use crate::util::debug_say;
/// This was directly ported from the Java version. I make no quality assurances.
use serenity::framework::standard::{macros::command, Args, CommandResult};
use serenity::model::channel::Message;
use serenity::prelude::Context;
use unicode_segmentation::UnicodeSegmentation;

#[command]
pub(crate) async fn cube(ctx: &Context, msg: &Message, mut args: Args) -> CommandResult {
    let resp = match args
        .iter()
        .map(|e: Result<String, _>| e.unwrap())
        .collect::<Vec<_>>()
        .as_slice()
    {
        [] => "What do you wanna cube?".to_string(),
        args => {
            let to_cube: &str = &args.join(" ");
            let to_cube = UnicodeSegmentation::graphemes(to_cube, true).collect::<Vec<_>>();
            let cube_len = to_cube.len();
            let should_reverse = to_cube.last() != to_cube.first();

            let offset = cube_len / 2;
            let mut field =
                vec![vec![" ".to_string(); (cube_len + offset) * 2 - 1]; cube_len + offset];

            draw_diagonal(&mut field, cube_len, offset);
            draw_box(&mut field, &to_cube, should_reverse, offset * 2, 0);
            draw_box(&mut field, &to_cube, should_reverse, 0, offset);

            let text = field
                .iter()
                .map(|r| r.join("").trim_end().to_string())
                .collect::<Vec<_>>()
                .join("\n");

            ["```\n".to_string(), text, "```".to_string()].concat()
        }
    };

    debug_say(msg, ctx, resp).await?;

    Ok(())
}

fn draw_diagonal(field: &mut Vec<Vec<String>>, cube_len: usize, offset: usize) {
    let diag_char = "/".to_string();
    for x in 0..offset {
        field[offset - x][x * 2] = diag_char.clone();
        field[cube_len - x + offset - 1][x * 2] = diag_char.clone();
        field[offset - x][(x + cube_len - 1) * 2] = diag_char.clone();
        field[cube_len - x + offset - 1][(x + cube_len - 1) * 2] = diag_char.clone();
    }
}

fn draw_box(field: &mut Vec<Vec<String>>, chars: &[&str], should_rev: bool, x: usize, y: usize) {
    let word_len = chars.len();

    // Magic numbers are good as long as they're 1 or 2 right?
    for i in 0..word_len {
        field[y + i][x] = chars[i].to_string();
        field[y][x + i * 2] = chars[i].to_string();
        field[y + (word_len - 1)][x + (word_len - 1 - i) * 2] = if should_rev {
            chars[i].to_string()
        } else {
            chars[word_len - i - 1].to_string()
        };
        field[y + (word_len - 1) - i][x + (word_len - 1) * 2] = if should_rev {
            chars[i].to_string()
        } else {
            chars[word_len - i - 1].to_string()
        };
    }
}