progress.hpp

/*
    SPDX-License-Identifier: MIT
    Copyright © 2023 Amebis
*/
 
#pragma once
 
#include "compat.hpp"
#include "interval.hpp"
#include <chrono>
 
namespace stdex
{
    template <class T>
    class progress
    {
    public:
        virtual void set_text(_In_z_ const char* msg)
        {
            _Unreferenced_(msg);
        }
 
        virtual void set_range(_In_ T start, _In_ T end)
        {
            start; end;
        }
 
        virtual void set(_In_ T value)
        {
            value;
        }
 
        virtual void show(_In_ bool show = true)
        {
            _Unreferenced_(show);
        }
 
        virtual bool cancel()
        {
            return false;
        }
    };
 
    template <class T>
    class lazy_progress : public progress<T>
    {
    public:
        lazy_progress(_In_ const std::chrono::nanoseconds& timeout = std::chrono::nanoseconds(500000)) :
            m_timeout(timeout),
            m_start(0),
            m_end(0),
            m_value(-1)
        {}
 
        virtual void set_range(_In_ T start, _In_ T end)
        {
            m_start = start;
            m_end = end;
        }
 
        virtual void set(_In_ T value)
        {
            if (value == m_start || value == m_end)
                m_last = std::chrono::high_resolution_clock::now();
            else if (value == m_value)
                return;
            else {
                auto now = std::chrono::high_resolution_clock::now();
                if (now - m_last < m_timeout)
                    return;
                m_last = now;
            }
            m_value = value;
            do_set();
        }
 
    protected:
        virtual void do_set() {}
 
    protected:
        std::chrono::nanoseconds m_timeout;
        std::chrono::system_clock::time_point m_last;
        T m_start, m_end, m_value;
    };
 
    template <class T>
    class global_progress : public progress<T>
    {
    public:
        global_progress(_In_opt_ progress<T>* host = NULL) : m_host(host)
        {}
 
        void attach(_In_opt_ progress<T>* host)
        {
            m_host = host;
        }
 
        progress<T>* detach()
        {
            progress<T>* k = m_host;
            m_host = NULL;
            return k;
        }
 
        void set_global_range(_In_ T start, _In_ T end)
        {
            m_global.start = start;
            m_global.end = end;
            if (m_host)
                m_host->set_range(m_global.start, m_global.end);
        }
 
        void set_section_range(_In_ T start, _In_ T end)
        {
            m_section.start = start;
            m_section.end = end;
        }
 
        virtual void set_text(_In_ const char* msg)
        {
            if (m_host)
                m_host->set_text(msg);
        }
 
        virtual void set_range(_In_ T start, _In_ T end)
        {
            m_local.start = start;
            m_local.end = end;
        }
 
        virtual void set(_In_ T value)
        {
            if (m_host) {
                T size = m_local.size();
                if (size != 0) {
                    // TODO: Implement with muldiv.
                    m_host->set(((value - m_local.start) * m_section.size() / size) + m_section.start);
                }
            }
        }
 
        virtual void show(_In_ bool show = true)
        {
            if (m_host)
                m_host->show(show);
        }
 
        virtual bool cancel()
        {
            return m_host && m_host->cancel();
        }
 
    protected:
        progress<T>* m_host;
        interval<T> m_local, m_global, m_section;
    };
 
 
    template <class T>
    class progress_switcher : public global_progress<T>
    {
    public:
        progress_switcher(progress<T>*& host) :
            global_progress<T>(host),
            m_host_ref(host)
        {
            m_host_ref = this;
        }
 
        ~progress_switcher()
        {
            m_host_ref = this->detach();
        }
 
    protected:
        progress<T>*& m_host_ref;
    };
}