{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://cityresourcegraph.com/schemas/websocket_event.json",
  "title": "WebSocket Event",
  "description": "Schema for real-time WebSocket events",
  "type": "object",
  "properties": {
    "event_type": {
      "type": "string",
      "enum": ["match_found", "resource_updated", "price_changed", "notification", "system_status"],
      "description": "Type of event"
    },
    "event_id": {
      "type": "string",
      "format": "uuid",
      "description": "Unique event identifier"
    },
    "timestamp": {
      "type": "string",
      "format": "date-time",
      "description": "Event timestamp"
    },
    "user_id": {
      "type": "string",
      "format": "uuid",
      "description": "Target user (if applicable)"
    },
    "data": {
      "oneOf": [
        {"$ref": "#/definitions/match_event"},
        {"$ref": "#/definitions/resource_event"},
        {"$ref": "#/definitions/notification_event"},
        {"$ref": "#/definitions/system_event"}
      ]
    }
  },
  "required": ["event_type", "event_id", "timestamp", "data"],
  "definitions": {
    "match_event": {
      "type": "object",
      "properties": {
        "match": {
          "$ref": "https://cityresourcegraph.com/schemas/match_response.json#/definitions/match"
        },
        "reason": {
          "type": "string",
          "enum": ["new_resource", "improved_match", "price_change"],
          "description": "Why this match was triggered"
        }
      },
      "required": ["match"]
    },
    "resource_event": {
      "type": "object",
      "properties": {
        "resource_id": {
          "type": "string",
          "format": "uuid"
        },
        "changes": {
          "type": "object",
          "description": "Changed fields and new values"
        },
        "affected_matches": {
          "type": "array",
          "items": {
            "type": "string",
            "format": "uuid"
          },
          "description": "Match IDs affected by this change"
        }
      },
      "required": ["resource_id", "changes"]
    },
    "notification_event": {
      "type": "object",
      "properties": {
        "title": {
          "type": "string",
          "maxLength": 200
        },
        "message": {
          "type": "string",
          "maxLength": 1000
        },
        "priority": {
          "type": "string",
          "enum": ["low", "medium", "high", "urgent"],
          "default": "medium"
        },
        "action_url": {
          "type": "string",
          "format": "uri"
        },
        "expires_at": {
          "type": "string",
          "format": "date-time"
        }
      },
      "required": ["title", "message"]
    },
    "system_event": {
      "type": "object",
      "properties": {
        "component": {
          "type": "string",
          "enum": ["api", "matching_engine", "database", "cache", "queue"]
        },
        "status": {
          "type": "string",
          "enum": ["healthy", "degraded", "down", "maintenance"]
        },
        "message": {
          "type": "string",
          "maxLength": 500
        },
        "estimated_resolution": {
          "type": "string",
          "format": "date-time"
        }
      },
      "required": ["component", "status"]
    }
  },
  "additionalProperties": false
}