import json
import os
import time
from datetime import datetime, timezone
from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
from pathlib import Path

# Shared liveness logic — the SAME module the observer and operator_ui use, so
# all three agree on what "dead" means.  This image only copies web.py +
# index.html, so liveness.py is bind-mounted in at /app/liveness.py (see this
# service's docker-compose.yml).  Imported defensively: if the mount is missing
# we fall back to trusting the observer-written status rather than crashing the
# whole panel — the observer remains authoritative either way.
try:
    from liveness import compute_liveness, ttls_for, node_health as _liveness_health, degrade_for_node
    _LIVENESS_OK = True
except Exception:  # pragma: no cover - only when liveness.py mount is absent
    _LIVENESS_OK = False


STATE_DIR = Path(os.getenv("HOMELAB_STATE_ROOT", "/opt/homelab/state"))
EVENTS_DIR = Path(os.getenv("HOMELAB_EVENTS_ROOT", "/opt/homelab/events"))
WORLD_DIR = Path(os.getenv("HOMELAB_WORLD_ROOT", "/opt/homelab/world"))
ACTIONS_DIR = Path(os.getenv("HOMELAB_ACTIONS_ROOT", "/opt/homelab/actions"))
CONFIG_DIR = Path(os.getenv("HOMELAB_CONFIG_ROOT", "/opt/homelab/config"))

STATIC_DIR = Path(__file__).parent

DEFAULT_CONFIG = {
    "operator_mode": "approval",
    "auto_mode": True,
    "action_thresholds": {
        "restart_ha": 0.8,
        "check_network": 0.9,
    },
    "default_threshold": 0.9,
    "allowed_auto_actions": ["restart_ha"],
}


def read_json_file(path, default=None):
    if not path.exists():
        return default if default is not None else []
    try:
        return json.loads(path.read_text())
    except Exception:
        return default if default is not None else []


def get_config():
    config_path = STATE_DIR / "operator-config.json"
    if config_path.exists():
        return read_json_file(config_path, DEFAULT_CONFIG)
    return DEFAULT_CONFIG


def save_config(config):
    STATE_DIR.mkdir(parents=True, exist_ok=True)
    (STATE_DIR / "operator-config.json").write_text(json.dumps(config, indent=2))


def _node_liveness_map():
    """Return {node_name: liveness_tier} from nodes.json (empty if unavailable)."""
    if not _LIVENESS_OK:
        return {}
    raw = read_json_file(WORLD_DIR / "nodes.json", default={})
    if not isinstance(raw, dict):
        return {}
    return {
        name: compute_liveness(info.get("last_seen"),
                               ttls=ttls_for(name, info.get("roles", [])))
        for name, info in raw.items()
    }


def current_nodes():
    """Nodes shaped as a list with a freshness-aware health field.

    nodes.json is a dict keyed by name; index.html does nodes.map() and reads
    node.health, so we shape to a list and compute health here.  The health is
    the read-time safety net (worse of persisted status and last_seen
    freshness) so a stalled observer cannot make a dead node look nominal.
    """
    raw = read_json_file(WORLD_DIR / "nodes.json", default={})
    if isinstance(raw, list):
        return raw
    result = []
    for name, info in raw.items():
        health = _liveness_health(info, name=name) if _LIVENESS_OK else (
            "error" if info.get("status") == "offline"
            else "nominal" if info.get("status") == "online" else info.get("status", "unknown")
        )
        result.append({
            "id":             name,
            "hostname":       name,
            "health":         health,
            "status":         info.get("status", "unknown"),
            "capabilities":   info.get("roles", []),
            "connectivity":   "tailscale",
            "incidents":      0,
            "last_seen":      info.get("last_seen"),
            "disk_usage_pct": info.get("disk_usage_pct"),
            "mem_usage_pct":  info.get("mem_usage_pct"),
            "cpu_usage_pct":  info.get("cpu_usage_pct"),
            "disk_pressure":  info.get("disk_pressure"),
        })
    return result


def current_services():
    """Services shaped as a list, with the node-liveness cascade (variant B)."""
    raw = read_json_file(WORLD_DIR / "services.json", default={})
    if isinstance(raw, list):
        return raw
    node_liveness = _node_liveness_map()
    result = []
    for key, info in raw.items():
        svc_status = info.get("status", "unknown")
        health = ("nominal" if svc_status == "healthy"
                  else ("error" if svc_status == "unhealthy" else svc_status))
        node_name = info.get("node", "")
        if _LIVENESS_OK and node_name in node_liveness:
            health = degrade_for_node(health, node_liveness[node_name])
        result.append({
            "id":           key,
            "name":         info.get("service", key),
            "node":         node_name,
            "health":       health,
            "actual_state": svc_status,
            "last_check":   info.get("last_check"),
            "incident_id":  info.get("incident_id"),
        })
    return result


def current_deployments():
    return read_json_file(WORLD_DIR / "deployments.json")


def current_incidents():
    return read_json_file(WORLD_DIR / "incidents.json")


def current_recommendations():
    return read_json_file(WORLD_DIR / "recommendations.json")


def current_summary():
    path = WORLD_DIR / "runtime-summary.json"
    summary = read_json_file(path, default={})
    if summary:
        last_update_val = summary.get("last_update")
        if last_update_val:
            try:
                if isinstance(last_update_val, str):
                    last_update = datetime.fromisoformat(last_update_val.replace('Z', '+00:00')).timestamp()
                else:
                    last_update = float(last_update_val)
            except Exception:
                last_update = os.path.getmtime(path)
        else:
            last_update = os.path.getmtime(path)
        summary["last_update"] = last_update
        summary["stale"] = (time.time() - last_update) > 60
    return summary


def current_events():
    return read_json_file(WORLD_DIR / "events.json", default=[])


def current_actions():
    actions = {}
    statuses = ["pending", "approved", "running", "completed", "failed", "rejected"]
    for status in statuses:
        actions[status] = []
        status_dir = ACTIONS_DIR / status
        if status_dir.exists():
            for f in status_dir.glob("*.json"):
                data = read_json_file(f)
                if data:
                    # Injects some metadata for UI
                    data["id"] = data.get("action_id") or f.stem
                    data["status"] = status
                    actions[status].append(data)
    return actions


def mutate_action(action_id, target_status):
    statuses = ["pending", "approved", "running", "completed", "failed", "rejected"]
    if target_status not in statuses:
        return False, f"Invalid target status: {target_status}"

    # Find where the action is
    source_path = None
    current_status = None
    for status in statuses:
        p = ACTIONS_DIR / status / f"{action_id}.json"
        if p.exists():
            source_path = p
            current_status = status
            break

    if not source_path:
        return False, f"Action {action_id} not found"

    target_dir = ACTIONS_DIR / target_status
    target_dir.mkdir(parents=True, exist_ok=True)
    target_path = target_dir / f"{action_id}.json"

    try:
        data = json.loads(source_path.read_text())
        data["status"] = target_status
        data["updated_at"] = time.time()
        
        # Keep history of transitions
        history = data.get("transition_history", [])
        history.append({
            "from": current_status,
            "to": target_status,
            "timestamp": time.time()
        })
        data["transition_history"] = history

        target_path.write_text(json.dumps(data, indent=2))
        if source_path != target_path:
            source_path.unlink()
        return True, "Success"
    except Exception as e:
        return False, str(e)


def get_snapshot():
    nodes = current_nodes()
    services = current_services()
    incidents = current_incidents()
    events = current_events()
    summary = current_summary()

    non_nominal = [s for s in services if s.get("health") != "nominal"]
    nominal_count = len(services) - len(non_nominal)

    return {
        "timestamp": datetime.now(timezone.utc).isoformat(),
        "summary": summary,
        "nodes": nodes,
        "non_nominal_services": non_nominal,
        "nominal_service_count": nominal_count,
        "total_service_count": len(services),
        "incidents": incidents,
        "events": events[:10],
    }


def send_json(status, payload, handler):
    body = (json.dumps(payload) + "\n").encode("utf-8")
    handler.send_response(status)
    handler.send_header("Content-Type", "application/json")
    handler.send_header("Content-Length", str(len(body)))
    handler.end_headers()
    handler.wfile.write(body)


class Handler(BaseHTTPRequestHandler):
    def do_GET(self):
        if self.path == "/config":
            send_json(200, get_config(), self)
            return

        if self.path == "/nodes":
            send_json(200, current_nodes(), self)
            return

        if self.path == "/services":
            send_json(200, current_services(), self)
            return

        if self.path == "/deployments":
            send_json(200, current_deployments(), self)
            return

        if self.path == "/incidents":
            send_json(200, current_incidents(), self)
            return

        if self.path == "/recommendations":
            send_json(200, current_recommendations(), self)
            return

        if self.path == "/summary":
            send_json(200, current_summary(), self)
            return

        if self.path == "/events":
            send_json(200, current_events(), self)
            return

        if self.path == "/actions":
            send_json(200, current_actions(), self)
            return

        if self.path == "/snapshot":
            send_json(200, get_snapshot(), self)
            return

        if self.path in ("/", "/index.html"):
            body = (STATIC_DIR / "index.html").read_bytes()
            self.send_response(200)
            self.send_header("Content-Type", "text/html; charset=utf-8")
            self.send_header("Content-Length", str(len(body)))
            self.end_headers()
            self.wfile.write(body)
            return

        self.send_error(404)

    def do_POST(self):
        if self.path not in (
            "/config",
            "/action/mutate",
            "/mode",
        ):
            self.send_error(404)
            return

        length = int(self.headers.get("Content-Length", "0"))
        raw_body = self.rfile.read(length).decode("utf-8")
        try:
            payload = json.loads(raw_body)
        except json.JSONDecodeError:
            self.send_error(400, "Invalid JSON")
            return

        if self.path == "/config":
            config = get_config()
            config.update(payload)
            save_config(config)
            send_json(200, {"status": "ok"}, self)
            return

        if self.path == "/mode":
            mode = payload.get("mode")
            if not mode:
                self.send_error(400, "mode is required")
                return
            config = get_config()
            config["operator_mode"] = mode
            save_config(config)
            send_json(200, {"status": "ok"}, self)
            return

        if self.path == "/action/mutate":
            action_id = payload.get("id")
            target = payload.get("status")
            if not action_id or not target:
                self.send_error(400, "id and status are required")
                return
            success, msg = mutate_action(action_id, target)
            if success:
                send_json(200, {"status": "ok"}, self)
            else:
                self.send_error(500, msg)
            return

    def log_message(self, format, *args):
        return


if __name__ == "__main__":
    # Ensure directories exist
    for d in [STATE_DIR, EVENTS_DIR, WORLD_DIR, ACTIONS_DIR, CONFIG_DIR]:
        d.mkdir(parents=True, exist_ok=True)
    for s in ["pending", "approved", "running", "completed", "failed", "rejected"]:
        (ACTIONS_DIR / s).mkdir(parents=True, exist_ok=True)
        
    port = int(os.getenv("PORT", "8080"))
    print(f"Operator Control Plane starting on 0.0.0.0:{port}")
    server = ThreadingHTTPServer(("0.0.0.0", port), Handler)
    server.serve_forever()