"""Shared, bounded-raw-memory DRMHB examples for vibframe-anndata 0.3.0.

Evaluation is explicitly requested, never copied into X or obs. Compressed
VibFrame inputs are not modified. No scalar ground-truth value becomes a feature.
"""

from __future__ import annotations

from pathlib import Path
from typing import Any

import h5py
import pandas as pd
from vibframe_anndata import (
    __version__,
    add_features_to_h5ad,
    add_ground_truth_to_h5ad,
    get_snapshot_ground_truth,
    get_waveform_ground_truth,
    import_raw_to_h5ad,
    list_evaluation_files,
    validate_streamed_h5ad,
)

try:
    from anndata.io import read_elem
except ImportError:
    from anndata.experimental import read_elem

EXPECTED_VERSION = "0.3.0"
SPECTRAL_FEATURES = (
    "vel_overall_rms",
    "acc_overall_rms",
    "band_subsync_rms",
    "band_1X_rms",
    "band_harmonics_low_rms",
    "amp_1X",
    "amp_2X",
    "amp_BPFO",
    "amp_BPFI",
    "family_rms_VPF",
)
WAVEFORM_FEATURES = ("rms", "crest_factor", "kurtosis")
REFERENCE_FEATURE_CONFIG = {
    "version": 1,
    "output": {"dtype": "float32"},
    "feature_policy": {"on_conflict": "error", "on_error": "nan"},
    "features": (
        [{"name": name, "source": "spectrum"} for name in SPECTRAL_FEATURES]
        + [{"name": name, "source": "waveform"} for name in WAVEFORM_FEATURES]
    ),
}


def check_version() -> None:
    """Pin semantics rather than silently using an untested API version."""
    if __version__ != EXPECTED_VERSION:
        raise RuntimeError(
            f"Install vibframe-anndata=={EXPECTED_VERSION}; found {__version__}"
        )


def positive_int(value: str) -> int:
    """Reject non-positive block sizes and metadata budgets before opening files."""
    import argparse

    try:
        number = int(value)
    except ValueError as exc:
        raise argparse.ArgumentTypeError("Expected a positive integer") from exc
    if number <= 0:
        raise argparse.ArgumentTypeError("Expected a positive integer")
    return number


def prepare_output(output: Path, *inputs: Path, overwrite: bool = False) -> Path:
    """Prevent accidental clobbering and input/output aliases."""
    result = output.expanduser().resolve()
    if result.suffix.lower() != ".h5ad":
        raise ValueError("Output must have the .h5ad extension")
    if any(result == item.expanduser().resolve() for item in inputs):
        raise ValueError("Input and output must be different files")
    if result.exists() and not overwrite:
        raise FileExistsError(
            f"{result} exists; use a new output or --overwrite explicitly"
        )
    result.parent.mkdir(parents=True, exist_ok=True)
    return result


def raw_config(
    *, scope: str = "all", dtype: str = "float32", max_sidecar_mib: int = 512
) -> dict[str, Any]:
    """The full annotation contract is opt-in at package level, explicit here."""
    if scope not in {"all", "snapshot", "none"}:
        raise ValueError("scope must be all, snapshot or none")
    if max_sidecar_mib <= 0:
        raise ValueError("max_sidecar_mib must be positive")
    return {
        "version": 1,
        "raw_import": {"waveforms": True, "spectra": True, "on_missing_signal": "nan"},
        "ground_truth": {
            "enabled": scope != "none",
            "scope": "all" if scope == "none" else scope,
            "on_missing": "error",
            "max_sidecar_mib": max_sidecar_mib,
        },
        "output": {"dtype": dtype, "raw_compression": "none"},
        "features": [],
        "obs": {
            "include": [
                "snapshot_id",
                "timestamp",
                "snap_t",
                "source",
                "machine",
                "speed_hz",
                "has_waveform",
                "has_spectrum",
            ]
        },
    }


def read_metadata(path: Path) -> dict[str, Any]:
    """Read only obs/var and package metadata; do not decode uns or raw obsm wholesale.

    AnnData backed mode is not a promise that obsm/uns stay on disk. In 0.3.0,
    uns also contains byte buffers for the complete evaluation archive.
    """
    with h5py.File(path, "r") as handle:
        return {
            "obs": read_elem(handle["obs"]),
            "var": read_elem(handle["var"]),
            "uns": {"vibframe_anndata": read_elem(handle["uns"]["vibframe_anndata"])},
            "shape": tuple(handle["X"].shape),
            "obsm_keys": list(handle["obsm"].keys()),
            "uns_keys": list(handle["uns"].keys()),
        }


def inventory_or_empty(path: Path) -> pd.DataFrame:
    """Absence is explicit; errors in an existing archive must not be swallowed."""
    with h5py.File(path, "r") as handle:
        present = "vibframe_evaluation" in handle["uns"]
    if not present:
        return pd.DataFrame(columns=["source", "path", "kind", "size_bytes", "sha256"])
    return list_evaluation_files(path)


def require_complete_drmhb(path: Path) -> dict[str, Any]:
    """Require construction snapshot/waveform truth and originals for DRMHB EDA."""
    result = validate_streamed_h5ad(path)
    if result.get("ground_truth_rows", 0) != result["n_obs"]:
        raise RuntimeError(
            "No complete snapshot truth; run example 04 or recreate with scope=all"
        )
    if result.get("waveform_ground_truth_snapshots", 0) != result["n_obs"]:
        raise RuntimeError(
            "No waveform truth; run example 04 or recreate with scope=all"
        )
    if result.get("evaluation_files", 0) == 0:
        raise RuntimeError(
            "No archived originals; run example 04 or recreate with scope=all"
        )
    return result


def preservation_signature(path: Path) -> tuple[dict[str, Any], pd.DataFrame]:
    """Small signature for numerical dimensions and original annotation identities."""
    report = validate_streamed_h5ad(path)
    keys = (
        "n_obs",
        "waveform_signals",
        "waveform_samples",
        "spectrum_signals",
        "spectrum_samples",
        "ground_truth_rows",
        "waveform_ground_truth_snapshots",
    )
    counts = {key: report.get(key, 0) for key in keys}
    files = inventory_or_empty(path)
    cols = ["source", "path", "size_bytes", "sha256"]
    return counts, files[cols].sort_values(["source", "path"]).reset_index(drop=True)


def assert_preserved(before: tuple, output: Path) -> None:
    """Check dimensions and lossless archive identity after feature engineering."""
    after = preservation_signature(output)
    if before[0] != after[0] or not before[1].equals(after[1]):
        raise RuntimeError("Signal/annotation coverage or archived originals changed")


def create_base(
    source: Path,
    output: Path,
    *,
    scope: str = "all",
    dtype: str = "float32",
    block_size_mib: int = 8,
    max_sidecar_mib: int = 512,
    overwrite: bool = False,
) -> Path:
    """Import a ZIP or extracted VibFrame with no calculated features."""
    check_version()
    if not source.exists():
        raise FileNotFoundError(source)
    if block_size_mib <= 0:
        raise ValueError("block_size_mib must be positive")
    output = prepare_output(output, source, overwrite=overwrite)
    result = import_raw_to_h5ad(
        source,
        output,
        config=raw_config(scope=scope, dtype=dtype, max_sidecar_mib=max_sidecar_mib),
        block_size_mib=block_size_mib,
    )
    report = validate_streamed_h5ad(result)
    if report["n_vars"] != 0:
        raise RuntimeError("Featureless base must have zero features")
    if scope == "all":
        require_complete_drmhb(result)
    elif scope == "snapshot" and report.get("ground_truth_rows", 0) != report["n_obs"]:
        raise RuntimeError("Incomplete snapshot annotation coverage")
    return result


def add_reference_features(
    source: Path,
    output: Path,
    *,
    block_rows: int = 256,
    config: Any = None,
    overwrite: bool = False,
) -> Path:
    """Compute unchanged reference features; keep raw signals and all annotations."""
    check_version()
    output = prepare_output(output, source, overwrite=overwrite)
    if block_rows <= 0:
        raise ValueError("block_rows must be positive")
    if validate_streamed_h5ad(source)["n_vars"] != 0:
        raise ValueError("This example expects a featureless base")
    before = preservation_signature(source)
    result = add_features_to_h5ad(
        source, config or REFERENCE_FEATURE_CONFIG, output=output, block_rows=block_rows
    )
    assert_preserved(before, result)
    if validate_streamed_h5ad(result)["n_vars"] == 0:
        raise RuntimeError("Feature calculation returned zero variables")
    return result


def enrich_existing(
    source: Path,
    vibframe: Path,
    output: Path,
    *,
    max_sidecar_mib: int = 512,
    overwrite: bool = False,
) -> Path:
    """Add original annotations to a legacy file, without numerical recomputation."""
    check_version()
    output = prepare_output(output, source, vibframe, overwrite=overwrite)
    if not vibframe.exists():
        raise FileNotFoundError(vibframe)
    before = validate_streamed_h5ad(source)
    result = add_ground_truth_to_h5ad(
        source,
        vibframe,
        config=raw_config(max_sidecar_mib=max_sidecar_mib),
        output=output,
    )
    after = require_complete_drmhb(result)
    for key in (
        "n_obs",
        "n_vars",
        "waveform_signals",
        "waveform_samples",
        "spectrum_signals",
        "spectrum_samples",
    ):
        if before.get(key) != after.get(key):
            raise RuntimeError(f"Existing numerical dimensions changed: {key}")
    return result


def read_truth(path: Path) -> tuple[pd.DataFrame, pd.DataFrame]:
    """Convenience labels are for evaluation; never place these frames in X."""
    return get_snapshot_ground_truth(path), get_waveform_ground_truth(path)