/**
 * 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"


static _EGL_DECLARE_MUTEX(_eglDisplayInitMutex);
static _EGLHashtable *_eglDisplayHash;
/* TODO surface hash table should be per-display */
static _EGLHashtable *_eglSurfaceHash;


/**
 * Finish display management.
 */
static void
_eglFiniDisplay(void)
{
   _eglLockMutex(&_eglDisplayInitMutex);
   if (_eglDisplayHash) {
      EGLuint key = _eglHashFirstEntry(_eglDisplayHash);

      while (key) {
         _EGLDisplay *dpy = (_EGLDisplay *)
            _eglHashLookup(_eglDisplayHash, key);
         assert(dpy);

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

         _eglCleanupDisplay(dpy);
         free(dpy);

         key = _eglHashNextEntry(_eglDisplayHash, key);
      }

      _eglDeleteHashTable(_eglDisplayHash);
      _eglDisplayHash = NULL;
      _eglDeleteHashTable(_eglSurfaceHash);
      _eglSurfaceHash = NULL;
   }
   _eglUnlockMutex(&_eglDisplayInitMutex);
}


/* This can be avoided if hash table can be statically initialized */
static INLINE void
_eglInitDisplay(void)
{
   if (!_eglDisplayHash) {
      _eglLockMutex(&_eglDisplayInitMutex);

      /* check again after acquiring lock */
      if (!_eglDisplayHash) {
         _eglDisplayHash = _eglNewHashTable();
         _eglSurfaceHash = _eglNewHashTable();

         _eglAddAtExitCall(_eglFiniDisplay);
      }

      _eglUnlockMutex(&_eglDisplayInitMutex);
   }
}


/**
 * 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

      _eglInitDisplay();
      dpy->SurfaceHash = _eglSurfaceHash;

      dpy->DriverName = _eglChooseDriver(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)
{
   EGLuint key;

   _eglInitDisplay();

   key = _eglHashGenKey(_eglDisplayHash);
   assert(key);
   /* "link" the display to the hash table */
   _eglHashInsert(_eglDisplayHash, key, dpy);
   dpy->Handle = (EGLDisplay) _eglUIntToPointer(key);

   return dpy->Handle;
}


/**
 * Unlink a linked display from itself.
 * Accessing an unlinked display should generate EGL_BAD_DISPLAY error.
 */
void
_eglUnlinkDisplay(_EGLDisplay *dpy)
{
   EGLuint key = _eglPointerToUInt((void *) dpy->Handle);

   _eglInitDisplay();

   _eglHashRemove(_eglDisplayHash, key);
   dpy->Handle = EGL_NO_DISPLAY;
}


/**
 * Return the handle of a linked display, or EGL_NO_DISPLAY.
 */
EGLDisplay
_eglGetDisplayHandle(_EGLDisplay *display)
{
   if (display)
      return display->Handle;
   else
      return EGL_NO_DISPLAY;
}


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

   _eglInitDisplay();

   return (_EGLDisplay *) _eglHashLookup(_eglDisplayHash, key);
}


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

   _eglInitDisplay();

   /* Walk the hash table.  Should switch to list if it is a problem. */
   key = _eglHashFirstEntry(_eglDisplayHash);
   while (key) {
      _EGLDisplay *dpy = (_EGLDisplay *)
            _eglHashLookup(_eglDisplayHash, key);
      assert(dpy);

      if (dpy->NativeDisplay == nativeDisplay)
         return dpy;
      key = _eglHashNextEntry(_eglDisplayHash, key);
   }

   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;

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

   /* XXX incomplete */

   free((void *) disp->DriverName);
   disp->DriverName = NULL;

   /* driver deletes the _EGLDisplay object */
}


/**
 * 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)
{
   EGLuint key;

   surf->Display = dpy;
   surf->Next = dpy->SurfaceList;
   dpy->SurfaceList = surf;

   key = _eglHashGenKey(dpy->SurfaceHash);
   assert(key);
   _eglHashInsert(dpy->SurfaceHash, key, surf);

   surf->Handle = (EGLSurface) _eglUIntToPointer(key);
   return surf->Handle;
}


/**
 * Unlink a linked surface from its display.
 * Accessing an unlinked surface should generate EGL_BAD_SURFACE error.
 */
void
_eglUnlinkSurface(_EGLSurface *surf)
{
   _EGLSurface *prev;
   EGLuint key = _eglPointerToUInt((void *) surf->Handle);

   _eglHashRemove(surf->Display->SurfaceHash, key);
   surf->Handle = EGL_NO_SURFACE;

   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 *surface)
{
   if (surface)
      return surface->Handle;
   else
      return EGL_NO_SURFACE;
}


/**
 * Lookup a handle to find the linked surface.
 * Return NULL if the handle has no corresponding linked surface.
 */
_EGLSurface *
_eglLookupSurface(EGLSurface surf, _EGLDisplay *dpy)
{
   EGLuint key = _eglPointerToUInt((void *) surf);
   return (_EGLSurface *) _eglHashLookup(dpy->SurfaceHash, key);
}