#include "first_app.hpp"

// std
#include <stdexcept>
#include <array>

namespace hk
{
    FirstApp::FirstApp()
    {
        loadModels();
        createPipelineLayout();
        recreateSwapChain();
        createCommandBuffers();
    }

    FirstApp::~FirstApp()
    {
        vkDestroyPipelineLayout(device.device(), pipelineLayout, nullptr);
    }

    void FirstApp::run()
    {
        while (!window.shouldClose())
        {
            glfwPollEvents();
            drawFrame();
        }

        vkDeviceWaitIdle(device.device());
    }

    void FirstApp::loadModels()
    {
        std::vector<Model::Vertex> vertices{
            {{0.0f, -0.5f}, {1.0f, 0.0f, 0.0f}},
            {{0.5f, 0.5f}, {0.0f, 1.0f, 0.0f}},
            {{-0.5f, 0.5f}, {0.0f, 0.0f, 1.0f}}
        };
        model = std::make_unique<Model>(device, vertices);
    }

    void FirstApp::createPipelineLayout()
    {
        VkPipelineLayoutCreateInfo pipelineLayoutInfo{};
        pipelineLayoutInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
        pipelineLayoutInfo.setLayoutCount = 0;
        pipelineLayoutInfo.pSetLayouts = nullptr;
        pipelineLayoutInfo.pushConstantRangeCount = 0;
        pipelineLayoutInfo.pPushConstantRanges = nullptr;

        if (vkCreatePipelineLayout(device.device(), &pipelineLayoutInfo, nullptr, &pipelineLayout) !=
            VK_SUCCESS)
        {
            throw std::runtime_error("failed to create pipeline layout!");
        }
    }

    void FirstApp::createPipeline()
    {
        auto pipelineConfig =
            Pipeline::defaultPipelineConfigInfo(swapChain->width(), swapChain->height());

        pipelineConfig.renderPass = swapChain->getRenderPass();
        pipelineConfig.pipelineLayout = pipelineLayout;
        pipeline = std::make_unique<Pipeline>(
            device,
            "shaders/simple_shader.vert.spv",
            "shaders/simple_shader.frag.spv",
            pipelineConfig);
    }

    void FirstApp::recreateSwapChain()
    {
        auto extent = window.getExtend();
        while (extent.width == 0 || extent.height == 0)
        {
            extent = window.getExtend();
            glfwWaitEvents();
        }

        vkDeviceWaitIdle(device.device());
        swapChain = std::make_unique<SwapChain>(device, extent);
        createPipeline();
    }

    void FirstApp::createCommandBuffers()
    {
        commandBuffers.resize(swapChain->imageCount());

        VkCommandBufferAllocateInfo allocInfo{};
        allocInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
        allocInfo.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
        allocInfo.commandPool = device.getCommandPool();
        allocInfo.commandBufferCount = static_cast<uint32_t>(commandBuffers.size());

        if (vkAllocateCommandBuffers(device.device(), &allocInfo, commandBuffers.data()) !=
            VK_SUCCESS)
        {
            throw std::runtime_error("failed to allocate command buffers!");
        }
    }

    void FirstApp::recordCommandBuffer(int imageIndex)
    {
        VkCommandBufferBeginInfo beginInfo{};
        beginInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
        if (vkBeginCommandBuffer(commandBuffers[imageIndex], &beginInfo) != VK_SUCCESS)
        {
            throw std::runtime_error("failed to begin recording command buffer!");
        }

        VkRenderPassBeginInfo renderPassInfo{};
        renderPassInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
        renderPassInfo.renderPass = swapChain->getRenderPass();
        renderPassInfo.framebuffer = swapChain->getFrameBuffer(imageIndex);

        renderPassInfo.renderArea.offset = {0, 0};
        renderPassInfo.renderArea.extent = swapChain->getSwapChainExtent();

        std::array<VkClearValue, 2> clearValues{};
        clearValues[0].color = {0.1f, 0.1f, 0.1f, 1.0f};
        clearValues[1].depthStencil = {1.0f, 0};
        renderPassInfo.clearValueCount = static_cast<uint32_t>(clearValues.size());
        renderPassInfo.pClearValues = clearValues.data();

        vkCmdBeginRenderPass(commandBuffers[imageIndex], &renderPassInfo, VK_SUBPASS_CONTENTS_INLINE);

        pipeline->bind(commandBuffers[imageIndex]);
        model->bind(commandBuffers[imageIndex]);
        model->draw(commandBuffers[imageIndex]);

        vkCmdEndRenderPass(commandBuffers[imageIndex]);
        if (vkEndCommandBuffer(commandBuffers[imageIndex]) != VK_SUCCESS)
        {
            throw std::runtime_error("failed to record command buffer!");
        }
    }

    void FirstApp::drawFrame()
    {
        uint32_t imageIndex;
        auto result = swapChain->acquireNextImage(&imageIndex);

        if (result == VK_ERROR_OUT_OF_DATE_KHR)
        {
            recreateSwapChain();
            return;
        }

        if (result != VK_SUCCESS && result != VK_SUBOPTIMAL_KHR)
        {
            throw std::runtime_error("failed to acquire swap chain image!");
        }

        recordCommandBuffer(imageIndex);
        result = swapChain->submitCommandBuffers(&commandBuffers[imageIndex], &imageIndex);
        if (result == VK_ERROR_OUT_OF_DATE_KHR || result == VK_SUBOPTIMAL_KHR || window.wasWindowResized())
        {
            window.resetWindowResizedFlag();
            recreateSwapChain();
            return;
        }
        
        if (result != VK_SUCCESS)
        {
            throw std::runtime_error("failed to present swap chain image!");
        }
    }
}