# -----------------------------------------------------------------------------
# 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 tempfile
from dataclasses import dataclass, field
from typing import List

from layout_files import load_layout_cell_files, write_layout_cells_to_directory
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, warnings = _load_project_cells(project_dir)
    if not cells:
        raise ValueError("No saved cell YAML files found for this project")

    with tempfile.TemporaryDirectory(prefix="mxpic_gds_project_") as staged_project_dir:
        write_layout_cells_to_directory(cells, staged_project_dir)
        result = _build_with_mxpic_router(
            staged_project_dir,
            output_path,
            pdk_public_root,
            technology_manifest_path,
            prefer_full_gds,
        )

    return BuildResult(
        output_path=result.output_path,
        engine=result.engine,
        cells_built=result.cells_built,
        warnings=warnings + result.warnings,
    )


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):
    """Load saved cell YAML documents from a project directory."""
    return load_layout_cell_files(project_dir)