Add seed generator/populate w/tests

3 files changed, 140 insertions, 4 deletions

diff --git a/CLI/rust/Cargo.lock b/CLI/rust/Cargo.lock
index 841b96e..2ef9298 100644
--- a/CLI/rust/Cargo.lock
+++ b/CLI/rust/Cargo.lock
@@ -177,6 +177,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9385f66bf6105b241aa65a61cb923ef20efc665cb9f9bb50ac2f0c4b7f378d41"
 
 [[package]]
+name = "libm"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c7d73b3f436185384286bd8098d17ec07c9a7d2388a6599f824d8502b529702a"
+
+[[package]]
 name = "libz-sys"
 version = "1.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -227,6 +233,16 @@ dependencies = [
 ]
 
 [[package]]
+name = "num-traits"
+version = "0.2.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a64b1ec5cda2586e284722486d802acf1f7dbdc623e2bfc57e65ca1cd099290"
+dependencies = [
+ "autocfg",
+ "libm",
+]
+
+[[package]]
 name = "openssl-probe"
 version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -337,6 +353,16 @@ dependencies = [
 ]
 
 [[package]]
+name = "rand_distr"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "da9e8f32ad24fb80d07d2323a9a2ce8b30d68a62b8cb4df88119ff49a698f038"
+dependencies = [
+ "num-traits",
+ "rand",
+]
+
+[[package]]
 name = "rand_hc"
 version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -418,6 +444,7 @@ dependencies = [
  "curl",
  "mocktopus",
  "rand",
+ "rand_distr",
  "regex",
  "terminal_size",
 ]
diff --git a/CLI/rust/Cargo.toml b/CLI/rust/Cargo.toml
index 41aff9e..90153e5 100644
--- a/CLI/rust/Cargo.toml
+++ b/CLI/rust/Cargo.toml
@@ -15,10 +15,11 @@ path = "src/main.rs"
 
 [dependencies]
 clap = { version = "3.0.0-beta.2", features = ["wrap_help"] }
+ctrlc = "3.1.8"
 curl = "0.4.35"
 rand = "0.8.3"
+rand_distr = "0.4.0"
 regex = "1.4.5"
-ctrlc = "3.1.8"
 terminal_size = "0.1.16"
 
 [dev-dependencies]
diff --git a/CLI/rust/src/game_of_life/generators/seed.rs b/CLI/rust/src/game_of_life/generators/seed.rs
index 41c8f5d..e3e3f12 100644
--- a/CLI/rust/src/game_of_life/generators/seed.rs
+++ b/CLI/rust/src/game_of_life/generators/seed.rs
@@ -1,6 +1,9 @@
 use crate::game_of_life::opts::Opts;
-use crate::game_of_life::simulation::universe::Universe;
+use crate::game_of_life::simulation::{plane::Plane, universe::Universe};
 use clap::Error;
+use rand::rngs::StdRng;
+use rand::{Rng, SeedableRng};
+use rand_distr::{Distribution, Uniform};
 
 #[cfg(test)]
 use mocktopus::macros::mockable;
@@ -10,6 +13,111 @@ use mocktopus::macros::mockable;
 /// The generation of the seed should be stable across different machines
 /// using the same language package, version, width and height.
 #[cfg_attr(test, mockable)]
-pub(crate) fn new(_opts: Opts) -> Result<Universe, Error> {
-    unimplemented!()
+pub(crate) fn new(opts: Opts) -> Result<Universe, Error> {
+    let range = generator(opts.seed);
+    Ok(populate(opts, range))
+}
+
+/// Create a StdRng using Uniform distribution for generating same data from
+/// the same seed
+fn generator(seed: usize) -> StdRng {
+    let mut range = StdRng::seed_from_u64(seed as u64);
+    Uniform::new_inclusive(0, 1).sample(&mut range);
+    range
+}
+
+#[cfg(test)]
+mod generator {
+    use super::*;
+
+    #[test]
+    fn seed_1337() {
+        let mut rng = generator(1337);
+        assert_eq!(rng.gen::<bool>(), true);
+        assert_eq!(rng.gen::<bool>(), false);
+        assert_eq!(rng.gen::<bool>(), true);
+        assert_eq!(rng.gen::<bool>(), true);
+        assert_eq!(rng.gen::<bool>(), false);
+    }
+
+    #[test]
+    fn seed_42() {
+        let mut rng = generator(42);
+        assert_eq!(rng.gen::<bool>(), true);
+        assert_eq!(rng.gen::<bool>(), false);
+        assert_eq!(rng.gen::<bool>(), true);
+        assert_eq!(rng.gen::<bool>(), true);
+        assert_eq!(rng.gen::<bool>(), true);
+    }
+}
+
+/// Return a universe struct with populated data from the seedable range
+fn populate(opts: Opts, mut range: StdRng) -> Universe {
+    let (width, height) = (opts.width as usize, opts.height as usize);
+    let mut current = Plane(vec![Plane(vec![false; width]); height]);
+    for i in 0..height {
+        for j in 0..width {
+            current[i as isize][j as isize] = range.gen()
+        }
+    }
+    Universe {
+        opts,
+        current,
+        future: Plane(vec![Plane(vec![false; width]); height]),
+    }
+}
+
+#[cfg(test)]
+mod populate {
+    use super::*;
+
+    fn opts(seed: usize) -> Opts {
+        Opts {
+            seed,
+            input: None,
+            width: 5,
+            height: 3,
+            live_cell: 'L',
+            dead_cell: 'D',
+            delay: 13,
+        }
+    }
+
+    #[test]
+    fn seed_1337() {
+        let rng = generator(1337);
+        let opts = opts(1337);
+        let universe = populate(opts.clone(), rng);
+        assert_eq!(
+            universe,
+            Universe {
+                opts,
+                future: Plane(vec![Plane(vec![false; 5]); 3]),
+                current: Plane(vec![
+                    Plane(vec![true, false, true, true, false]),
+                    Plane(vec![true, false, true, false, true]),
+                    Plane(vec![false, false, true, true, true]),
+                ]),
+            }
+        )
+    }
+
+    #[test]
+    fn seed_42() {
+        let rng = generator(42);
+        let opts = opts(42);
+        let universe = populate(opts.clone(), rng);
+        assert_eq!(
+            universe,
+            Universe {
+                opts,
+                future: Plane(vec![Plane(vec![false; 5]); 3]),
+                current: Plane(vec![
+                    Plane(vec![true, false, true, true, true]),
+                    Plane(vec![true, false, true, false, true]),
+                    Plane(vec![false, false, true, false, true]),
+                ]),
+            }
+        )
+    }
 }