# -----------------------------------------------------------------------------
# Description: Routed layout preview helpers that invoke the routing/build flow and return preview artifacts.
# Inside functions: create_routed_layout_svg, layout_has_links
# Developer : Qin Yue @ 2026
# Organization : OptiHK Limited
# -----------------------------------------------------------------------------
import os
import sys
import tempfile

import yaml


def create_routed_layout_svg(
    yaml_content: str,
    output_path: str,
    pdk_root: str,
    project_dir: str,
    technology_manifest_path: str = None,
    prefer_full_gds: bool = False,
) -> str:
    """Create an SVG preview from routed GDS geometry generated by mxpic_router."""
    import gdstk

    layout = yaml.safe_load(yaml_content) or {}
    cell_name = str(layout.get("name") or "layout")
    # mxpic_router is kept as a sibling repository, so the backend adds it to
    # sys.path only when the local checkout is available.
    router_root = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", "..", "mxpic_router"))
    if os.path.isdir(router_root) and router_root not in sys.path:
        sys.path.insert(0, router_root)
    from mxpic_router import build_project_gds

    os.makedirs(os.path.dirname(output_path), exist_ok=True)
    # Build into a temporary GDS first, then convert the generated top cell into
    # the SVG preview consumed by the canvas.
    with tempfile.TemporaryDirectory(prefix="mxpic_routed_preview_") as temp_dir:
        temp_gds = os.path.join(temp_dir, f"{cell_name}.gds")
        build_project_gds(
            project_dir=project_dir,
            output_path=temp_gds,
            pdk_root=pdk_root,
            technology_manifest_path=technology_manifest_path,
            prefer_full_gds=prefer_full_gds,
            target_cell_name=cell_name,
        )
        library = gdstk.read_gds(temp_gds)
        top_cells = library.top_level()
        if not top_cells:
            raise RuntimeError("Routed preview GDS has no top-level cell")
        top_cells[0].write_svg(output_path)
    return output_path


def layout_has_links(yaml_content: str) -> bool:
    """Detect whether a layout YAML document contains routed bundle links."""
    layout = yaml.safe_load(yaml_content) or {}
    # Any bundle link means preview generation must use the routed builder
    # instead of simple component placement.
    for bundle in (layout.get("bundles") or {}).values():
        links = bundle.get("links") or []
        if links:
            return True
    return False