From cb0998fe8302b4e2fe63b415fa27009883536d4c Mon Sep 17 00:00:00 2001
From: Nick Ferguson <98440329+itprodirect@users.noreply.github.com>
Date: Thu, 5 Jun 2025 20:31:32 -0400
Subject: [PATCH] feat: add CLI and document workflow

---
 README.md         | 13 +++++++++-
 src/cli.py        | 64 +++++++++++++++++++++++++++++++++++++++++++++++
 tests/test_cli.py | 33 ++++++++++++++++++++++++
 3 files changed, 109 insertions(+), 1 deletion(-)
 create mode 100644 src/cli.py
 create mode 100644 tests/test_cli.py

diff --git a/README.md b/README.md
index 83226c7e..ae7c3f80 100644
--- a/README.md
+++ b/README.md
@@ -89,7 +89,18 @@ This tutorial walks through how to:
 ✅ **Test MCP tools locally**  
 ✅ **Expand MCP with custom functions**  
 ✅ **Read and process CSV files**  
-✅ **Deploy and use MCP tools efficiently**  
+✅ **Deploy and use MCP tools efficiently**
+
+## 🔄 Workflow
+Use the command-line interface to run common tasks directly from the terminal.
+
+```bash
+# Calculate profit from revenue and cost
+python src/cli.py profit 1000 600
+
+# Total commission from the sample dataset
+python src/cli.py commission data/insurance_sales.csv
+```
 
 ---
 ## 📂 Project Structure
diff --git a/src/cli.py b/src/cli.py
new file mode 100644
index 00000000..642c6b59
--- /dev/null
+++ b/src/cli.py
@@ -0,0 +1,64 @@
+"""Command line interface for business tools.
+
+Provides a small set of utilities to perform
+common calculations from the terminal.
+"""
+
+from __future__ import annotations
+
+import argparse
+from pathlib import Path
+
+from business_tools import (
+    calculate_profit,
+    calculate_total_premium,
+    load_insurance_sales,
+    total_commission,
+)
+
+
+def main(argv: list[str] | None = None) -> None:
+    """Run the command line interface.
+
+    Args:
+        argv: Optional list of arguments for easier testing.
+    """
+    parser = argparse.ArgumentParser(
+        description="Business tools command line interface",
+    )
+    subparsers = parser.add_subparsers(dest="command", required=True)
+
+    profit_parser = subparsers.add_parser(
+        "profit", help="Calculate profit from revenue and cost"
+    )
+    profit_parser.add_argument("revenue", type=float, help="Revenue in USD")
+    profit_parser.add_argument("cost", type=float, help="Cost in USD")
+
+    commission_parser = subparsers.add_parser(
+        "commission",
+        help="Calculate total commission from an insurance sales CSV",
+    )
+    commission_parser.add_argument(
+        "file", type=Path, help="Path to insurance_sales.csv"
+    )
+
+    premium_parser = subparsers.add_parser(
+        "premium", help="Calculate total premium from an insurance sales CSV"
+    )
+    premium_parser.add_argument("file", type=Path, help="Path to insurance_sales.csv")
+
+    args = parser.parse_args(argv)
+
+    if args.command == "profit":
+        result = calculate_profit(args.revenue, args.cost)
+        print(int(result) if result.is_integer() else result)
+    elif args.command == "commission":
+        records = load_insurance_sales(str(args.file))
+        print(total_commission(records))
+    elif args.command == "premium":
+        records = load_insurance_sales(str(args.file))
+        print(calculate_total_premium(records))
+
+
+if __name__ == "__main__":
+    main()
diff --git a/tests/test_cli.py b/tests/test_cli.py
new file mode 100644
index 00000000..0b4ef07e
--- /dev/null
+++ b/tests/test_cli.py
@@ -0,0 +1,33 @@
+import subprocess
+import sys
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+CLI = REPO_ROOT / "src" / "cli.py"
+
+
+def run_cli(args: list[str]) -> str:
+    """Run the CLI with the given arguments and return stdout."""
+    cmd = [sys.executable, str(CLI), *args]
+    result = subprocess.check_output(cmd, text=True)
+    return result.strip()
+
+
+def test_profit_cli():
+    assert run_cli(["profit", "100", "40"]) == "60"
+
+
+def test_commission_cli(tmp_path: Path):
+    src = REPO_ROOT / "data" / "insurance_sales.csv"
+    dst = tmp_path / "insurance_sales.csv"
+    dst.write_text(src.read_text())
+    out = run_cli(["commission", str(dst)])
+    assert out == "2545.0"
+
+
+def test_premium_cli(tmp_path: Path):
+    src = REPO_ROOT / "data" / "insurance_sales.csv"
+    dst = tmp_path / "insurance_sales.csv"
+    dst.write_text(src.read_text())
+    out = run_cli(["premium", str(dst)])
+    assert out == "18480.0"