// Diopser: a phase rotation plugin
// Copyright (C) 2021-2022 Robbert van der Helm
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

use nih_plug::nih_debug_assert_failure;
use nih_plug::prelude::{Editor, Plugin};
use nih_plug_vizia::vizia::prelude::*;
use nih_plug_vizia::widgets::*;
use nih_plug_vizia::{assets, create_vizia_editor, ViziaState, ViziaTheming};
use std::sync::atomic::AtomicBool;
use std::sync::Arc;

use self::button::SafeModeButton;
use crate::{Diopser, DiopserParams};

mod button;

const EDITOR_WIDTH: u32 = 600;
const EDITOR_HEIGHT: u32 = 490;

const SPECTRUM_ANALYZER_HEIGHT: f32 = 260.0;

const DARK_GRAY: Color = Color::rgb(0xc4, 0xc4, 0xc4);
const DARKER_GRAY: Color = Color::rgb(0x69, 0x69, 0x69);

#[derive(Lens)]
struct Data {
    params: Arc<DiopserParams>,

    /// Whether the safe mode button is enabled. The number of filter stages is capped at 40 while
    /// this is active.
    safe_mode: Arc<AtomicBool>,
}

impl Model for Data {}

// Makes sense to also define this here, makes it a bit easier to keep track of
pub(crate) fn default_state() -> Arc<ViziaState> {
    ViziaState::from_size(EDITOR_WIDTH, EDITOR_HEIGHT)
}

pub(crate) fn create(
    params: Arc<DiopserParams>,
    editor_state: Arc<ViziaState>,
) -> Option<Box<dyn Editor>> {
    create_vizia_editor(editor_state, ViziaTheming::Custom, move |cx, _| {
        assets::register_noto_sans_light(cx);
        assets::register_noto_sans_thin(cx);

        cx.add_theme(include_str!("editor/theme.css"));

        Data {
            params: params.clone(),

            safe_mode: params.safe_mode.clone(),
        }
        .build(cx);

        ResizeHandle::new(cx);

        VStack::new(cx, |cx| {
            top_bar(cx);
            spectrum_analyzer(cx);
            other_params(cx);
        });
    })
}

/// This contain's the plugin's name, a bypass button, and some other controls.
fn top_bar(cx: &mut Context) {
    HStack::new(cx, |cx| {
        Label::new(cx, "Diopser")
            .font(assets::NOTO_SANS_THIN)
            .font_size(37.0)
            .top(Pixels(-2.0))
            .left(Pixels(8.0))
            .on_mouse_down(|_, _| {
                // Try to open the Diopser plugin's page when clicking on the title. If this fails
                // then that's not a problem
                let result = open::that(Diopser::URL);
                if cfg!(debug) && result.is_err() {
                    nih_debug_assert_failure!("Failed to open web browser: {:?}", result);
                }
            });
        Label::new(cx, Diopser::VERSION)
            .color(DARKER_GRAY)
            .top(Stretch(1.0))
            .bottom(Pixels(7.5))
            .left(Pixels(2.0));

        HStack::new(cx, |cx| {
            ParamSlider::new(cx, Data::params, |params| &params.automation_precision)
                .with_label("Automation Precision")
                .id("automation-precision");

            SafeModeButton::new(cx, Data::safe_mode, "Safe mode").left(Pixels(10.0));

            ParamButton::new(cx, Data::params, |params| &params.bypass)
                .for_bypass()
                .left(Pixels(10.0));
        })
        .child_space(Pixels(10.0))
        .left(Stretch(1.0));
    })
    .id("top-bar");
}

/// This shows a spectrum analyzer for the plugin's output, and also acts as an X-Y pad for the
/// frequency and resonance parameters.
fn spectrum_analyzer(cx: &mut Context) {
    const LABEL_HEIGHT: f32 = 20.0;

    HStack::new(cx, |cx| {
        Label::new(cx, "Resonance")
            .font_size(18.0)
            // HACK: Rotating doesn't really work in vizia, but with text wrap disabled this at
            //       least visually does the right thing
            .text_wrap(false)
            .rotate(270.0f32)
            .width(Pixels(LABEL_HEIGHT))
            .height(Pixels(SPECTRUM_ANALYZER_HEIGHT))
            // HACK: The `.space()` on the HStack doesn't seem to work correctly here
            .left(Pixels(10.0))
            .right(Pixels(-5.0))
            .child_space(Stretch(1.0));

        VStack::new(cx, |cx| {
            ZStack::new(cx, |cx| {
                Label::new(cx, "When I grow up, I want to be a spectrum analyzer!");

                Label::new(
                    cx,
                    "When I close my eyes sometimes I\npretend to be an X-Y pad.",
                )
                .font_size(25.0)
                .rotate(17.0f32);
            })
            .child_space(Stretch(1.0))
            .width(Percentage(100.0))
            .background_color(DARK_GRAY)
            .height(Pixels(SPECTRUM_ANALYZER_HEIGHT));

            Label::new(cx, "Frequency")
                .font_size(18.0)
                .width(Stretch(1.0))
                .height(Pixels(20.0))
                .child_space(Stretch(1.0));
        })
        .space(Pixels(10.0))
        .width(Stretch(1.0));
    });
}

/// The area below the spectrum analyzer that contains all of the other parameters.
fn other_params(cx: &mut Context) {
    VStack::new(cx, |cx| {
        HStack::new(cx, move |cx| {
            Label::new(cx, "Filter Stages").class("param-label");
            ParamSlider::new(cx, Data::params, |params| &params.filter_stages);
        })
        .bottom(Pixels(10.0));

        HStack::new(cx, move |cx| {
            Label::new(cx, "Frequency Spread").class("param-label");
            ParamSlider::new(cx, Data::params, |params| &params.filter_spread_octaves);
        })
        .bottom(Pixels(10.0));

        HStack::new(cx, move |cx| {
            Label::new(cx, "Spread Style").class("param-label");
            ParamSlider::new(cx, Data::params, |params| &params.filter_spread_style)
                .set_style(ParamSliderStyle::CurrentStepLabeled { even: true });
        });
    })
    .id("param-sliders")
    .width(Percentage(100.0))
    .top(Pixels(7.0))
    // This should take up all remaining space
    .bottom(Stretch(1.0))
    .child_space(Stretch(1.0))
    .child_left(Stretch(1.0));
}