#include <crow_all.h>
#include <filesystem>
#include <string>
#include <array>
#include <memory>
#include <curl/curl.h>

std::string exec(const std::string &cmd) {
    std::array<char, 128> buffer;
    std::string result;
    std::unique_ptr<FILE, decltype(&pclose)> pipe(popen(cmd.c_str(), "r"), pclose);
    if (!pipe) {
        throw std::runtime_error("popen() failed!");
    }
    while (fgets(buffer.data(), static_cast<int>(buffer.size()), pipe.get()) != nullptr) {
        result += buffer.data();
    }
    return result;
}

std::string url_decode(const std::string& encoded) {
    int output_length;
    const auto decoded_value = curl_easy_unescape(nullptr, encoded.c_str(), static_cast<int>(encoded.length()), &output_length);
    std::string result(decoded_value, output_length);
    curl_free(decoded_value);
    return result;
}

std::string process_file(const std::filesystem::path &path) {
    return exec("pandoc --template='templates/post.txt' -t plain '" + path.string() + "'");;
}

namespace route {
    std::string root() {
	return crow::mustache::load_text("index.html");
    }  

    crow::mustache::rendered_template blog() {
	std::string posts = "";
	std::filesystem::path postsDir("posts");
	std::vector<std::future<std::string>> futures;
	for (auto const& entry : std::filesystem::directory_iterator{postsDir}) {
	    if (entry.path().extension() == ".md")
		futures.emplace_back(std::async(std::launch::async, process_file, entry.path()));
	}


	for (auto& future : futures) {
	    posts += future.get();
	}

	auto page = crow::mustache::load("posts.html");
	crow::mustache::context ctx( {{"posts", posts}} );
	return page.render(ctx);
    }

    std::string post(const std::string &name) {
	std::string decoded_name = url_decode(name);
	if (std::filesystem::exists("posts/" + decoded_name)) 
	    return exec("pandoc --standalone --template templates/template.html './posts/" + decoded_name + "'");
	else
	    return std::string("<h1>Not found</h1>");
    }
};

int main() {
    crow::SimpleApp app;

    CROW_ROUTE(app, "/")(route::root);

    CROW_ROUTE(app, "/blog")(route::blog);

    CROW_ROUTE(app, "/blog/<string>")(route::post);

    app.port(8080).multithreaded().run();
}