import os
from dataclasses import dataclass
from typing import Optional

import yaml


@dataclass
class PdkAsset:
    component: str
    yaml_path: Optional[str] = None
    gds_path: Optional[str] = None
    metadata: Optional[dict] = None


class PdkRegistry:
    """Resolve public PDK component names to metadata and public GDS assets."""

    def __init__(self, public_root: str):
        self.public_root = os.path.abspath(public_root)
        self._asset_cache = {}

    def resolve(self, component: str) -> PdkAsset:
        key = (component or "").strip().replace("\\", "/").strip("/")
        if not key:
            return PdkAsset(component=component)
        if key in self._asset_cache:
            return self._asset_cache[key]

        yaml_path = self._find_yaml(key)
        gds_path = self._find_gds(key, yaml_path)
        metadata = self._load_yaml(yaml_path) if yaml_path else None
        asset = PdkAsset(component=component, yaml_path=yaml_path, gds_path=gds_path, metadata=metadata)
        self._asset_cache[key] = asset
        return asset

    def _find_yaml(self, key: str) -> Optional[str]:
        direct = os.path.join(self.public_root, *key.split("/"))
        candidates = []
        if direct.lower().endswith((".yml", ".yaml")):
            candidates.append(direct)
        else:
            name = key.split("/")[-1]
            candidates.append(os.path.join(direct, f"{name}.yml"))
            candidates.append(os.path.join(direct, f"{name}.yaml"))

        for candidate in candidates:
            if self._inside_root(candidate) and os.path.exists(candidate):
                return os.path.abspath(candidate)

        name = key.split("/")[-1]
        for root, dirs, files in os.walk(self.public_root):
            if os.path.basename(root) == name:
                for filename in files:
                    if filename.lower().endswith((".yml", ".yaml")):
                        return os.path.join(root, filename)
                dirs.clear()
        return None

    def _find_gds(self, key: str, yaml_path: Optional[str]) -> Optional[str]:
        search_dir = os.path.dirname(yaml_path) if yaml_path else os.path.join(self.public_root, *key.split("/"))
        name = key.split("/")[-1]
        candidates = [
            os.path.join(search_dir, f"{name}_BB.gds"),
            os.path.join(search_dir, f"{name}.gds"),
        ]
        for candidate in candidates:
            if self._inside_root(candidate) and os.path.exists(candidate):
                return os.path.abspath(candidate)
        if os.path.isdir(search_dir):
            for filename in sorted(os.listdir(search_dir)):
                if filename.lower().endswith("_bb.gds"):
                    return os.path.join(search_dir, filename)
            for filename in sorted(os.listdir(search_dir)):
                if filename.lower().endswith(".gds"):
                    return os.path.join(search_dir, filename)
        return None

    def _load_yaml(self, yaml_path: Optional[str]) -> Optional[dict]:
        if not yaml_path:
            return None
        with open(yaml_path, "r", encoding="utf-8") as file:
            return yaml.safe_load(file) or {}

    def _inside_root(self, path: str) -> bool:
        target = os.path.abspath(path)
        return target == self.public_root or target.startswith(self.public_root + os.sep)