#!/usr/bin/env python3
"""Parser parity: tai.py build_parser() (in process) versus build/cli/cli_driver.

Compares stdout, stderr and exit code for every argv in tests/cli_cases.txt (one shlex line
each) at COLUMNS=80 and 40, and --help plus the usage printed by an error for every terminal
width from 12 to 200. The Python side is the real argparse of the installed interpreter.
Usage: tests/cli_parity.py --driver build/cli/cli_driver [--verbose]
"""
import argparse
import contextlib
import io
import json
import os
import random
import shlex
import subprocess
import sys

HERE = os.path.dirname(os.path.abspath(__file__))
ROOT = os.path.dirname(HERE)
sys.path.insert(0, os.path.dirname(ROOT))
import tai  # noqa: E402  (the tai.py next to taicpp/)


def reference(argv, columns):
    os.environ["COLUMNS"] = str(columns)
    out, err = io.StringIO(), io.StringIO()
    code, text = 0, ""
    try:
        with contextlib.redirect_stdout(out), contextlib.redirect_stderr(err):
            ns = tai.build_parser().parse_args(argv)
        keep = {}
        for key, value in vars(ns).items():
            if value is None or value is False or (key == "prompt" and value == []):
                continue
            keep[key] = value
        text = json.dumps(keep, sort_keys=True) + "\n"
    except SystemExit as exc:
        code = exc.code or 0
    return out.getvalue() + text, err.getvalue(), code


def candidate(driver, argv, columns):
    env = dict(os.environ, COLUMNS=str(columns))
    p = subprocess.run([driver] + argv, capture_output=True, text=True, env=env, timeout=30)
    return p.stdout, p.stderr, p.returncode


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--driver", default=os.path.join(ROOT, "build", "cli", "cli_driver"))
    ap.add_argument("--verbose", action="store_true")
    ap.add_argument("--fuzz", type=int, default=1500, help="random argv count (seeded, deterministic)")
    args = ap.parse_args()
    cases = []
    with open(os.path.join(HERE, "cli_cases.txt"), encoding="utf-8") as fh:
        for line in fh.read().split("\n"):
            if line.strip():
                cases.append(shlex.split(line))
    jobs = [(a, c) for a in cases for c in (80, 40)]
    for c in range(12, 201):
        jobs.append((["--help"], c))
        jobs.append((["--bogus"], c))
    rng = random.Random(20260101)
    vocab = ["--profile", "--yes", "--debug", "--debug-format", "--cap", "--cap-m", "--cap-max-turns", "--cap-permission-mode",
             "--mcp-port", "--mplex", "--ins", "--tui", "--tui-", "--vers", "--version", "-h", "-hx", "-z", "--", "-", "-3",
             "-3x", "--x=1", "--yes=1", "--debug=stdout", "--profile=p", "a", "b c", "file", "stdout", "json", "none", "7",
             "abc", "", "--theme", "--env", "-1.5", "--y", "--u"]
    for _ in range(max(args.fuzz, 0)):
        jobs.append(([rng.choice(vocab) for _ in range(rng.randint(1, 5))], rng.choice((80, 50, 100))))
    bad = 0
    for argv, columns in jobs:
        want, got = reference(argv, columns), candidate(args.driver, argv, columns)
        if want != got:
            bad += 1
            print("FAIL argv=%r COLUMNS=%d" % (argv, columns))
            if args.verbose or bad <= 3:
                for name, w, g in zip(("stdout", "stderr", "exit"), want, got):
                    if w != g:
                        print("  %s\n  --- python\n%s\n  --- detz\n%s" % (name, w, g))
    print("cli parity: %d jobs, %d failed" % (len(jobs), bad))
    return 1 if bad else 0


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