#!/usr/bin/env python3
"""Validate IV-CAN-v1 labels and frame CSVs without loading tables into memory."""

from __future__ import annotations

import argparse
import ast
import csv
import json
import math
import re
import sys
from pathlib import Path
from typing import Any, Iterable

try:
    import yaml
except ImportError as exc:  # pragma: no cover
    raise SystemExit("PyYAML is required: python -m pip install PyYAML") from exc


COLUMNS = [
    "timestamp", "can_id", "is_extended_id", "dlc", "data", "RX_or_TX",
    "type", "is_fd", "domain", "is_attack", "traced_from", "uuid",
    "is_traced_attack",
]
BOOL = {"True": True, "False": False}
CAN_ID = re.compile(r"^0x(?:[0-9A-F]{4}|[0-9A-F]{8})$")
BYTE_STRING = re.compile(r"^(?:[0-9A-F]{2}(?: [0-9A-F]{2})*)?$")
CLASSIC_LENGTHS = set(range(9))
FD_LENGTHS = CLASSIC_LENGTHS | {12, 16, 20, 24, 32, 48, 64}
ROAD_TYPES = {
    "UrbanOrdinaryRoad", "RuralRoad", "InternalRoad", "UORWithLKN",
    "HighwayWithLKN", "Highway", "UrbanExpressway",
}
ATTACK_TYPES = {"DoS", "fuzzing", "replay", "spoofing", "suspension", "masquerade"}
EFFECT_LEVELS = {
    "no effect", "system warning", "non-motion control compromised",
    "motion control compromised",
}


class Problems:
    def __init__(self) -> None:
        self.items: list[str] = []

    def add(self, path: Path, message: str, row: int | None = None) -> None:
        where = f"{path}:{row}" if row is not None else str(path)
        self.items.append(f"{where}: {message}")


def require_keys(value: Any, keys: set[str], path: Path, problems: Problems, context: str) -> bool:
    if not isinstance(value, dict):
        problems.add(path, f"{context} must be a mapping")
        return False
    missing = keys - value.keys()
    extra = value.keys() - keys
    if missing:
        problems.add(path, f"{context} missing keys: {sorted(missing)}")
    if extra:
        problems.add(path, f"{context} has unknown keys: {sorted(extra)}")
    return not missing


def validate_label(path: Path, problems: Problems) -> None:
    try:
        value = yaml.safe_load(path.read_text(encoding="utf-8"))
    except Exception as exc:
        problems.add(path, f"cannot parse YAML: {exc}")
        return

    top = {
        "attack_end_timestamp", "attack_start_timestamp", "attacking_duration_sec",
        "collection_duration_sec", "data_attack_info", "data_collection_info", "group_name",
    }
    if not require_keys(value, top, path, problems, "label"):
        return
    if value["group_name"] != path.parent.name:
        problems.add(path, "group_name must equal the containing case directory")
    for key in ("collection_duration_sec", "attacking_duration_sec"):
        number = value[key]
        if not isinstance(number, (int, float)) or isinstance(number, bool) or number < 0:
            problems.add(path, f"{key} must be a non-negative number")
    for key in ("attack_start_timestamp", "attack_end_timestamp"):
        number = value[key]
        if number is not None and (not isinstance(number, (int, float)) or isinstance(number, bool) or number < 0):
            problems.add(path, f"{key} must be null or a non-negative number")

    collection = value["data_collection_info"]
    collection_keys = {"avg_speed", "description", "end_place", "intelligent_driving", "road_type", "start_place"}
    if require_keys(collection, collection_keys, path, problems, "data_collection_info"):
        if collection["road_type"] not in ROAD_TYPES:
            problems.add(path, f"unknown road_type: {collection['road_type']!r}")
        if not isinstance(collection["intelligent_driving"], bool):
            problems.add(path, "intelligent_driving must be boolean")

    attack = value["data_attack_info"]
    if attack is None:
        if not str(value["group_name"]).startswith("benign_"):
            problems.add(path, "only benign cases may have data_attack_info: null")
        return
    if not require_keys(attack, {"attack_effect", "attack_type", "attacked_domain"}, path, problems, "data_attack_info"):
        return
    domain = attack["attacked_domain"]
    if not isinstance(domain, int) or isinstance(domain, bool) or not 1 <= domain <= 5:
        problems.add(path, "attacked_domain must be an integer from 1 through 5")
    effect = attack["attack_effect"]
    if require_keys(effect, {"description", "level"}, path, problems, "attack_effect") and effect["level"] not in EFFECT_LEVELS:
        problems.add(path, f"unknown attack effect level: {effect['level']!r}")
    attack_type = attack["attack_type"]
    if not require_keys(attack_type, {"kind", "config"}, path, problems, "attack_type"):
        return
    kind, config = attack_type["kind"], attack_type["config"]
    if kind not in ATTACK_TYPES:
        problems.add(path, f"unknown attack kind: {kind!r}")
        return
    expected_prefix = "dos" if kind == "DoS" else kind
    if not str(value["group_name"]).startswith(expected_prefix + "_"):
        problems.add(path, "attack kind does not agree with group_name")
    validate_attack_config(kind, config, path, problems)


def validate_attack_config(kind: str, config: Any, path: Path, problems: Problems) -> None:
    if kind in {"spoofing", "masquerade"}:
        if config is not None:
            problems.add(path, f"{kind} config must be null")
        return
    if not isinstance(config, dict):
        problems.add(path, f"{kind} config must be a mapping")
        return
    enums: dict[str, dict[str, set[str]]] = {
        "DoS": {"id_option": {"aliveId", "zeroId"}, "dlc_option": {"dlcChange", "dlcKeep"}, "ext_option": {"extendedId", "standardId"}, "data_option": {"FFData", "randomData"}},
        "fuzzing": {"id_option": {"aliveId", "randomId"}, "dlc_option": {"dlcChange", "dlcKeep"}},
        "replay": {"timing": {"delay", "immediate"}},
    }
    if kind in enums:
        if not require_keys(config, set(enums[kind]), path, problems, f"{kind} config"):
            return
        for key, allowed in enums[kind].items():
            if config[key] not in allowed:
                problems.add(path, f"invalid {kind} {key}: {config[key]!r}")
        return
    if kind == "suspension":
        if not require_keys(config, {"suspension_CAN_id_list", "suspension_duration_sec"}, path, problems, "suspension config"):
            return
        ids = config["suspension_CAN_id_list"]
        if not isinstance(ids, list) or not ids or any(not isinstance(item, str) or not CAN_ID.fullmatch(item) for item in ids):
            problems.add(path, "suspension_CAN_id_list must contain canonical CAN IDs")
        duration = config["suspension_duration_sec"]
        if not isinstance(duration, (int, float)) or isinstance(duration, bool) or duration <= 0:
            problems.add(path, "suspension_duration_sec must be positive")


def parse_bool(raw: str) -> bool:
    if raw not in BOOL:
        raise ValueError("expected True or False")
    return BOOL[raw]


def grow_bitset(bitset: bytearray, index: int) -> None:
    if index >= len(bitset):
        bitset.extend(b"\0" * (index + 1 - len(bitset)))


def validate_frame(row: dict[str, str], path: Path, line: int, seen: bytearray, graph: dict[int, list[int]], problems: Problems) -> None:
    try:
        timestamp = float(row["timestamp"])
        if not math.isfinite(timestamp) or timestamp < 0:
            raise ValueError("timestamp must be finite and non-negative")
        can_id = row["can_id"]
        if not CAN_ID.fullmatch(can_id):
            raise ValueError("can_id is not canonical uppercase hexadecimal")
        extended = parse_bool(row["is_extended_id"])
        if (len(can_id) == 10) != extended:
            raise ValueError("can_id width disagrees with is_extended_id")
        dlc = int(row["dlc"])
        payload = row["data"]
        if not BYTE_STRING.fullmatch(payload):
            raise ValueError("data is not canonical space-separated uppercase hex")
        if len(payload.split()) != dlc:
            raise ValueError("dlc does not equal payload byte count")
        if row["RX_or_TX"] not in {"RX", "TX"}:
            raise ValueError("RX_or_TX must be RX or TX")
        frame_type = row["type"]
        if frame_type not in {"DT", "FB", "BI"}:
            raise ValueError("type must be DT, FB, or BI")
        is_fd = parse_bool(row["is_fd"])
        if frame_type in {"FB", "BI"} and not is_fd:
            raise ValueError("FB or BI requires is_fd=True")
        if dlc not in (FD_LENGTHS if is_fd else CLASSIC_LENGTHS):
            raise ValueError("dlc is invalid for the frame protocol")
        domain = int(row["domain"])
        if not 1 <= domain <= 5:
            raise ValueError("domain must be 1 through 5")
        parse_bool(row["is_attack"])
        parse_bool(row["is_traced_attack"])
        uuid = int(row["uuid"])
        if uuid <= 0:
            raise ValueError("uuid must be positive")
        grow_bitset(seen, uuid)
        if seen[uuid]:
            raise ValueError("duplicate case-local uuid")
        seen[uuid] = 1
        parents = ast.literal_eval(row["traced_from"])
        if not isinstance(parents, list) or any(type(parent) is not int or parent <= 0 for parent in parents):
            raise ValueError("traced_from must be a list of positive integers")
        if len(parents) != len(set(parents)):
            raise ValueError("traced_from contains duplicates")
        if uuid in parents:
            raise ValueError("traced_from contains a self-reference")
        if parents:
            graph[uuid] = parents
    except (ValueError, SyntaxError, KeyError) as exc:
        problems.add(path, str(exc), line)


def validate_graph(path: Path, graph: dict[int, list[int]], seen: bytearray, problems: Problems) -> None:
    for child, parents in graph.items():
        for parent in parents:
            if parent >= len(seen) or not seen[parent]:
                problems.add(path, f"uuid {child} traces from missing case-local uuid {parent}")
    state: dict[int, int] = {}

    def visit(node: int) -> bool:
        if state.get(node) == 1:
            return False
        if state.get(node) == 2:
            return True
        state[node] = 1
        for parent in graph.get(node, []):
            if parent in graph and not visit(parent):
                return False
        state[node] = 2
        return True

    for node in graph:
        if not visit(node):
            problems.add(path, "traced_from graph contains a cycle")
            break


def validate_csv(path: Path, max_rows: int | None, problems: Problems) -> int:
    seen = bytearray(1)
    graph: dict[int, list[int]] = {}
    rows = 0
    with path.open("r", encoding="utf-8", newline="") as handle:
        reader = csv.DictReader(handle)
        if reader.fieldnames != COLUMNS:
            problems.add(path, f"unexpected header: {reader.fieldnames!r}", 1)
            return 0
        for line, row in enumerate(reader, 2):
            if max_rows is not None and rows >= max_rows:
                break
            validate_frame(row, path, line, seen, graph, problems)
            rows += 1
    if max_rows is None:
        validate_graph(path, graph, seen, problems)
    return rows


def iter_cases(root: Path) -> Iterable[tuple[Path, Path]]:
    for label in sorted((root / "data").glob("**/label.yaml")):
        yield label, label.with_name("data.csv")


def main(argv: list[str] | None = None) -> int:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--root", type=Path, default=Path(__file__).resolve().parents[1])
    group = parser.add_mutually_exclusive_group()
    group.add_argument("--max-rows", type=int, default=1000, help="rows checked per case (default: 1000)")
    group.add_argument("--all", action="store_true", help="scan every row and validate trace references/cycles")
    args = parser.parse_args(argv)
    root = args.root.resolve()
    max_rows = None if args.all else args.max_rows
    if max_rows is not None and max_rows <= 0:
        parser.error("--max-rows must be positive")

    problems = Problems()
    cases = rows = 0
    for label, data in iter_cases(root):
        cases += 1
        validate_label(label, problems)
        if not data.is_file():
            problems.add(data, "missing data.csv")
        else:
            rows += validate_csv(data, max_rows, problems)
    if not cases:
        problems.add(root / "data", "no cases found")
    if problems.items:
        for item in problems.items[:100]:
            print(f"ERROR: {item}", file=sys.stderr)
        if len(problems.items) > 100:
            print(f"ERROR: {len(problems.items) - 100} additional errors omitted", file=sys.stderr)
        return 1
    mode = "all rows" if max_rows is None else f"up to {max_rows} rows/case"
    print(f"OK: validated {cases} cases and {rows:,} frame rows ({mode})")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())