/*****************************************************************************
 * Open MCT Web, Copyright (c) 2014-2015, United States Government
 * as represented by the Administrator of the National Aeronautics and Space
 * Administration. All rights reserved.
 *
 * Open MCT Web is licensed under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0.
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 * Open MCT Web includes source code licensed under additional open source
 * licenses. See the Open Source Licenses file (LICENSES.md) included with
 * this source code distribution or the Licensing information page available
 * at runtime from the About dialog for additional information.
 *****************************************************************************/

/**
 * MergeModelsSpec. Created by vwoeltje on 11/6/14.
 */
define(
    ["../src/GLChart"],
    function (GLChart) {

        describe("A WebGL chart", function () {
            var mockCanvas,
                mockGL,
                glChart;

            beforeEach(function () {
                mockCanvas = jasmine.createSpyObj("canvas", ["getContext"]);
                mockGL = jasmine.createSpyObj(
                    "gl",
                    [
                        "createShader",
                        "compileShader",
                        "shaderSource",
                        "attachShader",
                        "createProgram",
                        "linkProgram",
                        "useProgram",
                        "enableVertexAttribArray",
                        "getAttribLocation",
                        "getUniformLocation",
                        "createBuffer",
                        "lineWidth",
                        "enable",
                        "blendFunc",
                        "viewport",
                        "clear",
                        "uniform2fv",
                        "uniform4fv",
                        "bufferData",
                        "bindBuffer",
                        "vertexAttribPointer",
                        "drawArrays"
                    ]
                );
                mockGL.ARRAY_BUFFER = "ARRAY_BUFFER";
                mockGL.DYNAMIC_DRAW = "DYNAMIC_DRAW";
                mockGL.TRIANGLE_FAN = "TRIANGLE_FAN";
                mockGL.LINE_STRIP = "LINE_STRIP";

                // Echo back names for uniform locations, so we can
                // test which of these are set for certain operations.
                mockGL.getUniformLocation.andCallFake(function (a, name) {
                    return name;
                });

                mockCanvas.getContext.andReturn(mockGL);

                glChart = new GLChart(mockCanvas);
            });

            it("allows the canvas to be cleared", function () {
                glChart.clear();
                expect(mockGL.clear).toHaveBeenCalled();
            });

            it("doees not construct if WebGL is unavailable", function () {
                mockCanvas.getContext.andReturn(undefined);
                expect(function () {
                    return new GLChart(mockCanvas);
                }).toThrow();
            });

            it("allows dimensions to be set", function () {
                glChart.setDimensions([120, 120], [0, 10]);
                expect(mockGL.uniform2fv)
                    .toHaveBeenCalledWith("uDimensions", [120, 120]);
                expect(mockGL.uniform2fv)
                    .toHaveBeenCalledWith("uOrigin", [0, 10]);
            });

            it("allows lines to be drawn", function () {
                var testBuffer = [0, 1, 3, 8],
                    testColor = [0.25, 0.33, 0.66, 1.0],
                    testPoints = 2;
                glChart.drawLine(testBuffer, testColor, testPoints);
                expect(mockGL.bufferData).toHaveBeenCalledWith(
                    mockGL.ARRAY_BUFFER,
                    testBuffer,
                    mockGL.DYNAMIC_DRAW
                );
                expect(mockGL.uniform4fv)
                    .toHaveBeenCalledWith("uColor", testColor);
                expect(mockGL.drawArrays)
                    .toHaveBeenCalledWith("LINE_STRIP", 0, testPoints);
            });

            it("allows squares to be drawn", function () {
                var testMin = [0, 1],
                    testMax = [10, 10],
                    testColor = [0.25, 0.33, 0.66, 1.0];

                glChart.drawSquare(testMin, testMax, testColor);

                expect(mockGL.uniform4fv)
                    .toHaveBeenCalledWith("uColor", testColor);
                expect(mockGL.drawArrays)
                    .toHaveBeenCalledWith("TRIANGLE_FAN", 0, 4);
            });

            it("uses buffer sizes reported by WebGL", function () {
                // Make sure that GLChart uses the GL buffer size, which may
                // differ from what canvas requested. WTD-852
                mockCanvas.width = 300;
                mockCanvas.height = 150;
                mockGL.drawingBufferWidth = 200;
                mockGL.drawingBufferHeight = 175;

                glChart.clear();

                expect(mockGL.viewport).toHaveBeenCalledWith(0, 0, 200, 175);
            });
        });
    }
);