1 files changed, 75 insertions, 0 deletions
diff --git a/src/cli.rs b/src/cli.rs
new file mode 100644
index 0000000..bc22a0f
--- /dev/null
+++ b/src/cli.rs
@@ -0,0 +1,75 @@
+/*
+    hitomezashi-rs  Generates classical colored Hitomezashi stitch patterns
+    Copyright (C) 2024  Nicholas Johnson
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+use clap::Parser;
+use std::ops::RangeInclusive;
+
+#[derive(Parser)]
+#[command(version, about, long_about = None)] // Read from `Cargo.toml`
+struct Cli {
+    /// Pattern width
+    #[arg(value_parser = dimension_in_range)]
+    width: usize,
+
+    /// Pattern height
+    #[arg(value_parser = dimension_in_range)]
+    height: usize,
+
+    /// Set skew
+    #[arg(short, long)]
+    #[arg(default_value_t = 0.5)]
+    #[arg(value_parser = skew_in_range)]
+    skew: f64,
+}
+
+
+const DIMENSION_RANGE: RangeInclusive<usize> = 1..=std::usize::MAX;
+
+fn dimension_in_range(s: &str) -> Result<usize, String> {
+    let dimension: usize = s
+        .parse()
+        .map_err(|_| format!("`{s}` isn't a dimension value!"))?;
+
+    if DIMENSION_RANGE.contains(&dimension) {
+        Ok(dimension)
+    } else {
+        Err(format!(
+            "Dimension not in range {}-{}",
+            DIMENSION_RANGE.start(),
+            DIMENSION_RANGE.end()
+        ))
+    }
+}
+
+const SKEW_RANGE: RangeInclusive<f64> = 0.0..=1.0;
+
+fn skew_in_range(s: &str) -> Result<f64, String> {
+    let skew: f64 = s
+        .parse()
+        .map_err(|_| format!("`{s}` isn't a skew value!"))?;
+
+    if SKEW_RANGE.contains(&skew) {
+        Ok(skew)
+    } else {
+        Err(format!(
+            "Skew not in range {}-{}",
+            SKEW_RANGE.start(),
+            SKEW_RANGE.end()
+        ))
+    }
+}