#include "gtest/gtest.h"

#include <mbgl/map/map.hpp>
#include <mbgl/util/image.hpp>
#include <mbgl/util/io.hpp>
#include <mbgl/util/std.hpp>

#include <rapidjson/document.h>
#include <rapidjson/writer.h>
#include <rapidjson/stringbuffer.h>

#include <mbgl/platform/default/headless_view.hpp>
#include <mbgl/platform/default/headless_display.hpp>

#include "./fixtures/fixture_log.hpp"

#include <dirent.h>

const std::string base_directory = []{
    std::string fn = __FILE__;
    fn.erase(fn.find_last_of("/"));
    fn.erase(fn.find_last_of("/"));
    return fn + "/test/suite/";
}();

auto display_ = std::make_shared<mbgl::HeadlessDisplay>();

class HeadlessTest : public ::testing::TestWithParam<std::string> {};

TEST_P(HeadlessTest, render) {
    using namespace mbgl;

    const std::string &base = GetParam();

    std::string style = util::read_file(base_directory + "tests/" + base + "/style.json");
    std::string info = util::read_file(base_directory + "tests/" + base + "/info.json");

    // Parse style.
    rapidjson::Document styleDoc;
    styleDoc.Parse<0>((const char *const)style.c_str());
    ASSERT_FALSE(styleDoc.HasParseError());
    ASSERT_TRUE(styleDoc.IsObject());

    rapidjson::StringBuffer buffer;
    rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
    styleDoc.Accept(writer);
    style = buffer.GetString();

    // Parse settings.
    rapidjson::Document infoDoc;
    infoDoc.Parse<0>((const char *const)info.c_str());
    ASSERT_FALSE(infoDoc.HasParseError());
    ASSERT_TRUE(infoDoc.IsObject());

    Log::Set<FixtureLogBackend>();

    for (auto it = infoDoc.MemberBegin(), end = infoDoc.MemberEnd(); it != end; it++) {
        const std::string name { it->name.GetString(), it->name.GetStringLength() };
        const rapidjson::Value &value = it->value;
        ASSERT_TRUE(value.IsObject());
        if (value.HasMember("center")) ASSERT_TRUE(value["center"].IsArray());

        const std::string actual_image = base_directory + "tests/" + base + "/" + name +  "/actual.png";

        const double zoom = value.HasMember("zoom") ? value["zoom"].GetDouble() : 0;
        const double bearing = value.HasMember("bearing") ? value["bearing"].GetDouble() : 0;
        const double latitude = value.HasMember("center") ? value["center"][rapidjson::SizeType(0)].GetDouble() : 0;
        const double longitude = value.HasMember("center") ? value["center"][rapidjson::SizeType(1)].GetDouble() : 0;
        const unsigned int width = value.HasMember("width") ? value["width"].GetUint() : 512;
        const unsigned int height = value.HasMember("height") ? value["height"].GetUint() : 512;
        const unsigned int pixelRatio = value.HasMember("pixelRatio") ? value["pixelRatio"].GetUint() : 1;

        std::vector<std::string> classes;
        if (value.HasMember("classes")) {
            const rapidjson::Value &js_classes = value["classes"];
            ASSERT_TRUE(js_classes.IsArray());
            for (rapidjson::SizeType i = 0; i < js_classes.Size(); i++) {
                const rapidjson::Value &js_class = js_classes[i];
                ASSERT_TRUE(js_class.IsString());
                classes.push_back({ js_class.GetString(), js_class.GetStringLength() });
            }
        }

        HeadlessView view(display_);
        Map map(view);

        map.setStyleJSON(style, base_directory);
        map.setAppliedClasses(classes);

        view.resize(width, height, pixelRatio);
        map.resize(width, height, pixelRatio);
        map.setLonLatZoom(longitude, latitude, zoom);
        map.setBearing(bearing);

        // Run the loop. It will terminate when we don't have any further listeners.
        map.run();

        const unsigned int w = width * pixelRatio;
        const unsigned int h = height * pixelRatio;

        const std::string image = util::compress_png(w, h, view.readPixels().get(), true);
        util::write_file(actual_image, image);
    }
}

INSTANTIATE_TEST_CASE_P(Headless, HeadlessTest, ::testing::ValuesIn([] {
    std::vector<std::string> names;

    DIR *dir = opendir((base_directory + "tests").c_str());
    if (dir == nullptr) {
        return names;
    }

    for (dirent *dp = nullptr; (dp = readdir(dir)) != nullptr;) {
        const std::string name = dp->d_name;
        if (name != "." && name != ".." && name != "index.html") {
            names.push_back(name);
        }
    }

    closedir(dir);

    return names;
}()));