mod bib;
mod minecraft;
mod users;

use chrono::Datelike;
use core::str;

use crate::{Context, Data, Error};

type EmbedField = (String, String, bool);

const DAY_TERMS: [&str; 3] = ["today", "tomorrow", "overmorrow"];

#[derive(Clone)]
pub struct HumanNaiveDate(chrono::NaiveDate);

impl str::FromStr for HumanNaiveDate {
    type Err = chrono::format::ParseError;

    fn from_str(s: &str) -> chrono::format::ParseResult<Self> {
        if let Some(days_to_add) = DAY_TERMS.iter().position(|term| s.to_lowercase() == *term) {
            let now = chrono::Local::now().naive_local().date();

            // days_to_add will never be greater than 2
            Ok(HumanNaiveDate(
                now + chrono::Duration::days(days_to_add.try_into().unwrap()),
            ))
        } else if let Ok(weekday) = s.parse::<chrono::Weekday>() {
            let now = chrono::Local::now().naive_local().date();
            let cur_day = now.weekday();
            let cur_day_index = cur_day.num_days_from_monday();
            let parsed_day_index = weekday.num_days_from_monday();

            let days_to_add = if cur_day_index <= parsed_day_index {
                parsed_day_index - cur_day_index
            } else {
                7 - (cur_day_index - parsed_day_index)
            };

            Ok(HumanNaiveDate(
                now + chrono::Duration::days(days_to_add.into()),
            ))
        } else {
            chrono::NaiveDate::from_str(s).map(HumanNaiveDate)
        }
    }
}

impl From<HumanNaiveDate> for chrono::NaiveDate {
    fn from(val: HumanNaiveDate) -> chrono::NaiveDate {
        val.0
    }
}

pub fn commands() -> Vec<poise::structs::Command<Data, Error>> {
    vec![
        help(),
        bib::bib(),
        minecraft::mc(),
        users::register(),
        users::registered(),
    ]
}

/// Show this help menu
#[poise::command(prefix_command, track_edits, slash_command)]
pub async fn help(
    ctx: Context<'_>,
    #[description = "Specific command to show help about"]
    #[autocomplete = "poise::builtins::autocomplete_command"]
    command: Option<String>,
) -> Result<(), Error> {
    poise::builtins::help(
        ctx,
        command.as_deref(),
        poise::builtins::HelpConfiguration {
            extra_text_at_bottom: "Brought to you by Doofenshmirtz Evil Incorporated.",
            ..Default::default()
        },
    )
    .await?;
    Ok(())
}