#include "download.hpp"
#include "utils.hpp"
#include "progress_event.hpp"
#include "fs.hpp"
#include <switch.h>
#include <algorithm>
#include <time.h>
#include <math.h>
#include <curl/curl.h>
#include <chrono>
#include <string>
#include <regex>

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)
        {
            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;
        }
    }

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)
{
    ProgressEvent::instance().reset();
    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;
}

}