/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "WebGL2Context.h"
#include "GLContext.h"
#include "WebGLQuery.h"
#include "gfxPrefs.h"
#include "nsThreadUtils.h"

namespace mozilla {

/*
 * We fake ANY_SAMPLES_PASSED and ANY_SAMPLES_PASSED_CONSERVATIVE with
 * SAMPLES_PASSED on desktop.
 *
 * OpenGL ES 3.0 spec 4.1.6:
 *     If the target of the query is ANY_SAMPLES_PASSED_CONSERVATIVE, an
 *     implementation may choose to use a less precise version of the test which
 *     can additionally set the samples-boolean state to TRUE in some other
 *     implementation-dependent cases.
 */

WebGLRefPtr<WebGLQuery>* WebGLContext::ValidateQuerySlotByTarget(
    const char* funcName, GLenum target) {
  if (IsWebGL2()) {
    switch (target) {
      case LOCAL_GL_ANY_SAMPLES_PASSED:
      case LOCAL_GL_ANY_SAMPLES_PASSED_CONSERVATIVE:
        return &mQuerySlot_SamplesPassed;

      case LOCAL_GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:
        return &mQuerySlot_TFPrimsWritten;

      default:
        break;
    }
  }

  if (IsExtensionEnabled(WebGLExtensionID::EXT_disjoint_timer_query)) {
    switch (target) {
      case LOCAL_GL_TIME_ELAPSED_EXT:
        return &mQuerySlot_TimeElapsed;

      default:
        break;
    }
  }

  ErrorInvalidEnum("%s: Bad `target`.", funcName);
  return nullptr;
}

// -------------------------------------------------------------------------
// Query Objects

already_AddRefed<WebGLQuery> WebGLContext::CreateQuery(const char* funcName) {
  if (!funcName) {
    funcName = "createQuery";
  }

  if (IsContextLost()) return nullptr;

  RefPtr<WebGLQuery> globj = new WebGLQuery(this);
  return globj.forget();
}

void WebGLContext::DeleteQuery(WebGLQuery* query, const char* funcName) {
  if (!funcName) {
    funcName = "deleteQuery";
  }

  if (!ValidateDeleteObject(funcName, query)) return;

  query->DeleteQuery();
}

bool WebGLContext::IsQuery(const WebGLQuery* query, const char* funcName) {
  if (!funcName) {
    funcName = "isQuery";
  }

  if (!ValidateIsObject(funcName, query)) return false;

  return query->IsQuery();
}

void WebGLContext::BeginQuery(GLenum target, WebGLQuery& query,
                              const char* funcName) {
  if (!funcName) {
    funcName = "beginQuery";
  }

  if (IsContextLost()) return;

  if (!ValidateObject(funcName, query)) return;

  const auto& slot = ValidateQuerySlotByTarget(funcName, target);
  if (!slot) return;

  if (*slot)
    return ErrorInvalidOperation("%s: Query target already active.", funcName);

  ////

  query.BeginQuery(target, *slot);
}

void WebGLContext::EndQuery(GLenum target, const char* funcName) {
  if (!funcName) {
    funcName = "endQuery";
  }

  if (IsContextLost()) return;

  const auto& slot = ValidateQuerySlotByTarget(funcName, target);
  if (!slot) return;

  const auto& query = *slot;
  if (!query)
    return ErrorInvalidOperation("%s: Query target not active.", funcName);

  query->EndQuery();
}

void WebGLContext::GetQuery(JSContext* cx, GLenum target, GLenum pname,
                            JS::MutableHandleValue retval,
                            const char* funcName) {
  if (!funcName) {
    funcName = "getQuery";
  }

  retval.setNull();
  if (IsContextLost()) return;

  switch (pname) {
    case LOCAL_GL_CURRENT_QUERY_EXT: {
      if (IsExtensionEnabled(WebGLExtensionID::EXT_disjoint_timer_query) &&
          target == LOCAL_GL_TIMESTAMP) {
        // Doesn't seem illegal to ask about, but is always null.
        // TIMESTAMP has no slot, so ValidateQuerySlotByTarget would generate
        // INVALID_ENUM.
        return;
      }

      const auto& slot = ValidateQuerySlotByTarget(funcName, target);
      if (!slot || !*slot) return;

      const auto& query = *slot;
      if (target != query->Target()) return;

      JS::Rooted<JS::Value> v(cx);
      dom::GetOrCreateDOMReflector(cx, slot->get(), &v);
      retval.set(v);
    }
      return;

    case LOCAL_GL_QUERY_COUNTER_BITS_EXT:
      if (!IsExtensionEnabled(WebGLExtensionID::EXT_disjoint_timer_query))
        break;

      if (target != LOCAL_GL_TIME_ELAPSED_EXT &&
          target != LOCAL_GL_TIMESTAMP_EXT) {
        ErrorInvalidEnum("%s: Bad pname for target.", funcName);
        return;
      }

      {
        GLint bits = 0;
        gl->fGetQueryiv(target, pname, &bits);

        if (!Has64BitTimestamps() && bits > 32) {
          bits = 32;
        }
        retval.set(JS::Int32Value(bits));
      }
      return;

    default:
      break;
  }

  ErrorInvalidEnum("%s: Bad pname.", funcName);
}

void WebGLContext::GetQueryParameter(JSContext*, const WebGLQuery& query,
                                     GLenum pname,
                                     JS::MutableHandleValue retval,
                                     const char* funcName) {
  if (!funcName) {
    funcName = "getQueryParameter";
  }

  retval.setNull();
  if (IsContextLost()) return;

  if (!ValidateObject(funcName, query)) return;

  query.GetQueryParameter(pname, retval);
}

}  // namespace mozilla