from collections import Counter, defaultdict
from datetime import datetime, timedelta
from typing import Dict, List, Tuple


IMPORTANT_ATTR_TERMS = {
    "Alarm": 10,
    "Error": 9,
    "Fault": 9,
    "Battery": 6,
    "LockState": 5,
    "Occupancy": 4,
    "BooleanState": 4,
    "OperationalStatus": 5,
    "Position": 5,
    "OnOff": 3,
    "Smoke": 6,
    "CO": 6,
    "Water": 6,
}


def _format_value(attribute: str, value) -> str:
    if isinstance(value, bool):
        return str(value)
    if isinstance(value, (int, float)) and "Temperature" in attribute:
        return f"{value / 100:.2f}C" if abs(value) > 100 else str(value)
    return str(value)


def format_event_line(event: Dict) -> str:
    ts = event.get("timestamp", "?")
    dev = event.get("device_id", "?")
    etype = event.get("event_type", "")
    if etype == "attribute_change":
        cluster = event.get("cluster", "")
        attr = event.get("attribute", "")
        value = _format_value(attr, event.get("value"))
        left = f"{cluster}.{attr}" if cluster else attr
        return f"[{ts}] {dev} | {left} = {value}"
    if etype == "device_event":
        name = event.get("event_name", "")
        fields = event.get("fields", {})
        field_text = ", ".join(f"{k}={v}" for k, v in fields.items())
        return f"[{ts}] {dev} | Event: {name}({field_text})"
    if etype == "command":
        return f"[{ts}] {dev} | Command: {event.get('command', '')}"
    return f"[{ts}] {dev} | {etype}"


def _device_room_map(home_state: Dict) -> Dict[str, str]:
    mapping = {}
    for device_id, info in home_state.get("devices", {}).items():
        mapping[device_id] = info.get("room_id", "unknown")
    return mapping


def _filter_events_by_query_window(events: List[Dict], query: str) -> List[Dict]:
    import re

    match = re.search(r"过去\s*(\d+)\s*小时", query)
    if not match or not events:
        return events
    try:
        last_dt = datetime.fromisoformat(events[-1]["timestamp"])
    except Exception:
        return events
    cutoff = last_dt - timedelta(hours=int(match.group(1)))
    cutoff_ts = cutoff.isoformat()
    return [evt for evt in events if evt.get("timestamp", "") >= cutoff_ts]


def _event_salience(event: Dict) -> int:
    score = 0
    etype = event.get("event_type", "")
    if etype == "device_event":
        score += 8
    elif etype == "command":
        score += 4
    attr = f"{event.get('cluster', '')}.{event.get('attribute', '')}"
    for term, weight in IMPORTANT_ATTR_TERMS.items():
        if term in attr:
            score += weight
    if event.get("attribute") == "MeasuredValue":
        score += 1
    return score


def _temperature_patterns(events: List[Dict]) -> List[str]:
    series = defaultdict(list)
    for evt in events:
        if evt.get("event_type") != "attribute_change":
            continue
        if evt.get("attribute") != "MeasuredValue":
            continue
        if "Temperature" not in evt.get("cluster", ""):
            continue
        value = evt.get("value")
        if isinstance(value, (int, float)):
            series[evt["device_id"]].append(value)

    findings = []
    for device_id, values in series.items():
        if len(values) < 12:
            continue
        span = max(values) - min(values)
        same_ratio = max(Counter(values).values()) / len(values)
        increasing = sum(1 for a, b in zip(values, values[1:]) if b >= a)
        decreasing = sum(1 for a, b in zip(values, values[1:]) if b <= a)
        trend_ratio = max(increasing, decreasing) / max(1, len(values) - 1)
        if span <= 2 and same_ratio >= 0.9:
            findings.append(f"{device_id}: near-flat temperature readings across {len(values)} samples")
        elif span >= 80 and trend_ratio >= 0.85:
            direction = "upward" if increasing >= decreasing else "downward"
            findings.append(f"{device_id}: strong {direction} monotonic temperature trend, span={span/100:.2f}C")
    return findings


def _summarize_layout(home_state: Dict) -> str:
    by_room = defaultdict(list)
    for device_id, info in home_state.get("devices", {}).items():
        by_room[info.get("room_id", "unknown")].append(
            f"{info.get('display_name', device_id)}<{info.get('device_type', '?')}>"
        )
    lines = [f"Layout: {home_state.get('layout_name', 'unknown')}"]
    for room in sorted(by_room):
        lines.append(f"- {room}: {', '.join(sorted(by_room[room]))}")
    return "\n".join(lines)


def extract_evidence_packet(
    episode: Dict,
    max_salient_events: int = 60,
    max_focus_events: int = 120,
) -> Dict:
    events = _filter_events_by_query_window(episode.get("event_sequence", []), episode.get("query", ""))
    home_state = episode.get("home_state", {})
    room_map = _device_room_map(home_state)

    scored: List[Tuple[int, int, Dict]] = []
    for idx, evt in enumerate(events):
        score = _event_salience(evt)
        if score > 0:
            scored.append((score, idx, evt))
    scored.sort(key=lambda item: (-item[0], item[1]))
    top = scored[:max_salient_events]

    salient_indices = sorted({idx for _, idx, _ in top})
    focus_indices = set()
    for idx in salient_indices:
        for near in range(max(0, idx - 1), min(len(events), idx + 2)):
            focus_indices.add(near)
    focus_events = [events[i] for i in sorted(focus_indices)[:max_focus_events]]

    room_activity = Counter(room_map.get(evt.get("device_id", ""), "unknown") for evt in focus_events)
    suspicious_signals = [format_event_line(evt) for _, _, evt in top[:20]]
    focus_log_text = "\n".join(format_event_line(evt) for evt in focus_events)

    packet = {
        "episode_id": episode.get("episode_id", ""),
        "sq_type": episode.get("metadata", {}).get("sq_type", ""),
        "query": episode.get("query", ""),
        "layout_summary": _summarize_layout(home_state),
        "event_count": len(events),
        "salient_event_count": len(salient_indices),
        "focus_event_count": len(focus_events),
        "room_activity": dict(room_activity),
        "temperature_patterns": _temperature_patterns(events),
        "suspicious_signals": suspicious_signals,
        "focus_log_text": focus_log_text,
    }
    return packet