"""Build hypothesis spatial codes from existing native or combined geometry caches."""

from __future__ import annotations

import argparse
import gzip
import json
import os
from pathlib import Path
import pickle
import sys
import types

WORKSPACE_ROOT = Path(__file__).resolve().parent.parent
if str(WORKSPACE_ROOT) not in sys.path:
    sys.path.insert(0, str(WORKSPACE_ROOT))

from encoder import adapters  # noqa: E402
from encoder import config as encoder_config  # noqa: E402
from experiments import config, loader  # noqa: E402
from experiments import adapters as format_adapters  # noqa: E402


class CachedDA3Prediction:
    """Attribute container used only to deserialize cached DA3 Prediction objects."""


class CachedAddictDict(dict):
    """Minimal attribute-access dictionary required by cached DA3 metadata."""

    def __getattr__(self, name):
        if name.startswith("__") and name.endswith("__"):
            raise AttributeError(name)
        try:
            return self[name]
        except KeyError as exc:
            raise AttributeError(name) from exc

    def __setattr__(self, name, value):
        self[name] = value


def install_da3_pickle_compatibility() -> None:
    """Provide the exact pickle class when the original DA3 package is unavailable."""
    try:
        __import__("depth_anything_3.specs")
    except ModuleNotFoundError:
        package = types.ModuleType("depth_anything_3")
        package.__path__ = []
        specs = types.ModuleType("depth_anything_3.specs")
        CachedDA3Prediction.__module__ = "depth_anything_3.specs"
        CachedDA3Prediction.__name__ = "Prediction"
        CachedDA3Prediction.__qualname__ = "Prediction"
        specs.Prediction = CachedDA3Prediction
        package.specs = specs
        sys.modules["depth_anything_3"] = package
        sys.modules["depth_anything_3.specs"] = specs
    try:
        __import__("addict.addict")
    except ModuleNotFoundError:
        package = types.ModuleType("addict")
        package.__path__ = []
        module = types.ModuleType("addict.addict")
        CachedAddictDict.__module__ = "addict.addict"
        CachedAddictDict.__name__ = "Dict"
        CachedAddictDict.__qualname__ = "Dict"
        module.Dict = CachedAddictDict
        package.addict = module
        package.Dict = CachedAddictDict
        sys.modules["addict"] = package
        sys.modules["addict.addict"] = module


def configure_single_scene_threads() -> int:
    """Give a direct single-scene run every CPU available to the process."""
    try:
        count = max(1, len(os.sched_getaffinity(0)))
    except AttributeError:
        count = max(1, os.cpu_count() or 1)
    value = str(count)
    for variable in (
        "OMP_NUM_THREADS",
        "MKL_NUM_THREADS",
        "OPENBLAS_NUM_THREADS",
        "NUMEXPR_NUM_THREADS",
        "VSI_KD_WORKERS",
    ):
        os.environ.setdefault(variable, value)
    return count


def load_existing_geometry(scene, depth, input_selection, tracking, frame_count):
    """Read existing caches without ever creating or modifying source caches."""
    combined_path = Path(
        encoder_config.cache_file(scene, depth, input_selection, tracking, frame_count)
    )
    if combined_path.is_file():
        with gzip.open(combined_path, "rb") as stream:
            return adapters.validate(pickle.load(stream))

    da3_path = Path(
        encoder_config.da3_cache_file(scene, depth, input_selection, frame_count)
    )
    sam3_path = Path(
        encoder_config.sam3_cache_file(scene, input_selection, tracking, frame_count)
    )
    missing = [str(path) for path in (da3_path, sam3_path) if not path.is_file()]
    if missing:
        raise FileNotFoundError(
            "required native cache(s) are missing: " + ", ".join(missing)
        )
    install_da3_pickle_compatibility()
    geometry = adapters.adapt(
        encoder_config.MODEL,
        scene=scene,
        root=str(encoder_config.CACHE_ROOT),
        rebuild=False,
        da3_path=str(da3_path),
        sam3_path=str(sam3_path),
    )
    return adapters.validate(geometry)


def run_scene(
    scene,
    hypothesis,
    depth="metric",
    tracking="tracking",
    input_selection="uniform",
    frame_count=64,
    rebuild=False,
    spatial_code_format="explicit",
):
    output = config.spatial_code_path(
        scene,
        hypothesis,
        depth,
        tracking,
        input_selection,
        frame_count,
        spatial_code_format,
    )
    if output.is_file() and not rebuild:
        with output.open(encoding="utf-8") as stream:
            return json.load(stream), "loaded", output
    geometry = load_existing_geometry(
        scene, depth, input_selection, tracking, frame_count
    )
    geometry_math = loader.load_hypothesis(hypothesis)
    code, *_ = format_adapters.build(geometry_math, geometry, spatial_code_format)
    output.parent.mkdir(parents=True, exist_ok=True)
    geometry_math.dump_spatial_code(code, str(output))
    return code, "built", output


def main() -> None:
    parser = argparse.ArgumentParser()
    parser.add_argument("scene", nargs="?")
    parser.add_argument("--hypothesis")
    parser.add_argument(
        "--depth", default="metric", choices=encoder_config.DEPTH_VARIANTS
    )
    parser.add_argument(
        "--input",
        default="uniform",
        choices=encoder_config.INPUT_SELECTIONS,
        dest="input_selection",
    )
    parser.add_argument(
        "--tracking", default="tracking", choices=encoder_config.TRACKING_MODES
    )
    parser.add_argument("--frames", type=int, default=64)
    parser.add_argument(
        "--format",
        default="explicit",
        choices=config.SPATIAL_CODE_FORMATS,
        dest="spatial_code_format",
    )
    parser.add_argument("--rebuild", action="store_true")
    parser.add_argument("--list", action="store_true", dest="list_only")
    args = parser.parse_args()
    if args.list_only:
        print("\n".join(loader.list_hypotheses()))
        return
    if not args.scene:
        parser.error("scene is required unless --list is used")
    if not args.hypothesis:
        parser.error("--hypothesis is required unless --list is used")
    if args.frames < 1:
        parser.error("--frames must be positive")
    configure_single_scene_threads()
    _, status, path = run_scene(
        args.scene,
        args.hypothesis,
        args.depth,
        args.tracking,
        args.input_selection,
        args.frames,
        args.rebuild,
        args.spatial_code_format,
    )
    print(f"[{args.scene}] {status} -> {path}")


if __name__ == "__main__":
    main()