"""
Nacrith CPU compressor -- same interface as the GPU version.

Internally uses trigram tables + arithmetic coding instead of a neural model.
Supports two formats:
  TC01 -- lossless text compression (replaces NC01)
  NC05 -- hybrid multi-table binary compression (replaces NC02)
"""

from trigram_compressor import TrigramCompressor

# Magic bytes exported for app.py validation
MAGIC = b'TC01'       # CPU text format
MAGIC_BIN = b'NC05'   # CPU binary format
HEADER_SIZE = 12      # minimum header bytes (magic + 2 x uint32)


class _ModelProxy:
    """Exposes tokenizer under comp.model.tokenizer, matching GPU interface."""

    def __init__(self, tokenizer):
        self.tokenizer = tokenizer


class NeuralCompressor:
    """CPU compressor with the same public API as the GPU NeuralCompressor.

    Replaces the SmolLM2-135M neural model with trigram tables for
    probability prediction, eliminating the GPU requirement.
    """

    def __init__(self, verbose: bool = False):
        self._trigram = TrigramCompressor(verbose=verbose)
        # Expose tokenizer at comp.model.tokenizer (same as GPU version)
        self.model = _ModelProxy(self._trigram.tokenizer)

    def compress(self, text: str) -> bytes:
        """Compress text string -> TC01 format bytes."""
        return self._trigram.compress(text)

    def compress_bytes(self, data: bytes) -> bytes:
        """Compress raw bytes -> NC05 hybrid format bytes."""
        return self._trigram.compress_bytes(data)

    def decompress(self, data: bytes):
        """Decompress TC01 / NC03 / NC05 -> original text str or raw bytes."""
        return self._trigram.decompress(data)