import struct
import logging
from typing import Any

from app.services.asr_providers import create_asr_provider, ASRError, _to_traditional  # noqa: F401

logger = logging.getLogger(__name__)


def float32_to_s16le(float32_bytes: bytes) -> bytes:
    num_samples = len(float32_bytes) // 4
    floats = struct.unpack(f"<{num_samples}f", float32_bytes)
    int16_samples = [max(-32768, min(32767, int(f * 32767.0))) for f in floats]
    return struct.pack(f"<{num_samples}h", *int16_samples)


def build_display_text(accumulated: str, current: str) -> str:
    parts = [p for p in (accumulated, current) if p and p.strip()]
    return " ".join(parts)


class ASRClient:
    def __init__(self, settings: Any):
        self._settings = settings
        self._provider = create_asr_provider(settings)

    async def transcribe_full(self, audio_bytes: bytes, language: str = "yue") -> str:
        try:
            return await self._provider.transcribe(audio_bytes, language)
        except ASRError:
            raise
        except Exception as e:
            logger.error("transcribe_full failed: %s", e)
            raise ASRError(f"Transcription failed: {e}") from e