/*
 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include "ProfileTimelineWidget.h"
#include "Profile.h"
#include <LibGUI/Painter.h>
#include <LibGfx/Font.h>

namespace Profiler {

ProfileTimelineWidget::ProfileTimelineWidget(Profile& profile)
    : m_profile(profile)
{
    set_fill_with_background_color(true);
    set_fixed_height(80);
    m_hover_time = m_profile.first_timestamp();
}

ProfileTimelineWidget::~ProfileTimelineWidget()
{
}

void ProfileTimelineWidget::paint_event(GUI::PaintEvent& event)
{
    GUI::Frame::paint_event(event);

    GUI::Painter painter(*this);
    painter.add_clip_rect(event.rect());

    const u64 start_of_trace = m_profile.first_timestamp();
    const u64 end_of_trace = start_of_trace + m_profile.length_in_ms();

    const auto clamp_timestamp = [start_of_trace, end_of_trace](u64 timestamp) -> u64 {
        return min(end_of_trace, max(timestamp, start_of_trace));
    };

    float column_width = (float)frame_inner_rect().width() / (float)m_profile.length_in_ms();
    float frame_height = (float)frame_inner_rect().height() / (float)m_profile.deepest_stack_depth();

    for (auto& event : m_profile.events()) {
        u64 t = clamp_timestamp(event.timestamp) - start_of_trace;
        int x = (int)((float)t * column_width);
        int cw = max(1, (int)column_width);

        int column_height = frame_inner_rect().height() - (int)((float)event.frames.size() * frame_height);

        bool in_kernel = event.in_kernel;
        Color color = in_kernel ? Color::from_rgb(0xc25e5a) : Color::from_rgb(0x5a65c2);
        for (int i = 1; i <= cw; ++i)
            painter.draw_line({ x + i, frame_thickness() + column_height }, { x + i, height() - frame_thickness() * 2 }, color);
    }

    u64 normalized_start_time = clamp_timestamp(min(m_select_start_time, m_select_end_time));
    u64 normalized_end_time = clamp_timestamp(max(m_select_start_time, m_select_end_time));
    u64 normalized_hover_time = clamp_timestamp(m_hover_time);

    int select_start_x = (int)((float)(normalized_start_time - start_of_trace) * column_width);
    int select_end_x = (int)((float)(normalized_end_time - start_of_trace) * column_width);
    int select_hover_x = (int)((float)(normalized_hover_time - start_of_trace) * column_width);
    painter.fill_rect({ select_start_x, frame_thickness(), select_end_x - select_start_x, height() - frame_thickness() * 2 }, Color(0, 0, 0, 60));
    painter.fill_rect({ select_hover_x, frame_thickness(), 1, height() - frame_thickness() * 2 }, Color::NamedColor::Black);

    {
        StringBuilder timeline_desc_builder;

        timeline_desc_builder.appendff("Time: {} ms", normalized_hover_time - start_of_trace);
        if (normalized_start_time != normalized_end_time) {
            auto start = normalized_start_time - start_of_trace;
            auto end = normalized_end_time - start_of_trace;
            timeline_desc_builder.appendff(", Selection: {} - {} ms", start, end);
        }
        const auto text = timeline_desc_builder.build();
        Gfx::IntRect rect {
            frame_thickness() + 3,
            frame_thickness() + 3,
            font().width(text),
            font().glyph_height()
        };
        painter.draw_text(rect, text, font());
    }
}

u64 ProfileTimelineWidget::timestamp_at_x(int x) const
{
    float column_width = (float)frame_inner_rect().width() / (float)m_profile.length_in_ms();
    float ms_into_profile = (float)x / column_width;
    return m_profile.first_timestamp() + (u64)ms_into_profile;
}

void ProfileTimelineWidget::mousedown_event(GUI::MouseEvent& event)
{
    if (event.button() != GUI::MouseButton::Left)
        return;

    m_selecting = true;
    m_select_start_time = timestamp_at_x(event.x());
    m_select_end_time = m_select_start_time;
    m_profile.set_timestamp_filter_range(m_select_start_time, m_select_end_time);
    update();
}

void ProfileTimelineWidget::mousemove_event(GUI::MouseEvent& event)
{
    m_hover_time = timestamp_at_x(event.x());

    if (m_selecting) {
        m_select_end_time = m_hover_time;
        m_profile.set_timestamp_filter_range(m_select_start_time, m_select_end_time);
    }

    update();
}

void ProfileTimelineWidget::mouseup_event(GUI::MouseEvent& event)
{
    if (event.button() != GUI::MouseButton::Left)
        return;

    m_selecting = false;
    if (m_select_start_time == m_select_end_time)
        m_profile.clear_timestamp_filter_range();
}

}