import os
import json
import datetime
import uuid
import socket

EVENTS_BASE_DIR = os.getenv("RUNTIME_PATH", "/opt/homelab") + "/events"

def emit_event(event_type, severity, source, service, correlation_id, payload=None):
    """
    Emits a normalized JSON event to the filesystem.
    """
    if payload is None:
        payload = {}
        
    node = socket.gethostname()
    now = datetime.datetime.now(datetime.timezone.utc)
    timestamp = now.strftime("%Y-%m-%dT%H:%M:%SZ")
    date_dir = now.strftime("%Y-%m-%d")
    
    event_dir = os.path.join(EVENTS_BASE_DIR, date_dir, node)
    os.makedirs(event_dir, exist_ok=True)
    
    event_id = str(uuid.uuid4())
    filename = f"{timestamp}_{event_type}_{event_id}.json"
    event_path = os.path.join(event_dir, filename)
    
    event_data = {
        "timestamp": timestamp,
        "node": node,
        "type": event_type,
        "severity": severity,
        "source": source,
        "service": service,
        "correlation_id": correlation_id,
        "payload": payload
    }
    
    with open(event_path, "w") as f:
        json.dump(event_data, f, indent=2)
    
    return event_path

def list_events(date_str=None, node=None):
    """
    Lists paths to event files for a specific date and/or node.
    """
    if date_str is None:
        date_str = datetime.datetime.now(datetime.timezone.utc).strftime("%Y-%m-%d")
        
    search_path = os.path.join(EVENTS_BASE_DIR, date_str)
    if node:
        search_path = os.path.join(search_path, node)
        
    if not os.path.exists(search_path):
        return []
        
    event_files = []
    for root, dirs, files in os.walk(search_path):
        for file in files:
            if file.endswith(".json"):
                event_files.append(os.path.join(root, file))
                
    return sorted(event_files)

def get_event(event_path):
    """
    Reads and parses an event file.
    """
    with open(event_path, "r") as f:
        return json.load(f)

if __name__ == "__main__":
    # Simple CLI for emitting events from Python
    import sys
    if len(sys.argv) > 1 and sys.argv[1] == "emit":
        # emit <type> <severity> <source> <service> <cid> [payload_json]
        etype = sys.argv[2]
        sev = sys.argv[3]
        src = sys.argv[4]
        svc = sys.argv[5]
        cid = sys.argv[6]
        payload = json.loads(sys.argv[7]) if len(sys.argv) > 7 else {}
        path = emit_event(etype, sev, src, svc, cid, payload)
        print(f"Event emitted: {path}")