"""軽量ステータスページ。targets.txt の各サービスを定期チェックし HTML / JSON で公開する。"""
import json
import os
import socket
import threading
import time
import urllib.error
import urllib.parse
import urllib.request
from collections import deque
from concurrent.futures import ThreadPoolExecutor
from datetime import datetime, timezone
from html import escape
from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer

TARGETS_FILE = os.environ.get("TARGETS_FILE", "/app/targets.txt")
INTERVAL = int(os.environ.get("CHECK_INTERVAL", "60"))
TIMEOUT = float(os.environ.get("CHECK_TIMEOUT", "10"))
HISTORY = int(os.environ.get("HISTORY_SIZE", "90"))
PORT = int(os.environ.get("PORT", "8080"))
NTFY_URL = os.environ.get("NTFY_URL", "")  # 例: http://ntfy/status（空なら通知しない）
NTFY_TOKEN = os.environ.get("NTFY_TOKEN", "")
FAIL_THRESHOLD = int(os.environ.get("FAIL_THRESHOLD", "2"))  # 連続失敗この回数で DOWN 通知
PUBLIC_URL = os.environ.get("PUBLIC_URL", "https://status.yyamashita.com")

lock = threading.Lock()
state = {}  # name -> {"url", "up", "detail", "ms", "checked_at", "history": deque[bool], "fails", "alerted"}


def load_targets():
    targets = []
    with open(TARGETS_FILE) as f:
        for line in f:
            line = line.strip()
            if not line or line.startswith("#"):
                continue
            name, url = line.split(None, 1)
            targets.append((name, url.strip()))
    return targets


def check(url):
    start = time.monotonic()
    parsed = urllib.parse.urlparse(url)
    try:
        if parsed.scheme == "tcp":
            with socket.create_connection((parsed.hostname, parsed.port), timeout=TIMEOUT):
                pass
            up, detail = True, "connected"
        else:
            req = urllib.request.Request(url, headers={"User-Agent": "status-check/1.0"})
            try:
                with urllib.request.urlopen(req, timeout=TIMEOUT) as r:
                    code = r.status
            except urllib.error.HTTPError as e:
                code = e.code
            up, detail = code < 500, f"HTTP {code}"
    except Exception as e:
        up, detail = False, f"{type(e).__name__}: {e}"
    return up, detail, int((time.monotonic() - start) * 1000)


def notify(title, message, down):
    if not NTFY_URL:
        return
    headers = {
        "Title": title,
        "Tags": "rotating_light" if down else "white_check_mark",
        "Priority": "high" if down else "default",
        "Click": PUBLIC_URL,
    }
    if NTFY_TOKEN:
        headers["Authorization"] = f"Bearer {NTFY_TOKEN}"
    req = urllib.request.Request(NTFY_URL, data=message.encode(), headers=headers, method="POST")
    try:
        urllib.request.urlopen(req, timeout=TIMEOUT).close()
    except Exception as e:
        print(f"ntfy notify failed: {e}", flush=True)


def run_checks():
    targets = load_targets()
    with ThreadPoolExecutor(max_workers=max(1, len(targets))) as pool:
        results = list(pool.map(lambda t: check(t[1]), targets))
    now = datetime.now(timezone.utc).isoformat(timespec="seconds")
    alerts = []
    with lock:
        for name in set(state) - {n for n, _ in targets}:
            del state[name]
        for (name, url), (up, detail, ms) in zip(targets, results):
            entry = state.setdefault(
                name, {"history": deque(maxlen=HISTORY), "fails": 0, "alerted": False}
            )
            entry.update(url=url, up=up, detail=detail, ms=ms, checked_at=now)
            entry["history"].append(up)
            entry["fails"] = 0 if up else entry["fails"] + 1
            if not up and entry["fails"] >= FAIL_THRESHOLD and not entry["alerted"]:
                entry["alerted"] = True
                alerts.append((f"{name} is DOWN", f"{url}\n{detail}", True))
            elif up and entry["alerted"]:
                entry["alerted"] = False
                alerts.append((f"{name} recovered", f"{url}\n{detail} ({ms} ms)", False))
    for alert in alerts:
        notify(*alert)


def checker_loop():
    while True:
        try:
            run_checks()
        except Exception as e:
            print(f"check failed: {e}", flush=True)
        time.sleep(INTERVAL)


def snapshot():
    with lock:
        services = [
            {
                "name": name,
                "url": e["url"],
                "up": e["up"],
                "detail": e["detail"],
                "ms": e["ms"],
                "checked_at": e["checked_at"],
                "uptime": round(100 * sum(e["history"]) / len(e["history"]), 1),
                "history": list(e["history"]),
            }
            for name, e in state.items()
        ]
    return {"all_up": all(s["up"] for s in services), "services": services}


def render_html(data):
    rows = []
    for s in data["services"]:
        bars = "".join(
            f'<i class="{"u" if ok else "d"}"></i>' for ok in s["history"]
        )
        rows.append(
            f'<tr><td><span class="dot {"u" if s["up"] else "d"}"></span>{escape(s["name"])}</td>'
            f'<td>{escape(s["detail"])}</td><td>{s["ms"]} ms</td><td>{s["uptime"]}%</td>'
            f'<td class="bars">{bars}</td></tr>'
        )
    if not data["services"]:
        banner = '<div class="banner">Checking...</div>'
    elif data["all_up"]:
        banner = '<div class="banner u">All systems operational</div>'
    else:
        banner = '<div class="banner d">Some systems are down</div>'
    checked = data["services"][0]["checked_at"] if data["services"] else "-"
    return f"""<!DOCTYPE html>
<html><head><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1">
<meta http-equiv="refresh" content="{INTERVAL}"><title>Status - yyamashita.com</title>
<style>
body{{font-family:system-ui,sans-serif;max-width:860px;margin:2em auto;padding:0 1em;color:#222}}
.banner{{padding:.8em 1em;border-radius:6px;color:#fff;background:#888;font-weight:600}}
.banner.u{{background:#2a9d4b}}.banner.d{{background:#d0393e}}
table{{width:100%;border-collapse:collapse;margin-top:1em}}td{{padding:.5em;border-bottom:1px solid #eee;white-space:nowrap}}
.dot{{display:inline-block;width:10px;height:10px;border-radius:50%;margin-right:.5em}}
.u{{background:#2a9d4b}}.d{{background:#d0393e}}
.bars{{width:100%}}.bars i{{display:inline-block;width:4px;height:18px;margin-right:1px;border-radius:1px}}
small{{color:#888}}
</style></head><body>
<h2>yyamashita.com status</h2>
{banner}
<table>{"".join(rows)}</table>
<p><small>Last checked: {checked} (every {INTERVAL}s) · <a href="/api/status">JSON</a></small></p>
</body></html>"""


class Handler(BaseHTTPRequestHandler):
    def do_GET(self):
        data = snapshot()
        if self.path == "/api/status":
            body = json.dumps(data).encode()
            ctype = "application/json"
        elif self.path == "/healthz":
            body, ctype = b"ok", "text/plain"
        elif self.path == "/":
            body = render_html(data).encode()
            ctype = "text/html; charset=utf-8"
        else:
            self.send_error(404)
            return
        self.send_response(200)
        self.send_header("Content-Type", ctype)
        self.send_header("Content-Length", str(len(body)))
        self.end_headers()
        self.wfile.write(body)

    def log_message(self, *args):
        pass


if __name__ == "__main__":
    threading.Thread(target=checker_loop, daemon=True).start()
    ThreadingHTTPServer(("0.0.0.0", PORT), Handler).serve_forever()