{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://raw.githubusercontent.com/api-evangelist/navis/refs/heads/main/json-schema/navis-unit-schema.json",
  "title": "Navis N4 Container Unit",
  "description": "A container or cargo unit managed within the Navis N4 Terminal Operating System",
  "type": "object",
  "required": ["unitNbr", "category", "freightKind"],
  "properties": {
    "unitNbr": {
      "type": "string",
      "description": "ISO 6346 container number",
      "pattern": "^[A-Z]{4}[0-9]{7}$"
    },
    "unitId": {
      "type": "integer",
      "description": "N4 internal unit identifier"
    },
    "category": {
      "type": "string",
      "enum": ["IMPORT", "EXPORT", "TRANSSHIP", "EMPTY"],
      "description": "Container category in terminal operations"
    },
    "freightKind": {
      "type": "string",
      "enum": ["FCL", "LCL", "MTY"],
      "description": "Full Container Load, Less Container Load, or Empty"
    },
    "equipmentType": {
      "type": "string",
      "description": "Equipment type code (CTR, TRL, etc.)"
    },
    "equipmentLength": {
      "type": "integer",
      "enum": [20, 40, 45, 48, 53],
      "description": "Container length in feet"
    },
    "lineOperator": {
      "type": "string",
      "description": "Shipping line SCAC code"
    },
    "currentPosition": {
      "$ref": "#/$defs/YardPosition"
    },
    "arrivalVesselVisit": {
      "type": ["string", "null"],
      "description": "Visit ID of the vessel that delivered the container"
    },
    "departureVesselVisit": {
      "type": ["string", "null"],
      "description": "Visit ID of the vessel that will take the container"
    },
    "holds": {
      "type": "array",
      "items": { "$ref": "#/$defs/Hold" }
    },
    "hazardous": {
      "type": "boolean"
    },
    "imdgClass": {
      "type": ["string", "null"],
      "description": "IMDG dangerous goods class (e.g., 3.0 for flammable liquids)"
    },
    "reefer": {
      "type": "boolean",
      "description": "Whether the container requires temperature control"
    },
    "temperature": {
      "type": ["number", "null"],
      "description": "Required setpoint temperature in Celsius for reefer units"
    },
    "weight": {
      "type": ["number", "null"],
      "minimum": 0,
      "description": "Gross weight in kilograms"
    },
    "inGateDate": {
      "type": ["string", "null"],
      "format": "date-time",
      "description": "Timestamp when the unit entered the terminal"
    },
    "outGateDate": {
      "type": ["string", "null"],
      "format": "date-time",
      "description": "Timestamp when the unit departed the terminal"
    }
  },
  "$defs": {
    "YardPosition": {
      "type": "object",
      "properties": {
        "locType": {
          "type": "string",
          "enum": ["YARD", "VESSEL", "TRUCK", "RAIL", "DOCK", "VESSEL_BUFFER"]
        },
        "blockName": { "type": "string" },
        "bayNbr": { "type": "integer" },
        "rowNbr": { "type": "integer" },
        "tierNbr": { "type": "integer" },
        "slotName": {
          "type": "string",
          "description": "Full slot identifier (block-bay-row-tier)"
        }
      }
    },
    "Hold": {
      "type": "object",
      "required": ["holdType", "holdStatus"],
      "properties": {
        "holdId": { "type": "string" },
        "holdType": {
          "type": "string",
          "description": "Hold type code (CUSTOMS, LINE, PORT, FREIGHT)"
        },
        "holdStatus": {
          "type": "string",
          "enum": ["ACTIVE", "RELEASED", "EXPIRED"]
        },
        "appliedBy": { "type": "string" },
        "appliedDate": { "type": "string", "format": "date-time" },
        "releasedDate": { "type": ["string", "null"], "format": "date-time" },
        "reason": { "type": "string" }
      }
    }
  }
}