"""Build a reach-intent benchmark from PLOS ONE supplementary archive S3.

The builder reads the source archive without extracting it, joins event logs to
the approximately 16 Hz skeleton stream, and writes viewer-friendly CSV files.
It intentionally excludes the clinical table and fine-grained demographics.
"""

from __future__ import annotations

import argparse
import csv
import gzip
import hashlib
import io
import json
import re
import urllib.request
import zipfile
from collections import Counter, defaultdict
from datetime import date, datetime
from pathlib import Path
from typing import Iterable, Iterator

SOURCE_URL = (
    "https://journals.plos.org/plosone/article/file?type=supplementary&"
    "id=info:doi/10.1371/journal.pone.0170472.s003"
)
SOURCE_SHA256 = "21fc2ae8d8bce10b3cecd6416fdda390ba98476c9b9abe95be91857aea07d008"

TARGET_NAMES = {
    0: "right_low_45",
    1: "right_lateral",
    2: "right_up_30",
    3: "right_up_60",
    4: "right_top",
    5: "left_low_45",
    6: "left_lateral",
    7: "left_up_30",
    8: "left_up_60",
    9: "left_top",
}

# The two session-level PCA outliers removed in the public analysis workflow.
QC_OUTLIER_FEATURE_KEYS = {
    "1024_2015.03.19_19.19",
    "1038_2014.12.11_17.45",
}

EVENT_RE = re.compile(
    r"\t(?P<timestamp>\d+)\tObject (?P<object>\d+) "
    r"(?P<event>appeared|timed out|reached by (?P<hand>right|left) hand)!"
)
SESSION_RE = re.compile(
    r"(?P<participant>\d+)_(?P<date>\d{4}\.\d{2}\.\d{2})_"
    r"(?P<time>\d{2}\.\d{2}\.\d{2})\.txt$"
)


def _open_text(data: bytes) -> io.TextIOWrapper:
    return io.TextIOWrapper(io.BytesIO(data), encoding="utf-8-sig", newline="")


def _write_csv(path: Path, fieldnames: list[str], rows: Iterable[dict]) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    if path.suffix == ".gz":
        raw = path.open("wb")
        binary = gzip.GzipFile(filename="", mode="wb", fileobj=raw, mtime=0)
        handle = io.TextIOWrapper(binary, encoding="utf-8", newline="")
    else:
        handle = path.open("w", encoding="utf-8", newline="")
    try:
        writer = csv.DictWriter(handle, fieldnames=fieldnames, extrasaction="ignore")
        writer.writeheader()
        writer.writerows(rows)
    finally:
        handle.close()


def download_source(destination: Path) -> Path:
    """Download and checksum the canonical PLOS supplementary archive."""
    destination.parent.mkdir(parents=True, exist_ok=True)
    request = urllib.request.Request(SOURCE_URL, headers={"User-Agent": "open-sma-hub/0.1"})
    with urllib.request.urlopen(request) as response, destination.open("wb") as output:
        while block := response.read(1024 * 1024):
            output.write(block)
    digest = hashlib.sha256(destination.read_bytes()).hexdigest()
    if digest != SOURCE_SHA256:
        destination.unlink(missing_ok=True)
        raise ValueError(f"Source checksum mismatch: expected {SOURCE_SHA256}, got {digest}")
    return destination


def _read_features(outer: zipfile.ZipFile) -> dict[str, str]:
    data = outer.read("S1_Dataset/full_features_class.txt")
    rows = csv.DictReader(_open_text(data), delimiter="\t")
    return {
        row["name"]: "sma" if row["class"].strip().lower() == "sma" else "control"
        for row in rows
    }


def _read_clinical_context(
    outer: zipfile.ZipFile,
) -> tuple[set[str], dict[tuple[str, date], int]]:
    """Read only IDs, dates, and visit numbers needed for source-study filtering."""
    rows = csv.DictReader(_open_text(outer.read("S1_Dataset/clinical_data.csv")))
    participants: set[str] = set()
    visits: dict[tuple[str, date], int] = {}
    for row in rows:
        participant_id = row["ID"]
        participants.add(participant_id)
        visits[(participant_id, datetime.strptime(row["DATE"], "%d.%m.%Y").date())] = int(
            row["VISIT"]
        )
    return participants, visits


def _parse_raw(data: bytes) -> list[dict[str, str]]:
    reader = csv.DictReader(_open_text(data), delimiter="\t")
    rows = []
    for row in reader:
        if not row.get("currentTimeMillis"):
            continue
        cleaned = {key.strip(): value.strip() for key, value in row.items() if key is not None}
        cleaned["currentTimeMillis"] = str(int(float(cleaned["currentTimeMillis"])))
        rows.append(cleaned)
    return rows


def _parse_events(data: bytes, raw_start_ms: int | None = None) -> list[dict]:
    active: dict[int, int] = {}
    trials: list[dict] = []
    inferred_first_object_closed = False
    for line in data.decode("utf-8-sig", errors="replace").splitlines():
        match = EVENT_RE.search(line)
        if not match:
            continue
        timestamp = int(match.group("timestamp"))
        object_index = int(match.group("object"))
        event = match.group("event")
        if event == "appeared":
            active[object_index] = timestamp
        elif object_index in active:
            trials.append(
                {
                    "object_index": object_index,
                    "target_label": object_index % 10,
                    "target_name": TARGET_NAMES[object_index % 10],
                    "repeat_index": object_index // 10,
                    "start_ms": active.pop(object_index),
                    "end_ms": timestamp,
                    "status": "reached" if event.startswith("reached") else "timed_out",
                    "hand": match.group("hand") or "",
                    "start_inferred": False,
                }
            )
        elif (
            raw_start_ms is not None
            and object_index == 0
            and timestamp >= raw_start_ms
            and not inferred_first_object_closed
        ):
            # The game source starts object 0 without logging an "appeared" event.
            # Raw recording begins after game initialization, so raw_start_ms is
            # the earliest observable bound for its first presentation.
            trials.append(
                {
                    "object_index": 0,
                    "target_label": 0,
                    "target_name": TARGET_NAMES[0],
                    "repeat_index": 0,
                    "start_ms": raw_start_ms,
                    "end_ms": timestamp,
                    "status": "reached" if event.startswith("reached") else "timed_out",
                    "hand": match.group("hand") or "",
                    "start_inferred": True,
                }
            )
            inferred_first_object_closed = True
    return trials


def _nested_archive(outer: zipfile.ZipFile, name: str) -> zipfile.ZipFile:
    return zipfile.ZipFile(io.BytesIO(outer.read(name)))


def build(source_zip: Path, output_dir: Path) -> dict:
    digest = hashlib.sha256(source_zip.read_bytes()).hexdigest()
    if digest != SOURCE_SHA256:
        raise ValueError(f"Source checksum mismatch: expected {SOURCE_SHA256}, got {digest}")

    trials_out: list[dict] = []
    frames_out: list[dict] = []
    sessions: list[dict] = []

    with zipfile.ZipFile(source_zip) as outer:
        groups = _read_features(outer)
        clinical_participants, clinical_visits = _read_clinical_context(outer)
        with _nested_archive(outer, "S1_Dataset/Full_RawData.zip") as raw_zip, _nested_archive(
            outer, "S1_Dataset/Full_LogFile.zip"
        ) as log_zip:
            raw_names = sorted(name for name in raw_zip.namelist() if name.endswith(".txt"))
            log_by_session = {
                Path(name).name.removeprefix("log_").removesuffix(".txt"): name
                for name in log_zip.namelist()
                if name.endswith(".txt")
            }
            raw_session_ids = {Path(name).name.removesuffix(".txt") for name in raw_names}
            unmatched_raw_sessions = sorted(raw_session_ids - set(log_by_session))
            unmatched_log_sessions = sorted(set(log_by_session) - raw_session_ids)
            invalid_date_sessions: list[str] = []
            for raw_name in raw_names:
                filename = Path(raw_name).name
                match = SESSION_RE.match(filename)
                if not match:
                    continue
                session_id = filename.removesuffix(".txt")
                participant_id = match.group("participant")
                # Reproduce the public R preprocessing rules from the study.
                if participant_id == "1018":  # Marked "not SMA" in StatisticalAnalysis.Rmd.
                    continue
                if participant_id not in clinical_participants:
                    continue
                if session_id.startswith("1027_2014.07.10_"):  # Marked "no real game".
                    continue
                session_date = datetime.strptime(match.group("date"), "%Y.%m.%d").date()
                visit_number = clinical_visits.get((participant_id, session_date))
                # These fallbacks exactly reproduce 1_dataPreprocessing.R.
                if visit_number is None and session_date > date(2015, 1, 1):
                    visit_number = 4
                if participant_id in {"1035", "1039"} and session_date == date(2014, 12, 18):
                    visit_number = 3
                if visit_number is None:
                    invalid_date_sessions.append(session_id)
                    continue
                feature_key = session_id.rsplit(".", 1)[0]
                group = groups.get(feature_key)
                if group is None:
                    raise KeyError(f"No group label for {session_id}")
                qc_outlier = feature_key in QC_OUTLIER_FEATURE_KEYS
                log_name = log_by_session.get(session_id)
                if log_name is None:
                    continue
                raw_rows = _parse_raw(raw_zip.read(raw_name))
                if not raw_rows:
                    continue
                raw_min = int(raw_rows[0]["currentTimeMillis"])
                raw_max = int(raw_rows[-1]["currentTimeMillis"])
                events = _parse_events(log_zip.read(log_name), raw_start_ms=raw_min)
                kept = 0
                reached = 0
                for sequence, trial in enumerate(events):
                    start = max(trial["start_ms"], raw_min)
                    end = min(trial["end_ms"], raw_max)
                    selected = [
                        row for row in raw_rows if start <= int(row["currentTimeMillis"]) <= end
                    ]
                    if end <= start or len(selected) < 2:
                        continue
                    trial_id = f"{session_id}__{sequence:02d}_o{trial['object_index']:02d}"
                    duration = end - start
                    trial_row = {
                        "trial_id": trial_id,
                        "session_id": session_id,
                        "participant_id": participant_id,
                        "group": group,
                        "qc_outlier": qc_outlier,
                        **trial,
                        "start_ms": start,
                        "end_ms": end,
                        "duration_ms": duration,
                        "n_frames": len(selected),
                    }
                    trials_out.append(trial_row)
                    kept += 1
                    reached += trial["status"] == "reached"
                    for frame_index, row in enumerate(selected):
                        timestamp = int(row["currentTimeMillis"])
                        frames_out.append(
                            {
                                "trial_id": trial_id,
                                "session_id": session_id,
                                "participant_id": participant_id,
                                "group": group,
                                "qc_outlier": qc_outlier,
                                "target_label": trial["target_label"],
                                "target_name": trial["target_name"],
                                "repeat_index": trial["repeat_index"],
                                "status": trial["status"],
                                "hand": trial["hand"],
                                "start_inferred": trial["start_inferred"],
                                "frame_index": frame_index,
                                "timestamp_ms": timestamp,
                                "elapsed_ms": timestamp - start,
                                "progress": round((timestamp - start) / duration, 6),
                                **{
                                    key: value
                                    for key, value in row.items()
                                    if key not in {"Time", "currentTimeMillis"}
                                },
                            }
                        )
                sessions.append(
                    {
                        "session_id": session_id,
                        "participant_id": participant_id,
                        "group": group,
                        "qc_outlier": qc_outlier,
                        "session_datetime": f"{match.group('date').replace('.', '-') }T{match.group('time').replace('.', ':')}",
                        "visit_index": visit_number - 1,
                        "n_trials": kept,
                        "n_reached_trials": reached,
                    }
                )

    by_participant: dict[str, list[dict]] = defaultdict(list)
    for session in sessions:
        by_participant[session["participant_id"]].append(session)
    participants_by_group: dict[str, list[str]] = defaultdict(list)
    for participant_id, participant_sessions in by_participant.items():
        participants_by_group[participant_sessions[0]["group"]].append(participant_id)
    folds: dict[str, int] = {}
    for group, participant_ids in participants_by_group.items():
        for index, participant_id in enumerate(sorted(participant_ids)):
            folds[participant_id] = index % 5

    session_lookup = {session["session_id"]: session for session in sessions}
    for session in sessions:
        session["fold"] = folds[session["participant_id"]]
    for row in trials_out:
        row["visit_index"] = session_lookup[row["session_id"]]["visit_index"]
        row["fold"] = folds[row["participant_id"]]
    for row in frames_out:
        row["visit_index"] = session_lookup[row["session_id"]]["visit_index"]
        row["fold"] = folds[row["participant_id"]]

    coordinate_columns = [
        key
        for key in frames_out[0]
        if key.endswith("-X") or key.endswith("-Y") or key.endswith("-Z")
    ]
    trial_fields = [
        "trial_id", "session_id", "participant_id", "group", "qc_outlier", "visit_index", "fold",
        "object_index", "target_label", "target_name", "repeat_index", "status", "hand", "start_inferred",
        "start_ms", "end_ms", "duration_ms", "n_frames",
    ]
    frame_fields = [
        "trial_id", "session_id", "participant_id", "group", "qc_outlier", "visit_index", "fold",
        "target_label", "target_name", "repeat_index", "status", "hand", "start_inferred", "frame_index",
        "timestamp_ms", "elapsed_ms", "progress", *coordinate_columns,
    ]
    session_fields = [
        "session_id", "participant_id", "group", "qc_outlier", "session_datetime", "visit_index", "fold",
        "n_trials", "n_reached_trials",
    ]
    split_rows = [
        {
            "participant_id": participant_id,
            "group": participant_sessions[0]["group"],
            "fold": folds[participant_id],
        }
        for participant_id, participant_sessions in sorted(by_participant.items())
    ]

    _write_csv(output_dir / "reach_trials.csv.gz", trial_fields, trials_out)
    _write_csv(output_dir / "reach_frames.csv.gz", frame_fields, frames_out)
    _write_csv(output_dir / "sessions.csv", session_fields, sessions)
    _write_csv(output_dir / "participant_folds.csv", ["participant_id", "group", "fold"], split_rows)

    summary = {
        "source_sha256": digest,
        "participants": len(by_participant),
        "sessions": len(sessions),
        "trials": len(trials_out),
        "frames": len(frames_out),
        "groups": Counter(session["group"] for session in sessions),
        "participant_groups": Counter(row["group"] for row in split_rows),
        "trial_status": Counter(row["status"] for row in trials_out),
        "targets": Counter(row["target_name"] for row in trials_out),
        "inferred_start_trials": sum(bool(row["start_inferred"]) for row in trials_out),
        "qc_outlier_sessions": sorted(
            session["session_id"] for session in sessions if session["qc_outlier"]
        ),
        "unmatched_raw_sessions": unmatched_raw_sessions,
        "unmatched_log_sessions": unmatched_log_sessions,
        "study_preprocessing_exclusions": {
            "participant_not_sma": ["1018"],
            "participant_without_clinical_record": ["1036"],
            "invalid_game": ["1027_2014.07.10"],
            "invalid_or_nonstudy_session_dates": invalid_date_sessions,
        },
    }
    summary = {key: dict(value) if isinstance(value, Counter) else value for key, value in summary.items()}
    (output_dir / "build_summary.json").write_text(
        json.dumps(summary, indent=2, sort_keys=True) + "\n", encoding="utf-8"
    )
    return summary


def main(argv: list[str] | None = None) -> None:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--source-zip", type=Path, help="Downloaded PLOS supplementary S3 archive")
    parser.add_argument("--output-dir", type=Path, default=Path("kinect/data"))
    parser.add_argument(
        "--download",
        type=Path,
        metavar="PATH",
        help="Download the canonical source archive to PATH before building",
    )
    args = parser.parse_args(argv)
    source = download_source(args.download) if args.download else args.source_zip
    if source is None:
        parser.error("provide --source-zip or --download")
    print(json.dumps(build(source, args.output_dir), indent=2, sort_keys=True))


if __name__ == "__main__":
    main()