#!/usr/bin/env python3
"""gofmt_gate.py — every Go file in this module is gofmt-clean (R-454).

MEASURED 2026-09-02: five internal/web test files had been gofmt-unclean for an unknown length of
time and nothing noticed — `go vet` does not check formatting and no gate did. By 2026-10-05 the five
were clean and TWELVE others were not: the count only grows while nothing looks, and every `gofmt -l`
someone runs by hand is then noise that hides a real one.

Run from controller/:  python3 scripts/gofmt_gate.py
Exit 0 clean · 1 convicted (lists the files) · 2 inconclusive (gofmt not found — never a pass).

gofmt is the Go toolchain's own formatter (not a shell utility), found on PATH or under
`go env GOROOT`/bin. Decoy: scripts/test_gate_decoys.py ("gofmt").
"""
import os
import shutil
import subprocess
import sys

CTRL = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
ROOTS = ["cmd", "internal"]


def find_gofmt():
    p = shutil.which("gofmt")
    if p:
        return p
    go = shutil.which("go")
    if go:
        try:
            root = subprocess.check_output([go, "env", "GOROOT"], text=True).strip()
            cand = os.path.join(root, "bin", "gofmt")
            if os.path.isfile(cand):
                return cand
        except Exception:
            pass
    return None


def main():
    gofmt = find_gofmt()
    if not gofmt:
        print("gofmt gate INCONCLUSIVE: gofmt not found on PATH or under `go env GOROOT`/bin")
        return 2
    roots = [r for r in ROOTS if os.path.isdir(os.path.join(CTRL, r))]
    if not roots:
        print("gofmt gate INCONCLUSIVE: none of %s exists under %s" % (ROOTS, CTRL))
        return 2
    p = subprocess.run([gofmt, "-l"] + roots, cwd=CTRL, capture_output=True, text=True)
    if p.returncode != 0:
        print("gofmt gate INCONCLUSIVE: gofmt exited %d: %s" % (p.returncode, p.stderr.strip()[:400]))
        return 2
    bad = [l for l in p.stdout.splitlines() if l.strip()]
    if bad:
        for f in bad:
            print("  not gofmt-clean: %s" % f)
        print("GOFMT GATE FAILED: %d file(s) — run `gofmt -w <file>` (formatting only, no behaviour change)" % len(bad))
        return 1
    print("gofmt gate OK — every Go file under %s is gofmt-clean" % ", ".join(roots))
    return 0


if __name__ == "__main__":
    sys.exit(main())