#include "phigrape.h"
#include <string>
#include <unordered_map>
#include <stdexcept>
#include <cstdio>
#include <fstream>

using Dictionary = std::unordered_map<std::string,std::string>;

std::string strip(const std::string str)
{
    std::string str_new = str;
    auto pos = str_new.find_first_not_of(" \t");
    if (pos != std::string::npos) str_new = str_new.substr(pos, str_new.size());
    pos = str_new.find_last_not_of(" \t");
    if (pos != std::string::npos) str_new = str_new.substr(0, pos+1);
    return str_new;
}

Dictionary read_config_file(const std::string file_name)
{
    std::unordered_map<std::string,std::string> dictionary;
    std::ifstream file(file_name);
    if (!file.good()) throw std::runtime_error("File not found.");
    std::string str;
    int line_number = 0;
    while (std::getline(file, str)) {
        line_number++;
        auto pos = str.find('#');
        if (pos != std::string::npos) str = str.substr(0, pos);
        str = strip(str);
        if (str.size() == 0) continue;
        pos = str.find_first_of("=");
        if (pos == std::string::npos) throw std::runtime_error("Error: expected a key-value pair in line " + std::to_string(line_number) + " of file " + file_name);
        std::string key = strip(str.substr(0, pos));
        pos = str.find_first_not_of(" \t", pos+1);
        std::string val = strip(str.substr(pos, str.size()));
        dictionary[key] = val;
    }
    return dictionary;
}

template<typename T> T string_cast(const std::string str);

template<> std::string string_cast(const std::string str)
{
    return str;
}

template<> double string_cast(const std::string str)
{
    size_t idx;
    auto value = std::stod(str, &idx);
    if (idx == str.size()) return value;
    else throw std::runtime_error("Cannot convert \"" + str + "\" into a double");
}

template<> int string_cast(const std::string str)
{
    size_t idx;
    auto value = std::stoi(str, &idx);
    if (idx == str.size()) return value;
    else throw std::runtime_error("Cannot convert \"" + str + "\" into an int");
}

template<> bool string_cast(const std::string str)
{
    if      ((str=="true")  || (str=="True")  || (str=="yes") || (str=="Yes") || (str=="1")) return true;
    else if ((str=="false") || (str=="False") || (str=="no")  || (str=="No")  || (str=="0")) return false;
    throw std::runtime_error("Cannot convert \"" + str + "\" into a bool");
}


// For mandatory parameters
template<typename T>
T get_parameter(Dictionary dictionary, std::string name)
{
    auto item = dictionary.find(name);
    if (item==dictionary.end()) throw std::runtime_error("Mandatory parameter " + name + " must be defined");
    else return string_cast<T>((*item).second);
}

// For optional parameters
template<typename T>
T get_parameter(Dictionary dictionary, std::string name, T default_value)
{
    auto item = dictionary.find(name);
    if (item==dictionary.end()) return default_value;
    else return string_cast<T>((*item).second);
}

int main()
{
    auto dictionary = read_config_file("phigrape.conf");

    for (auto key_value : dictionary) {
        auto key   = key_value.first;
        auto value = key_value.second;
        printf("dictionary[\"%s\"] = \"%s\"\n", key.c_str(), value.c_str());
    }


    Parameters parameters;

    // TODO check if dt_disk and dt_contr are powers of two
    parameters.dt_bh = get_parameter<double>(dictionary, "eps");
    parameters.t_end = get_parameter<double>(dictionary, "t_end");
    parameters.dt_disk = get_parameter<double>(dictionary, "dt_disk");
    parameters.dt_contr = get_parameter<double>(dictionary, "dt_contr");
    parameters.dt_bh = get_parameter<double>(dictionary, "dt_bh", parameters.dt_contr);
    parameters.eta = get_parameter<double>(dictionary, "eta");
    parameters.input_file_name = get_parameter<std::string>(dictionary, "dt_bh", "data.con");
    parameters.dt_min_warning = get_parameter<bool>(dictionary, "dt_min_warning", false);
    parameters.live_smbh_count = get_parameter<int>(dictionary, "live_smbh_count", 0);
    parameters.live_smbh_custom_eps = get_parameter<double>(dictionary, "live_smbh_custom_eps", -1);
    parameters.live_smbh_output = get_parameter<bool>(dictionary, "live_smbh_output", false);
    parameters.live_smbh_neighbor_output = get_parameter<bool>(dictionary, "live_smbh_neighbor_output", false);
    parameters.live_smbh_neighbor_number = get_parameter<int>(dictionary, "live_smbh_neighbor_number", 10);
    parameters.binary_smbh_pn = get_parameter<bool>(dictionary, "binary_smbh_pn", false);
    parameters.binary_smbh_influence_sphere_output = get_parameter<bool>(dictionary, "binary_smbh_influence_sphere_output", false);
    parameters.binary_smbh_influence_radius_factor = get_parameter<double>(dictionary, "binary_smbh_influence_radius_factor", 10.);

}