import hashlib
import json
from datetime import datetime
from pathlib import Path

from app.infrastructure.service.wechat.config import LOG_ROOT_DIR


ALLOWED_MODULES = {"api", "bot", "ocr", "ai", "db", "capture", "audit", "error"}
DOMAIN_MODULES = {"api", "bot", "ocr", "ai", "db", "capture"}


def _infer_domain(row: dict) -> str:
    module = str(row.get("module") or "").strip().lower()
    if module in DOMAIN_MODULES:
        return module
    if module == "error":
        event = str(row.get("event") or "")
        prefix = event.split(".", 1)[0].strip().lower()
        if prefix in DOMAIN_MODULES:
            return prefix
    return "api"


def _event_id(row: dict) -> str:
    raw = json.dumps(row or {}, ensure_ascii=False, sort_keys=True)
    return hashlib.md5(raw.encode("utf-8")).hexdigest()


def _enrich_row(row: dict) -> dict:
    x = dict(row or {})
    x["domain"] = _infer_domain(x)
    x["event_id"] = _event_id(x)
    return x


def _read_jsonl(module: str):
    p = Path(LOG_ROOT_DIR) / f"{module}.jsonl"
    if not p.exists():
        return []
    rows = []
    with p.open("r", encoding="utf-8", errors="replace") as f:
        for line in f:
            line = line.strip()
            if not line:
                continue
            try:
                rows.append(json.loads(line))
            except Exception:
                continue
    return rows


def query_events(module=None, level=None, event=None, trace_id=None, start_ts=None, end_ts=None, keyword=None, page=1, size=50):
    modules = [module] if module in ALLOWED_MODULES else sorted(ALLOWED_MODULES)
    all_rows = []
    for m in modules:
        all_rows.extend(_read_jsonl(m))
    def ok(row):
        if level and str(row.get("level", "")).upper() != str(level).upper():
            return False
        if event and str(row.get("event", "")) != str(event):
            return False
        if trace_id and str(row.get("trace_id", "")) != str(trace_id):
            return False
        if keyword and keyword not in json.dumps(row, ensure_ascii=False):
            return False
        ts = str(row.get("ts") or "")
        if start_ts and ts < start_ts:
            return False
        if end_ts and ts > end_ts:
            return False
        return True
    rows = [_enrich_row(r) for r in all_rows if ok(r)]
    rows.sort(key=lambda x: str(x.get("ts") or ""), reverse=True)
    page = max(1, int(page or 1))
    size = max(1, min(200, int(size or 50)))
    start = (page - 1) * size
    end = start + size
    return {"total": len(rows), "page": page, "size": size, "items": rows[start:end]}


def query_trace(trace_id: str):
    if not trace_id:
        return []
    result = query_events(trace_id=trace_id, size=500)
    items = result.get("items") or []
    items.sort(key=lambda x: str(x.get("ts") or ""))
    return items


def query_event_json(event_id: str):
    event_id = str(event_id or "").strip().lower()
    if not event_id:
        return None
    for m in sorted(ALLOWED_MODULES):
        rows = _read_jsonl(m)
        for row in rows:
            x = _enrich_row(row)
            if str(x.get("event_id") or "") == event_id:
                return x
    return None


def clear_logs(module=None):
    modules = [module] if module in ALLOWED_MODULES else sorted(ALLOWED_MODULES)
    root = Path(LOG_ROOT_DIR)
    deleted = []
    for m in modules:
        for p in root.glob(f"{m}.log*"):
            p.write_text("", encoding="utf-8")
            deleted.append(str(p.name))
        for p in root.glob(f"{m}.jsonl*"):
            p.write_text("", encoding="utf-8")
            deleted.append(str(p.name))
    return {"modules": modules, "files": deleted}


def query_summary(limit=300):
    events = query_events(size=limit).get("items") or []
    error_count = sum(1 for e in events if str(e.get("level", "")).upper() in {"ERROR"})
    fallback_count = sum(1 for e in events if str(e.get("event", "")).endswith("fallback"))
    reasons = {}
    domain_counts = {"api": 0, "bot": 0, "ocr": 0, "ai": 0, "db": 0, "capture": 0}
    for e in events:
        reason = str(e.get("reason") or "").strip()
        if reason:
            reasons[reason] = reasons.get(reason, 0) + 1
        domain = str(e.get("domain") or _infer_domain(e))
        if domain in domain_counts:
            domain_counts[domain] += 1
    reason_top = sorted(reasons.items(), key=lambda x: x[1], reverse=True)[:20]
    domain_top = sorted(domain_counts.items(), key=lambda x: x[1], reverse=True)
    return {
        "window": len(events),
        "error_count": error_count,
        "fallback_count": fallback_count,
        "top_reasons": [{"reason": k, "count": v} for k, v in reason_top],
        "domain_counts": [{"domain": k, "count": v} for k, v in domain_top],
        "generated_at": datetime.now().astimezone().isoformat(timespec="seconds"),
    }