# -----------------------------------------------------------------------------
# Description: Backend integration wrapper for required mxpic_router project GDS generation.
# Inside functions: build_project_gds, _build_with_mxpic_router, _load_project_cells
# Developer : Qin Yue @ 2026
# Organization : OptiHK Limited
# -----------------------------------------------------------------------------
import os
from dataclasses import dataclass, field
from typing import Dict, List

import yaml

from router_dependency import require_router_stack


@dataclass
class BuildResult:
    """Container for GDS build output paths, status details, and engine metadata."""

    output_path: str
    engine: str
    cells_built: List[str] = field(default_factory=list)
    warnings: List[str] = field(default_factory=list)


def build_project_gds(
    project_dir: str,
    output_path: str,
    pdk_public_root: str,
    technology_manifest_path: str = None,
    prefer_full_gds: bool = False,
) -> BuildResult:
    """Build a hierarchical project GDS from saved cell YAML files with mxpic_router."""
    cells = _load_project_cells(project_dir)
    if not cells:
        raise ValueError("No saved cell YAML files found for this project")

    return _build_with_mxpic_router(
        project_dir,
        output_path,
        pdk_public_root,
        technology_manifest_path,
        prefer_full_gds,
    )


def _build_with_mxpic_router(
    project_dir: str,
    output_path: str,
    pdk_root: str,
    technology_manifest_path: str,
    prefer_full_gds: bool,
) -> BuildResult:
    """Delegate project GDS generation to the required external mxpic_router package."""
    require_router_stack()
    from mxpic_router import build_project_gds as build_routed_project_gds

    result = build_routed_project_gds(
        project_dir=project_dir,
        output_path=output_path,
        pdk_root=pdk_root,
        technology_manifest_path=technology_manifest_path,
        prefer_full_gds=prefer_full_gds,
    )
    return BuildResult(
        output_path=result.get("output_path", output_path),
        engine=result.get("engine", "mxpic_router"),
        cells_built=result.get("cells_built", []),
        warnings=result.get("warnings", []),
    )


def _load_project_cells(project_dir: str) -> Dict[str, dict]:
    """Load saved cell YAML documents from a project directory."""
    cells = {}
    for filename in sorted(os.listdir(project_dir)):
        if not filename.lower().endswith((".yml", ".yaml")):
            continue
        path = os.path.join(project_dir, filename)
        with open(path, "r", encoding="utf-8") as file:
            data = yaml.safe_load(file) or {}
        cell_name = str(data.get("name") or os.path.splitext(filename)[0])
        cells[cell_name] = data
    return cells