use std::sync::Arc;

use time::{
	Date, OffsetDateTime, PrimitiveDateTime, Time, format_description, macros::format_description,
};
use twilight_model::{
	application::interaction::application_command::{CommandData, CommandOptionValue},
	gateway::payload::incoming::InteractionCreate,
	http::interaction::InteractionResponseData,
	id::{
		Id,
		marker::{GuildMarker, UserMarker},
	},
};
use twilight_util::builder::{InteractionResponseDataBuilder, embed::EmbedBuilder};

use crate::{
	bail,
	brain::Brain,
	database::{BoardRow, Error as DbError, PermissionSetting},
	success, util,
};

pub async fn revise(
	brain: Arc<Brain>,
	guild: Id<GuildMarker>,
	create: &InteractionCreate,
	data: &CommandData,
) -> InteractionResponseData {
	let mut points = None;
	let mut users: Vec<Id<UserMarker>> = vec![];
	let mut date_string = None;

	for opt in &data.options {
		match opt.name.as_str() {
			"points" => match opt.value {
				CommandOptionValue::Integer(num) => points = Some(num),
				_ => unreachable!(),
			},
			"users" => match &opt.value {
				CommandOptionValue::String(raw) => {
					let mentions = util::extract_user_mentions(&raw);
					users = mentions;
				}
				_ => unreachable!(),
			},
			"date" => match &opt.value {
				CommandOptionValue::String(raw) => {
					date_string = Some(raw);
				}
				_ => unreachable!(),
			},
			_ => unreachable!(),
		}
	}

	let date_fmt = format_description::parse("[year]-[month]-[day]").unwrap();
	let datetime_fmt =
		format_description::parse("[year]-[month]-[day] [hour]:[minute]:[second]").unwrap();

	if users.len() == 0 {
		bail!("No users mentioned! Who do we add points to?")
	}

	if let Some(date) = date_string {
		println!("date = \"{date}\"");
	}

	let date = match date_string {
		None => bail!("What date were these points earned?"),
		Some(str) if str.is_empty() => bail!("You must specify a date!"),
		Some(date) => match Date::parse(date.trim(), &date_fmt) {
			Err(_e) => match PrimitiveDateTime::parse(date.trim(), &datetime_fmt) {
				Err(_e) => bail!(
					"Cannot parse the given date/time. Did you write it like \"2025-04-13\" or, with time, \"2025-04-13 02:33\"?"
				),
				Ok(datetime) => datetime,
			},
			Ok(date) => PrimitiveDateTime::new(date, Time::from_hms(12, 0, 0).unwrap()),
		},
	};

	let (points, points_display, points_verb) = match points {
		Some(p) if p > 0 => (p, p, "added to"),
		Some(p) if p < 0 => (p, -p, "removed from"),
		Some(0) => {
			return success!("adding 0 points is a no-operation! I won't do anything :)");
		}
		Some(_) | None => unreachable!(),
	};

	brain.create_leaderboard_if_not_exists(guild);

	let settings = brain.db.get_leaderboard_settings(guild.get()).unwrap();
	if let PermissionSetting::RoleRequired = settings.permission {
		if let Some(role) = settings.role {
			let member = create.member.clone().unwrap();
			let found_role = member.roles.iter().find(|vrole| vrole.get() == role);

			if found_role.is_none() {
				bail!("You do not have the right permissions to change the score");
			}
		} else {
			// Seeing as the role is a required input on the subcommand, this
			// would only happen with direct database fiddling or like, some
			// really weird arcane bullshit?
			bail!(
				"Permissions set to Role Required, but no role is set. \
				This shouldn't be able to happen. \
				Maybe try to set the permissions again?"
			);
		}
	}

	for user in &users {
		match brain.db.give_user_points(guild.get(), user.get(), points) {
			Err(DbError::UserNotExist) => {
				let member = brain.guild_member(guild, *user).await;
				let row = BoardRow {
					user_id: user.get(),
					user_handle: member.handle,
					user_nickname: member.nick.or(member.global_name),
					points,
				};
				brain.db.add_user_to_leaderboard(guild.get(), row).unwrap();
			}
			_ => (),
		}

		//FIXME: gen 2025-08-14: do not assume UTC!
		brain
			.db
			.revise_last_history_date(guild.get(), user.get(), points, date.assume_utc())
			.unwrap();
	}

	let users_string = users
		.into_iter()
		.map(|u| format!("<@{u}>"))
		.collect::<Vec<String>>()
		.join(", ");

	let msg = format!(
		"{points_display} points {points_verb} {users_string} on date {}",
		date.format(&datetime_fmt).unwrap()
	);
	let embed = EmbedBuilder::new().description(msg).build();
	InteractionResponseDataBuilder::new()
		.embeds([embed])
		.build()
}