#!/usr/bin/env python3
from __future__ import annotations

import argparse
import csv
import json
import sys
from pathlib import Path
from time import perf_counter
from typing import Any

sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "src"))

from romani_asr.env import configure_certifi  # noqa: E402
from romani_asr.manifest import read_manifest_csv  # noqa: E402
from romani_asr.metrics import compute_asr_metrics  # noqa: E402
from romani_asr.mms import normalize_for_mms_ctc, resolve_audio_path  # noqa: E402
from romani_asr.text import has_non_latin_script, normalize_for_metric  # noqa: E402


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="Evaluate MMS/Wav2Vec2 CTC ASR.")
    parser.add_argument("--manifest", type=Path, default=Path("artifacts/manifests/test.csv"))
    parser.add_argument("--model-id", default="facebook/mms-1b-all")
    parser.add_argument("--processor-dir", type=Path, default=None)
    parser.add_argument(
        "--adapter-dir",
        type=Path,
        default=None,
        help="Directory containing adapter.<target_lang>.safetensors.",
    )
    parser.add_argument("--target-lang", default="rmc-script_latin")
    parser.add_argument("--output-dir", type=Path, required=True)
    parser.add_argument("--limit", type=int, default=0)
    parser.add_argument("--sampling-rate", type=int, default=16000)
    parser.add_argument("--device", default="auto")
    return parser.parse_args()


def default_device() -> str:
    import torch

    if torch.cuda.is_available():
        return "cuda"
    if hasattr(torch.backends, "mps") and torch.backends.mps.is_available():
        return "mps"
    return "cpu"


def load_audio(path: str, sampling_rate: int) -> Any:
    import librosa

    audio, _ = librosa.load(path, sr=sampling_rate, mono=True)
    return audio


def load_local_adapter(model: Any, adapter_dir: Path, target_lang: str) -> None:
    from safetensors.torch import load_file
    from transformers.models.wav2vec2.modeling_wav2vec2 import (
        WAV2VEC2_ADAPTER_SAFE_FILE,
    )

    adapter_path = adapter_dir / WAV2VEC2_ADAPTER_SAFE_FILE.format(target_lang)
    adapter_state = load_file(str(adapter_path))
    adapter_weights = model._get_adapters()
    missing = sorted(set(adapter_weights) - set(adapter_state))
    unexpected = sorted(set(adapter_state) - set(adapter_weights))
    if missing or unexpected:
        raise ValueError(
            "Adapter state does not match model adapter keys: "
            f"missing={missing[:5]}, unexpected={unexpected[:5]}"
        )
    for name, parameter in adapter_weights.items():
        parameter.data.copy_(adapter_state[name].to(parameter.device))


def write_predictions(path: Path, rows: list[dict[str, Any]]) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    fieldnames = [
        "id",
        "file_name",
        "audio_path",
        "reference",
        "prediction",
        "reference_metric",
        "prediction_metric",
        "reference_ctc",
        "prediction_ctc",
        "has_non_latin_script",
        "duration_sec",
        "latency_sec",
    ]
    with path.open("w", newline="", encoding="utf-8") as handle:
        writer = csv.DictWriter(handle, fieldnames=fieldnames)
        writer.writeheader()
        writer.writerows(rows)


def main() -> None:
    args = parse_args()
    configure_certifi()

    import torch
    from transformers import Wav2Vec2ForCTC, Wav2Vec2Processor

    records = read_manifest_csv(args.manifest)
    if args.limit:
        records = records[: args.limit]

    processor_source = str(args.processor_dir or args.model_id)
    processor = Wav2Vec2Processor.from_pretrained(
        processor_source,
        target_lang=args.target_lang,
    )
    processor.tokenizer.set_target_lang(args.target_lang)

    model = Wav2Vec2ForCTC.from_pretrained(
        args.model_id,
        target_lang=args.target_lang,
        vocab_size=len(processor.tokenizer),
        pad_token_id=processor.tokenizer.pad_token_id,
        ignore_mismatched_sizes=True,
    )
    if args.adapter_dir:
        load_local_adapter(model, args.adapter_dir, args.target_lang)

    device = default_device() if args.device == "auto" else args.device
    model.to(device)
    model.eval()

    predictions: list[dict[str, Any]] = []
    for index, record in enumerate(records, start=1):
        audio_path = resolve_audio_path(record["audio_path"])
        audio = load_audio(audio_path, args.sampling_rate)
        started = perf_counter()
        inputs = processor(
            audio,
            sampling_rate=args.sampling_rate,
            return_tensors="pt",
            padding=True,
        )
        inputs = {key: value.to(device) for key, value in inputs.items()}
        with torch.no_grad():
            logits = model(**inputs).logits
        pred_ids = torch.argmax(logits, dim=-1)[0]
        prediction = processor.decode(pred_ids)
        latency_sec = perf_counter() - started

        reference = record["transcript"]
        predictions.append(
            {
                "id": record["id"],
                "file_name": record["file_name"],
                "audio_path": record["audio_path"],
                "reference": reference,
                "prediction": prediction,
                "reference_metric": normalize_for_metric(reference),
                "prediction_metric": normalize_for_metric(prediction),
                "reference_ctc": normalize_for_mms_ctc(reference),
                "prediction_ctc": normalize_for_mms_ctc(prediction),
                "has_non_latin_script": has_non_latin_script(prediction),
                "duration_sec": record["duration_sec"],
                "latency_sec": f"{latency_sec:.4f}",
            }
        )
        print(
            f"[{index}/{len(records)}] {record['file_name']} {latency_sec:.2f}s",
            flush=True,
        )

    references = [row["reference"] for row in predictions]
    hypotheses = [row["prediction"] for row in predictions]
    ctc_references = [row["reference_ctc"] for row in predictions]
    ctc_hypotheses = [row["prediction_ctc"] for row in predictions]
    metrics = {
        "model_id": args.model_id,
        "target_lang": args.target_lang,
        "adapter_dir": str(args.adapter_dir) if args.adapter_dir else None,
        "processor_dir": str(args.processor_dir) if args.processor_dir else None,
        "manifest": str(args.manifest),
        "count": len(predictions),
        "diacritic_sensitive": compute_asr_metrics(
            references, hypotheses, keep_diacritics=True
        ),
        "ascii_folded": compute_asr_metrics(
            references, hypotheses, keep_diacritics=False
        ),
        "ctc_normalized": compute_asr_metrics(
            ctc_references, ctc_hypotheses, keep_diacritics=True
        ),
        "non_latin_prediction_count": sum(
            has_non_latin_script(row["prediction"]) for row in predictions
        ),
        "total_audio_hours": sum(float(row["duration_sec"]) for row in predictions)
        / 3600,
        "total_latency_sec": sum(float(row["latency_sec"]) for row in predictions),
    }

    args.output_dir.mkdir(parents=True, exist_ok=True)
    write_predictions(args.output_dir / "predictions.csv", predictions)
    (args.output_dir / "metrics.json").write_text(
        json.dumps(metrics, indent=2, ensure_ascii=False),
        encoding="utf-8",
    )
    print(json.dumps(metrics, indent=2, ensure_ascii=False), flush=True)


if __name__ == "__main__":
    main()