from __future__ import annotations

import asyncio
import logging
import httpx
from dataclasses import dataclass, field
from typing import Any, Dict, List, Optional

logger = logging.getLogger(__name__)

# ---------------------------------------------------------------------------
# GraphQL query for the Unraid built-in API (6.12+)
# ---------------------------------------------------------------------------

_GRAPHQL_QUERY = """
{
  online
  info {
    os { hostname uptime }
    cpu { model cores threads }
    memory { layout { size type } }
  }
  docker {
    containers { names state status image }
  }
  array {
    state
    capacity { kilobytes { free used total } }
  }
  shares { name free size }
}
""".strip()


@dataclass
class ServerConfig:
    """Configuration for a single Unraid server."""

    name: str
    host: str
    api_key: str = ""
    port: int = 80


def _empty_stats(server: ServerConfig) -> Dict[str, Any]:
    """Return a default stats dictionary for a server that has not yet been queried."""
    return {
        "name": server.name,
        "host": server.host,
        "online": False,
        "uptime": "",
        "cpu": {"usage_pct": 0, "cores": 0, "temp_c": None},
        "ram": {"used_gb": 0, "total_gb": 0, "pct": 0},
        "array": {"status": "unknown", "disks": []},
        "docker": {"running": 0, "containers": []},
        "error": None,
    }


# ---------------------------------------------------------------------------
# GraphQL parser (Unraid 6.12+ built-in API)
# ---------------------------------------------------------------------------

def _parse_graphql_response(data: Dict[str, Any], result: Dict[str, Any]) -> None:
    """Parse a successful GraphQL response into the standard result dict."""
    result["online"] = data.get("online", True)

    # --- Info ---
    info = data.get("info", {})
    os_info = info.get("os", {})
    result["uptime"] = os_info.get("uptime", "")

    cpu_info = info.get("cpu", {})
    result["cpu"]["cores"] = cpu_info.get("cores", 0)
    # GraphQL API doesn't expose CPU usage % — keep 0
    # Store threads for the frontend to show
    result["cpu"]["threads"] = cpu_info.get("threads", 0)

    # Memory: sum layout slots for total GB
    mem_layout = info.get("memory", {}).get("layout", [])
    total_bytes = sum(slot.get("size", 0) for slot in mem_layout)
    result["ram"]["total_gb"] = round(total_bytes / (1024 ** 3), 1)
    # GraphQL API doesn't expose used memory — keep 0

    # --- Docker ---
    docker_data = data.get("docker", {})
    containers_raw: List[Dict[str, Any]] = docker_data.get("containers", [])
    containers: List[Dict[str, Any]] = []
    running_count = 0
    for c in containers_raw:
        names = c.get("names", [])
        name = names[0].lstrip("/") if names else "unknown"
        state = c.get("state", "unknown")
        is_running = state == "RUNNING"
        if is_running:
            running_count += 1
        containers.append({
            "name": name,
            "status": c.get("status", ""),
            "image": c.get("image", ""),
            "running": is_running,
        })
    result["docker"]["running"] = running_count
    result["docker"]["containers"] = containers

    # --- Array ---
    array_data = data.get("array", {})
    result["array"]["status"] = array_data.get("state", "unknown").lower()

    cap = array_data.get("capacity", {}).get("kilobytes", {})
    total_kb = int(cap.get("total", 0))
    used_kb = int(cap.get("used", 0))
    if total_kb > 0:
        result["array"]["total_tb"] = round(total_kb / (1024 ** 2), 1)  # KB → TB
        result["array"]["used_tb"] = round(used_kb / (1024 ** 2), 1)

    # --- Shares (expose as top-level) ---
    shares_raw = data.get("shares", [])
    shares: List[Dict[str, Any]] = []
    for s in shares_raw:
        free_kb = s.get("free", 0)
        shares.append({
            "name": s.get("name", ""),
            "free_gb": round(free_kb / (1024 ** 2), 1),
        })
    result["shares"] = shares


async def _try_graphql_endpoint(
    client: httpx.AsyncClient,
    server: ServerConfig,
    result: Dict[str, Any],
) -> bool:
    """Attempt to fetch stats via the Unraid GraphQL API (6.12+).

    Returns True if successful, False otherwise.
    """
    if not server.api_key:
        return False

    base = f"http://{server.host}:{server.port}"
    headers = {
        "x-api-key": server.api_key,
        "Content-Type": "application/json",
        "Origin": base,
    }

    try:
        resp = await client.post(
            f"{base}/graphql",
            headers=headers,
            json={"query": _GRAPHQL_QUERY},
        )

        if resp.status_code == 403:
            # 403 means the endpoint exists but auth failed
            logger.warning("[UNRAID] %s (%s): GraphQL 403 — invalid API key?",
                          server.name, server.host)
            return False

        if resp.status_code != 200:
            return False

        body = resp.json()

        # Check for GraphQL-level errors
        errors = body.get("errors")
        if errors and not body.get("data"):
            first_msg = errors[0].get("message", "") if errors else ""
            logger.warning("[UNRAID] %s (%s): GraphQL error: %s",
                          server.name, server.host, first_msg)
            return False

        data = body.get("data")
        if not data:
            return False

        _parse_graphql_response(data, result)
        logger.info(
            "[UNRAID] %s (%s): GraphQL OK — %d containers (%d running), %s cores",
            server.name, server.host,
            len(result["docker"]["containers"]),
            result["docker"]["running"],
            result["cpu"]["cores"],
        )
        return True

    except Exception as exc:
        logger.debug("[UNRAID] %s (%s): GraphQL failed: %s",
                    server.name, server.host, exc)
        return False


# ---------------------------------------------------------------------------
# Legacy REST parser (custom Unraid API plugins)
# ---------------------------------------------------------------------------

def _parse_system_info(data: Dict[str, Any], result: Dict[str, Any]) -> None:
    """Populate *result* from a generic ``/api/system`` JSON response."""
    result["online"] = True
    result["uptime"] = data.get("uptime", "")

    cpu_data = data.get("cpu", {})
    result["cpu"]["usage_pct"] = cpu_data.get("usage_pct", cpu_data.get("usage", 0))
    result["cpu"]["cores"] = cpu_data.get("cores", 0)
    result["cpu"]["temp_c"] = cpu_data.get("temp_c", cpu_data.get("temp", None))

    ram_data = data.get("ram", data.get("memory", {}))
    result["ram"]["used_gb"] = round(ram_data.get("used_gb", ram_data.get("used", 0)), 2)
    result["ram"]["total_gb"] = round(ram_data.get("total_gb", ram_data.get("total", 0)), 2)
    total = result["ram"]["total_gb"]
    if total > 0:
        result["ram"]["pct"] = round(result["ram"]["used_gb"] / total * 100, 1)
    else:
        result["ram"]["pct"] = 0


def _parse_array_info(data: Dict[str, Any], result: Dict[str, Any]) -> None:
    """Populate array information from an API response."""
    array_data = data.get("array", {})
    result["array"]["status"] = array_data.get("status", "unknown")

    disks_raw: List[Dict[str, Any]] = array_data.get("disks", [])
    parsed_disks: List[Dict[str, Any]] = []
    for disk in disks_raw:
        parsed_disks.append({
            "name": disk.get("name", ""),
            "status": disk.get("status", "unknown"),
            "size": disk.get("size", ""),
            "used": disk.get("used", ""),
            "temp_c": disk.get("temp_c", None),
        })
    result["array"]["disks"] = parsed_disks


def _parse_docker_info(data: Dict[str, Any], result: Dict[str, Any]) -> None:
    """Populate Docker container information from an API response."""
    docker_data = data.get("docker", {})
    containers_raw: List[Dict[str, Any]] = docker_data.get("containers", [])

    containers: List[Dict[str, Any]] = []
    running_count = 0
    for container in containers_raw:
        status = container.get("status", "unknown")
        is_running = "running" in status.lower() if isinstance(status, str) else False
        if is_running:
            running_count += 1
        containers.append({
            "name": container.get("name", ""),
            "status": status,
            "image": container.get("image", ""),
            "running": is_running,
        })

    result["docker"]["running"] = docker_data.get("running", running_count)
    result["docker"]["containers"] = containers


async def _try_rest_endpoint(
    client: httpx.AsyncClient,
    server: ServerConfig,
    result: Dict[str, Any],
) -> bool:
    """Attempt to fetch stats via legacy REST API endpoints.

    Returns True if successful, False otherwise.
    """
    if not server.api_key:
        return False

    headers = {"Authorization": f"Bearer {server.api_key}"}
    base = f"http://{server.host}:{server.port}"

    try:
        resp = await client.get(f"{base}/api/system", headers=headers)
        if resp.status_code == 200:
            data = resp.json()
            _parse_system_info(data, result)
            _parse_array_info(data, result)
            _parse_docker_info(data, result)
            logger.info("[UNRAID] %s (%s): REST API OK", server.name, server.host)
            return True
        else:
            logger.debug("[UNRAID] %s (%s): /api/system returned HTTP %d",
                        server.name, server.host, resp.status_code)
    except Exception as exc:
        logger.debug("[UNRAID] %s (%s): /api/system failed: %s",
                    server.name, server.host, exc)

    # Try individual endpoints if the combined one failed
    fetched_any = False

    for endpoint, parser in [
        ("/api/cpu", lambda d: (
            result["cpu"].update({
                "usage_pct": d.get("usage_pct", d.get("usage", 0)),
                "cores": d.get("cores", 0),
                "temp_c": d.get("temp_c", None),
            }),
        )),
        ("/api/memory", lambda d: (
            result["ram"].update({
                "used_gb": round(d.get("used_gb", d.get("used", 0)), 2),
                "total_gb": round(d.get("total_gb", d.get("total", 0)), 2),
            }),
        )),
    ]:
        try:
            resp = await client.get(f"{base}{endpoint}", headers=headers)
            if resp.status_code == 200:
                parser(resp.json())
                result["online"] = True
                fetched_any = True
        except Exception:
            pass

    try:
        resp = await client.get(f"{base}/api/array", headers=headers)
        if resp.status_code == 200:
            _parse_array_info(resp.json(), result)
            result["online"] = True
            fetched_any = True
    except Exception:
        pass

    try:
        resp = await client.get(f"{base}/api/docker", headers=headers)
        if resp.status_code == 200:
            _parse_docker_info(resp.json(), result)
            result["online"] = True
            fetched_any = True
    except Exception:
        pass

    return fetched_any


# ---------------------------------------------------------------------------
# Connectivity fallback
# ---------------------------------------------------------------------------

async def _try_connectivity_check(
    client: httpx.AsyncClient,
    server: ServerConfig,
    result: Dict[str, Any],
) -> None:
    """Perform a basic HTTP connectivity check as a fallback."""
    try:
        resp = await client.get(
            f"http://{server.host}:{server.port}/",
            follow_redirects=True,
        )
        result["online"] = resp.status_code < 500
    except Exception:
        result["online"] = False


# ---------------------------------------------------------------------------
# Main fetch function
# ---------------------------------------------------------------------------

async def fetch_server_stats(server: ServerConfig) -> Dict[str, Any]:
    """Fetch system stats from an Unraid server.

    Strategy:
    1. Try Unraid GraphQL API (built-in since 6.12, uses ``x-api-key`` header)
    2. Fall back to legacy REST API (custom plugins, uses ``Bearer`` token)
    3. Fall back to simple HTTP connectivity check

    Args:
        server: A :class:`ServerConfig` describing the target server.

    Returns:
        Dictionary with server name, host, online status, and detailed stats
        for CPU, RAM, array, and Docker containers.
    """
    result = _empty_stats(server)

    if not server.host:
        result["error"] = "No host configured"
        return result

    try:
        async with httpx.AsyncClient(timeout=10, verify=False) as client:
            # 1) Try GraphQL first (modern Unraid 6.12+)
            api_ok = await _try_graphql_endpoint(client, server, result)

            # 2) Fall back to REST
            if not api_ok:
                api_ok = await _try_rest_endpoint(client, server, result)

            # 3) Fall back to connectivity check
            if not api_ok and not result["online"]:
                logger.info("[UNRAID] %s: APIs failed, trying connectivity check", server.name)
                await _try_connectivity_check(client, server, result)

    except Exception as exc:
        result["online"] = False
        result["error"] = str(exc)
        logger.error("[UNRAID] %s (%s): connection failed: %s", server.name, server.host, exc)

    if not result["online"]:
        logger.warning("[UNRAID] %s (%s): offline (error=%s)", server.name, server.host, result.get("error"))

    return result


async def fetch_all_servers(servers: List[ServerConfig]) -> List[Dict[str, Any]]:
    """Fetch stats from all configured Unraid servers in parallel.

    Args:
        servers: List of :class:`ServerConfig` instances.

    Returns:
        List of stats dictionaries, one per server.
    """
    if not servers:
        return []

    tasks = [fetch_server_stats(srv) for srv in servers]
    return list(await asyncio.gather(*tasks))