#include <iostream>
#include <vector>
#include "histogram.h"
#include "svg.h"
#include <curl/curl.h>
#include <sstream>
#include <string>
using namespace std;

struct Input {
    vector<double> numbers;
    size_t bin_count{};
};

Input
input_data(istream& in, bool prompt) {
    size_t number_count;
    if (prompt) {
            cerr << "Enter number count: ";
    }
    in >> number_count;
    Input inn;
    inn.numbers.resize(number_count);
    if (prompt) {
            cerr << "Enter numbers: ";
    }
    for (size_t i = 0; i < number_count; i++) {
        in >> inn.numbers[i];
    }
    if (prompt) {
            cerr << "Enter bin count: ";
    }
    in >> inn.bin_count;
    return inn;
}

static size_t
write_data(void* items, size_t item_size, size_t item_count, void* ctx){
    size_t data_size = item_size * item_count;
    stringstream* buffer = reinterpret_cast<stringstream*>(ctx);
    buffer->write(reinterpret_cast<const char*>(items), data_size);
    return data_size;
}

size_t header_callback(void *items, size_t item_size, size_t item_count, void *userdata){
    size_t data_size = item_size * item_count;
    stringstream* buffer = reinterpret_cast<stringstream*>(userdata);
    buffer->write(reinterpret_cast<const char*>(items), data_size);
    return data_size;
}

Input
download(const string& address){
    stringstream buffer;
    CURL *curl = curl_easy_init();
        if(curl) {
            CURLcode res;
            curl_easy_setopt(curl, CURLOPT_URL, address.c_str());
            curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
            curl_easy_setopt(curl, CURLOPT_WRITEDATA, &buffer);
            curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, header_callback);
            curl_easy_setopt(curl, CURLOPT_HEADERDATA, &buffer);
            res = curl_easy_perform(curl);
            if (res != CURLE_OK) {
                curl_easy_strerror(res);
                exit(1);
            }
            curl_easy_cleanup(curl);
        }
    return input_data(buffer, false);
}

int
main(int argc, char* argv[]) {
    curl_global_init(CURL_GLOBAL_ALL);
    Input input;
    if (argc > 1) {
            input = download(argv[1]);
    }
    else {
            input = input_data(cin, true);
        }

        const auto bins = make_histogram(input.numbers, input.bin_count);
        show_histogram_svg(bins);

    }