{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://raw.githubusercontent.com/zarr-conventions/spatial/refs/tags/v0.1/schema.json",
  "title": "Spatial Coordinate Convention (spatial:)",
  "description": "Schema for spatial coordinate information in Zarr. Properties use the 'spatial:' namespace prefix. This convention defines the relationship between array indices and spatial coordinates.",
  "type": "object",
  "properties": {
    "zarr_format": {
      "type": "integer",
      "description": "Zarr format version"
    },
    "node_type": {
      "type": "string",
      "enum": ["array", "group"],
      "description": "Type of Zarr node"
    },
    "attributes": {
      "type": "object",
      "description": "Zarr attributes containing convention metadata and spatial: prefixed properties",
      "properties": {
        "zarr_conventions": {
          "type": "array",
          "description": "Array of convention metadata objects",
          "contains": {
            "$ref": "#/$defs/conventionMetadata"
          }
        }
      },
      "required": ["zarr_conventions"],
      "$ref": "#/$defs/spatialAttributes"
    }
  },
  "required": ["zarr_format", "node_type", "attributes"],
  "additionalProperties": true,
  "allOf": [
    {
      "if": {
        "properties": { "node_type": { "const": "array" } },
        "required": ["node_type"]
      },
      "then": {
        "properties": {
          "attributes": {
            "type": "object",
            "required": ["spatial:dimensions"]
          }
        }
      }
    }
  ],
  "$defs": {
    "conventionMetadata": {
      "type": "object",
      "description": "Spatial coordinate convention metadata object for use in zarr_conventions array",
      "properties": {
        "schema_url": {
          "type": "string",
          "const": "https://raw.githubusercontent.com/zarr-conventions/spatial/refs/tags/v0.1/schema.json",
          "description": "URL to the JSON Schema definition for this convention"
        },
        "spec_url": {
          "type": "string",
          "const": "https://github.com/zarr-conventions/spatial/blob/v0.1/README.md",
          "description": "URL to the full specification document"
        },
        "uuid": {
          "type": "string",
          "const": "689b58e2-cf7b-45e0-9fff-9cfc0883d6b4",
          "description": "UUID that permanently identifies this convention"
        },
        "name": {
          "type": "string",
          "const": "spatial",
          "description": "Human-readable name of the convention"
        },
        "description": {
          "type": "string",
          "const": "Spatial coordinate information",
          "description": "Brief description of the convention's purpose and usage"
        }
      },
      "anyOf": [
        {
          "required": ["schema_url"]
        },
        {
          "required": ["spec_url"]
        },
        {
          "required": ["uuid"]
        }
      ],
      "additionalProperties": false
    },
    "spatialAttributes": {
      "type": "object",
      "description": "Spatial coordinate properties using spatial: key prefix",
      "properties": {
        "zarr_conventions": true,
        "spatial:dimensions": {
          "type": "array",
          "description": "Names of the two spatial (X/Y) dimensions, in row-major order (e.g., [\"y\", \"x\"]).",
          "minItems": 2,
          "maxItems": 2,
          "items": {
            "type": "string"
          }
        },
        "spatial:bbox": {
          "type": "array",
          "description": "2D bounding box in coordinate space: [xmin, ymin, xmax, ymax].",
          "minItems": 4,
          "maxItems": 4,
          "items": {
            "type": "number"
          }
        },
        "spatial:transform_type": {
          "type": "string",
          "description": "Type of transformation used to map array indices to coordinates. Defaults to 'affine' if not specified. Currently defined types: 'affine'. Additional transform types may be defined in future versions (e.g., 'rpc', 'polynomial', 'lookup'). Custom types are allowed for extensibility."
        },
        "spatial:transform": {
          "type": "array",
          "description": "2D affine transformation coefficients [a, b, c, d, e, f] mapping array indices to coordinates, where x = a*col_index + b*row_index + c and y = d*col_index + e*row_index + f. Used when transform_type is 'affine' (default).",
          "minItems": 6,
          "maxItems": 6,
          "items": {
            "type": "number"
          }
        },
        "spatial:shape": {
          "type": "array",
          "description": "Shape of the two spatial dimensions [height, width], corresponding to [y, x].",
          "minItems": 2,
          "maxItems": 2,
          "items": {
            "type": "integer",
            "minimum": 1
          }
        },
        "spatial:registration": {
          "type": "string",
          "description": "Grid cell registration type. 'node' (grid-registered) means cells are centered on coordinate points with footprints extending 1/2 cell width outside the range. 'pixel' (cell-registered) means cell boundaries align with coordinate points. Defaults to 'pixel' if not specified.",
          "enum": ["node", "pixel"]
        },
        "multiscales": {
          "type": "object",
          "description": "When composing with multiscales convention, spatial: properties can be added to layout items",
          "properties": {
            "layout": {
              "type": "array",
              "items": {
                "type": "object",
                "properties": {
                  "spatial:shape": {
                    "type": "array",
                    "description": "Shape override for this resolution level [height, width]",
                    "minItems": 2,
                    "maxItems": 2,
                    "items": {
                      "type": "integer",
                      "minimum": 1
                    }
                  },
                  "spatial:transform": {
                    "type": "array",
                    "description": "2D affine transform override for this resolution level [a, b, c, d, e, f]",
                    "minItems": 6,
                    "maxItems": 6,
                    "items": {
                      "type": "number"
                    }
                  }
                },
                "additionalProperties": true
              }
            }
          },
          "additionalProperties": true
        }
      },
      "additionalProperties": true
    }
  }
}