"""Schema-driven Parquet writer for compact v1 metadata tables.

Used by ``python/ingest_osz.py``. Consumes the NDJSON stream produced by
``crates/osu_indexer/`` (one row per line, tagged with ``_table``).

Key contracts:
- Compact all-revisions writes use one Parquet file per table per chunk.
- Rows are sorted within each output group by the schema's ``sort_keys``.
- Every parquet is written with
  ``compression='zstd', use_dictionary=True,
  use_content_defined_chunking=True, write_page_index=True``
  for Xet-friendly delta uploads.
"""

from __future__ import annotations

import concurrent.futures
import json
import os
import sys
from collections import defaultdict
from dataclasses import dataclass
from pathlib import Path
from typing import Any, Callable, Iterator

import pyarrow as pa
import pyarrow.parquet as pq

from tqdm.auto import tqdm

try:
    import orjson
except ImportError:  # pragma: no cover - exercised only without optional wheel
    orjson = None


# ---------------------------------------------------------------------------
# Progress logging.
# ---------------------------------------------------------------------------
#
# We use ``tqdm`` for any loop or byte-stream where the total is known up
# front, and :func:`_log` for one-off "doing X" / "done X" lines. Bars
# auto-detect TTY: in an interactive terminal they redraw in place; under
# ``tee`` they fall back to
# periodic line writes governed by ``mininterval``.

_BAR_MININTERVAL = 1.0


def _log(msg: str) -> None:
    """Print ``msg`` to stderr with ``flush=True``.

    Once stderr is no longer a TTY, Python switches it to block buffering,
    and a one-off "doing X" line for a long-running step stops appearing in
    real time. Forcing flush per-call keeps the log live without nudging the
    host terminal's buffering policy. ``tqdm`` handles its own flushing.
    """
    print(msg, file=sys.stderr, flush=True)


def _loads_ndjson_row(raw_line: bytes | str) -> dict[str, Any]:
    if orjson is not None:
        return orjson.loads(raw_line)
    if isinstance(raw_line, bytes):
        raw_line = raw_line.decode("utf-8")
    return json.loads(raw_line)


def _tqdm(iterable=None, *, total=None, desc=None, unit="it", **kwargs):
    """Project-wide tqdm wrapper with sensible defaults.

    ``mininterval=1.0`` keeps the bar feeling live in a TTY without flooding
    a tee'd log file (one redraw per second instead of ten). ``leave=True``
    preserves the final state in captured logs.
    """
    return tqdm(
        iterable,
        total=total,
        desc=desc,
        unit=unit,
        file=sys.stderr,
        mininterval=_BAR_MININTERVAL,
        dynamic_ncols=True,
        leave=True,
        **kwargs,
    )


# ---------------------------------------------------------------------------
# Schema loading: parse JSON schema files into PyArrow schemas.
# ---------------------------------------------------------------------------


@dataclass(frozen=True)
class TableSchema:
    name: str
    columns: tuple[dict[str, Any], ...]
    primary_key: tuple[str, ...]
    partition_keys: tuple[str, ...]
    sort_keys: tuple[str, ...]
    arrow_schema: pa.Schema  # full schema, including any partition columns

    def file_schema(self) -> pa.Schema:
        """Schema for the on-disk parquet.

        Partition columns stay in the file body so HF ``load_dataset`` exposes
        them even when it reads files from explicit ``data_files`` globs instead
        of reconstructing Hive path partitions.
        """
        return self.arrow_schema


def parse_arrow_type(spec: str) -> pa.DataType:
    s = spec.strip()
    if s.startswith("list<") and s.endswith(">"):
        return pa.list_(parse_arrow_type(s[len("list<") : -1]))
    primitives = {
        "string": pa.string(),
        "int8": pa.int8(),
        "int16": pa.int16(),
        "int32": pa.int32(),
        "int64": pa.int64(),
        "float32": pa.float32(),
        "float64": pa.float64(),
        "bool": pa.bool_(),
        "timestamp[ms]": pa.timestamp("ms"),
    }
    if s in primitives:
        return primitives[s]
    raise ValueError(f"unknown type spec: {spec!r}")


PARTITION_FIELD_TYPES: dict[str, pa.DataType] = {
    "ruleset": pa.string(),
    "key_count": pa.int32(),
}


def load_schemas(schemas_dir: Path) -> dict[str, TableSchema]:
    out: dict[str, TableSchema] = {}
    for path in sorted(schemas_dir.glob("*.schema.json")):
        with path.open(encoding="utf-8") as f:
            doc = json.load(f)
        for tname, tspec in doc.get("tables", {}).items():
            cols = tspec["columns"]
            column_names = {c["name"] for c in cols}
            fields = [
                pa.field(
                    c["name"],
                    parse_arrow_type(c["type"]),
                    nullable=bool(c.get("nullable", True)),
                )
                for c in cols
            ]
            for key in tspec.get("partition_keys", []):
                if key in column_names:
                    continue
                field_type = PARTITION_FIELD_TYPES.get(key)
                if field_type is None:
                    raise ValueError(
                        f"partition key {key!r} in table {tname!r} has no column "
                        "definition and no registered Arrow type"
                    )
                fields.append(pa.field(key, field_type, nullable=False))
            out[tname] = TableSchema(
                name=tname,
                columns=tuple(cols),
                primary_key=tuple(tspec.get("primary_key", [])),
                partition_keys=tuple(tspec.get("partition_keys", [])),
                sort_keys=tuple(tspec.get("sort_keys", [])),
                arrow_schema=pa.schema(fields),
            )
    return out


# ---------------------------------------------------------------------------
# NDJSON ingestion. The Rust indexer emits one row per line with a `_table`
# discriminator added by output::emit. We split by table here.
# ---------------------------------------------------------------------------


def iter_ndjson(path: Path) -> Iterator[tuple[str, dict[str, Any]]]:
    """Stream ``(table_name, row_dict)`` pairs; the ``_table`` key is removed."""
    with path.open("rb") as f:
        for line in f:
            line = line.strip()
            if not line:
                continue
            row = _loads_ndjson_row(line)
            table = row.pop("_table", None)
            if table is None:
                raise ValueError(f"row missing _table: {row!r}")
            yield table, row


def _parse_ndjson_chunk(raw_chunk: bytes) -> tuple[dict[str, list[dict[str, Any]]], int]:
    """Parse one complete-line NDJSON byte chunk.

    Kept at module top level so ``ProcessPoolExecutor`` can pickle it.
    """
    by_table: dict[str, list[dict[str, Any]]] = defaultdict(list)
    rows = 0
    for raw_line in raw_chunk.splitlines():
        line = raw_line.strip()
        if not line:
            continue
        row = _loads_ndjson_row(line)
        table = row.pop("_table", None)
        if table is None:
            raise ValueError(f"row missing _table: {row!r}")
        by_table[table].append(row)
        rows += 1
    return dict(by_table), rows


def _iter_complete_ndjson_chunks(path: Path, chunk_bytes: int) -> Iterator[bytes]:
    """Yield byte chunks that end on NDJSON line boundaries."""
    carry = b""
    with path.open("rb") as f:
        while True:
            block = f.read(chunk_bytes)
            if not block:
                break
            data = carry + block
            split_at = data.rfind(b"\n")
            if split_at < 0:
                carry = data
                continue
            yield data[: split_at + 1]
            carry = data[split_at + 1 :]
    if carry:
        yield carry


def _merge_grouped_rows(
    target: dict[str, list[dict[str, Any]]],
    grouped: dict[str, list[dict[str, Any]]],
) -> None:
    for table, rows in grouped.items():
        target[table].extend(rows)


def group_rows_by_table(ndjson_path: Path) -> dict[str, list[dict[str, Any]]]:
    """Parse the indexer's NDJSON output into ``{table_name: [row_dict, ...]}``.

    Renders a tqdm bar against the file's byte size — chunk_size=1000 NDJSON
    is typically 2-5 GB and can take tens of seconds to parse on slow disks,
    so a known-total bar gives an accurate ETA. The file is opened in binary
    mode because text-mode line iteration disables ``f.tell()`` (read-ahead
    buffer); we get byte-progress for free from ``len(raw_line)``.
    """
    try:
        total_bytes = ndjson_path.stat().st_size
    except OSError:
        total_bytes = 0

    # Process-parallel parsing looks attractive, but the parent needs the full
    # {table: [row dicts]} object graph. Pickling those rows back from workers
    # often costs more than the JSON decode it parallelizes, so keep parallel
    # parsing opt-in instead of surprising production runs.
    worker_default = 1
    workers = max(1, int(os.environ.get("OSU_NDJSON_PARSE_WORKERS", worker_default)))
    chunk_mb = max(1, int(os.environ.get("OSU_NDJSON_PARSE_CHUNK_MB", "8")))
    chunk_bytes = chunk_mb << 20
    min_parallel_bytes = int(os.environ.get("OSU_NDJSON_PARSE_MIN_MB", "64")) << 20
    backend = os.environ.get("OSU_NDJSON_PARSE_BACKEND", "process").strip().lower()
    use_parallel = workers > 1 and total_bytes >= min_parallel_bytes
    desc = f"parsing {ndjson_path.name}"
    if use_parallel:
        desc += f" ({workers} {backend} workers)"

    bar = _tqdm(
        total=total_bytes or None,
        desc=desc,
        unit="B",
        unit_scale=True,
        unit_divisor=1024,
    )
    by_table: dict[str, list[dict[str, Any]]] = defaultdict(list)
    rows = 0
    try:
        if not use_parallel:
            for chunk in _iter_complete_ndjson_chunks(ndjson_path, chunk_bytes):
                grouped, chunk_rows = _parse_ndjson_chunk(chunk)
                _merge_grouped_rows(by_table, grouped)
                rows += chunk_rows
                bar.update(len(chunk))
        else:
            if backend == "thread":
                executor_cls = concurrent.futures.ThreadPoolExecutor
            elif backend == "process":
                executor_cls = concurrent.futures.ProcessPoolExecutor
            else:
                raise ValueError(
                    "OSU_NDJSON_PARSE_BACKEND must be 'process' or 'thread', "
                    f"got {backend!r}"
                )
            chunk_iter = iter(_iter_complete_ndjson_chunks(ndjson_path, chunk_bytes))
            pending: list[tuple[concurrent.futures.Future, int]] = []

            def submit_next(executor) -> bool:
                try:
                    chunk = next(chunk_iter)
                except StopIteration:
                    return False
                pending.append((executor.submit(_parse_ndjson_chunk, chunk), len(chunk)))
                return True

            with executor_cls(max_workers=workers) as executor:
                for _ in range(workers * 2):
                    if not submit_next(executor):
                        break
                while pending:
                    future, nbytes = pending.pop(0)
                    grouped, chunk_rows = future.result()
                    _merge_grouped_rows(by_table, grouped)
                    rows += chunk_rows
                    bar.update(nbytes)
                    submit_next(executor)
    finally:
        bar.set_postfix_str(f"{rows:,} rows -> {len(by_table)} table(s)")
        bar.close()
    return dict(by_table)


# ---------------------------------------------------------------------------
# Partition column derivation.
# ---------------------------------------------------------------------------


# Map of (ruleset, attributes_json key) → (column name, type-coercer). Used by
# :func:`hoist_difficulty_attributes` to denormalize the most useful rosu-pp
# fields out of the JSON blob and into typed top-level columns. The JSON blob
# remains the source of truth for less common attributes (e.g. is_convert flags
# on edge-case converted maps).
_OSU_DIFFICULTY_HOISTS: tuple[tuple[str, str, str], ...] = (
    ("aim", "aim_difficulty", "f64"),
    ("speed", "speed_difficulty", "f64"),
    ("flashlight", "flashlight_difficulty", "f64"),
    ("slider_factor", "slider_factor", "f64"),
    ("speed_note_count", "speed_note_count", "f64"),
    ("great_hit_window", "great_hit_window", "f64"),
    ("ok_hit_window", "ok_hit_window", "f64"),
    ("meh_hit_window", "meh_hit_window", "f64"),
    ("ar", "ar", "f64"),
    ("hp", "hp", "f64"),
    ("n_circles", "n_circles", "i32"),
    ("n_sliders", "n_sliders", "i32"),
    ("n_spinners", "n_spinners", "i32"),
)
_TAIKO_DIFFICULTY_HOISTS: tuple[tuple[str, str, str], ...] = (
    ("stamina", "stamina", "f64"),
    ("rhythm", "rhythm", "f64"),
    ("color", "color", "f64"),
    ("reading", "reading", "f64"),
    ("mono_stamina_factor", "mono_stamina_factor", "f64"),
    ("great_hit_window", "great_hit_window", "f64"),
    ("ok_hit_window", "ok_hit_window", "f64"),
    ("is_convert", "is_convert", "bool"),
)
_CATCH_DIFFICULTY_HOISTS: tuple[tuple[str, str, str], ...] = (
    ("n_fruits", "n_fruits", "i32"),
    ("n_droplets", "n_droplets", "i32"),
    ("n_tiny_droplets", "n_tiny_droplets", "i32"),
    ("is_convert", "is_convert", "bool"),
)
# rosu-pp 4.0.1's ManiaDifficultyAttributes exposes only stars / max_combo /
# n_objects / n_hold_notes / is_convert — no hit windows or post-mod OD. Do not
# add great_hit_window / ok_hit_window / meh_hit_window / od here; the hoist
# would always return null.
_MANIA_DIFFICULTY_HOISTS: tuple[tuple[str, str, str], ...] = (
    ("n_objects", "n_objects", "i32"),
    ("n_hold_notes", "n_hold_notes", "i32"),
    ("is_convert", "is_convert", "bool"),
)


def _coerce_hoist(value: Any, kind: str) -> Any:
    if value is None:
        return None
    if kind == "f64":
        try:
            return float(value)
        except (TypeError, ValueError):
            return None
    if kind == "i32":
        try:
            return int(value)
        except (TypeError, ValueError):
            return None
    if kind == "bool":
        return bool(value)
    return value


def hoist_difficulty_attributes(
    difficulty_rows: list[dict[str, Any]],
) -> list[dict[str, Any]]:
    """Denormalize key ``attributes_json`` fields into typed top-level columns.

    Modifies and returns ``difficulty_rows``. Rows with
    ``calculation_status='failed'`` keep nulls in every hoisted column. The
    JSON blob is preserved in place so consumers can still recover any field
    we don't denormalize. Idempotent: running twice on the same rows is a
    no-op.
    """
    if not difficulty_rows:
        return difficulty_rows

    for row in difficulty_rows:
        attrs_text = row.get("attributes_json") or ""
        try:
            attrs = json.loads(attrs_text) if attrs_text else {}
        except (TypeError, json.JSONDecodeError):
            attrs = {}
        ruleset = (attrs.get("ruleset") or row.get("ruleset") or "").lower()
        if ruleset == "osu":
            hoists = _OSU_DIFFICULTY_HOISTS
        elif ruleset == "taiko":
            hoists = _TAIKO_DIFFICULTY_HOISTS
        elif ruleset == "catch":
            hoists = _CATCH_DIFFICULTY_HOISTS
        elif ruleset == "mania":
            hoists = _MANIA_DIFFICULTY_HOISTS
        else:
            hoists = ()
        for json_key, column_name, kind in hoists:
            if column_name not in row or row[column_name] is None:
                row[column_name] = _coerce_hoist(attrs.get(json_key), kind)
    return difficulty_rows


def _mania_key_count_from_cs(cs: Any) -> int | None:
    """Mirror of the Rust indexer's ``mania_key_count`` (round + clamp 1..18)."""
    if cs is None:
        return None
    try:
        cs_f = float(cs)
    except (TypeError, ValueError):
        return None
    rounded = int(round(cs_f))
    if rounded < 1:
        return 1
    if rounded > 18:
        return 18
    return rounded


def _beatmap_revision_key(row: dict[str, Any]) -> tuple[str, str] | None:
    """Composite key for joining beatmap-scoped rows across tables.

    Returns ``(set_revision_id, beatmap_uid)`` — the actual primary key. Joining
    on ``beatmap_uid`` alone is wrong because a single chunk can contain two
    revisions of the same submitted beatmapset. Any in-memory denormalization
    must use this composite key to avoid blending values across revisions.
    """
    srid = row.get("set_revision_id")
    uid = row.get("beatmap_uid")
    if srid is None or uid is None:
        return None
    return (str(srid), str(uid))


def enrich_beatmaps(
    beatmaps: list[dict[str, Any]],
    hit_objects_common: list[dict[str, Any]],
) -> list[dict[str, Any]]:
    """Backfill denormalized columns onto every beatmap row.

    Adds:
    - ``key_count``: round(circle_size) clamped to 1..18 for mania, null else.
    - ``first_object_time_ms`` / ``last_object_time_ms`` / ``total_length_ms``:
      derived from ``hit_objects_common`` of this batch (one pass, O(n)).

    Aggregation key is ``(set_revision_id, beatmap_uid)`` — the schema's
    primary key. Keying on ``beatmap_uid`` alone would blend bounds across
    revisions when one chunk contains two ``.osz`` revisions of the same
    submitted set.

    Audio metadata (``audio_duration_ms`` / ``audio_sample_rate`` /
    ``audio_channels``) is filled separately by :func:`backfill_beatmap_audio_metadata`
    when a caller provides probe results. The compact v1 workflow does not
    probe extracted blobs, so those fields are normally null.
    Idempotent: running twice on the same rows is a no-op.
    """
    if not beatmaps:
        return beatmaps

    # Aggregate per (set_revision_id, beatmap_uid): (min_start, max_end). end is
    # max(start, end_ms) so spinners and slider tail times count toward
    # total_length_ms.
    bounds: dict[tuple[str, str], list[int | None]] = {}
    for ho in hit_objects_common:
        key = _beatmap_revision_key(ho)
        if key is None:
            continue
        start = ho.get("time_ms")
        if start is None:
            continue
        try:
            start = int(start)
        except (TypeError, ValueError):
            continue
        end_raw = ho.get("end_time_ms")
        try:
            end = int(end_raw) if end_raw is not None else start
        except (TypeError, ValueError):
            end = start
        bucket = bounds.get(key)
        if bucket is None:
            bounds[key] = [start, max(start, end)]
        else:
            if bucket[0] is None or start < bucket[0]:
                bucket[0] = start
            if bucket[1] is None or end > bucket[1]:
                bucket[1] = end

    for bm in beatmaps:
        ruleset = (bm.get("ruleset") or "").lower()
        if "key_count" not in bm or bm["key_count"] is None:
            bm["key_count"] = (
                _mania_key_count_from_cs(bm.get("circle_size"))
                if ruleset == "mania"
                else None
            )
        key = _beatmap_revision_key(bm)
        b = bounds.get(key) if key is not None else None
        if b is not None:
            bm.setdefault("first_object_time_ms", b[0])
            bm.setdefault("last_object_time_ms", b[1])
            if b[0] is not None and b[1] is not None and b[1] >= b[0]:
                bm.setdefault("total_length_ms", b[1] - b[0])
            else:
                bm.setdefault("total_length_ms", None)
        else:
            bm.setdefault("first_object_time_ms", None)
            bm.setdefault("last_object_time_ms", None)
            bm.setdefault("total_length_ms", None)
    return beatmaps


def backfill_beatmap_audio_metadata(
    beatmaps: list[dict[str, Any]],
    audio_probe_by_sha: dict[str, dict[str, Any]],
) -> list[dict[str, Any]]:
    """Stamp audio probe results onto each beatmap row from a sha→probe map.

    ``audio_probe_by_sha`` maps ``audio_blob_sha256`` to a dict carrying at
    least ``audio_duration_ms`` / ``audio_sample_rate`` / ``audio_channels``;
    compact v1 normally passes an empty map because extracted blob probing is
    not part of the maintained workflow. Beatmaps with a null/missing audio
    reference get nulls. Idempotent.
    """
    if not beatmaps:
        return beatmaps
    for bm in beatmaps:
        sha = bm.get("audio_blob_sha256")
        if not sha:
            bm.setdefault("audio_duration_ms", None)
            bm.setdefault("audio_sample_rate", None)
            bm.setdefault("audio_channels", None)
            continue
        probe = audio_probe_by_sha.get(sha) or {}
        if "audio_duration_ms" not in bm or bm["audio_duration_ms"] is None:
            bm["audio_duration_ms"] = probe.get("audio_duration_ms")
        if "audio_sample_rate" not in bm or bm["audio_sample_rate"] is None:
            bm["audio_sample_rate"] = probe.get("audio_sample_rate")
        if "audio_channels" not in bm or bm["audio_channels"] is None:
            bm["audio_channels"] = probe.get("audio_channels")
    return beatmaps


# Per-mode tables that should carry the denormalized ``audio_blob_sha256``.
_HIT_OBJECTS_TABLES_FOR_AUDIO_BACKFILL: tuple[str, ...] = (
    "hit_objects_common",
    "hit_objects_osu",
    "hit_objects_taiko",
    "hit_objects_catch",
    "hit_objects_mania",
)


def backfill_hit_objects_audio_blob(
    rows_by_table: dict[str, list[dict[str, Any]]],
) -> None:
    """Stamp ``audio_blob_sha256`` from beatmaps onto every hit-objects row.

    Audio-conditioned models that stream `hit_objects_*` partition-pruned by
    ``key_count`` / ``ruleset`` would otherwise need a join to ``beatmaps`` to
    locate the audio blob. Denormalize so the join is unnecessary.

    The mapping key is ``(set_revision_id, beatmap_uid)`` — the schema's
    primary key. Keying on ``beatmap_uid`` alone is wrong because a single
    chunk can contain two ``.osz`` revisions of the same submitted set with
    different audio blobs; the second revision's sha would silently overwrite
    the first, and hit objects from revision A would be stamped with revision
    B's audio. That would corrupt audio-conditioned modeling pairs.

    Mutates rows in place. Idempotent: rows already carrying
    ``audio_blob_sha256`` are not overwritten.
    """
    beatmaps = rows_by_table.get("beatmaps", [])
    if not beatmaps:
        return
    audio_by_key: dict[tuple[str, str], str | None] = {}
    for bm in beatmaps:
        key = _beatmap_revision_key(bm)
        if key is None:
            continue
        audio_by_key[key] = bm.get("audio_blob_sha256")
    if not audio_by_key:
        return
    for table_name in _HIT_OBJECTS_TABLES_FOR_AUDIO_BACKFILL:
        rows = rows_by_table.get(table_name)
        if not rows:
            continue
        for row in rows:
            if row.get("audio_blob_sha256") is not None:
                continue
            key = _beatmap_revision_key(row)
            if key is None:
                continue
            if key in audio_by_key:
                row["audio_blob_sha256"] = audio_by_key[key]


def derive_storyboard_source_to_set_revision_map(
    storyboard_sources: list[dict[str, Any]],
) -> dict[str, str]:
    return {r["storyboard_source_id"]: r["set_revision_id"] for r in storyboard_sources}


def derive_partition_values(
    table_name: str,
    row: dict[str, Any],
    partition_keys: tuple[str, ...],
) -> dict[str, Any]:
    """Read physical partition values from a single row."""
    values: dict[str, Any] = {}
    for k in partition_keys:
        if k in row:
            values[k] = row[k]
        else:
            raise ValueError(
                f"cannot derive partition value for {k!r} in table {table_name}"
            )
    return values


def partition_dir_name(key: str, value: Any) -> str:
    """Physical directory name for a logical partition value.

    The ``p_`` prefix prevents PyArrow's automatic Hive partition discovery
    from inventing a second column with the same name as the real in-file
    column. That keeps ``pq.read_table(<file>)`` and ``ds.dataset(...,
    partitioning="hive")`` from failing on duplicate logical fields while HF
    still sees those fields in the Parquet body.
    """
    return f"p_{key}={value}"


# ---------------------------------------------------------------------------
# Sort + Arrow conversion.
# ---------------------------------------------------------------------------


def _sort_key_for(row: dict[str, Any], keys: tuple[str, ...]) -> tuple:
    """Stable sort key handling None values (puts nulls first within a tier)."""
    out = []
    for k in keys:
        v = row.get(k)
        if v is None:
            out.append((0, 0))
        elif isinstance(v, bool):
            out.append((1, int(v)))
        elif isinstance(v, (int, float)):
            out.append((1, v))
        else:
            out.append((2, str(v)))
    return tuple(out)


def rows_to_arrow_table(
    rows: list[dict[str, Any]], file_schema: pa.Schema
) -> pa.Table:
    """Convert rows (dicts) to a PyArrow Table conforming to ``file_schema``.

    Missing keys become nulls. Extra keys are ignored. Type coercion is
    delegated to PyArrow (ints accepted for timestamp[ms], etc.).
    """
    columns: dict[str, list[Any]] = {name: [] for name in file_schema.names}
    for row in rows:
        for name in columns:
            columns[name].append(row.get(name))
    arrays = []
    for field in file_schema:
        arrays.append(pa.array(columns[field.name], type=field.type))
    return pa.Table.from_arrays(arrays, schema=file_schema)


# ---------------------------------------------------------------------------
# Parquet writing.
# ---------------------------------------------------------------------------


PARQUET_WRITE_KWARGS = dict(
    compression="zstd",
    use_dictionary=True,
    use_content_defined_chunking=True,
    write_page_index=True,
)


def _atomic_write_parquet(
    arrow_table: pa.Table,
    target: Path,
    **kwargs: Any,
) -> Path:
    """Write a parquet file via tmp-sidecar + rename — crash-safe.

    A SIGINT / power loss between ``pq.write_table`` and ``replace`` leaves
    a ``<name>.tmp.<pid>`` file on disk (no corrupt ``<name>``); our startup
    GC pass (``ingest_osz.cleanup_orphan_tmp_files``) sweeps these. The
    final ``replace`` is atomic on NTFS within a volume (``MoveFileExW``
    with ``MOVEFILE_REPLACE_EXISTING``), so readers never observe a
    truncated parquet.
    """
    target.parent.mkdir(parents=True, exist_ok=True)
    tmp = target.with_name(f"{target.name}.tmp.{os.getpid()}")
    pq.write_table(arrow_table, tmp, **kwargs)
    tmp.replace(target)
    return target


def write_table_partitioned(
    rows: list[dict[str, Any]],
    table: TableSchema,
    output_root: Path,
    batch_id: str,
    physical_partition_keys: tuple[str, ...] | None = None,
) -> list[Path]:
    """Partition rows by partition_keys, sort, and write Parquet files.

    Returns the list of files written. No-op (returns ``[]``) when ``rows``
    is empty — partition directories aren't created for empty tables.
    Each parquet write is atomic (tmp+rename) so a crash mid-write never
    leaves a truncated file at the canonical path.
    """
    if not rows:
        return []

    if physical_partition_keys is None:
        physical_partition_keys = table.partition_keys

    # Group rows by the tuple of partition values and keep those values in the
    # file-body row.
    by_partition: dict[tuple, list[dict[str, Any]]] = defaultdict(list)
    for row in rows:
        pvs = derive_partition_values(
            table.name, row, table.partition_keys
        )
        ptuple = tuple(pvs[k] for k in physical_partition_keys)
        body_row = dict(row)
        body_row.update(pvs)
        by_partition[ptuple].append(body_row)

    file_schema = table.file_schema()
    paths_written: list[Path] = []

    for ptuple, prows in by_partition.items():
        prows.sort(key=lambda r: _sort_key_for(r, table.sort_keys))

        if physical_partition_keys:
            parts = [
                partition_dir_name(k, v)
                for k, v in zip(physical_partition_keys, ptuple)
            ]
            target_dir = output_root / table.name
            for p in parts:
                target_dir = target_dir / p
        else:
            target_dir = output_root / table.name

        arrow_table = rows_to_arrow_table(prows, file_schema)
        target_path = target_dir / f"part-{batch_id}.parquet"
        _atomic_write_parquet(arrow_table, target_path, **PARQUET_WRITE_KWARGS)
        paths_written.append(target_path)

    return paths_written


# ---------------------------------------------------------------------------
# Top-level convenience: write every table from one batch's grouped rows.
# ---------------------------------------------------------------------------


def write_all_revisions_tables(
    rows_by_table: dict[str, list[dict[str, Any]]],
    schemas: dict[str, TableSchema],
    all_revisions_root: Path,
    batch_id: str,
    defer_tables: tuple[str, ...] = (),
    audio_probe_by_sha: dict[str, dict[str, Any]] | None = None,
    physical_partitioning: str = "schema",
) -> dict[str, list[Path]]:
    """Write every recognized table from this batch into all_revisions/.

    ``defer_tables`` lets the caller skip selected tables here so it can
    write them in a controlled order (e.g. defer ``archive_revisions`` so
    it lands LAST as a chunk-level commit marker; then a crashed run
    leaves no archive_revisions row, and ``ingest_osz`` skip-already-
    ingested correctly re-tries the chunk). The deferred tables can be
    written via :func:`commit_archive_revisions` (or directly via
    :func:`write_table_partitioned`).

    Returns ``{table_name: [paths_written, ...]}``. Tables with zero rows
    in the batch produce zero files. Deferred tables map to ``[]``.
    """
    if physical_partitioning == "schema":
        physical_keys_by_table: dict[str, tuple[str, ...]] | None = None
    elif physical_partitioning == "none":
        physical_keys_by_table = {name: () for name in schemas}
    else:
        raise ValueError(f"unknown physical partitioning mode: {physical_partitioning!r}")

    # Denormalize the most useful rosu-pp attribute fields out of the JSON
    # blob and into typed top-level columns. Done before partitioning so the
    # latest writer sees the same enriched rows.
    if "difficulty_attributes" in rows_by_table:
        hoist_difficulty_attributes(rows_by_table["difficulty_attributes"])

    # Denormalize beatmap-level fields (key_count for mania; first/last/total
    # object times) and audio probe metadata.
    if "beatmaps" in rows_by_table:
        enrich_beatmaps(
            rows_by_table["beatmaps"],
            rows_by_table.get("hit_objects_common", []),
        )
        if audio_probe_by_sha:
            backfill_beatmap_audio_metadata(
                rows_by_table["beatmaps"], audio_probe_by_sha
            )

    # Denormalize audio_blob_sha256 onto every hit_objects_* row so audio-
    # conditioned models can stream hit objects partition-pruned without a join.
    # Must run AFTER beatmap audio enrichment (above) so the source column is
    # populated; before partitioning so the latest writer sees the same rows.
    backfill_hit_objects_audio_blob(rows_by_table)

    deferred = set(defer_tables)
    written: dict[str, list[Path]] = {}
    eligible = [
        (name, rows)
        for name, rows in rows_by_table.items()
        if name not in deferred and name in schemas and rows
    ]
    table_write_workers = max(
        1,
        int(os.environ.get("OSU_PARQUET_WRITE_WORKERS", "1")),
    )
    table_write_workers = min(table_write_workers, max(len(eligible), 1))
    total_rows = sum(len(rs) for _, rs in eligible)
    bar = _tqdm(
        total=len(eligible) or None,
        desc=(
            f"writing all_revisions ({total_rows:,} rows"
            f", {table_write_workers} workers)"
        ),
        unit="table",
    )
    try:
        for table_name in rows_by_table:
            if table_name in deferred:
                written[table_name] = []
            elif table_name not in schemas:
                # Unknown table — skip silently; caller sees [] in the result.
                written[table_name] = []

        def write_one(table_name: str, rows: list[dict[str, Any]]) -> tuple[str, list[Path]]:
            paths = write_table_partitioned(
                rows,
                schemas[table_name],
                all_revisions_root,
                batch_id,
                physical_partition_keys=(
                    None
                    if physical_keys_by_table is None
                    else physical_keys_by_table[table_name]
                ),
            )
            return table_name, paths

        if table_write_workers <= 1 or len(eligible) <= 1:
            for table_name, rows in eligible:
                bar.set_postfix_str(f"{table_name} ({len(rows):,} rows)")
                table_name, paths = write_one(table_name, rows)
                written[table_name] = paths
                bar.update(1)
        else:
            with concurrent.futures.ThreadPoolExecutor(
                max_workers=table_write_workers
            ) as executor:
                futures = {
                    executor.submit(write_one, table_name, rows): (
                        table_name,
                        len(rows),
                    )
                    for table_name, rows in eligible
                }
                for future in concurrent.futures.as_completed(futures):
                    table_name, row_count = futures[future]
                    bar.set_postfix_str(f"{table_name} ({row_count:,} rows)")
                    written_name, paths = future.result()
                    written[written_name] = paths
                    bar.update(1)
    finally:
        bar.close()
    return written


def commit_archive_revisions(
    rows_by_table: dict[str, list[dict[str, Any]]],
    schemas: dict[str, TableSchema],
    all_revisions_root: Path,
    batch_id: str,
    physical_partitioning: str = "schema",
) -> list[Path]:
    """Atomically write the chunk's ``archive_revisions`` parquet.

    This is the **chunk commit marker**. ``ingest_osz``'s skip-already-
    ingested treats ``archive_sha256`` rows in ``archive_revisions/`` as
    proof that the chunk's other tables are already on disk. So this MUST
    be the last write in a chunk's pipeline. Only call it after
    ``write_all_revisions_tables(defer_tables=("archive_revisions",))`` has
    completed.
    """
    rows = rows_by_table.get("archive_revisions", [])
    if not rows:
        return []
    if physical_partitioning == "schema":
        physical_partition_keys = None
    elif physical_partitioning == "none":
        physical_partition_keys = ()
    else:
        raise ValueError(f"unknown physical partitioning mode: {physical_partitioning!r}")
    return write_table_partitioned(
        rows,
        schemas["archive_revisions"],
        all_revisions_root,
        batch_id,
        physical_partition_keys=physical_partition_keys,
    )


# ---------------------------------------------------------------------------
# Latest view helpers.
# ---------------------------------------------------------------------------

# Tables that get a ``data/v1/latest/`` view, in the order they're written.
# Each entry: (schema_table_name, latest_dir_basename, optional row filter).
# The filter, when present, decides whether a row of the source schema goes
# into THIS latest_dir; ``logical_files`` is separated into two siblings by
# ``media_kind``.
LATEST_TABLE_SPECS: tuple[tuple[str, str, Callable[[dict], bool] | None], ...] = (
    ("logical_files", "logical_files", lambda r: (r.get("media_kind") or "") != "video"),
    ("logical_files", "logical_files_video", lambda r: (r.get("media_kind") or "") == "video"),
    ("beatmaps", "beatmaps", None),
    ("hit_objects_common", "hit_objects_common", None),
    ("hit_objects_osu", "hit_objects_osu", None),
    ("hit_objects_taiko", "hit_objects_taiko", None),
    ("hit_objects_catch", "hit_objects_catch", None),
    ("hit_objects_mania", "hit_objects_mania", None),
    ("storyboard_sources", "storyboard_sources", None),
    ("storyboard_elements", "storyboard_elements", None),
    ("storyboard_commands", "storyboard_commands", None),
    ("storyboard_variables", "storyboard_variables", None),
    ("asset_references", "asset_references", None),
    ("difficulty_attributes", "difficulty_attributes", None),
    ("colours", "colours", None),
    ("breaks", "breaks", None),
)


def derive_set_key(set_revision_row: dict[str, Any]) -> str:
    """Compute the canonical ``set_key`` for a ``set_revisions`` row.

    The set revision id includes the per-archive SHA suffix. ``set_key`` strips
    that suffix for known and fingerprinted sets so all revisions of the same
    logical set share one key. Unknown archives keep their full id because
    there is no stable cross-archive identity to merge on.
    """
    srid = set_revision_row.get("set_revision_id") or ""
    if not srid:
        return srid
    parts = str(srid).split(":", 2)
    prefix = parts[0]
    if prefix == "fingerprint" and len(parts) >= 2:
        return f"fingerprint:{parts[1]}"
    if prefix == "unknown":
        return str(srid)
    try:
        return str(int(prefix))
    except ValueError:
        return str(srid)


def _coerce_ms(value: Any) -> int:
    """Coerce a timestamp-like value (int / datetime) to unix milliseconds.

    Avoids ``datetime.timestamp()`` because it makes an OS-level mktime call
    that fails on Windows for sub-1970 (or sub-1980 on some locales) values.
    Use direct epoch math instead.
    """
    if value is None:
        return 0
    if isinstance(value, bool):
        return int(value)
    if isinstance(value, int):
        return value
    # datetime — both naive and aware
    import datetime as _dt
    if isinstance(value, _dt.datetime):
        if value.tzinfo is None:
            epoch = _dt.datetime(1970, 1, 1)
        else:
            epoch = _dt.datetime(1970, 1, 1, tzinfo=_dt.timezone.utc)
        delta = value - epoch
        return delta.days * 86400_000 + delta.seconds * 1000 + delta.microseconds // 1000
    return int(value)


def write_latest_revisions(
    new_latest: dict[str, dict[str, Any]],
    path: Path,
    schemas: dict[str, TableSchema],
) -> Path:
    """Write the canonical ``latest_revisions.parquet`` atomically.

    Single small file (no partitioning per the schema). Atomic semantics
    are critical here — this file is the COMMIT MARKER for a batch's
    promotion of latest set_revisions; readers must never see a half-
    written or empty version.
    """
    table_schema = schemas["latest_revisions"]
    rows = sorted(new_latest.values(), key=lambda r: r["set_key"])
    arrow_table = rows_to_arrow_table(rows, table_schema.file_schema())
    return _atomic_write_parquet(arrow_table, path, **PARQUET_WRITE_KWARGS)