# -*- coding: utf-8 -*-
"""graders.tree_hash crashes if an agent leaves a file named `nul` in the build.

`nul` is a reserved DOS device name. A shell command like `... >nul 2>&1` run under
a POSIX-flavoured shell (Git Bash / MSYS, which is what `run_command` reaches on
this machine) creates a REAL FILE called nul instead of discarding output. os.walk
then hands that path to os.path.relpath, which reports it on mount \\\\.\\nul and
raises ValueError.

Effect: the whole versus run dies mid-session with an unhandled exception, after
the API spend for that turn has already happened.

No API calls. Creates the file via the \\\\?\\ prefix, which bypasses the reserved-name
check the same way MSYS does.
"""
import os
import shutil
import sys
import tempfile
import traceback

sys.path.insert(0, r'C:\xampp\htdocs\axium\python')
from versus import graders as G  # noqa: E402

build = tempfile.mkdtemp(prefix='nulprobe-')
os.makedirs(os.path.join(build, 'shop'), exist_ok=True)
with open(os.path.join(build, 'shop', 'pricing.py'), 'w') as f:
    f.write('X = 1\n')

print('build:', build)
print()
print('1. tree_hash on a clean build')
try:
    h = G.tree_hash(build)
    print('   OK  %d files: %s' % (len(h), sorted(h)))
except Exception as e:                                  # noqa: BLE001
    print('   FAILED unexpectedly: %r' % e)

# create the reserved name the way a redirect under MSYS does
nul = '\\\\?\\' + os.path.join(build, 'nul')
made = False
try:
    with open(nul, 'wb') as f:
        f.write(b'')
    made = True
    print('\n2. created a file named `nul` in the build')
except OSError as e:
    print('\n2. could not create `nul` via \\\\?\\ (%s)' % e)

if made:
    print('\n3. tree_hash on the same build, one extra file')
    try:
        h = G.tree_hash(build)
        print('   OK  %d files -> no crash: %s' % (len(h), sorted(h)))
    except Exception:                                   # noqa: BLE001
        line = traceback.format_exc().strip().splitlines()[-1]
        print('   CRASH  %s' % line)
        print('   -> versus.runner dies mid-session; the turn is paid for and lost.')

    print('\n4. the one-line fix, demonstrated')
    orig = os.path.relpath

    def safe_walk(root):
        out = {}
        for dirpath, dirs, files in os.walk(root):
            dirs[:] = [d for d in dirs if d not in G.IGNORE_DIRS]
            for fn in files:
                if fn.endswith(G.IGNORE_SUFFIX):
                    continue
                p = os.path.join(dirpath, fn)
                try:
                    rel = orig(p, root).replace('\\', '/')
                except ValueError:
                    # reserved device name (nul, con, aux, prn...) — not a project file
                    continue
                out[rel] = 'hashed'
        return out

    print('   guarded version returns %s' % sorted(safe_walk(build)))

try:
    if made:
        os.remove(nul)
    shutil.rmtree(build, ignore_errors=True)
except OSError:
    pass