use std::{ops::Deref, rc::Rc};

use anyhow::Error;
use wasm_bindgen::{prelude::wasm_bindgen, JsValue};
use web_sys::{window, Node};
use yew::{
    function_component, html, use_effect_with, use_node_ref, use_state_eq, AttrValue, Callback,
    Html, Properties, UseStateHandle,
};

use crate::{FrameId, GlobalLayoutState, GlobalMemoCell, PanelDirection, SplitPanel};

#[derive(Properties, PartialEq, Clone)]
pub struct EditorViewProps {
    pub frame: FrameId,
    pub global_memo: GlobalMemoCell,
    pub global_layout: UseStateHandle<Rc<GlobalLayoutState>>,
}

fn close_editor(frame: &FrameId, global_layout: &UseStateHandle<Rc<GlobalLayoutState>>) {
    let mut gl_new: GlobalLayoutState = global_layout.as_ref().clone();
    gl_new.frame_views.remove(frame);
    global_layout.set(gl_new.into());
}

#[derive(PartialEq, Clone)]
pub struct EditorState {
    error_msg: Option<AttrValue>,
    available_files: Vec<AttrValue>,
}

fn fetch_initial_editor_state_or_fail() -> anyhow::Result<EditorState> {
    let win = window().ok_or_else(|| Error::msg("Can't get window"))?;
    win.local_storage()
        .map_err(|_| Error::msg("Error retrieving localStorage"))?
        .ok_or_else(|| Error::msg("Local storage not available"))?;
    Ok(EditorState {
        error_msg: None,
        available_files: vec![],
    })
}

fn fetch_initial_editor_state() -> EditorState {
    match fetch_initial_editor_state_or_fail() {
        Ok(s) => s,
        Err(e) => EditorState {
            error_msg: Some(format!("Can't load editor data: {}", e.to_string()).into()),
            available_files: vec![],
        },
    }
}

#[function_component(EditorNav)]
fn editor_nav(props: &EditorViewProps) -> Html {
    let global_layout = props.global_layout.clone();
    let frame = props.frame.clone();
    html! {
        <div class="editornav">
          <nav class="navbar navbar-expand-lg bg-body-tertiary">
            <button class="btn" aria-label="New file" title="New file"><i class="bi bi-file-earmark-plus"></i></button>
            <div class="flex-fill"/>
            <button class="btn" onclick={move |_ev| close_editor(&frame, &global_layout)} aria-label="Close Editor" title="Close editor"><i class="bi bi-arrow-return-left"></i></button>
          </nav>
        </div>
    }
}

#[wasm_bindgen(getter_with_clone)]
struct EditorViewConfig {
    pub doc: String,
    pub extensions: Vec<CMExtension>,
    pub parent: Node,
}

#[wasm_bindgen(module = codemirror)]
extern "C" {
    type EditorView;
    #[derive(Clone)]
    type CMExtension;

    #[wasm_bindgen(constructor)]
    fn new(settings: EditorViewConfig) -> EditorView;

    #[wasm_bindgen(js_name = basicSetup, thread_local)]
    static BASIC_SETUP: CMExtension;
}

#[wasm_bindgen(module = "@codemirror/legacy-modes/mode/lua")]
extern "C" {
    #[wasm_bindgen(js_name = lua, thread_local)]
    static LUA: StreamLanguage;
}

#[wasm_bindgen(module = "@codemirror/language")]
extern "C" {
    #[derive(Clone)]
    type StreamLanguage;

    #[wasm_bindgen(js_namespace = StreamLanguage, js_name = define)]
    fn streamlanguage_define(input: StreamLanguage) -> CMExtension;
}

#[function_component(EditorArea)]
fn editor_area(props: &EditorViewProps) -> Html {
    let node_ref = use_node_ref();
    use_effect_with(node_ref.clone(), |node_ref| match node_ref.get() {
        None => {}
        Some(node) => {
            EditorView::new(EditorViewConfig {
                doc: "Hello World".to_owned(),
                extensions: vec![
                    BASIC_SETUP.with(CMExtension::clone),
                    StreamLanguage::streamlanguage_define(LUA.with(StreamLanguage::clone)),
                ],
                parent: node,
            });
        }
    });
    html! {
        <div class="editorarea" ref={node_ref.clone()}>
        </div>
    }
}

#[derive(Properties, PartialEq, Clone)]
pub struct ErrorBarProps {
    pub msg: AttrValue,
    pub dismiss: Callback<()>,
}

#[function_component(ErrorBar)]
fn error_bar(props: &ErrorBarProps) -> Html {
    let props = props.clone();
    html! {
        <div class="errorbar alert alert-danger alert-dismissible" role="alert">
            <span class="errorbar-msg">{props.msg.clone()}</span>
            <button class="btn-close" aria-label="Close" onclick={move |_ev| props.dismiss.emit(())}></button>
        </div>
    }
}

#[function_component(CodeEditorView)]
pub fn editor_view(props: &EditorViewProps) -> Html {
    let editor_state: UseStateHandle<EditorState> = use_state_eq(fetch_initial_editor_state);

    html! {
        <>
        {match editor_state.error_msg.as_ref() {
            None => { html! { <></> }}
                Some(msg) => html! {
                    <ErrorBar msg={msg.clone()}
                    dismiss={move |()| editor_state.set(EditorState {
                        error_msg: None,
                        ..(editor_state.deref().clone())
                      })
                    }/> }
        }}
        <SplitPanel direction={PanelDirection::Horizontal}
             first={html!{<EditorNav ..props.clone()/>}}
             second={html!{<EditorArea ..props.clone()/>}}
        />
        </>
    }
}