1 files changed, 120 insertions, 0 deletions
diff --git a/scripts/analyze_prereqs.py b/scripts/analyze_prereqs.py
new file mode 100644
index 0000000..7c580f7
--- /dev/null
+++ b/scripts/analyze_prereqs.py
@@ -0,0 +1,120 @@
+#!/usr/bin/env python3
+import argparse
+import json
+import re
+from typing import Any, Dict, Iterable, List
+
+
+COURSE_TOKEN = re.compile(r"\b([A-Z]{2,4})\s*(\d{2,3}[A-Z]?)\b")
+NONE_PATTERNS = [
+    re.compile(r"^\s*none\.?\s*$", re.IGNORECASE),
+    re.compile(r"no prerequisites", re.IGNORECASE),
+    re.compile(r"prerequisite[s]?:\s*none\b", re.IGNORECASE),
+]
+
+
+def is_none_text(text: str) -> bool:
+    t = text.strip()
+    return any(p.search(t) for p in NONE_PATTERNS)
+
+
+def extract_course_refs(text: str) -> List[str]:
+    refs = []
+    for m in COURSE_TOKEN.finditer(text):
+        subject, number = m.group(1), m.group(2)
+        refs.append(f"{subject} {number}")
+    return refs
+
+
+NON_COURSE_KEYWORDS = [
+    r"consent", r"permission", r"approval",
+    r"standing", r"senior", r"junior", r"sophomore", r"freshman",
+    r"major", r"minor", r"program", r"restricted", r"enrollment", r"enrolled",
+    r"gpa", r"grade", r"minimum", r"credit hour", r"credits?", r"hours?",
+    r"registration", r"concurrent", r"co-requisite", r"corequisite",
+    r"department", r"instructor",
+]
+
+def has_non_course_requirements(text: str) -> bool:
+    t = text.lower()
+    return any(re.search(k, t) for k in NON_COURSE_KEYWORDS)
+
+
+def is_course_only(text: str) -> bool:
+    t = text.strip()
+    if has_non_course_requirements(t):
+        return False
+    # Remove course tokens, then see if any nontrivial tokens remain besides basic connectors
+    placeholder = COURSE_TOKEN.sub("COURSE", t)
+    # Remove conjunctions and punctuation
+    simplified = re.sub(r"[(),.;]", " ", placeholder)
+    simplified = re.sub(r"\b(and|or|and/or|either|both|one of|two of|with|credit in)\b", " ", simplified, flags=re.IGNORECASE)
+    # Remove common quantifiers
+    simplified = re.sub(r"\b(at\s+least)\b", " ", simplified, flags=re.IGNORECASE)
+    # Collapse whitespace
+    simplified = re.sub(r"\s+", " ", simplified).strip()
+    # If empty or only words like COURSE left, treat as course-only
+    return simplified == "" or re.fullmatch(r"(COURSE\s*)+", simplified) is not None
+
+
+def analyze(courses: Iterable[Dict[str, Any]]) -> Dict[str, List[Dict[str, Any]]]:
+    results = {
+        "none": [],
+        "course_only": [],
+        "remaining": [],
+    }
+
+    for c in courses:
+        prereq = c.get("prerequisites") or ""
+        if not prereq.strip():
+            results["none"].append(c)
+            continue
+        if is_none_text(prereq):
+            results["none"].append(c)
+            continue
+        if is_course_only(prereq):
+            results["course_only"].append({
+                "index": c.get("index"),
+                "name": c.get("name"),
+                "prerequisites": prereq,
+                "courses": extract_course_refs(prereq),
+            })
+        else:
+            results["remaining"].append({
+                "index": c.get("index"),
+                "name": c.get("name"),
+                "prerequisites": prereq,
+            })
+    return results
+
+
+def main() -> int:
+    ap = argparse.ArgumentParser(description="Analyze UIUC course prerequisite text")
+    ap.add_argument("input", default="data/courses.json", nargs="?", help="Input courses JSON array")
+    ap.add_argument("--outdir", default="data/analysis", help="Output directory")
+    args = ap.parse_args()
+
+    with open(args.input, "r", encoding="utf-8") as f:
+        data = json.load(f)
+
+    res = analyze(data)
+
+    import os
+    os.makedirs(args.outdir, exist_ok=True)
+    with open(os.path.join(args.outdir, "none.json"), "w", encoding="utf-8") as f:
+        json.dump(res["none"], f, ensure_ascii=False, indent=2)
+    with open(os.path.join(args.outdir, "course_only.json"), "w", encoding="utf-8") as f:
+        json.dump(res["course_only"], f, ensure_ascii=False, indent=2)
+    with open(os.path.join(args.outdir, "remaining.json"), "w", encoding="utf-8") as f:
+        json.dump(res["remaining"], f, ensure_ascii=False, indent=2)
+
+    print(f"none: {len(res['none'])}")
+    print(f"course_only: {len(res['course_only'])}")
+    print(f"remaining: {len(res['remaining'])}")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
+
+