#include "skypass.h"

#include <array>

#include "renderer.h"

SkyPass::SkyPass(Renderer& renderer) : renderer_(renderer) {
    createPipeline();
}

SkyPass::~SkyPass() {
    vkDestroyPipeline(renderer_.getDevice(), pipeline_, nullptr);
    vkDestroyPipelineLayout(renderer_.getDevice(), pipelineLayout_, nullptr);
}

void SkyPass::render(VkCommandBuffer commandBuffer) {
    vkCmdBindPipeline(commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipeline_);
    vkCmdDraw(commandBuffer, 3, 1, 0, 0);
}

void SkyPass::createPipeline() {
    VkShaderModule vertShaderModule = renderer_.createShader("shaders/sky.vert.spv");
    VkShaderModule fragShaderModule = renderer_.createShader("shaders/sky.frag.spv");

    VkPipelineShaderStageCreateInfo vertShaderStageInfo = {};
    vertShaderStageInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
    vertShaderStageInfo.stage = VK_SHADER_STAGE_VERTEX_BIT;
    vertShaderStageInfo.module = vertShaderModule;
    vertShaderStageInfo.pName = "main";

    VkPipelineShaderStageCreateInfo fragShaderStageInfo = {};
    fragShaderStageInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
    fragShaderStageInfo.stage = VK_SHADER_STAGE_FRAGMENT_BIT;
    fragShaderStageInfo.module = fragShaderModule;
    fragShaderStageInfo.pName = "main";

    const std::array<VkPipelineShaderStageCreateInfo, 2> shaderStages = {vertShaderStageInfo, fragShaderStageInfo};

    VkPipelineVertexInputStateCreateInfo vertexInputInfo = {};
    vertexInputInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;

    VkPipelineInputAssemblyStateCreateInfo inputAssembly = {};
    inputAssembly.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;
    inputAssembly.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;

    VkPipelineViewportStateCreateInfo viewportState = {};
    viewportState.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO;
    viewportState.viewportCount = 1;
    viewportState.scissorCount = 1;

    VkPipelineRasterizationStateCreateInfo rasterizer = {};
    rasterizer.sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO;
    rasterizer.polygonMode = VK_POLYGON_MODE_FILL;
    rasterizer.cullMode = VK_CULL_MODE_NONE;
    rasterizer.frontFace = VK_FRONT_FACE_COUNTER_CLOCKWISE;
    rasterizer.lineWidth = 1.0f;

    VkPipelineMultisampleStateCreateInfo multisampling = {};
    multisampling.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;
    multisampling.rasterizationSamples = VK_SAMPLE_COUNT_1_BIT;

    VkPipelineColorBlendAttachmentState colorBlendAttachment = {};
    colorBlendAttachment.colorWriteMask = VK_COLOR_COMPONENT_R_BIT | VK_COLOR_COMPONENT_G_BIT | VK_COLOR_COMPONENT_B_BIT | VK_COLOR_COMPONENT_A_BIT;

    VkPipelineColorBlendStateCreateInfo colorBlending = {};
    colorBlending.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO;
    colorBlending.attachmentCount = 1;
    colorBlending.pAttachments = &colorBlendAttachment;

    VkPipelineDepthStencilStateCreateInfo depthState = {};
    depthState.sType = VK_STRUCTURE_TYPE_PIPELINE_DEPTH_STENCIL_STATE_CREATE_INFO;
    depthState.depthTestEnable = VK_TRUE;
    depthState.depthWriteEnable = VK_FALSE;
    depthState.depthCompareOp = VK_COMPARE_OP_LESS_OR_EQUAL;

    const std::array<VkDynamicState, 2> dynamicStates = {
        VK_DYNAMIC_STATE_VIEWPORT,
        VK_DYNAMIC_STATE_SCISSOR
    };

    VkPipelineDynamicStateCreateInfo dynamicState = {};
    dynamicState.sType = VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO;
    dynamicState.dynamicStateCount = dynamicStates.size();
    dynamicState.pDynamicStates = dynamicStates.data();

    VkPipelineLayoutCreateInfo pipelineLayoutInfo = {};
    pipelineLayoutInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;

    vkCreatePipelineLayout(renderer_.getDevice(), &pipelineLayoutInfo, nullptr, &pipelineLayout_);

    VkGraphicsPipelineCreateInfo pipelineInfo = {};
    pipelineInfo.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;
    pipelineInfo.stageCount = shaderStages.size();
    pipelineInfo.pStages = shaderStages.data();
    pipelineInfo.pVertexInputState = &vertexInputInfo;
    pipelineInfo.pInputAssemblyState = &inputAssembly;
    pipelineInfo.pViewportState = &viewportState;
    pipelineInfo.pRasterizationState = &rasterizer;
    pipelineInfo.pMultisampleState = &multisampling;
    pipelineInfo.pColorBlendState = &colorBlending;
    pipelineInfo.pDepthStencilState = &depthState;
    pipelineInfo.pDynamicState = &dynamicState;
    pipelineInfo.layout = pipelineLayout_;
    pipelineInfo.renderPass = renderer_.getWorldPass().getRenderPass();

    vkCreateGraphicsPipelines(renderer_.getDevice(), nullptr, 1, &pipelineInfo, nullptr, &pipeline_);

    vkDestroyShaderModule(renderer_.getDevice(), fragShaderModule, nullptr);
    vkDestroyShaderModule(renderer_.getDevice(), vertShaderModule, nullptr);
}