use super::{PassiveResponder, PassiveResponse};
use crate::util::debug_say_owned;
use futures::future::BoxFuture;
use lazy_static::lazy_static;
use log::trace;
use rand::seq::SliceRandom;
use rand::thread_rng;
use rand::Rng;
use regex::Regex;
use serenity::model::channel::Message;
use serenity::prelude::Context;

lazy_static! {
    #[derive(Debug)]
    static ref FUFUFU_REGEX: Regex = Regex::new("(?i:fu){3,}").unwrap();
    #[derive(Debug)]
    static ref DESU_REGEX: Regex = Regex::new("(?i:desu)|(?:です)").unwrap();
}

pub(crate) struct DesuResponder;

impl PassiveResponder for DesuResponder {
    fn get_message(
        &self,
        received_msg: String,
        ctx: Context,
        message: Message,
    ) -> Option<PassiveResponse<'_>> {
        let fufufu_match = FUFUFU_REGEX.is_match(&received_msg);
        let desu_match = DESU_REGEX.is_match(&received_msg) && thread_rng().gen::<f32>() < 0.1;
        if fufufu_match || desu_match {
            trace!(
                "Responding to `{}` because one of the following matched: fufufu={}, desu={}",
                received_msg,
                fufufu_match,
                desu_match
            );

            Some(DESU_ACTIONS.choose(&mut thread_rng()).unwrap().clone()(
                ctx, message,
            ))
        } else {
            None
        }
    }
}

type DesuAction<'r, T> = &'r (dyn Fn(Context, Message) -> T + Sync);

const DESU_ACTIONS: &[DesuAction<BoxFuture<Result<Option<Message>, serenity::Error>>>] = &[
    &|ctx, msg| Box::pin(debug_say_owned(msg, ctx, "です。")),
    &|ctx, msg| Box::pin(debug_say_owned(msg, ctx, "desu~")),
    &|ctx, msg| Box::pin(debug_say_owned(msg, ctx, "desu.")),
    &|ctx, msg| {
        Box::pin(debug_say_owned(
            msg,
            ctx,
            r#"
```
ででででででででででで　　　　　　すす
　　　　　ででで　　　　　すすすすすすすすす
　　　　でで　　でで　　　　　　すす
　　　でで　　　でで　　　　　すすす
　　でで　　　　　　　　　　　す　す
　　でで　　　　　　　　　　　すすす
　　　でで　　　　　　　　　　　すす
　　　　でで　　　　　　　　　　すす
　　　　　でで　　　　　　　　すす
```"#,
        ))
    },
    &|ctx, msg| {
        // https://imgur.com/a/yOb5n
        // One day.
        Box::pin(debug_say_owned(
            msg,
            ctx,
            "https://www.youtube.com/watch?v=60mLvBWOMb4",
        ))
    },
    &|ctx, msg| Box::pin(send_desu_image(ctx, msg)),
];

async fn send_desu_image(ctx: Context, msg: Message) -> Result<Option<Message>, serenity::Error> {
    Ok(Some(
        msg.channel_id
            .send_message(ctx, |m| {
                m.add_file(serenity::http::AttachmentType::Bytes {
                    data: std::borrow::Cow::from(&include_bytes!("../../res/desu.jpg")[..]),
                    filename: "desu.jpg".to_string(),
                })
            })
            .await?,
    ))
}