#!/usr/bin/env python3
"""Rotated fresh-process time-to-first-embedding benchmark."""

from __future__ import annotations

import argparse
import json
import os
import resource
import statistics
import subprocess
import sys
import time
from pathlib import Path


APP_RESOURCES = Path("/Applications/oMLX.app/Contents/Resources")
APP_SITE_PACKAGES = (
    APP_RESOURCES
    / "Python/framework-mlx-base/lib/python3.11/site-packages"
)
for dependency_path in (APP_RESOURCES, APP_SITE_PACKAGES):
    sys.path.insert(0, str(dependency_path))


def worker(args: argparse.Namespace) -> int:
    import mlx.core as mx
    import numpy as np
    from mlx_lm import load

    if hasattr(mx, "reset_peak_memory"):
        mx.reset_peak_memory()
    started = time.perf_counter()
    model, tokenizer = load(args.model)
    token_ids = tokenizer.encode(
        "Instruct: Retrieve a passage for local file search\n"
        "Query:Which process owns this localhost port?"
    )
    hidden = model.model(mx.array([token_ids]))
    if isinstance(hidden, tuple):
        hidden = hidden[0]
    vector = hidden[0, -1].astype(mx.float32)
    vector /= mx.maximum(mx.sqrt(mx.sum(vector * vector)), mx.array(1e-12))
    mx.eval(vector)
    elapsed = time.perf_counter() - started
    result = {
        "label": args.label,
        "model": args.model,
        "internal_seconds": elapsed,
        "token_count": len(token_ids),
        "vector_dimension": int(vector.shape[0]),
        "vector_norm": float(np.linalg.norm(np.asarray(vector))),
        "mlx_peak_bytes": (
            int(mx.get_peak_memory()) if hasattr(mx, "get_peak_memory") else 0
        ),
        "process_peak_rss": int(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss),
    }
    print(json.dumps(result, separators=(",", ":")), flush=True)
    return 0


def percentile(values: list[float], pct: float) -> float:
    ordered = sorted(values)
    rank = (len(ordered) - 1) * pct / 100.0
    low = int(rank)
    high = min(low + 1, len(ordered) - 1)
    fraction = rank - low
    return ordered[low] * (1 - fraction) + ordered[high] * fraction


def summary(values: list[float]) -> dict:
    return {
        "n": len(values),
        "median": statistics.median(values),
        "mean": statistics.fmean(values),
        "min": min(values),
        "max": max(values),
        "p95": percentile(values, 95),
    }


def parse_worker_output(stdout: str) -> dict:
    for line in reversed(stdout.splitlines()):
        try:
            return json.loads(line)
        except json.JSONDecodeError:
            continue
    raise RuntimeError(f"worker returned no JSON record: {stdout[-1000:]}")


def run_all(args: argparse.Namespace) -> int:
    models = []
    for item in args.models:
        if "=" not in item:
            raise ValueError(f"expected label=path, got {item}")
        label, path = item.split("=", 1)
        models.append((label, path))

    records = []
    script = str(Path(__file__).resolve())
    for round_index in range(args.rounds):
        rotation = models[round_index % len(models) :] + models[: round_index % len(models)]
        for position, (label, model_path) in enumerate(rotation):
            command = [
                args.python,
                script,
                "worker",
                "--label",
                label,
                "--model",
                model_path,
            ]
            wall_started = time.perf_counter()
            completed = subprocess.run(command, text=True, capture_output=True)
            wall_seconds = time.perf_counter() - wall_started
            if completed.returncode != 0:
                raise RuntimeError(
                    f"{label} worker failed: {completed.stderr}\n{completed.stdout}"
                )
            record = parse_worker_output(completed.stdout)
            record.update(
                {
                    "round": round_index + 1,
                    "position": position + 1,
                    "wall_seconds": wall_seconds,
                }
            )
            records.append(record)
            print(
                f"round={round_index + 1} position={position + 1} "
                f"label={label} first={record['internal_seconds']:.3f}s",
                flush=True,
            )

    summaries = {}
    for label, _ in models:
        selected = [record for record in records if record["label"] == label]
        summaries[label] = {
            "internal_seconds": summary(
                [record["internal_seconds"] for record in selected]
            ),
            "wall_seconds": summary([record["wall_seconds"] for record in selected]),
            "mlx_peak_bytes": summary(
                [float(record["mlx_peak_bytes"]) for record in selected]
            ),
        }

    result = {
        "method": (
            "Fresh model process per observation; rotated format order; warm "
            "filesystem cache; time includes model load, lazy materialization, "
            "tokenization, and first embedding."
        ),
        "rounds": args.rounds,
        "records": records,
        "summaries": summaries,
    }
    Path(args.output).write_text(json.dumps(result, indent=2) + "\n")
    print(json.dumps({"output": args.output, "summaries": summaries}, indent=2))
    return 0


def parser() -> argparse.ArgumentParser:
    root = argparse.ArgumentParser()
    commands = root.add_subparsers(dest="command", required=True)
    one = commands.add_parser("worker")
    one.add_argument("--label", required=True)
    one.add_argument("--model", required=True)
    one.set_defaults(func=worker)
    all_runs = commands.add_parser("all")
    all_runs.add_argument("--output", required=True)
    all_runs.add_argument("--rounds", type=int, default=5)
    all_runs.add_argument("--python", required=True)
    all_runs.add_argument("--models", nargs="+", required=True)
    all_runs.set_defaults(func=run_all)
    return root


if __name__ == "__main__":
    parsed = parser().parse_args()
    raise SystemExit(parsed.func(parsed))