"""Exterior/interior part classification for assembly review.

Classifies parts based on name-pattern matching against configurable
exterior patterns. Everything that does not match is classified as interior.
"""
from __future__ import annotations

import logging
from dataclasses import dataclass

from config.settings import SplitterSettings
from src.loader.assembly_tree import AssemblyNode

logger = logging.getLogger(__name__)


@dataclass
class ClassificationResult:
    """Result of exterior/interior classification for a part."""
    node_id: str
    name: str
    classification: str  # "exterior" or "interior"
    score: int  # 1 = matched exterior pattern, 0 = no match
    reasons: list[str]


def classify_parts(
    root: AssemblyNode,
    settings: SplitterSettings | None = None,
) -> list[ClassificationResult]:
    """Classify all leaf parts as exterior or interior.

    Uses simple case-insensitive substring matching against the configured
    exterior_patterns. Any part whose name matches at least one pattern
    is classified as "exterior"; everything else is "interior".

    Args:
        root: Assembly tree root node.
        settings: Splitter settings with exterior_patterns.

    Returns:
        List of ClassificationResult for each leaf part.
    """
    if settings is None:
        settings = SplitterSettings()

    patterns = [p.lower() for p in settings.exterior_patterns]

    results: list[ClassificationResult] = []

    for leaf in root.iter_leaves():
        if leaf.shape is None or leaf.shape.IsNull():
            continue

        name_lower = leaf.name.lower()
        matched = [p for p in patterns if p in name_lower]

        if matched:
            classification = "exterior"
            score = 1
            reasons = [f"name matches exterior pattern(s): {', '.join(matched)}"]
        else:
            classification = "interior"
            score = 0
            reasons = ["no exterior pattern matched"]

        leaf.classification = classification

        result = ClassificationResult(
            node_id=leaf.id,
            name=leaf.name,
            classification=classification,
            score=score,
            reasons=reasons,
        )
        results.append(result)

        logger.debug("Part '%s': -> %s (%s)", leaf.name, classification, "; ".join(reasons))

    ext_count = sum(1 for r in results if r.classification == "exterior")
    int_count = sum(1 for r in results if r.classification == "interior")
    logger.info("Classification: %d exterior, %d interior", ext_count, int_count)

    return results