1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139

use super::*;

use rand::distributions::{Distribution, Uniform};

pub struct Roll;

impl Roll
{
	pub fn new_action() -> Box<dyn Action>
	{
		Box::new(Roll)
	}
}

/// Rolls the dice for a certain skill of the *Hero*, supports modifiers.
///
/// # Examples
///
/// ```
/// # use dsa::Quality::*;
/// # use dsa::Hero;
/// # use dsa::output::Output;
/// # use dsa::commands::Roll;
/// let mut roll = Roll::new_action();
/// # let mut hero = Hero::default();
/// hero.qualities.extend(
///     vec![
///         (Agility,1),
///         (Dexterity,2),
///         (Strength,3),
///     ]
/// );
/// hero.skills.insert("bogen".to_string(),(4,[Agility,Dexterity,Strength]));
/// let matches = roll.usage().get_matches_from(&["roll","-m","-5","--mod","3","bogen"]);
/// let output = roll.call(&hero,&matches).unwrap();
/// assert_eq!(1,output.len());
/// 
/// if let Output::Roll { base, stat, mods, .. } = &output[0] {
///     assert_eq!(4, *base);
///     assert_eq!(&[1,2,3], stat);
///     assert_eq!(-2, *mods);
/// }
/// # else {
/// #     panic!("unexpected output");
/// # }
/// ```
impl Action for Roll
{
	fn usage<'a,'b>(&'a self) -> App<'b,'b>
	{
		SubCommand::with_name("roll")
			.about("roll for a skill")
			.arg
				( Arg::with_name("modifier")
				.short("m")
				.long("modifier")
				.alias("mod")
				.help("modification as positive (bad) or negative (good) integer")
				.allow_hyphen_values(true)
				.takes_value(true)
				.multiple(true)
				.number_of_values(1)
				)
			.arg
				( Arg::with_name("skill")
				.value_name("SKILL")
				.help("the skills to test")
				.takes_value(true)
				.multiple(true)
				.required(true)
				)
	}

	fn call(&mut self, hero: &Hero, matches: &ArgMatches) -> Result<Vec<Output>>
	{
		let d20: Uniform<_> = (1..21).into();
		let mut rng = rand::thread_rng();

		matches.values_of("skill")
			.unwrap()
			.map(|skill|
			{
				let mods = matches.values_of("modifier")
					.map(|mods| mods
						.map(|modi| Ok(modi.parse()?))
						.collect::<Result<Vec<isize>>>()
						.map(|mods| mods.into_iter().sum())
					)
					.unwrap_or(Ok(0))?;

				// TODO: use custom error
				let (base,values_enum) = hero.skills.get(&skill.to_lowercase()).ok_or_else(|| format!("unknown skill '{}'", skill))?;

				let values =
				{
					let mut iter = values_enum.iter()
						.map(|value| -> Result<isize>
						{
							Ok(*hero.qualities.get(value).ok_or("cannot roll unknown quality")?)
						});
					[
						iter.next().ok_or("quality retrieval is broken")??,
						iter.next().ok_or("quality retrieval is broken")??,
						iter.next().ok_or("quality retrieval is broken")??,
					]
				};
				let rolls =
				{
					let mut iter = d20.sample_iter(&mut rng);
					[
						iter.next().ok_or("rng sampling is broken")?,
						iter.next().ok_or("rng sampling is broken")?,
						iter.next().ok_or("rng sampling is broken")?,
					]
				};
				let num_20 = rolls.iter().filter(|i| **i == 20).count();
				let num_1 = rolls.iter().filter(|i| **i == 1).count();
				let result = 0.max(base - mods) + values.iter()
					.map(|stat| stat + 0.min(base - mods))
					.zip(&rolls)
					.map(|(stat,die)| (stat-die).min(0))
					.sum::<isize>();

				Ok(Output::Roll
				{
					success: (num_20 < 2) && (result >= 0 || num_1 > 1),
					critical: (num_20 > 1) || (num_1 > 1),
					dice: rolls,
					checks: *values_enum,
					stat: values,
					remainder: result,
					base: *base,
					mods,
				})
			})
			.collect()
	}
}