#!/usr/bin/env python3
"""Build matched standard-Q, oQ, or oQe embedding checkpoints at 4/6/8 bits."""

from __future__ import annotations

import argparse
import json
import os
import shutil
import sys
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))

from mlx_lm.convert import convert as mlx_lm_convert  # noqa: E402
from omlx.oq import quantize_oq_streaming  # noqa: E402


SENTENCE_TRANSFORMERS_FILES = (
    ".gitattributes",
    "LICENSE",
    "README.md",
    "config_sentence_transformers.json",
    "modules.json",
    "1_Pooling",
)


def progress(phase: str, pct: float, detail: str = "", meta: dict | None = None) -> None:
    suffix = f" — {detail}" if detail else ""
    print(f"[{pct:5.1f}%] {phase}{suffix}", flush=True)


def preserve_embedding_metadata(source: Path, output: Path) -> None:
    for relative_name in SENTENCE_TRANSFORMERS_FILES:
        source_item = source / relative_name
        output_item = output / relative_name
        if source_item.is_dir():
            shutil.copytree(source_item, output_item, dirs_exist_ok=True)
        elif source_item.is_file():
            output_item.parent.mkdir(parents=True, exist_ok=True)
            shutil.copy2(source_item, output_item)


def validate_output(path: Path, mode: str, bits: int, source: Path) -> dict:
    config_path = path / "config.json"
    shards = sorted(path.glob("*.safetensors"))
    if not config_path.is_file() or not shards:
        raise RuntimeError("incomplete config or weight set")
    config = json.loads(config_path.read_text())
    quantization = config.get("quantization") or config.get("quantization_config")
    if not quantization or quantization.get("bits") != bits:
        raise RuntimeError(f"output does not declare {bits}-bit quantization")
    optional_embedding_metadata = (
        "modules.json",
        "config_sentence_transformers.json",
        "1_Pooling/config.json",
    )
    for required in optional_embedding_metadata:
        if (source / required).is_file() and not (path / required).is_file():
            raise RuntimeError(f"missing embedding metadata: {required}")
    report = path / "oq_imatrix_report.json"
    if mode == "oqe" and not report.is_file():
        raise RuntimeError(f"oQ{bits}e output is missing its imatrix application report")
    return {
        "mode": mode,
        "weight_files": len(shards),
        "weight_bytes": sum(item.stat().st_size for item in shards),
        "quantization": quantization,
        "imatrix_report": report.is_file(),
    }


def main() -> None:
    parser = argparse.ArgumentParser()
    parser.add_argument("--source", type=Path, required=True)
    parser.add_argument("--output", type=Path, required=True)
    parser.add_argument("--mode", choices=("q", "oq", "oqe"), required=True)
    parser.add_argument("--bits", type=int, choices=(4, 6, 8), default=6)
    parser.add_argument("--imatrix-cache", type=Path)
    parser.add_argument("--resume-partial", action="store_true")
    args = parser.parse_args()

    source = args.source.resolve()
    output = args.output.resolve()
    partial = output.with_name(f".{output.name}.partial")
    if not (source / "config.json").is_file():
        raise FileNotFoundError(source / "config.json")
    if output.exists():
        raise FileExistsError(output)
    if partial.exists() and not args.resume_partial:
        raise FileExistsError(f"stale partial output: {partial}")

    if args.resume_partial:
        if not partial.exists():
            raise FileNotFoundError(f"partial output not found: {partial}")
        print(f"Resuming validation from {partial}", flush=True)
    elif args.mode == "q":
        mlx_lm_convert(
            hf_path=str(source),
            mlx_path=str(partial),
            quantize=True,
            q_group_size=64,
            q_bits=args.bits,
            q_mode="affine",
            dtype="bfloat16",
        )
    else:
        enhanced = args.mode == "oqe"
        cache_path = ""
        if enhanced:
            if args.imatrix_cache is None:
                raise ValueError(f"--imatrix-cache is required for oQ{args.bits}e")
            cache_path = str(args.imatrix_cache.resolve())
        quantize_oq_streaming(
            str(source),
            str(partial),
            args.bits,
            group_size=64,
            progress_callback=progress,
            dtype="bfloat16",
            enhanced=enhanced,
            imatrix_cache_path=cache_path,
            imatrix_reuse_cache=True,
            imatrix_strict=False,
            imatrix_num_samples=128,
            imatrix_seq_length=512,
        )

    preserve_embedding_metadata(source, partial)
    result = validate_output(partial, args.mode, args.bits, source)
    os.rename(partial, output)
    result["output"] = str(output)
    print("VALIDATED_OUTPUT=" + json.dumps(result, sort_keys=True), flush=True)


if __name__ == "__main__":
    main()