//
// Created by dominik on 8/14/24.
//
#include "io.h"

#include <sstream>
#include <fstream>
#include <iostream>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <unordered_map>
#include <map>
#include <string>
#include <filesystem>



Arguments parse_args(const int argc, char **argv) {
    if (argc < 3) {
        throw std::runtime_error("Not enough arguments: missing parameter file");
    }

    Arguments args;

    for (int i=1; i<argc; i++) {
        if (std::string arg = argv[i]; arg[0] == '-') {
            if (arg == "--ste") {
                args.ste = true;
            } else if (arg == "--spectrum") {
                args.spectrum = true;
            } else {
                throw std::runtime_error("Unrecognized option: " + arg);
            }
        } else if (args.parameter_file.empty()) {
            args.parameter_file = arg;
        } else if (args.motion_type.empty()) {
            args.motion_type = arg;
        } else {
            throw std::invalid_argument("Too many options for parameter file");
        }
    }

    if (args.parameter_file.empty()) {
        throw std::invalid_argument("Missing parameter file");
    }

    if (args.motion_type.empty()) {
        throw std::invalid_argument("Missing motion model");
    }

    return args;
}


std::unordered_map<std::string, double> read_parameter(const std::filesystem::path& infile) {
    if (!std::filesystem::exists(infile)) {
        std::cerr << "File " << infile << " does not exist" << std::endl;
        exit(1);
    }

    std::ifstream instream(infile);

    std::unordered_map<std::string, double> parameter;

    std::string line;
    std::string delim = "=";
    std::string key;
    std::string value;
    size_t delim_pos;

    while (std::getline(instream, line)) {
        // skip comment lines starting with #, and empty lines
        if (line[0] == '#' || line.length() == 1) continue;

        // strip spaces from line to have always key=value
        line.erase(std::remove(line.begin(), line.end(), ' '), line.end());

        // split at '=' character and add to map
        delim_pos = line.find('=');
        key = line.substr(0, delim_pos);
        value = line.substr(delim_pos+1);
        parameter[key] = std::stod(value);
    }

    // print result
    std::cout << "Found parameter\n";
    for (const auto& [key, value]: parameter) {
        std::cout << "  " << key << ": " << std::to_string(value) << "\n";
    }
    std::cout << std::endl;

    return parameter;
}


void fid_write_out(const std::string& filename, const std::vector<double>& x, const std::vector<double>& y, const double tau, const double t_evo) {
    auto size = x.size();

    std::ostringstream sfile;
    sfile << filename << "_";
    sfile << std::setprecision(6) << std::scientific;
    sfile << "tau=" << tau << "_tevo=" << t_evo << ".dat";
    {
        std::string outfile = sfile.str();
        std::ofstream fid_file(outfile, std::ios::out);
        for (unsigned int i = 0; i < size; i++) {
            fid_file << x[i] << "\t" << y[i] << "\n";
        }
    }
}

void fid_write_out(const std::string& filename, const std::vector<double>& x, const std::map<double, std::vector<double>>& y, const double tau) {
    auto size = x.size();

    std::ostringstream sfile;
    sfile << filename << "_";
    sfile << std::setprecision(6) << std::scientific;
    sfile << "tau=" << tau << ".dat";
    {
        std::string outfile = sfile.str();
        std::ofstream fid_file(outfile, std::ios::out);
        fid_file << "#";
        for (const auto& [t_echo_j, _] : y) {
            fid_file << t_echo_j << "\t";
        }
        fid_file << std::endl;

        for (unsigned int i = 0; i < size; i++) {
            fid_file << x[i];
            for (const auto& [_, fid_j] : y) {
                fid_file << "\t" << fid_j[i];
            }
            fid_file << "\n";
        }
    }
}