import json
import logging
import os
import time
from datetime import datetime, timezone
from pathlib import Path

import httpx
import yaml

logging.basicConfig(level=logging.INFO, format="%(asctime)s [varys] %(message)s")
logger = logging.getLogger("varys")

SITES_DIR = Path(os.getenv("SITES_DIR", "/opt/sites"))
AGENT_OS_DIR = Path(os.getenv("AGENT_OS_DIR", "/opt/agent-os"))
RAVEN_URL = os.getenv("RAVEN_URL", "")
CONFIG_FILE = Path(__file__).parent / "config.yaml"


def _load_prev_states() -> dict:
    path = AGENT_OS_DIR / "logs" / "varys-monitor" / "service-states.json"
    if not path.exists():
        return {"services": {}, "agents": {}}
    try:
        data = json.loads(path.read_text())
        # migrate old flat format (services only)
        if "services" not in data:
            return {"services": data, "agents": {}}
        return data
    except Exception:
        return {"services": {}, "agents": {}}


def _save_states(services: list, agents: list):
    path = AGENT_OS_DIR / "logs" / "varys-monitor" / "service-states.json"
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(json.dumps({
        "services": {s["name"]: s["status"] for s in services},
        "agents": {a["name"]: a["status"] for a in agents},
    }))


def _notify_raven(message: str, severity: str):
    if not RAVEN_URL:
        return
    try:
        httpx.post(f"{RAVEN_URL}/notify", json={"message": message, "severity": severity, "source": "varys"}, timeout=5)
        logger.info(f"raven notified: {message}")
    except Exception as e:
        logger.warning(f"raven notify failed (raven not live yet?): {e}")


def check_service(name: str, url: str) -> dict:
    start = time.monotonic()
    try:
        # stream=True so we get the status code without reading the body (handles SSE endpoints)
        with httpx.stream("GET", url, timeout=5, verify=False, follow_redirects=True) as r:
            ms = int((time.monotonic() - start) * 1000)
            status = "up" if r.status_code < 500 else "degraded"
            return {"name": name, "status": status, "code": r.status_code, "ms": ms}
    except Exception:
        ms = int((time.monotonic() - start) * 1000)
        return {"name": name, "status": "down", "code": None, "ms": ms}


def read_agent_status(name: str) -> dict:
    path = AGENT_OS_DIR / "logs" / name / "last-run.json"
    if not path.exists():
        return {"name": name, "status": "unknown", "timestamp": None, "result": "no data"}
    try:
        data = json.loads(path.read_text())
        return {
            "name": name,
            "status": data.get("status", "unknown"),
            "timestamp": data.get("timestamp", ""),
            "result": data.get("result", ""),
        }
    except Exception as e:
        return {"name": name, "status": "error", "timestamp": None, "result": str(e)}


def render_html(services: list, agents: list) -> str:
    now_iso = datetime.now(timezone.utc).isoformat()

    SERVICE_COLOURS = {"up": "#3fb950", "degraded": "#d29922", "down": "#f85149"}
    AGENT_COLOURS = {"success": "#3fb950", "failure": "#f85149"}

    service_cards = ""
    for s in services:
        colour = SERVICE_COLOURS.get(s["status"], "#8b949e")
        label = s["status"].upper()
        ms_text = f"{s['ms']} ms" if s["status"] != "down" else "—"
        service_cards += f"""
    <div class="svc">
      <span class="dot" style="background:{colour}"></span>
      <span class="svc-name">{s['name']}</span>
      <span class="svc-label" style="color:{colour}">{label}</span>
      <span class="svc-ms">{ms_text}</span>
    </div>"""

    agent_rows = ""
    for a in agents:
        colour = AGENT_COLOURS.get(a["status"], "#8b949e")
        raw_ts = a["timestamp"]
        ts = f'<span data-utc="{raw_ts}"></span>' if raw_ts else "—"
        agent_rows += f"""
      <tr>
        <td><span class="dot" style="background:{colour}"></span>{a['name']}</td>
        <td style="color:{colour}">{a['status'].upper()}</td>
        <td>{ts}</td>
        <td class="dim">{a['result']}</td>
      </tr>"""

    return f"""<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <meta http-equiv="refresh" content="900">
  <title>Varys — Status</title>
  <style>
    * {{ box-sizing: border-box; margin: 0; padding: 0; }}
    body {{ font-family: monospace; background: #0d1117; color: #c9d1d9; padding: 2rem; }}
    h1 {{ color: #58a6ff; margin-bottom: 0.25rem; }}
    h2 {{ color: #8b949e; font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.05em; margin: 2rem 0 0.75rem; }}
    .desc {{ color: #8b949e; font-size: 0.9rem; margin: 0.4rem 0 0.25rem; }}
    .meta {{ color: #8b949e; font-size: 0.85rem; margin-bottom: 2rem; }}
    .meta a {{ color: #8b949e; }}
    .dot {{ display: inline-block; width: 8px; height: 8px; border-radius: 50%; margin-right: 6px; vertical-align: middle; }}
    .svc {{ display: flex; align-items: center; gap: 0.75rem; border: 1px solid #30363d; border-radius: 6px; padding: 0.6rem 1rem; margin-bottom: 0.5rem; }}
    .svc-name {{ flex: 1; }}
    .svc-label {{ font-size: 0.8rem; min-width: 5rem; }}
    .svc-ms {{ color: #8b949e; font-size: 0.8rem; min-width: 4rem; text-align: right; }}
    table {{ width: 100%; border-collapse: collapse; }}
    td {{ padding: 0.6rem 1rem; border-bottom: 1px solid #21262d; font-size: 0.9rem; }}
    .dim {{ color: #8b949e; }}
  </style>
</head>
<body>
  <h1>Varys — Status</h1>
  <p class="desc">Checks HTTP reachability for all services in the NxM stack and monitors agent run status. Refreshes every 15 minutes.</p>
  <p class="meta">Updated <span data-utc="{now_iso}"></span> &nbsp;·&nbsp; <a href="/">← home</a></p>
  <h2>Services</h2>
  {service_cards}
  <h2>Agents</h2>
  <table><tbody>{agent_rows}</tbody></table>
  <script>
    document.querySelectorAll('[data-utc]').forEach(el => {{
      el.textContent = new Date(el.dataset.utc).toLocaleString(undefined, {{year:'numeric',month:'2-digit',day:'2-digit',hour:'2-digit',minute:'2-digit'}});
    }});
  </script>
</body>
</html>"""


def render_summary_md(services: list, agents: list) -> str:
    now = datetime.now(timezone.utc).strftime("%Y-%m-%d %H:%M UTC")
    up = sum(1 for s in services if s["status"] == "up")
    down = [s["name"] for s in services if s["status"] in ("down", "degraded")]

    lines = [f"# Varys — Status Summary\n\nUpdated: {now}\n"]
    lines.append(f"## Services: {up}/{len(services)} up")
    if down:
        lines.append(f"Issues: {', '.join(down)}")
    lines.append("")
    lines.append("## Agents")
    for a in agents:
        ts = a["timestamp"][:16].replace("T", " ") + " UTC" if a["timestamp"] else "no data"
        lines.append(f"- {a['name']}: {a['status']} ({ts}) — {a['result']}")
    return "\n".join(lines)


def main():
    config = yaml.safe_load(CONFIG_FILE.read_text())

    services = []
    for svc in config.get("services", []):
        result = check_service(svc["name"], svc["url"])
        logger.info(f"{svc['name']}: {result['status']} ({result['ms']} ms)")
        services.append(result)

    agents = []
    for agent in config.get("agents", []):
        result = read_agent_status(agent["name"])
        logger.info(f"agent {agent['name']}: {result['status']}")
        agents.append(result)

    prev_states = _load_prev_states()
    prev_services = prev_states.get("services", {})
    prev_agents = prev_states.get("agents", {})

    for s in services:
        prev = prev_services.get(s["name"])
        if prev and prev != "down" and s["status"] == "down":
            _notify_raven(f"{s['name']} is DOWN", "critical")
        elif prev == "down" and s["status"] not in ("down", "degraded"):
            _notify_raven(f"{s['name']} recovered (UP)", "info")

    for a in agents:
        prev = prev_agents.get(a["name"])
        if a["status"] == "failure" and prev != "failure":
            detail = a.get("result", "no details")
            _notify_raven(f"{a['name']} failed: {detail}", "critical")
        elif prev == "failure" and a["status"] == "success":
            _notify_raven(f"{a['name']} recovered (success)", "info")

    _save_states(services, agents)

    out_dir = SITES_DIR / "varys"
    out_dir.mkdir(parents=True, exist_ok=True)
    (out_dir / "index.html").write_text(render_html(services, agents))
    (out_dir / "last-output.md").write_text(render_summary_md(services, agents))

    down_count = sum(1 for s in services if s["status"] != "up")
    status = {
        "agent": "varys-monitor",
        "timestamp": datetime.now(timezone.utc).isoformat(),
        "status": "success",
        "result": f"{len(services)} services checked, {down_count} not up",
    }
    log_dir = AGENT_OS_DIR / "logs" / "varys-monitor"
    log_dir.mkdir(parents=True, exist_ok=True)
    (log_dir / "last-run.json").write_text(json.dumps(status, indent=2))
    logger.info(f"done — {len(services)} services, {down_count} not up")


if __name__ == "__main__":
    main()