//! Widgets and utilities for making widgets to integrate VIZIA with NIH-plug.
//!
//! # Note
//!
//! None of these widgets are finalized, and their sizes or looks can change at any point. Feel free
//! to copy the widgets and modify them to your personal taste.

use nih_plug::{context::GuiContext, param::internals::ParamPtr};
use std::sync::Arc;

use vizia::Model;

/// An event that updates a parameter's value. Since NIH-plug manages the parameters, interacting
/// with parameter values with VIZIA works a little different from updating any other state. These
/// events are automatically handled by `nih_plug_vizia`.
#[derive(Debug, Clone, Copy)]
pub enum ParamEvent {
    /// Begin an automation gesture for a parameter.
    BeginSetParameter(ParamPtr),
    /// Set a parameter to a new normalized value. This needs to be surrounded by a matching
    /// `BeginSetParameter` and `EndSetParameter`.
    SetParameterNormalized(ParamPtr, f32),
    /// Reset a parameter to its default value. This needs to be surrounded by a matching
    /// `BeginSetParameter` and `EndSetParameter`.
    ResetParameter(ParamPtr),
    /// End an automation gesture for a parameter.
    EndSetParameter(ParamPtr),
}

/// Handles parameter updates for VIZIA GUIs. Registered in
/// [`ViziaEditor::spawn()`][super::ViziaEditor::spawn()].
pub(crate) struct ParamModel {
    pub context: Arc<dyn GuiContext>,
}

impl Model for ParamModel {
    fn event(&mut self, _cx: &mut vizia::Context, event: &mut vizia::Event) {
        if let Some(param_event) = event.message.downcast() {
            match *param_event {
                ParamEvent::BeginSetParameter(p) => unsafe {
                    self.context.raw_begin_set_parameter(p)
                },
                ParamEvent::SetParameterNormalized(p, v) => unsafe {
                    self.context.raw_set_parameter_normalized(p, v)
                },
                ParamEvent::ResetParameter(p) => unsafe {
                    let default_value = self.context.raw_default_normalized_param_value(p);
                    self.context.raw_set_parameter_normalized(p, default_value);
                },
                ParamEvent::EndSetParameter(p) => unsafe { self.context.raw_end_set_parameter(p) },
            }
        }
    }
}