From a9e1ccbf2e8f22b8588bdde73a7f24927084dc22 Mon Sep 17 00:00:00 2001
From: "Taylor C. Richberger" <taywee@gmx.com>
Date: Mon, 20 Apr 2020 11:19:50 -0600
Subject: [PATCH] restructure into dice module

---
 Cargo.lock               |  1 +
 src/dice.rs              | 44 ++++++++++++++++++++++++++++++++++++++++
 src/{ => dice}/parser.rs | 30 +++------------------------
 src/lib.rs               |  3 ++-
 src/roll.rs              | 39 +++++++++++++++++++++++++++++++++++
 5 files changed, 89 insertions(+), 28 deletions(-)
 create mode 100644 src/dice.rs
 rename src/{ => dice}/parser.rs (92%)
 create mode 100644 src/roll.rs

diff --git a/Cargo.lock b/Cargo.lock
index 00bfec5..4366697 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -26,6 +26,7 @@ name = "axfive-matrix-dicebot"
 version = "0.1.0"
 dependencies = [
  "nom",
+ "rand",
  "reqwest",
  "serde",
  "serde_json",
diff --git a/src/dice.rs b/src/dice.rs
new file mode 100644
index 0000000..7fd0254
--- /dev/null
+++ b/src/dice.rs
@@ -0,0 +1,44 @@
+pub mod parser;
+
+use std::ops::{Deref, DerefMut};
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub struct Dice {
+    pub(crate) count: u32,
+    pub(crate) sides: u32,
+}
+
+impl Dice {
+    fn new(count: u32, sides: u32) -> Dice {
+        Dice { count, sides }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum Element {
+    Dice(Dice),
+    Bonus(u32),
+}
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum SignedElement {
+    Positive(Element),
+    Negative(Element),
+}
+
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub struct ElementExpression(Vec<SignedElement>);
+
+impl Deref for ElementExpression {
+    type Target = Vec<SignedElement>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for ElementExpression {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
diff --git a/src/parser.rs b/src/dice/parser.rs
similarity index 92%
rename from src/parser.rs
rename to src/dice/parser.rs
index a31d1c3..7a1a672 100644
--- a/src/parser.rs
+++ b/src/dice/parser.rs
@@ -7,39 +7,14 @@ use nom::{
     tag, IResult,
 };
 
-#[derive(Debug, PartialEq, Eq)]
-struct Dice {
-    count: u32,
-    sides: u32,
-}
+use crate::dice::{Dice, Element, SignedElement, ElementExpression};
 
-impl Dice {
-    fn new(count: u32, sides: u32) -> Dice {
-        Dice { count, sides }
-    }
-}
-
-#[derive(Debug, PartialEq, Eq)]
-enum Element {
-    Dice(Dice),
-    Bonus(u32),
-}
-
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
 enum Sign {
     Plus,
     Minus,
 }
 
-#[derive(Debug, PartialEq, Eq)]
-enum SignedElement {
-    Positive(Element),
-    Negative(Element),
-}
-
-#[derive(Debug, PartialEq, Eq)]
-struct ElementExpression(Vec<SignedElement>);
-
 fn is_whitespace(input: char) -> bool {
     input == ' ' || input == '\n' || input == '\t' || input == '\r'
 }
@@ -205,3 +180,4 @@ mod tests {
         );
     }
 }
+
diff --git a/src/lib.rs b/src/lib.rs
index bc0754b..8f10660 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,4 @@
 pub mod bot;
+pub mod dice;
 pub mod matrix;
-pub mod parser;
+pub mod roll;
diff --git a/src/roll.rs b/src/roll.rs
new file mode 100644
index 0000000..3738bd8
--- /dev/null
+++ b/src/roll.rs
@@ -0,0 +1,39 @@
+use rand::prelude::*;
+use crate::dice;
+
+pub trait Roll {
+    type Output;
+
+    fn roll(&self) -> Self::Output;
+}
+
+impl Roll for dice::Dice {
+    type Output = u32; 
+
+    fn roll(&self) -> u32 {
+        let mut rng = rand::thread_rng();
+        (0..self.count).map(|_| rng.gen_range(1, self.sides + 1)).sum()
+    }
+}
+
+impl Roll for dice::Element {
+    type Output = u32; 
+
+    fn roll(&self) -> u32 {
+        match self {
+            dice::Element::Dice(d) => d.roll(),
+            dice::Element::Bonus(b) => *b,
+        }
+    }
+}
+
+impl Roll for dice::SignedElement {
+    type Output = i32; 
+
+    fn roll(&self) -> i32 {
+        match self {
+            dice::SignedElement::Positive(e) => e.roll() as i32,
+            dice::SignedElement::Negative(e) => -(e.roll() as i32),
+        }
+    }
+}