use leptos::prelude::*;

use crate::components::layout::{AdminShell, Breadcrumb};
use crate::terminal::{Renderer, TerminalOptions, TerminalPanel, TerminalRenderEvent};

#[component]
pub fn TerminalPage() -> impl IntoView {
    let renderer = RwSignal::new(initial_terminal_renderer());
    let terminal_options = Signal::derive(move || TerminalOptions {
        renderer: renderer.get(),
        ..TerminalOptions::default()
    });
    let on_render = Callback::new(update_terminal_bench_probe);

    view! {
        <AdminShell>
            <Breadcrumb current="浏览器终端" />
            <section class="cowa-work-surface terminal-page-shell">
                <TerminalRendererSwitch renderer=renderer />
                <TerminalPanel options=terminal_options on_render=on_render />
            </section>
        </AdminShell>
    }
}

#[component]
fn TerminalRendererSwitch(renderer: RwSignal<Renderer>) -> impl IntoView {
    view! {
        <div class="terminal-page-toolbar" role="toolbar" aria-label="终端渲染器">
            <span class="terminal-renderer-label">"Renderer"</span>
            <RendererButton renderer=renderer value=Renderer::WebGl label="WebGL" />
            <RendererButton renderer=renderer value=Renderer::Canvas label="Canvas" />
            <RendererButton renderer=renderer value=Renderer::Dom label="DOM" />
        </div>
    }
}

#[component]
fn RendererButton(
    renderer: RwSignal<Renderer>,
    value: Renderer,
    label: &'static str,
) -> impl IntoView {
    view! {
        <button
            type="button"
            class="terminal-renderer-option"
            class=("is-active", move || renderer.get() == value)
            aria-pressed=move || (renderer.get() == value).to_string()
            on:click=move |_| renderer.set(value)
        >
            {label}
        </button>
    }
}

#[cfg(target_arch = "wasm32")]
fn initial_terminal_renderer() -> Renderer {
    web_sys::window()
        .and_then(|window| window.location().search().ok())
        .and_then(|query| renderer_from_query(&query))
        .unwrap_or_default()
}

#[cfg(not(target_arch = "wasm32"))]
fn initial_terminal_renderer() -> Renderer {
    Renderer::default()
}

#[cfg(any(target_arch = "wasm32", test))]
fn renderer_from_query(query: &str) -> Option<Renderer> {
    query
        .trim_start_matches('?')
        .split('&')
        .filter_map(|part| part.split_once('='))
        .find_map(|(key, value)| (key == "renderer").then(|| parse_renderer(value)).flatten())
}

#[cfg(any(target_arch = "wasm32", test))]
fn parse_renderer(value: &str) -> Option<Renderer> {
    match value.to_ascii_lowercase().as_str() {
        "webgl" | "web-gl" => Some(Renderer::WebGl),
        "canvas" | "canvas2d" | "canvas-2d" => Some(Renderer::Canvas),
        "dom" => Some(Renderer::Dom),
        _ => None,
    }
}

#[cfg(target_arch = "wasm32")]
fn update_terminal_bench_probe(event: TerminalRenderEvent) {
    use wasm_bindgen::JsValue;

    let Some(window) = web_sys::window() else {
        return;
    };
    let Ok(probe) = js_sys::Reflect::get(&window, &JsValue::from_str("__terminalBench")) else {
        return;
    };
    let probe = if probe.is_object() {
        probe
    } else {
        let object = js_sys::Object::new();
        let _ = js_sys::Reflect::set(&window, &JsValue::from_str("__terminalBench"), &object);
        object.into()
    };

    let count = js_sys::Reflect::get(&probe, &JsValue::from_str("renderCount"))
        .ok()
        .and_then(|value| value.as_f64())
        .unwrap_or(0.0)
        + 1.0;
    let mode = if event.mode.is_live() {
        "live"
    } else {
        "history"
    };
    let renderer = format!("{:?}", event.renderer);
    let webgl_stats = event.webgl_stats;

    let _ = js_sys::Reflect::set(
        &probe,
        &JsValue::from_str("renderCount"),
        &JsValue::from_f64(count),
    );
    let _ = js_sys::Reflect::set(
        &probe,
        &JsValue::from_str("lastRenderAt"),
        &JsValue::from_f64(js_sys::Date::now()),
    );
    let _ = js_sys::Reflect::set(
        &probe,
        &JsValue::from_str("renderer"),
        &JsValue::from_str(&renderer),
    );
    let _ = js_sys::Reflect::set(&probe, &JsValue::from_str("mode"), &JsValue::from_str(mode));
    let _ = js_sys::Reflect::set(
        &probe,
        &JsValue::from_str("cols"),
        &JsValue::from_f64(f64::from(event.cols)),
    );
    let _ = js_sys::Reflect::set(
        &probe,
        &JsValue::from_str("rows"),
        &JsValue::from_f64(f64::from(event.rows)),
    );
    let _ = js_sys::Reflect::set(
        &probe,
        &JsValue::from_str("historyRows"),
        &JsValue::from_f64(event.history_rows as f64),
    );
    let _ = js_sys::Reflect::set(
        &probe,
        &JsValue::from_str("screenRows"),
        &JsValue::from_f64(event.screen_rows as f64),
    );
    if let Some(stats) = webgl_stats {
        append_webgl_stats(&probe, stats);
    }
}

#[cfg(target_arch = "wasm32")]
fn append_webgl_stats(probe: &wasm_bindgen::JsValue, stats: crate::terminal::WebGlRenderStats) {
    use wasm_bindgen::JsCast;
    use wasm_bindgen::JsValue;

    let frames = match js_sys::Reflect::get(probe, &JsValue::from_str("webglFrames")) {
        Ok(value) if js_sys::Array::is_array(&value) => value.unchecked_into::<js_sys::Array>(),
        _ => {
            let array = js_sys::Array::new();
            let _ = js_sys::Reflect::set(probe, &JsValue::from_str("webglFrames"), &array);
            array
        }
    };

    let frame = js_sys::Object::new();
    set_f64(&frame, "totalMs", stats.total_ms);
    set_f64(&frame, "syncDomMs", stats.sync_dom_ms);
    set_f64(&frame, "backdropMs", stats.backdrop_ms);
    set_f64(&frame, "collectMs", stats.collect_ms);
    set_f64(&frame, "backdropTextureMs", stats.backdrop_texture_ms);
    set_f64(&frame, "fallbackCanvasMs", stats.fallback_canvas_ms);
    set_f64(&frame, "atlasMs", stats.atlas_ms);
    set_f64(&frame, "atlasUploadMs", stats.atlas_upload_ms);
    set_f64(&frame, "vertexBuildMs", stats.vertex_build_ms);
    set_f64(&frame, "vertexUploadMs", stats.vertex_upload_ms);
    set_f64(&frame, "drawMs", stats.draw_ms);
    set_f64(&frame, "cells", stats.cells as f64);
    set_f64(&frame, "rowCacheHits", stats.row_cache_hits as f64);
    set_f64(&frame, "rowCacheMisses", stats.row_cache_misses as f64);
    set_f64(&frame, "vertexCacheHits", stats.vertex_cache_hits as f64);
    set_f64(
        &frame,
        "vertexCacheMisses",
        stats.vertex_cache_misses as f64,
    );
    set_f64(&frame, "atlasEntries", stats.atlas_entries as f64);
    set_f64(&frame, "atlasInsertions", stats.atlas_insertions as f64);
    set_f64(&frame, "atlasResets", stats.atlas_resets as f64);
    set_bool(&frame, "fallbackFullCanvas", stats.fallback_full_canvas);
    set_bool(&frame, "glyphDrawFailed", stats.glyph_draw_failed);

    frames.push(&frame);
    while frames.length() > 720 {
        frames.shift();
    }
}

#[cfg(target_arch = "wasm32")]
fn set_f64(target: &js_sys::Object, key: &str, value: f64) {
    use wasm_bindgen::JsValue;

    let _ = js_sys::Reflect::set(target, &JsValue::from_str(key), &JsValue::from_f64(value));
}

#[cfg(target_arch = "wasm32")]
fn set_bool(target: &js_sys::Object, key: &str, value: bool) {
    use wasm_bindgen::JsValue;

    let _ = js_sys::Reflect::set(target, &JsValue::from_str(key), &JsValue::from_bool(value));
}

#[cfg(not(target_arch = "wasm32"))]
fn update_terminal_bench_probe(_event: TerminalRenderEvent) {}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn renderer_query_parses_supported_values() {
        assert_eq!(
            renderer_from_query("?renderer=webgl"),
            Some(Renderer::WebGl)
        );
        assert_eq!(
            renderer_from_query("?foo=1&renderer=canvas2d"),
            Some(Renderer::Canvas)
        );
        assert_eq!(renderer_from_query("?renderer=dom"), Some(Renderer::Dom));
    }

    #[test]
    fn renderer_query_ignores_unknown_values() {
        assert_eq!(renderer_from_query("?renderer=auto"), None);
        assert_eq!(renderer_from_query("?other=webgl"), None);
        assert_eq!(renderer_from_query(""), None);
    }
}