rude/src/world/direction.rs

use std::default::Default;
use std::error::Error;
use std::str::FromStr;

use lazy_static::lazy_static;
use rusqlite::types::{FromSql, FromSqlError, FromSqlResult, ToSql, ToSqlOutput, ValueRef};
use serde_derive::{Deserialize, Serialize};

use crate::command::ParserError;
use crate::result::RudeResult;

lazy_static! {
	/// List of text directions and the associated Direction
	pub static ref DIRECTION_LIST: Vec<(&'static str, Direction)> = vec![
		("north", Direction::North),
		("south", Direction::South),
		("east", Direction::East),
		("west", Direction::West),
		("up", Direction::Up),
		("down", Direction::Down),
	];
}

/// Directions for an exit from a room.
#[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, Ord, PartialEq, PartialOrd, Serialize)]
pub enum Direction {
	/// Cardinal north
	North = 0,

	/// Cardinal east
	East,

	/// Cardinal south
	South,

	/// Cardinal west
	West,

	/// Up (towards the sky)
	Up,

	/// Down (towards the ground)
	Down,

	/// Default (internal usage only)
	Default,
}

impl Default for Direction {
	fn default() -> Self {
		Self::Default
	}
}

impl FromSql for Direction {
	fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
		let s = match value.as_str() {
			Ok(s) => s,
			Err(e) => {
				log::error!("{}({}) :: {} :: {}", file!(), line!(), "value.as_str()", e);
				return Err(e);
			}
		};

		match Self::from_str(s) {
			Ok(direction) => return Ok(direction),
			Err(e) => Err(FromSqlError::Other(e)),
		}
	}
}

impl ToSql for Direction {
	fn to_sql(&self) -> rusqlite::Result<ToSqlOutput<'_>> {
		Ok(ToSqlOutput::from(self.long()))
	}
}

impl FromStr for Direction {
	type Err = Box<dyn Error + Send + Sync + 'static>;

	fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
		let mut s: String = s.into();

		// get rid of extra characters
		if let Some(pos) = s.find(' ') {
			s.split_off(pos);
		}

		// no command
		if s.is_empty() {
			return Err(Box::from(ParserError::Empty));
		}

		// match directions with input
		let mut matches: Vec<(&str, Self)> = DIRECTION_LIST
			.iter()
			.filter_map(|(text, dir)| {
				if text.starts_with(&s) {
					Some((text.clone(), dir.clone()))
				} else {
					None
				}
			})
			.collect();

		// No matches here means unknown direction
		if matches.is_empty() {
			return Err(Box::from(ParserError::Unknown));
		}

		// exact match, do no more
		if matches.len() == 1 {
			return Ok(matches[0].1);
		}

		// look for directions that match
		for (text, direction) in DIRECTION_LIST.iter() {
			let direction: Self = direction.clone();
			if *text == s {
				// exact match
				matches = vec![(text, direction)];
				break;
			} else if text.starts_with(s.as_str()) {
				// starts the same, add to the list
				matches.push((text, direction));
			}
		}

		// check if there was a match
		if matches.is_empty() {
			return Err(Box::from(ParserError::Unknown));
		}

		// sort and take the first match
		// this allows possibly more directions, the original set shouldn't ever have multiple
		matches.sort();
		Ok(matches[0].1)
	}
}

impl Direction {
	/// Provide the opposite direction
	pub fn opposite(self) -> Direction {
		match self {
			Self::North => Self::South,
			Self::East => Self::West,
			Self::South => Self::North,
			Self::West => Self::East,
			Self::Up => Self::Down,
			Self::Down => Self::Up,
			Self::Default => Self::Default,
		}
	}

	/// Single character identifier for the direction.
	pub fn short(&self) -> &str {
		match self {
			Self::North => "N",
			Self::East => "E",
			Self::South => "S",
			Self::West => "W",
			Self::Up => "U",
			Self::Down => "D",
			Self::Default => "",
		}
	}

	/// String identifier for the direction.
	pub fn long(&self) -> &str {
		match self {
			Self::North => "north",
			Self::East => "east",
			Self::South => "south",
			Self::West => "west",
			Self::Up => "up",
			Self::Down => "down",
			Self::Default => "",
		}
	}

	pub fn try_from_long<S: AsRef<str>>(s: S) -> RudeResult<Self> {
		let s = s.as_ref();
		match s {
			"north" => Ok(Self::North),
			"east" => Ok(Self::East),
			"south" => Ok(Self::South),
			"west" => Ok(Self::West),
			"up" => Ok(Self::Up),
			"down" => Ok(Self::Down),
			_ => Err(format!("Invalid direction: {}", s).into()),
		}
	}
}