#!/usr/bin/env python3
"""
logwatch – unified app
- background thread: subscribes to ntfy, filters, stores, forwards
- FastAPI: REST API + static file serving
"""

import json
import logging
import os
import re
import sqlite3
import threading
import time
from contextlib import asynccontextmanager
from pathlib import Path

import requests
from fastapi import FastAPI
from fastapi.responses import FileResponse, JSONResponse
from fastapi.staticfiles import StaticFiles

# ── Config ────────────────────────────────────────────────
SOURCE_URL      = os.environ.get("SOURCE_URL",      "http://192.168.123.77/albert")
TARGET_URL      = os.environ.get("TARGET_URL",      "")
TARGET_TOKEN    = os.environ.get("TARGET_TOKEN",    "")
LOG_LEVEL       = os.environ.get("LOG_LEVEL",       "INFO").upper()
RECONNECT_DELAY = int(os.environ.get("RECONNECT_DELAY", "10"))
DB_PATH         = os.environ.get("DB_PATH",         "/data/logwatch.db")

logging.basicConfig(
    level=getattr(logging, LOG_LEVEL, logging.INFO),
    format="%(asctime)s  %(levelname)-7s  %(message)s",
    datefmt="%Y-%m-%d %H:%M:%S",
)
log = logging.getLogger("logwatch")

# ── Database ──────────────────────────────────────────────
def get_db():
    Path(DB_PATH).parent.mkdir(parents=True, exist_ok=True)
    conn = sqlite3.connect(DB_PATH, check_same_thread=False)
    conn.row_factory = sqlite3.Row
    return conn

def init_db():
    db = get_db()
    db.execute("""
        CREATE TABLE IF NOT EXISTS messages (
            id          INTEGER PRIMARY KEY AUTOINCREMENT,
            ntfy_id     TEXT,
            received_at TEXT NOT NULL,
            ntfy_time   INTEGER,
            topic       TEXT,
            title       TEXT,
            message     TEXT,
            priority    INTEGER,
            tags        TEXT,
            forwarded   INTEGER DEFAULT 0
        )
    """)
    db.commit()
    db.close()

_db_lock = threading.Lock()

def store_message(event: dict, forwarded: bool) -> None:
    received_at = time.strftime("%Y-%m-%dT%H:%M:%S", time.gmtime())
    tags = json.dumps(event.get("tags", []))
    with _db_lock:
        db = get_db()
        db.execute("""
            INSERT INTO messages
              (ntfy_id, received_at, ntfy_time, topic, title, message, priority, tags, forwarded)
            VALUES (?,?,?,?,?,?,?,?,?)
        """, (
            event.get("id"),
            received_at,
            event.get("time"),
            event.get("topic"),
            event.get("title", ""),
            event.get("message", ""),
            event.get("priority", 3),
            tags,
            1 if forwarded else 0,
        ))
        db.commit()
        db.close()

# ── Filter logic ──────────────────────────────────────────
IMPORTANT_PATTERNS = [re.compile(r, re.IGNORECASE) for r in [
    r"updated?\s+\d+",
    r"\d+\s+updated",
    r"fail(ed|ure)?",
    r"error",
    r"could not",
    r"unable to",
    r"pull(ed)?\s+\w+",
    r"restart(ed|ing)?",
    r"stopped",
    r"warn(ing)?",
]]

NOISE_PATTERNS = [re.compile(r, re.IGNORECASE) for r in [
    r"no\s+(new\s+)?updates?\s+(found|available)",
    r"checked\s+\d+\s+container",
    r"session\s+done",
    r"^watchtower\s+started",
    r"scanning\s+for\s+updates",
    r"0\s+updated.*0\s+failed",
]]

def is_important(title: str, message: str) -> bool:
    text = f"{title} {message}"
    for p in NOISE_PATTERNS:
        if p.search(text):
            return False
    for p in IMPORTANT_PATTERNS:
        if p.search(text):
            return True
    return False

def classify(title: str, message: str) -> tuple[str, list[str]]:
    text = f"{title} {message}".lower()
    if re.search(r"fail|error|could not|unable", text):
        return "high", ["rotating_light", "watchtower"]
    if re.search(r"updated|pulled|restart", text):
        return "default", ["arrow_up", "watchtower"]
    return "low", ["watchtower"]

def forward(title: str, message: str, priority: str, tags: list[str]) -> None:
    if not TARGET_URL:
        return
    headers = {"Title": title, "Priority": priority, "Tags": ",".join(tags)}
    if TARGET_TOKEN:
        headers["Authorization"] = f"Bearer {TARGET_TOKEN}"
    try:
        resp = requests.post(TARGET_URL, data=message.encode(), headers=headers, timeout=10)
        resp.raise_for_status()
        log.info("FORWARDED | [%s] %s", title, message[:100])
    except requests.RequestException as e:
        log.error("Forward failed: %s", e)

# ── Subscriber thread ─────────────────────────────────────
def listen_once():
    sse_url = SOURCE_URL.rstrip("/") + "/json"
    log.info("Connecting to %s", sse_url)
    with requests.get(sse_url, stream=True, timeout=(10, None)) as resp:
        resp.raise_for_status()
        for raw_line in resp.iter_lines():
            if not raw_line:
                continue
            try:
                event = json.loads(raw_line)
            except json.JSONDecodeError:
                continue

            if event.get("event", "message") != "message":
                continue

            title   = event.get("title", "")
            message = event.get("message", "")

            if title and "watchtower" not in title.lower():
                log.debug("SKIP (not watchtower) | [%s]", title)
                continue

            log.debug("RECEIVED | [%s] %s", title, message[:120])

            important = is_important(title, message)
            store_message(event, forwarded=important)

            if important:
                priority, tags = classify(title, message)
                forward(title, message, priority, tags)
            else:
                log.debug("FILTERED | [%s] %s", title, message[:80])

def subscriber_loop():
    log.info("Subscriber started – source: %s  target: %s",
             SOURCE_URL, TARGET_URL or "(dry-run)")
    while True:
        try:
            listen_once()
            log.warning("Stream ended, reconnecting in %ds…", RECONNECT_DELAY)
        except requests.RequestException as e:
            log.error("Connection error: %s – retry in %ds", e, RECONNECT_DELAY)
        time.sleep(RECONNECT_DELAY)

# ── FastAPI ───────────────────────────────────────────────
@asynccontextmanager
async def lifespan(app: FastAPI):
    init_db()
    t = threading.Thread(target=subscriber_loop, daemon=True, name="subscriber")
    t.start()
    yield

app = FastAPI(title="logwatch", lifespan=lifespan)

@app.get("/api/messages")
def api_messages():
    with _db_lock:
        db = get_db()
        rows = db.execute(
            "SELECT * FROM messages ORDER BY id DESC LIMIT 1000"
        ).fetchall()
        db.close()
    result = []
    for r in rows:
        result.append({
            "id":          r["id"],
            "ntfy_id":     r["ntfy_id"],
            "received_at": r["received_at"],
            "ntfy_time":   r["ntfy_time"],
            "topic":       r["topic"],
            "title":       r["title"],
            "message":     r["message"],
            "priority":    r["priority"],
            "tags":        json.loads(r["tags"] or "[]"),
            "forwarded":   bool(r["forwarded"]),
        })
    return JSONResponse(result)

@app.get("/api/health")
def health():
    return {"status": "ok"}

# static files
STATIC_DIR = Path(__file__).parent / "static"
app.mount("/", StaticFiles(directory=str(STATIC_DIR), html=True), name="static")