display from itself.
 * Accessing an unlinked display should generate EGL_BAD_DISPLAY error.
 */
void
_eglUnlinkDisplay(_EGLDisplay *dpy)
{
   _EGLDisplay *prev;

   _eglLockMutex(_eglGlobal.Mutex);

   prev = _eglGlobal.DisplayList;
   if (prev != dpy) {
      while (prev) {
         if (prev->Next == dpy)
            break;
         prev = prev->Next;
      }
      assert(prev);
      prev->Next = dpy->Next;
   }
   else {
      _eglGlobal.DisplayList = dpy->Next;
   }

   _eglUnlockMutex(_eglGlobal.Mutex);
}


/**
 * Return the handle of a linked display, or EGL_NO_DISPLAY.
 */
EGLDisplay
_eglGetDisplayHandle(_EGLDisplay *dpy)
{
   return (EGLDisplay) ((dpy) ? dpy : EGL_NO_DISPLAY);
}


/**
 * Lookup a handle to find the linked display.
 * Return NULL if the handle has no corresponding linked display.
 */
_EGLDisplay *
_eglLookupDisplay(EGLDisplay display)
{
   _EGLDisplay *dpy = (_EGLDisplay *) display;
   return dpy;
}


/**
 * Find the display corresponding to the specified native display id in all
 * linked displays.
 */
_EGLDisplay *
_eglFindDisplay(NativeDisplayType nativeDisplay)
{
   _EGLDisplay *dpy;

   _eglLockMutex(_eglGlobal.Mutex);

   dpy = _eglGlobal.DisplayList;
   while (dpy) {
      if (dpy->NativeDisplay == nativeDisplay) {
         _eglUnlockMutex(_eglGlobal.Mutex);
         return dpy;
      }
      dpy = dpy->Next;
   }

   _eglUnlockMutex(_eglGlobal.Mutex);

   return NULL;
}


/**
 * Destroy the contexts and surfaces that are linked to the display.
 */
void
_eglReleaseDisplayResources(_EGLDriver *drv, _EGLDisplay *display)
{
   _EGLContext *contexts;
   _EGLSurface *surfaces;

   contexts = display->ContextList;
   surfaces = display->SurfaceList;

   while (contexts) {
      _EGLContext *ctx = contexts;
      contexts = contexts->Next;

      _eglUnlinkContext(ctx);
      drv->API.DestroyContext(drv, display, ctx);
   }
   assert(!display->ContextList);

   while (surfaces) {
      _EGLSurface *surf = surfaces;
      surfaces = surfaces->Next;

      _eglUnlinkSurface(surf);
      drv->API.DestroySurface(drv, display, surf);
   }
   assert(!display->SurfaceList);
}


/**
 * Free all the data hanging of an _EGLDisplay object, but not
 * the object itself.
 */
void
_eglCleanupDisplay(_EGLDisplay *disp)
{
   EGLint i;

   if (disp->Configs) {
      for (i = 0; i < disp->NumConfigs; i++)
         free(disp->Configs[i]);
      free(disp->Configs);
      disp->Configs = NULL;
      disp->NumConfigs = 0;
   }

   /* XXX incomplete */
}


/**
 * Link a context to a display and return the handle of the link.
 * The handle can be passed to client directly.
 */
EGLContext
_eglLinkContext(_EGLContext *ctx, _EGLDisplay *dpy)
{
   ctx->Display = dpy;
   ctx->Next = dpy->ContextList;
   dpy->ContextList = ctx;
   return (EGLContext) ctx;
}


/**
 * Unlink a linked context from its display.
 * Accessing an unlinked context should generate EGL_BAD_CONTEXT error.
 */
void
_eglUnlinkContext(_EGLContext *ctx)
{
   _EGLContext *prev;

   prev = ctx->Display->ContextList;
   if (prev != ctx) {
      while (prev) {
         if (prev->Next == ctx)
            break;
         prev = prev->Next;
      }
      assert(prev);
      prev->Next = ctx->Next;
   }
   else {
      ctx->Display->ContextList = ctx->Next;
   }

   ctx->Next = NULL;
   ctx->Display = NULL;
}


/**
 * Return the handle of a linked context, or EGL_NO_CONTEXT.
 */
EGLContext
_eglGetContextHandle(_EGLContext *ctx)
{
   return (EGLContext) ((ctx && ctx->Display) ? ctx : EGL_NO_CONTEXT);
}


/**
 * Lookup a handle to find the linked context.
 * Return NULL if the handle has no corresponding linked context.
 */
_EGLContext *
_eglLookupContext(EGLContext ctx, _EGLDisplay *dpy)
{
   _EGLContext *context = (_EGLContext *) ctx;
   return (context && context->Display) ? context : NULL;
}


/**
 * Link a surface to a display and return the handle of the link.
 * The handle can be passed to client directly.
 */
EGLSurface
_eglLinkSurface(_EGLSurface *surf, _EGLDisplay *dpy)
{
   surf->Display = dpy;
   surf->Next = dpy->SurfaceList;
   dpy->SurfaceList = surf;
   return (EGLSurface) surf;
}


/**
 * Unlink a linked surface from its display.
 * Accessing an unlinked surface should generate EGL_BAD_SURFACE error.
 */
void
_eglUnlinkSurface(_EGLSurface *surf)
{
   _EGLSurface *prev;

   prev = surf->Display->SurfaceList;
   if (prev != surf) {
      while (prev) {
         if (prev->Next == surf)
            break;
         prev = prev->Next;
      }
      assert(prev);
      prev->Next = surf->Next;
   }
   else {
      prev = NULL;
      surf->Display->SurfaceList = surf->Next;
   }

   surf->Next = NULL;
   surf->Display = NULL;
}


/**
 * Return the handle of a linked surface, or EGL_NO_SURFACE.
 */
EGLSurface
_eglGetSurfaceHandle(_EGLSurface *surf)
{
   return (EGLSurface) ((surf && surf->Display) ? surf : EGL_NO_SURFACE);
}


/**
 * Lookup a handle to find the linked surface.
 * Return NULL if the handle has no corresponding linked surface.
 */
_EGLSurface *
_eglLookupSurface(EGLSurface surface, _EGLDisplay *dpy)
{
   _EGLSurface *surf = (_EGLSurface *) surface;
   return (surf && surf->Display) ? surf : NULL;
}