#include "Plottables.h"

#include "Curve_Sampling.h"
#include "../plot/Plot_Core.h"
#include "../render/Blend2D_Cache.h"

#include <algorithm>
#include <cmath>
#include <iomanip>
#include <sstream>

namespace renderive {
namespace {

RectF axes_rect(const Axis_Transform& horizontal, const Axis_Transform& vertical) {
    const double x1 = horizontal.coord_to_pixel(horizontal.coordinate_range.origin);
    const double x2 = horizontal.coord_to_pixel(horizontal.coordinate_range.target);
    const double y1 = vertical.coord_to_pixel(vertical.coordinate_range.origin);
    const double y2 = vertical.coord_to_pixel(vertical.coordinate_range.target);
    return {std::min(x1, x2), std::min(y1, y2), std::abs(x2 - x1), std::abs(y2 - y1)};
}

void draw_curve(detail::Painter& painter,
                std::span<const double> values,
                Range domain,
                const Axis_Transform& x_axis,
                const Axis_Transform& y_axis,
                bool visible_only,
                Line_Interpolation_Mode interpolation,
                const Pen& pen,
                const Brush& brush) {
    auto points = detail::curve_points(values, domain, x_axis, y_axis,
                                       visible_only, interpolation);
    if (points.size() < 2)
        return;
    if (brush.enabled()) {
        std::vector<PointF> polygon;
        polygon.reserve(points.size() + 2);
        polygon.push_back({points.front().x, y_axis.coord_to_pixel(y_axis.coordinate_range.target)});
        polygon.insert(polygon.end(), points.begin(), points.end());
        polygon.push_back({points.back().x, y_axis.coord_to_pixel(y_axis.coordinate_range.target)});
        painter.polygon(polygon, Pen{.style = Line_Style::None}, brush);
    }
    painter.polyline(points, pen);
}

} // namespace

Spectrum::Spectrum(Plot_Core& plot,
                   std::shared_ptr<Frequency_Axis> frequency_axis,
                   std::shared_ptr<Axis> power_axis)
    : Renderable(plot), state_{} {
    state_.frequency_axis = std::move(frequency_axis);
    state_.power_axis = std::move(power_axis);
}

#define RENDERIVE_SPECTRUM_PROPERTY(Type, Method, Field) \
    Type Spectrum::Method() const { std::lock_guard lock(mutex_); return state_.Field; } \
    void Spectrum::set_##Method(Type value) { { std::lock_guard lock(mutex_); state_.Field = std::move(value); } changed(); }

RENDERIVE_SPECTRUM_PROPERTY(std::shared_ptr<Frequency_Axis>, frequency_axis, frequency_axis)
RENDERIVE_SPECTRUM_PROPERTY(std::shared_ptr<Axis>, power_axis, power_axis)
RENDERIVE_SPECTRUM_PROPERTY(Range, frequency_range, frequency_range)
RENDERIVE_SPECTRUM_PROPERTY(double, center_frequency, center_frequency)
RENDERIVE_SPECTRUM_PROPERTY(Range, sweep_frequency_range, sweep_range)
RENDERIVE_SPECTRUM_PROPERTY(bool, max_hold_visible, max_hold)
RENDERIVE_SPECTRUM_PROPERTY(bool, min_hold_visible, min_hold)
RENDERIVE_SPECTRUM_PROPERTY(bool, max_marker_visible, max_marker)
RENDERIVE_SPECTRUM_PROPERTY(bool, use_min_marker, min_marker)
RENDERIVE_SPECTRUM_PROPERTY(bool, sweep_region_visible, sweep_visible)
RENDERIVE_SPECTRUM_PROPERTY(bool, visible_range_only, visible_only)
RENDERIVE_SPECTRUM_PROPERTY(Line_Interpolation_Mode, interpolation_mode, interpolation)
RENDERIVE_SPECTRUM_PROPERTY(Brush, max_brush, max_brush)
RENDERIVE_SPECTRUM_PROPERTY(Brush, current_brush, current_brush)
RENDERIVE_SPECTRUM_PROPERTY(Brush, min_brush, min_brush)
RENDERIVE_SPECTRUM_PROPERTY(Pen, max_pen, max_pen)
RENDERIVE_SPECTRUM_PROPERTY(Pen, current_pen, current_pen)
RENDERIVE_SPECTRUM_PROPERTY(Pen, min_pen, min_pen)
RENDERIVE_SPECTRUM_PROPERTY(Pen, selected_marker_pen, selected_marker_pen)
RENDERIVE_SPECTRUM_PROPERTY(Pen, marker_pen, marker_pen)
RENDERIVE_SPECTRUM_PROPERTY(Pen, middle_frequency_pen, middle_pen)
RENDERIVE_SPECTRUM_PROPERTY(Brush, sweep_region_brush, sweep_brush)

#undef RENDERIVE_SPECTRUM_PROPERTY

int Spectrum::frequency_point_size() const {
    std::lock_guard lock(mutex_);
    return state_.point_count;
}

void Spectrum::set_frequency_point_size(int value) {
    { std::lock_guard lock(mutex_); state_.point_count = std::max(0, value); }
    changed();
}

void Spectrum::update_samples(std::span<const double> values) {
    {
        std::lock_guard lock(mutex_);
        state_.samples.assign(values.begin(), values.end());
        if (state_.point_count <= 0)
            state_.point_count = static_cast<int>(values.size());
        if (state_.maxima.size() != values.size())
            state_.maxima.assign(values.begin(), values.end());
        else
            for (std::size_t index = 0; index < values.size(); ++index)
                state_.maxima[index] = std::max(state_.maxima[index], values[index]);
        if (state_.minima.size() != values.size())
            state_.minima.assign(values.begin(), values.end());
        else
            for (std::size_t index = 0; index < values.size(); ++index)
                state_.minima[index] = std::min(state_.minima[index], values[index]);
    }
    changed();
}

void Spectrum::update_samples(std::pmr::vector<double>&& values) {
    update_samples(std::span<const double>(values.data(), values.size()));
}

std::size_t Spectrum::sample_count() const {
    std::lock_guard lock(mutex_);
    return state_.samples.size();
}

std::size_t Spectrum::rendered_point_count() const {
    const State state = state_snapshot();
    if (!state.frequency_axis || !state.power_axis)
        return 0;
    return detail::curve_points(state.samples, state.frequency_range,
                                state.frequency_axis->transform(),
                                state.power_axis->transform(), state.visible_only,
                                state.interpolation)
        .size();
}

double Spectrum::power_at(double frequency, bool& ok) const {
    std::lock_guard lock(mutex_);
    ok = false;
    if (state_.samples.empty() || !state_.frequency_range.contains(frequency) ||
        state_.frequency_range.length() == 0.0)
        return 0.0;
    const double normalized = (frequency - state_.frequency_range.origin) /
                              state_.frequency_range.length();
    const double position = std::clamp(normalized, 0.0, 1.0) *
                            static_cast<double>(state_.samples.size() - 1);
    const auto lower = static_cast<std::size_t>(std::floor(position));
    const auto upper = std::min(lower + 1, state_.samples.size() - 1);
    const double fraction = position - static_cast<double>(lower);
    ok = true;
    return state_.samples[lower] * (1.0 - fraction) + state_.samples[upper] * fraction;
}

void Spectrum::add_custom_marker(double frequency) { add_custom_line_marker(frequency); }

void Spectrum::add_custom_line_marker(double frequency) {
    { std::lock_guard lock(mutex_); state_.markers.push_back(frequency); }
    changed();
}

void Spectrum::remove_custom_marker(double frequency) {
    {
        std::lock_guard lock(mutex_);
        if (state_.markers.empty())
            return;
        auto closest = std::min_element(state_.markers.begin(), state_.markers.end(),
                                        [frequency](double left, double right) {
                                            return std::abs(left - frequency) < std::abs(right - frequency);
                                        });
        const int removed = static_cast<int>(std::distance(state_.markers.begin(), closest));
        state_.markers.erase(closest);
        if (state_.selected_marker == removed)
            state_.selected_marker = -1;
        else if (state_.selected_marker > removed)
            --state_.selected_marker;
    }
    changed();
}

void Spectrum::remove_selected_marker() {
    {
        std::lock_guard lock(mutex_);
        if (state_.selected_marker < 0 || state_.selected_marker >= static_cast<int>(state_.markers.size()))
            return;
        state_.markers.erase(state_.markers.begin() + state_.selected_marker);
        state_.selected_marker = -1;
    }
    changed();
}

void Spectrum::clear_custom_markers() {
    { std::lock_guard lock(mutex_); state_.markers.clear(); state_.selected_marker = -1; }
    changed();
}

int Spectrum::selectable_line_marker_count() const {
    std::lock_guard lock(mutex_);
    return static_cast<int>(state_.markers.size());
}

int Spectrum::selected_marker_index() const { std::lock_guard lock(mutex_); return state_.selected_marker; }

void Spectrum::set_selected_marker_index(int index) {
    {
        std::lock_guard lock(mutex_);
        state_.selected_marker = index >= 0 && index < static_cast<int>(state_.markers.size()) ? index : -1;
    }
    changed();
}

void Spectrum::select_next_marker() {
    std::lock_guard lock(mutex_);
    if (state_.markers.empty())
        state_.selected_marker = -1;
    else
        state_.selected_marker = (state_.selected_marker + 1) % static_cast<int>(state_.markers.size());
    invalidate_cache();
    plot().notify_model_dirty();
}

void Spectrum::select_previous_marker() {
    std::lock_guard lock(mutex_);
    if (state_.markers.empty())
        state_.selected_marker = -1;
    else
        state_.selected_marker = (state_.selected_marker <= 0
                                      ? static_cast<int>(state_.markers.size())
                                      : state_.selected_marker) - 1;
    invalidate_cache();
    plot().notify_model_dirty();
}

void Spectrum::clear_marker_selection() { set_selected_marker_index(-1); }

double Spectrum::marker_frequency(int index) const {
    std::lock_guard lock(mutex_);
    return index >= 0 && index < static_cast<int>(state_.markers.size()) ? state_.markers[index] : 0.0;
}

void Spectrum::set_marker_frequency(int index, double frequency) {
    {
        std::lock_guard lock(mutex_);
        if (index < 0 || index >= static_cast<int>(state_.markers.size()))
            return;
        state_.markers[index] = frequency;
    }
    changed();
}

void Spectrum::set_current_marker_frequency(double frequency) {
    const int index = selected_marker_index();
    if (index >= 0)
        set_marker_frequency(index, frequency);
}

Spectrum::State Spectrum::state_snapshot() const {
    std::lock_guard lock(mutex_);
    return state_;
}

void Spectrum::handle_event(const Event& event) {
    update_hover(event);
}

void Spectrum::paint(detail::Painter& painter) {
    const State state = state_snapshot();
    if (!state.frequency_axis || !state.power_axis)
        return;
    const Axis_Transform horizontal = state.frequency_axis->transform();
    const Axis_Transform vertical = state.power_axis->transform();
    const RectF content = axes_rect(horizontal, vertical);

    if (state.sweep_visible) {
        const double first = horizontal.coord_to_pixel(state.sweep_range.origin);
        const double last = horizontal.coord_to_pixel(state.sweep_range.target);
        painter.rect({std::min(first, last), content.y, std::abs(last - first), content.height},
                     Pen{.style = Line_Style::None}, state.sweep_brush);
    }
    if (state.max_hold)
        draw_curve(painter, state.maxima, state.frequency_range, horizontal, vertical,
                   state.visible_only, state.interpolation, state.max_pen, state.max_brush);
    if (state.min_hold)
        draw_curve(painter, state.minima, state.frequency_range, horizontal, vertical,
                   state.visible_only, state.interpolation, state.min_pen, state.min_brush);
    draw_curve(painter, state.samples, state.frequency_range, horizontal, vertical,
               state.visible_only, state.interpolation, state.current_pen, state.current_brush);

    if (state.middle_pen.enabled()) {
        const double x = horizontal.coord_to_pixel(state.center_frequency);
        painter.line({x, content.y}, {x, content.bottom()}, state.middle_pen);
    }
    for (std::size_t index = 0; index < state.markers.size(); ++index) {
        const double frequency = state.markers[index];
        const double x = horizontal.coord_to_pixel(frequency);
        const Pen& pen = static_cast<int>(index) == state.selected_marker
                             ? state.selected_marker_pen
                             : state.marker_pen;
        painter.line({x, content.y}, {x, content.bottom()}, pen);
    }
    if (!state.samples.empty() && (state.max_marker || state.min_marker)) {
        const auto draw_extreme = [&](bool maximum) {
            auto iterator = maximum ? std::max_element(state.samples.begin(), state.samples.end())
                                    : std::min_element(state.samples.begin(), state.samples.end());
            const std::size_t index = static_cast<std::size_t>(std::distance(state.samples.begin(), iterator));
            const double denominator = state.samples.size() > 1 ? state.samples.size() - 1.0 : 1.0;
            const double frequency = state.frequency_range.origin +
                                     state.frequency_range.length() * index / denominator;
            const PointF point{horizontal.coord_to_pixel(frequency), vertical.coord_to_pixel(*iterator)};
            const Pen& pen = maximum ? state.max_pen : state.min_pen;
            painter.circle(point, 3.0, pen, Brush{pen.color, Brush_Style::Solid});
        };
        if (state.max_marker)
            draw_extreme(true);
        if (state.min_marker)
            draw_extreme(false);
    }

    const Hover_Tooltip_Snapshot tooltip = tooltip_snapshot();
    if (tooltip.enabled && tooltip.active && content.contains(tooltip.position)) {
        const double frequency = horizontal.pixel_to_coord(tooltip.position.x);
        bool ok{};
        const double power = power_at(frequency, ok);
        if (ok) {
            std::ostringstream text;
            text << std::fixed << std::setprecision(2) << frequency << " Hz  " << power;
            const RectF box{tooltip.position.x + 8.0, tooltip.position.y + 8.0, 170.0, 24.0};
            painter.rect(box, Pen{tooltip.text_pen.color}, tooltip.background);
            painter.text({box.x + 4.0, box.y + 3.0}, text.str(), tooltip.font, tooltip.text_pen);
        }
    }
}

Spectrum::Builder::Builder(std::shared_ptr<Renderable> parent,
                           std::shared_ptr<Frequency_Axis> frequency_axis,
                           std::shared_ptr<Axis> power_axis)
    : parent_(std::move(parent)), frequency_axis_(std::move(frequency_axis)),
      power_axis_(std::move(power_axis)) {}

std::shared_ptr<Spectrum> Spectrum::Builder::build() {
    if (!parent_ || !frequency_axis_ || !power_axis_)
        return {};
    auto result = parent_->plot().make_renderable<Spectrum>(parent_, frequency_axis_, power_axis_);
    result->set_frequency_range(frequency_range_);
    result->set_frequency_point_size(point_count_);
    result->set_center_frequency(center_);
    result->set_sweep_frequency_range(sweep_range_);
    result->set_max_hold_visible(max_hold_);
    result->set_min_hold_visible(min_hold_);
    result->set_max_marker_visible(max_marker_);
    result->set_use_min_marker(min_marker_);
    result->set_sweep_region_visible(sweep_visible_);
    result->set_visible_range_only(visible_only_);
    result->set_interpolation_mode(interpolation_);
    return result;
}

} // namespace renderive