"""Contract test for gitea-pr-review-filter.py.

Same discipline as gitea-pr-comment-filter-test.py: Hermes treats
"[SILENT]"/empty/nonzero-exit as ignore, a JSON object as a payload
replacement, and ANY OTHER stdout text as allow-with-script_output, so every
case asserts on the exact stdout, not just on the decision.
"""
import json, subprocess, sys, pathlib

SCRIPT = str(pathlib.Path(__file__).with_name("gitea-pr-review-filter.py"))

def payload(action="reviewed", reviewer="darman",
            review_type="pull_request_review_comment", content="please fix the typo",
            head="feature/x", state="open", number=7, repo="darman/homelab",
            with_review=True, with_pr=True):
    p = {"action": action, "number": number,
         "repository": {"full_name": repo},
         "sender": {"login": reviewer}}
    if with_pr:
        p["pull_request"] = {"title": "some PR", "state": state,
                             "html_url": "https://git.mgaction.town/darman/homelab/pulls/7",
                             "head": {"ref": head}}
    if with_review:
        p["review"] = {"type": review_type, "content": content}
    return p

def run(p):
    r = subprocess.run([sys.executable, SCRIPT], input=json.dumps(p),
                       capture_output=True, text=True)
    return r.returncode, r.stdout, r.stderr

def classify(rc, out):
    """Replicate Hermes's own interpretation of the script result."""
    if rc != 0 or out.strip() == "" or out.strip() == "[SILENT]":
        return "IGNORED"
    try:
        v = json.loads(out)
        return "ALLOWED" if isinstance(v, dict) else "ALLOWED(script_output)"
    except ValueError:
        return "ALLOWED(script_output)"

fails = []
def check(name, p, expect):
    rc, out, err = run(p)
    got = classify(rc, out)
    ok = got == expect
    print(f"{'PASS' if ok else 'FAIL'}  {name:<54} {got}")
    if not ok:
        fails.append(name); print(f"      expected {expect}; stdout={out!r} stderr={err.strip()!r}")
    return out

# --- the loop guard ---
check("luna's own review is dropped (LOOP GUARD)",   payload(reviewer="luna"), "IGNORED")
check("luna in different case is dropped",           payload(reviewer="LUNA"), "IGNORED")

# --- review types this route subscribes to ---
check("comment review by a human is allowed",        payload(), "ALLOWED")
check("changes-requested review is allowed",
      payload(review_type="pull_request_review_rejected", content="needs work"), "ALLOWED")
check("approval is dropped (not subscribed)",
      payload(review_type="pull_request_review_approved", content="lgtm"), "IGNORED")
check("unknown review type is dropped",
      payload(review_type="pull_request_review_request"), "IGNORED")
check("missing review object is dropped",            payload(with_review=False), "IGNORED")

# --- an EMPTY review body must still pass: the substance is in the line
#     comments, which the payload does not carry at all ---
check("empty review body is ALLOWED (body is optional)", payload(content=""), "ALLOWED")
check("null review body is ALLOWED",                 payload(content=None), "ALLOWED")

# --- action handling ---
check("action=opened is dropped",                    payload(action="opened"), "IGNORED")
check("action=synchronized is dropped",              payload(action="synchronized"), "IGNORED")
check("missing action is dropped",                   payload(action=""), "IGNORED")

# --- pull request state ---
check("review on a closed/merged PR is dropped",     payload(state="closed"), "IGNORED")
check("missing pull_request is dropped",             payload(with_pr=False), "IGNORED")
check("missing head.ref is dropped",                 payload(head=""), "IGNORED")

# --- incomplete payloads ---
check("missing repository.full_name is dropped",     payload(repo=""), "IGNORED")
check("missing PR number is dropped",                payload(number=None), "IGNORED")

# --- normalisation: every path the prompt template uses must resolve ---
out = check("allowed delivery is a JSON object",     payload(content=None), "ALLOWED")
allowed = json.loads(out)
for path in [("number",), ("repository", "full_name"), ("sender", "login"),
             ("pull_request", "title"), ("pull_request", "html_url"),
             ("pull_request", "head", "ref"), ("review", "type"), ("review", "content")]:
    cur, ok = allowed, True
    for k in path:
        if isinstance(cur, dict) and k in cur: cur = cur[k]
        else: ok = False; break
    label = ".".join(path)
    print(f"{'PASS' if ok else 'FAIL'}  {'prompt path survives: {' + label + '}':<54} {cur if ok else 'MISSING'}")
    if not ok: fails.append(f"path-{label}")

# a null content must normalise to "" and never to the literal "None"
c = allowed.get("review", {}).get("content")
print(f"{'PASS' if c == '' else 'FAIL'}  {'null review.content normalises to empty string':<54} {c!r}")
if c != "": fails.append("content-normalised")

# --- drop contract: nonzero exit + empty stdout + reason on stderr ---
rc, out, err = run(payload(reviewer="luna"))
print(f"{'PASS' if rc == 3 else 'FAIL'}  {'drop exits 3 (not 0, so Hermes logs it)':<54} rc={rc}")
if rc != 3: fails.append("drop-exit-code")
print(f"{'PASS' if out == '' else 'FAIL'}  {'drop writes nothing to stdout':<54} {out!r}")
if out != "": fails.append("drop-stdout-empty")
print(f"{'PASS' if 'luna' in err else 'FAIL'}  {'drop names the rule on stderr':<54} {err.strip()[-46:]!r}")
if "luna" not in err: fails.append("stderr-reason")

# a crash must stay distinguishable from a deliberate drop
rc, out, err = run("not-a-dict")
print(f"{'PASS' if rc == 3 else 'FAIL'}  {'malformed payload is a drop (3), not a crash':<54} rc={rc}")
if rc != 3: fails.append("malformed-exit-code")

print()
print("ALL PASSED" if not fails else "FAILURES: " + ", ".join(fails))
sys.exit(1 if fails else 0)