use crate::{Context, Error};
use mysql_async::{from_row, params, prelude::Queryable, Conn};
use rand::seq::IteratorRandom;

async fn autocomplete_command<'a>(ctx: Context<'_>, partial: &'a str) -> Vec<String> {
    let mut conn = match ctx.data().database.get_conn().await {
        Ok(c) => c,
        Err(_) => return vec![],
    };

    let stmt = conn.prep("SELECT sign FROM commands WHERE sign LIKE CONCAT('%', :partial, '%') AND enabled ORDER BY priority DESC, sign ASC LIMIT 25").await.unwrap();
    let result = match conn.exec_iter(stmt, params! {partial}).await {
        Ok(blah) => blah
            .map_and_drop(|row| from_row::<String>(row))
            .await
            .unwrap_or_default(),
        Err(e) => {
            println!("Error autocomplete coms {}", e);
            vec!["Error getting commands".to_owned()]
        }
    };
    result
}

pub async fn get_command(sign: &str, con: &mut Conn) -> Result<Option<String>, mysql_async::Error> {
    let a: Option<String> = con.exec_first(r"SELECT response FROM commands WHERE sign = :sign and enabled order by priority desc limit 1", (sign,)).await?;
    Ok(a)
}

/// Run any of a collection of arbitrary commands
#[poise::command(slash_command)]
pub async fn coms(
    ctx: Context<'_>,
    #[description = "Which command to execute?"]
    #[autocomplete = "autocomplete_command"]
    command: String,
) -> Result<(), Error> {
    let conn: &mut Conn = &mut ctx.data().database.get_conn().await?;
    match get_command(&command, conn).await? {
        None => {
            ctx.say(format!("Command `{}` not found", command)).await?;
        }
        Some(com) => {
            ctx.say(sky(&com)).await?;
        }
    }
    Ok(())
}

fn sky(input: &str) -> String {
    let result: String = input.to_string();
    let mut rng = rand::thread_rng();
    loop {
        match sky_open(&result) {
            None => return result,
            Some((left, end)) => {
                match sky_closed(&end) {
                    None => return result,
                    Some((mid, right)) => {
                        return sky(&format!(
                            "{}{}{}",
                            left,
                            mid.split('|').choose(&mut rng).unwrap(),
                            right
                        ))
                    }
                };
            }
        }
    }
}

fn sky_open(input: &str) -> Option<(String, String)> {
    match input.rsplit_once('{') {
        None => return None,
        Some((left, end)) => {
            if left.ends_with('\\') {
                match sky_open(left) {
                    None => return None,
                    Some((left, right)) => {
                        let mut end: String = end.to_string();
                        end.push('{');
                        end.push_str(right.as_str());
                        return Some((left.to_owned(), end));
                    }
                };
            } else {
                return Some((left.to_owned(), end.to_owned()));
            }
        }
    }
}

fn sky_closed(input: &str) -> Option<(String, String)> {
    match input.split_once('}') {
        None => return None,
        Some((left, end)) => {
            if left.ends_with('\\') {
                match sky_closed(end) {
                    None => return None,
                    Some((mid, right)) => {
                        let mut start: String = left.to_string();
                        start.push('}');
                        start.push_str(mid.as_str());
                        return Some((start, right.to_owned()));
                    }
                };
            } else {
                return Some((left.to_owned(), end.to_owned()));
            }
        }
    }
}