from __future__ import annotations

import json
import os
import tempfile
from concurrent.futures import ProcessPoolExecutor
from pathlib import Path

from navsea_tile_reencode_guard import decode_tile_with_extents, encode_layers_preserving_extents


DELIVERY_ROOT = Path("/home/wwwroot/pbf-delivery-full-semantic-unified-20260808")
NAVMARK_ROOT = Path("/home/wwwroot/pbf-navmarks-semantic-unified-20260808")


def merge_one(nav_path_str: str) -> int:
    nav_path = Path(nav_path_str)
    rel = nav_path.relative_to(NAVMARK_ROOT)
    target = DELIVERY_ROOT / rel
    if not target.exists():
        return 0
    base, extents = decode_tile_with_extents(target.read_bytes())
    nav, nav_extents = decode_tile_with_extents(nav_path.read_bytes())
    nav_layer = nav.get("navigation_marks")
    if nav_layer is None:
        return 0
    nav_layer = {"name": "navigation_marks", "features": nav_layer.get("features", [])}
    merged = []
    replaced = False
    for layer_name, layer in base.items():
        if layer_name == "navigation_marks":
            merged.append(nav_layer)
            replaced = True
        else:
            merged.append({"name": layer_name, "features": layer.get("features", [])})
    if not replaced:
        merged.append(nav_layer)
        extents["navigation_marks"] = nav_extents.get("navigation_marks", 4096)
    encoded = encode_layers_preserving_extents(merged, extents)
    target.parent.mkdir(parents=True, exist_ok=True)
    with tempfile.NamedTemporaryFile(dir=target.parent, prefix=target.name + ".", delete=False) as handle:
        temp_path = Path(handle.name)
        handle.write(encoded)
    os.replace(temp_path, target)
    return 1


def main() -> None:
    paths = [str(path) for path in NAVMARK_ROOT.rglob("*.pbf")]
    with ProcessPoolExecutor(max_workers=8) as executor:
        merged = sum(executor.map(merge_one, paths, chunksize=64))
    print(json.dumps({"navmark_tiles": len(paths), "merged_tiles": merged, "delivery_root": str(DELIVERY_ROOT)}, ensure_ascii=False, indent=2))


if __name__ == "__main__":
    main()