use crate::{
    theme::use_theme,
    utils::{dom::window_event_listener, mount_style::mount_style},
    Theme,
};
use leptos::*;
use stylers::style_sheet_str;
use wasm_bindgen::JsCast;

#[component]
pub fn Slider(
    cx: Scope,
    #[prop(optional, into)] value: MaybeSignal<f64>,
    #[prop(optional)] on_value: Option<SignalSetter<f64>>,
    #[prop(default = MaybeSignal::Static(100f64), into)] max: MaybeSignal<f64>,
) -> impl IntoView {
    let theme = use_theme(cx, Theme::light);
    let css_vars = create_memo(cx, move |_| {
        let mut css_vars = String::new();
        let theme = theme.get();
        let bg_color = theme.common.color_primary;
        css_vars.push_str(&format!("--background-color-fill: {bg_color};"));

        css_vars
    });

    let percentage = create_memo(cx, move |_| {
        if value.get() < 0.0 || max.get() <= 0.0 {
            0f64
        } else if value.get() >= max.get() {
            100f64
        } else {
            value.get() / max.get() * 100.0
        }
    });
    let class_name = mount_style("slider", || style_sheet_str!("./src/slider/slider.css"));

    let do_update_value = move |value| {
        if let Some(on_value) = on_value {
            on_value.set(value);
        }
    };

    let rail_ref = create_node_ref::<html::Div>(cx);
    let (mouse_move_value, set_mouse_move_value) = create_signal::<Option<f64>>(cx, None);
    let (is_mouse_move, set_mouse_move) = create_signal(cx, false);
    let on_mouse_down = move |_| {
        set_mouse_move.set(true);
    };

    let on_mouse_up = window_event_listener("mouseup", move |_| {
        set_mouse_move.set(false);
    });
    on_cleanup(cx, on_mouse_up);

    let on_mouse_move = window_event_listener("mousemove", move |ev| {
        if is_mouse_move.get_untracked() {
            if let Some(rail) = rail_ref.get_untracked() {
                let ev = ev.unchecked_into::<web_sys::MouseEvent>();
                let rect = rail.get_bounding_client_rect();
                let ev_x = f64::from(ev.x());
                if ev_x <= rect.x() {
                    set_mouse_move_value.set(Some(0.0));
                } else if ev_x >= rect.x() + rect.width() {
                    set_mouse_move_value.set(Some(max.get()));
                } else {
                    set_mouse_move_value.set(Some(((ev_x - rect.x()) / rect.width()) * max.get()));
                }
                if let Some(value) = mouse_move_value.get_untracked() {
                    do_update_value(value);
                }
            };
        }
    });
    on_cleanup(cx, on_mouse_move);

    view! {cx, class=class_name,
        <div class="melt-slider" style=move || css_vars.get()>
            <div class="melt-slider-rail" ref=rail_ref>
                <div class="melt-slider-rail__fill" style=move || format!("width: {}%", percentage.get())></div>
            </div>
            <div on:mousedown=on_mouse_down class="melt-slider-handle" style=move || format!("left: {}%; transform: translateX(-{}%)", percentage.get(), percentage.get())>
            </div>
        </div>
    }
}