mod add_points;
mod leaderboard;
mod revise;

pub use add_points::add_points;
pub use leaderboard::leaderboard;
pub use revise::revise;
use time::{Date, PrimitiveDateTime, Time, format_description};

use std::sync::Arc;

use twilight_model::{
	application::{
		command::{Command, CommandType},
		interaction::application_command::{CommandData, CommandOptionValue},
	},
	gateway::payload::incoming::InteractionCreate,
	guild::PartialMember,
	http::interaction::InteractionResponseData,
	id::{
		Id,
		marker::{GuildMarker, UserMarker},
	},
};
use twilight_util::builder::{
	InteractionResponseDataBuilder,
	command::{CommandBuilder, IntegerBuilder, RoleBuilder, StringBuilder, SubCommandBuilder},
	embed::{EmbedBuilder, EmbedFieldBuilder},
};

use crate::{bail, brain::Brain, database::PermissionSetting, fail, import, success, util};

pub enum Commands {
	About,
	Leaderboard,
	Points,
	Revise,
	Permission,
	Import,
}

pub async fn handler(
	brain: Arc<Brain>,
	guild: Id<GuildMarker>,
	create: &InteractionCreate,
	command: Commands,
	command_data: &CommandData,
) {
	// Handle the command and create our interaction response data
	let data = match command {
		Commands::About => about(brain.clone(), guild),
		Commands::Leaderboard => leaderboard(brain.clone(), guild, Some(command_data)),
		Commands::Points => add_points(brain.clone(), guild, create, command_data).await,
		Commands::Revise => revise(brain.clone(), guild, create, command_data).await,
		Commands::Permission => permission(brain.clone(), guild, create, command_data).await,
		Commands::Import => {
			import(brain.clone(), guild, create, command_data).await;
			return;
		}
	};

	// Finally, send back the response
	brain.interaction_respond(create, data).await;
}

pub async fn build() -> Vec<Command> {
	let about = CommandBuilder::new(
		"about",
		"Get information about the bot",
		CommandType::ChatInput,
	)
	.build();

	let leaderboard = CommandBuilder::new(
		"leaderboard",
		"View the server leaderboard",
		CommandType::ChatInput,
	)
	.option(
		StringBuilder::new("style", "style of leaderboard to display")
			.choices([("Ties Equal", "equal"), ("Ties Broken", "broken")]),
	)
	.build();

	let points = CommandBuilder::new("points", "Add and remove points!", CommandType::ChatInput)
		.option(IntegerBuilder::new("points", "number of points. - or +").required(true))
		.option(
			StringBuilder::new("users", "mention people to modify their points!!").required(true),
		)
		.validate()
		.unwrap()
		.build();

	let revise = CommandBuilder::new(
		"revise",
		"Change history by adding/removing points at a specific point in time",
		CommandType::ChatInput,
	)
	.option(IntegerBuilder::new("points", "number of points. - or +").required(true))
	.option(StringBuilder::new("users", "mention people to modify their points!!").required(true))
	.option(
		StringBuilder::new(
			"date",
			"Date string in the YYYY-DD-MM format, with optional time component (HH:MM:SS, 24-hour time)",
		)
		.required(true),
	)
	.validate()
	.unwrap()
	.build();

	let permission = CommandBuilder::new(
		"permission",
		"set who is allowed to change points",
		CommandType::ChatInput,
	)
	.option(
		SubCommandBuilder::new("role", "require a role to change the score")
			.option(RoleBuilder::new("role", "role required").required(true)),
	)
	.option(SubCommandBuilder::new(
		"none",
		"anyone can change the score",
	))
	.build();

	let import = CommandBuilder::new(
		"import",
		"import this server's emboard leaderboard by adding the points in emboard, to leaberblord's",
		CommandType::ChatInput,
	)
	.build();

	vec![about, leaderboard, points, revise, permission, import]
}

pub fn about(_brain: Arc<Brain>, _guild: Id<GuildMarker>) -> InteractionResponseData {
	let embed = EmbedBuilder::new()
		.title("About Leaberblord")
		.description(
			"A single-purpose bot for keeping score. Written in Rust using the twilight set of crates.",
		).field(EmbedFieldBuilder::new("Source", "The source is available on the author's [cgit instance](https://git.dreamy.place/whimsy/leaberblord/about)"))
		.field(EmbedFieldBuilder::new("Author", "Written by @gennyble. Her homepage is [dreamy.place](https://dreamy.place)"))
		.color(0x33aa88).build();

	InteractionResponseDataBuilder::new()
		.embeds([embed])
		.build()
}

pub async fn permission(
	brain: Arc<Brain>,
	guild: Id<GuildMarker>,
	create: &InteractionCreate,
	data: &CommandData,
) -> InteractionResponseData {
	let member = create.member.clone().unwrap();
	let permissions = member.permissions.unwrap();
	if !permissions.contains(twilight_model::guild::Permissions::MANAGE_GUILD) {
		bail!("You must have the Manage Server permission to perform this action");
	}

	for opt in &data.options {
		return match opt.name.as_str() {
			"none" => permission_none(brain, guild),
			"role" => permission_role(brain, guild, opt.value.clone()),
			_ => {
				eprintln!("permission command, unknown option '{}'", opt.name);
				fail!("this should be unreachable. report the bug maybe? to gennyble on discord")
			}
		};
	}

	fail!("this should be unreachable. report the bug maybe? to gennyble on discord")
}

fn permission_none(brain: Arc<Brain>, guild: Id<GuildMarker>) -> InteractionResponseData {
	if brain.create_leaderboard_if_not_exists(guild) {
		// If it already existed, we might not be on default none. So set it.
		brain
			.db
			.set_leaderboard_permission(guild.get(), PermissionSetting::None)
			.unwrap();
	}

	success!("Permission for leaderboard changed to none. Anyone may now set the score.")
}

fn permission_role(
	brain: Arc<Brain>,
	guild: Id<GuildMarker>,
	data: CommandOptionValue,
) -> InteractionResponseData {
	let role = if let CommandOptionValue::SubCommand(data) = data {
		match data.iter().find(|d| d.name == "role").unwrap().value {
			CommandOptionValue::Role(role) => role,
			_ => panic!(),
		}
	} else {
		panic!()
	};

	brain.create_leaderboard_if_not_exists(guild);

	brain
		.db
		.set_leaderboard_permission(guild.get(), PermissionSetting::RoleRequired)
		.unwrap();
	brain
		.db
		.set_leaderboard_permission_role(guild.get(), role.get())
		.unwrap();

	success!(format!(
		"Permission for leaderboard changed to Role Required. \
		Only members of <@&{role}> may now set the score"
	))
}

pub async fn import(
	brain: Arc<Brain>,
	guild: Id<GuildMarker>,
	create: &InteractionCreate,
	_data: &CommandData,
) {
	let member = create.member.clone().unwrap();
	let permissions = member.permissions.unwrap();
	if !permissions.contains(twilight_model::guild::Permissions::MANAGE_GUILD) {
		brain
			.interaction_respond(
				create,
				fail!("You must have the Manage Server permission to perform this action"),
			)
			.await;
	} else {
		import::emboard_direct::import(brain, guild, create).await;
	}
}

/// Checks the settings of the leaderboard associated with the provided guild.
///
/// Returns `None` if:
/// - The guild does not have permissions set
/// - The guild member has the appropriate permissions
///
/// Returns `Some` with InteractionResponseData if:
/// - The guild member does not have proper permissions
/// - The guild is set to role required, but no role is set, which should be
///   impossible to happen, but.
pub fn check_command_permissions(
	brain: &Brain,
	guild: Id<GuildMarker>,
	member: PartialMember,
) -> Option<InteractionResponseData> {
	let settings = brain.db.get_leaderboard_settings(guild.get()).unwrap();
	if let PermissionSetting::RoleRequired = settings.permission {
		if let Some(role) = settings.role {
			let member = member;
			let found_role = member.roles.iter().find(|vrole| vrole.get() == role);

			if found_role.is_none() {
				Some(fail!(
					"You do not have the right permissions to change the score"
				))
			} else {
				None
			}
		} 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?
			Some(fail!(
				"Permissions set to Role Required, but no role is set. \
				This shouldn't be able to happen. \
				Maybe try to set the permissions again?"
			))
		}
	} else {
		None
	}
}

pub struct PointsCommandData {
	points: i64,
	points_verb: &'static str,
	users: Vec<Id<UserMarker>>,
	date: Result<PrimitiveDateTime, InteractionResponseData>,
}

impl PointsCommandData {
	pub fn user_string(&self) -> String {
		self.users
			.iter()
			.map(|u| format!("<@{u}>"))
			.collect::<Vec<String>>()
			.join(", ")
	}
}

pub fn parse_points_command_data(
	data: &CommandData,
) -> Result<PointsCommandData, 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!(),
		}
	}

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

	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(_) | None => unreachable!(),
	};

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

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

	Ok(PointsCommandData {
		points,
		points_verb,
		users,
		date,
	})
}