#include "download.hpp"

#include <curl/curl.h>
#include <math.h>
#include <switch.h>
#include <time.h>

#include <algorithm>
#include <chrono>
#include <regex>
#include <string>

#include "fs.hpp"
#include "progress_event.hpp"
#include "utils.hpp"

namespace i18n = brls::i18n;
using namespace i18n::literals;

constexpr const char API_AGENT[] = "HamletDuFromage";
constexpr int _1MiB = 0x100000;

using json = nlohmann::json;

namespace download {

    namespace {

        std::chrono::_V2::steady_clock::time_point time_old;
        double dlold;

        typedef struct
        {
            char* memory;
            size_t size;
        } MemoryStruct_t;

        typedef struct
        {
            u_int8_t* data;
            size_t data_size;
            u_int64_t offset;
            FILE* out;
        } ntwrk_struct_t;

        static size_t WriteMemoryCallback(void* contents, size_t size, size_t num_files, void* userp)
        {
            if (ProgressEvent::instance().getInterupt()) {
                return 0;
            }
            ntwrk_struct_t* data_struct = (ntwrk_struct_t*)userp;
            size_t realsize = size * num_files;

            if (realsize + data_struct->offset >= data_struct->data_size) {
                fwrite(data_struct->data, data_struct->offset, 1, data_struct->out);
                data_struct->offset = 0;
            }

            memcpy(&data_struct->data[data_struct->offset], contents, realsize);
            data_struct->offset += realsize;
            data_struct->data[data_struct->offset] = 0;
            return realsize;
        }

        int download_progress(void* p, double dltotal, double dlnow, double ultotal, double ulnow)
        {
            if (dltotal <= 0.0) return 0;

            double fractionDownloaded = dlnow / dltotal;
            int counter = (int)(fractionDownloaded * ProgressEvent::instance().getMax());  //20 is the number of increments
            ProgressEvent::instance().setStep(std::min(ProgressEvent::instance().getMax() - 1, counter));
            ProgressEvent::instance().setNow(dlnow);
            ProgressEvent::instance().setTotalCount(dltotal);
            auto time_now = std::chrono::steady_clock::now();
            double elasped_time = ((std::chrono::duration<double>)(time_now - time_old)).count();
            if (elasped_time > 1.2f) {
                ProgressEvent::instance().setSpeed((dlnow - dlold) / elasped_time);
                dlold = dlnow;
                time_old = time_now;
            }
            return 0;
        }

        struct MemoryStruct
        {
            char* memory;
            size_t size;
        };

        static size_t WriteMemoryCallback2(void* contents, size_t size, size_t nmemb, void* userp)
        {
            size_t realsize = size * nmemb;
            struct MemoryStruct* mem = (struct MemoryStruct*)userp;

            char* ptr = static_cast<char*>(realloc(mem->memory, mem->size + realsize + 1));
            if (ptr == NULL) {
                /* out of memory! */
                return 0;
            }

            mem->memory = ptr;
            memcpy(&(mem->memory[mem->size]), contents, realsize);
            mem->size += realsize;
            mem->memory[mem->size] = 0;

            return realsize;
        }

        bool checkSize(CURL* curl, const std::string& url)
        {
            curl_off_t dl;
            curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
            curl_easy_setopt(curl, CURLOPT_USERAGENT, API_AGENT);
            curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
            curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
            curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
            curl_easy_setopt(curl, CURLOPT_NOBODY, 1L);
            curl_easy_perform(curl);
            auto res = curl_easy_getinfo(curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD_T, &dl);
            if (!res) {
                s64 freeStorage;
                if (R_SUCCEEDED(fs::getFreeStorageSD(freeStorage)) && dl * 1.1 > freeStorage) {
                    return false;
                }
            }
            return true;
        }
    }  // namespace

    long downloadFile(const std::string& url, const char* output, int api)
    {
        std::vector<std::uint8_t> dummy;
        return downloadFile(url, dummy, output, api);
    }

    long downloadFile(const std::string& url, std::vector<std::uint8_t>& res, const char* output, int api)
    {
        CURL* curl = curl_easy_init();
        ntwrk_struct_t chunk = {0};
        long status_code;
        time_old = std::chrono::steady_clock::now();
        dlold = 0.0f;
        bool can_download = true;

        if (curl) {
            FILE* fp = fopen(output, "wb");
            if (fp || *output == 0) {
                chunk.data = static_cast<u_int8_t*>(malloc(_1MiB));
                chunk.data_size = _1MiB;
                chunk.out = fp;

                if (*output != 0) {
                    can_download = checkSize(curl, url);
                }

                if (can_download) {
                    curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
                    curl_easy_setopt(curl, CURLOPT_USERAGENT, API_AGENT);
                    curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
                    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
                    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
                    curl_easy_setopt(curl, CURLOPT_NOBODY, 0L);
                    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
                    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &chunk);

                    if (api == OFF) {
                        curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0L);
                        curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, download_progress);
                    }
                    curl_easy_perform(curl);
                    curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &status_code);

                    if (fp && chunk.offset && can_download)
                        fwrite(chunk.data, 1, chunk.offset, fp);

                    curl_easy_cleanup(curl);
                    ProgressEvent::instance().setStep(ProgressEvent::instance().getMax());
                }
            }
        }

        fclose(chunk.out);
        if (!can_download) {
            brls::Application::crash("menus/errors/insufficient_storage"_i18n);
            usleep(2000000);
            brls::Application::quit();
            res = {};
        }

        if (*output == 0) {
            res.assign(chunk.data, chunk.data + chunk.offset);
        }

        free(chunk.data);

        return status_code;
    }

    std::string fetchTitle(const std::string& url)
    {
        CURL* curl_handle;
        struct MemoryStruct chunk;

        chunk.memory = static_cast<char*>(malloc(1)); /* will be grown as needed by the realloc above */
        chunk.size = 0;                               /* no data at this point */

        curl_global_init(CURL_GLOBAL_ALL);
        curl_handle = curl_easy_init();
        curl_easy_setopt(curl_handle, CURLOPT_URL, url);
        curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, WriteMemoryCallback2);
        curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void*)&chunk);
        curl_easy_setopt(curl_handle, CURLOPT_USERAGENT, API_AGENT);

        curl_easy_setopt(curl_handle, CURLOPT_SSL_VERIFYPEER, 0L);
        curl_easy_perform(curl_handle);

        /* check for errors */
        std::string ver = "-1";
        std::string s = std::string(chunk.memory);
        std::regex rgx("<title>.+</title>");
        std::smatch match;
        if (std::regex_search(s, match, rgx)) {
            //ver = std::stoi(match[0]);
            //std::cout << match[0].str().substr(match[0].str().find(" ") + 1, 6) << std::endl;
            ver = match[0].str().substr(match[0].str().find(" ") + 1, 5);
        }
        curl_easy_cleanup(curl_handle);
        free(chunk.memory);

        curl_global_cleanup();

        return ver;
    }

    long downloadPage(const std::string& url, std::string& res, const std::vector<std::string>& headers, const std::string& body)
    {
        CURL* curl_handle;
        struct MemoryStruct chunk;
        struct curl_slist* list = NULL;
        long status_code;

        chunk.memory = static_cast<char*>(malloc(1)); /* will be grown as needed by the realloc above */
        chunk.size = 0;                               /* no data at this point */

        curl_global_init(CURL_GLOBAL_ALL);
        curl_handle = curl_easy_init();
        curl_easy_setopt(curl_handle, CURLOPT_URL, url.c_str());
        if (!headers.empty()) {
            for (auto& h : headers) {
                list = curl_slist_append(list, h.c_str());
            }
            curl_easy_setopt(curl_handle, CURLOPT_HTTPHEADER, list);
        }
        if (body != "") {
            curl_easy_setopt(curl_handle, CURLOPT_POSTFIELDS, body.c_str());
        }

        curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, WriteMemoryCallback2);
        curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void*)&chunk);
        curl_easy_setopt(curl_handle, CURLOPT_USERAGENT, API_AGENT);

        curl_easy_setopt(curl_handle, CURLOPT_SSL_VERIFYPEER, 0L);
        curl_easy_perform(curl_handle);
        curl_easy_getinfo(curl_handle, CURLINFO_RESPONSE_CODE, &status_code);
        curl_easy_cleanup(curl_handle);
        res = std::string(chunk.memory);
        free(chunk.memory);

        curl_global_cleanup();
        return status_code;
    }

    long getRequest(const std::string& url, nlohmann::ordered_json& res, const std::vector<std::string>& headers, const std::string& body)
    {
        std::string request;
        long status_code = downloadPage(url, request, headers, body);

        if (json::accept(request))
            res = nlohmann::ordered_json::parse(request);
        else
            res = nlohmann::ordered_json::object();

        return status_code;
    }

    std::vector<std::pair<std::string, std::string>> getLinks(const std::string& url)
    {
        nlohmann::ordered_json request;
        getRequest(url, request);

        std::vector<std::pair<std::string, std::string>> res;
        for (auto it = request.begin(); it != request.end(); ++it) {
            res.push_back(std::make_pair(it.key(), it.value()));
        }
        return res;
    }

    std::vector<std::pair<std::string, std::string>> getLinksFromJson(const nlohmann::ordered_json& json_object)
    {
        std::vector<std::pair<std::string, std::string>> res;
        for (auto it = json_object.begin(); it != json_object.end(); ++it) {
            res.push_back(std::make_pair(it.key(), it.value()));
        }
        return res;
    }

}  // namespace download