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

use crate::{
    command_handler::execute_queue, FrameId, GlobalLayoutState, GlobalMemoCell, PanelDirection,
    SplitPanel,
};
use anyhow::Error;
use create_script_dialog::CreateScriptDialog;
use delete_script_dialog::DeleteScriptDialog;
use editor_area::EditorArea;
use editor_nav::EditorNav;
use storage::fetch_initial_editor_state;
use web_sys::KeyboardEvent;
use yew::{
    function_component, html, use_node_ref, use_state_eq, AttrValue, Callback, Html, Properties,
    UseStateHandle,
};

pub use self::storage::load_extant_file_contents;
use self::storage::load_file_contents;

mod create_script_dialog;
mod delete_script_dialog;
mod editor_area;
mod editor_nav;
mod storage;

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

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

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(Clone, PartialEq, Debug)]
pub struct EditorViewState {
    error_msg: Option<AttrValue>,
    available_files: Vec<AttrValue>,
    open_file: AttrValue,
    show_create_dialog: bool,
    show_delete_dialog: Option<AttrValue>,
}

pub fn try_run_script(script: &str, global_memo: &GlobalMemoCell) -> anyhow::Result<()> {
    let script = load_file_contents(script)?;
    global_memo
        .lua_engine
        .borrow_mut()
        .execute(&script)
        .map_err(Error::msg)?;
    Ok(())
}

// Only intended for use from the editor, since it borrows from global_memo.
fn run_script<F>(script: &str, global_memo: &GlobalMemoCell, set_err: Rc<F>, frame: &FrameId)
where
    F: Fn(Option<&str>),
{
    global_memo.lua_engine.borrow_mut().set_current_frame(frame);
    match try_run_script(script, global_memo) {
        Ok(()) => {
            set_err(None);
        }
        Err(e) => {
            set_err(Some(&format!("Script error: {}", e)));
        }
    }
    execute_queue(global_memo);
}

fn select_file(script: &AttrValue, state: &UseStateHandle<Rc<EditorViewState>>) {
    let mut new_state: EditorViewState = state.as_ref().clone();
    new_state.open_file = script.clone();
    state.set(new_state.into());
}

#[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>
    }
}

fn close_modals(state: &UseStateHandle<Rc<EditorViewState>>) {
    let mut new_state = (*state.deref().deref()).clone();
    new_state.show_create_dialog = false;
    new_state.show_delete_dialog = None;
    state.set(new_state.into());
}

fn keyboard_handler<F>(
    editor_state: UseStateHandle<Rc<EditorViewState>>,
    global_memo: GlobalMemoCell,
    global_layout: UseStateHandle<Rc<GlobalLayoutState>>,
    set_err: Rc<F>,
    frame: FrameId,
) -> impl Fn(KeyboardEvent)
where
    F: Fn(Option<&str>) + 'static,
{
    move |ev: KeyboardEvent| {
        if ev.code() == "Enter" && ev.get_modifier_state("Control") {
            run_script(
                &editor_state.open_file,
                &global_memo,
                set_err.clone(),
                &frame,
            );
            ev.prevent_default();
        } else if ev.code() == "Escape" || (ev.code() == "KeyX" && ev.get_modifier_state("Control"))
        {
            close_editor(&frame, &global_layout);
        }
    }
}

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

    let detail_props: EditorViewDetailProps = EditorViewDetailProps {
        frame: props.frame.clone(),
        global_memo: props.global_memo.clone(),
        global_layout: props.global_layout.clone(),
        editor_state: editor_state.clone(),
    };

    let set_err_state = editor_state.clone();
    let set_err = Rc::new(move |msg: Option<&str>| {
        let mut new_state = (*set_err_state.as_ref()).clone();
        new_state.error_msg = msg.map(|v| AttrValue::from(String::from(v)));
        set_err_state.set(new_state.into());
    });
    let editor_ref = use_node_ref();
    let global_layout = props.global_layout.clone();
    let frame = props.frame.clone();
    let global_memo = props.global_memo.clone();
    let kb_editor_state = editor_state.clone();

    html! {
        <div class="w-100 h-100" onkeydown={keyboard_handler(kb_editor_state, global_memo, global_layout, set_err, frame)} ref={editor_ref.clone()}>
        {if editor_state.show_create_dialog {
            html! { <CreateScriptDialog ..detail_props.clone() /> }
        } else if let Some(ref delete_file) = editor_state.show_delete_dialog {
            html! { <DeleteScriptDialog editor_state={editor_state.clone()}
                        filename={delete_file.clone()}/> }
        } else {
            html! { <></> }
        }}
        {match editor_state.error_msg.as_ref() {
            None => { html! { <></> }}
            Some(msg) => {
                let editor_state = editor_state.clone();
                html! {
                    <ErrorBar msg={msg.clone()}
                    dismiss={move |()| editor_state.set(EditorViewState {
                        error_msg: None,
                        ..((*editor_state.as_ref()).clone())
                      }.into())
                    }/>
                }
            }
        }}
        <SplitPanel direction={PanelDirection::Horizontal}
        first={html!{<EditorNav ..detail_props.clone() />}}
        second={html!{<EditorArea ..detail_props.clone()/>}}
        />
        </div>
    }
}