use super::props::Props;
use crate::{prelude::*, render};
use yew::{prelude::*, virtual_dom::VNode};

pub struct TextArea {
    link: ComponentLink<Self>,
    state: String,
    props: Props,
}

#[derive(Debug)]
pub struct InputChange(ChangeData);

impl Component for TextArea {
    type Message = InputChange;
    type Properties = Props;

    fn create(props: Self::Properties, link: ComponentLink<Self>) -> Self {
        let state = extract_state(&props);
        Self { props, state, link }
    }

    fn update(&mut self, msg: Self::Message) -> ShouldRender {
        if let InputChange(ChangeData::Value(value)) = msg {
            self.state = value.clone();
            self.props.on_change.emit(value);
            true
        } else {
            false
        }
    }

    fn change(&mut self, props: Self::Properties) -> ShouldRender {
        let should_render = render_if_ne(&mut self.props, props);
        if should_render {
            self.state = extract_state(&self.props);
        }
        should_render
    }

    fn view(&self) -> Html {
        let prefix = vec!["form-control", &valid_as_class(&self.props.valid)];
        let html = html! {
                <textarea
                    readonly=self.props.readonly
                    onchange=self.link.callback(|evt| InputChange(evt))
                >
                    { &self.state }
                </textarea>
        };
        render::render_with_prefix(&self.props, prefix, html)
    }
}

fn extract_state(props: &Props) -> String {
    if props.children.is_empty() {
        props.value.clone()
    } else {
        props.children.iter().fold(String::new(), |mut buf, node| {
            if let VNode::VText(text) = node {
                buf.push_str(&text.text);
            } else if let VNode::VList(list) = node {
                let text = list.iter().fold(String::new(), |mut buf, node| {
                    if let VNode::VText(text) = node {
                        buf.push_str(&text.text)
                    }
                    buf
                });
                buf.push_str(&text);
            }
            buf
        })
    }
}