// The MIT License (MIT)
//
// Copyright (c) 2019 Luigi Pertoldi
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//
// ============================================================================
//  ___   ___   ___   __    ___   ____  __   __   ___    __    ___
// | |_) | |_) / / \ / /`_ | |_) | |_  ( (` ( (` | |_)  / /\  | |_)
// |_|   |_| \ \_\_/ \_\_/ |_| \ |_|__ _)_) _)_) |_|_) /_/--\ |_| \_
//
// Very simple progress bar for c++ loops with internal running variable
//
// Author: Luigi Pertoldi
// Created: 3 dic 2016
//
// Notes: The bar must be used when there's no other possible source of output
//        inside the for loop
//

#ifndef __PROGRESSBAR_HPP
#define __PROGRESSBAR_HPP

#include <iostream>
#include <ostream>
#include <stdexcept>
#include <string>

class progressbar {
   public:
    // default destructor
    ~progressbar() = default;

    // delete everything else
    progressbar(progressbar const&) = delete;
    progressbar& operator=(progressbar const&) = delete;
    progressbar(progressbar&&) = delete;
    progressbar& operator=(progressbar&&) = delete;

    // default constructor, must call set_niter later
    inline progressbar();
    inline progressbar(
            int n,
            bool showbar = true,
            std::ostream& out = std::cerr);

    // reset bar to use it again
    inline void reset();
    // set number of loop iterations
    inline void set_niter(int iter);
    // chose your style
    inline void set_done_char(const std::string& sym) {
        done_char = sym;
    }
    inline void set_todo_char(const std::string& sym) {
        todo_char = sym;
    }
    inline void set_opening_bracket_char(const std::string& sym) {
        opening_bracket_char = sym;
    }
    inline void set_closing_bracket_char(const std::string& sym) {
        closing_bracket_char = sym;
    }
    // to show only the percentage
    inline void show_bar(bool flag = true) {
        do_show_bar = flag;
    }
    // set the output stream
    inline void set_output_stream(const std::ostream& stream) {
        output.rdbuf(stream.rdbuf());
    }
    // main function
    inline void update();

   private:
    int progress;
    int n_cycles;
    int last_perc;
    bool do_show_bar;
    bool update_is_called;

    std::string done_char;
    std::string todo_char;
    std::string opening_bracket_char;
    std::string closing_bracket_char;

    std::ostream& output;
};

inline progressbar::progressbar()
        : progress(0),
          n_cycles(0),
          last_perc(0),
          do_show_bar(true),
          update_is_called(false),
          done_char("#"),
          todo_char(" "),
          opening_bracket_char("["),
          closing_bracket_char("]"),
          output(std::cerr) {}

inline progressbar::progressbar(int n, bool showbar, std::ostream& out)
        : progress(0),
          n_cycles(n),
          last_perc(0),
          do_show_bar(showbar),
          update_is_called(false),
          done_char("#"),
          todo_char(" "),
          opening_bracket_char("["),
          closing_bracket_char("]"),
          output(out) {}

inline void progressbar::reset() {
    progress = 0, update_is_called = false;
    last_perc = 0;
    return;
}

inline void progressbar::set_niter(int niter) {
    if (niter <= 0)
        throw std::invalid_argument(
                "progressbar::set_niter: number of iterations null or negative");
    n_cycles = niter;
    return;
}

inline void progressbar::update() {
    if (n_cycles == 0)
        throw std::runtime_error(
                "progressbar::update: number of cycles not set");

    if (!update_is_called) {
        if (do_show_bar == true) {
            output << opening_bracket_char;
            for (int _ = 0; _ < 50; _++)
                output << todo_char;
            output << closing_bracket_char << " 0%";
        } else
            output << "0%";
    }
    update_is_called = true;

    int perc = 0;

    // compute percentage, if did not change, do nothing and return
    perc = progress * 100. / (n_cycles - 1);
    if (perc < last_perc)
        return;

    // update percentage each unit
    if (perc == last_perc + 1) {
        // erase the correct  number of characters
        if (perc <= 10)
            output << "\b\b" << perc << '%';
        else if (perc > 10 and perc < 100)
            output << "\b\b\b" << perc << '%';
        else if (perc == 100)
            output << "\b\b\b" << perc << '%';
    }
    if (do_show_bar == true) {
        // update bar every ten units
        if (perc % 2 == 0) {
            // erase closing bracket
            output << std::string(closing_bracket_char.size(), '\b');
            // erase trailing percentage characters
            if (perc < 10)
                output << "\b\b\b";
            else if (perc >= 10 && perc < 100)
                output << "\b\b\b\b";
            else if (perc == 100)
                output << "\b\b\b\b\b";

            // erase 'todo_char'
            for (int j = 0; j < 50 - (perc - 1) / 2; ++j) {
                output << std::string(todo_char.size(), '\b');
            }

            // add one additional 'done_char'
            if (perc == 0)
                output << todo_char;
            else
                output << done_char;

            // refill with 'todo_char'
            for (int j = 0; j < 50 - (perc - 1) / 2 - 1; ++j)
                output << todo_char;

            // readd trailing percentage characters
            output << closing_bracket_char << ' ' << perc << '%';
        }
    }
    last_perc = perc;
    ++progress;
    output << std::flush;

    return;
}

#endif