{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "3D PACT website public sample index",
  "description": "Public website index mapping, not a replacement for the source dataset standard. The sample template deliberately allows nulls while preparing content; publication needs release checks.",
  "type": "array",
  "items": {
    "$ref": "#/$defs/sample"
  },
  "$defs": {
    "sample": {
      "type": "object",
      "additionalProperties": false,
      "required": [
        "id",
        "title",
        "is_demo",
        "category",
        "split",
        "tags",
        "description",
        "preview",
        "dimensions",
        "axis_order",
        "spacing_mm",
        "wavelength_nm",
        "intensity_unit",
        "data_version",
        "provenance",
        "files"
      ],
      "properties": {
        "id": {
          "type": "string",
          "minLength": 1,
          "pattern": "^[A-Za-z0-9][A-Za-z0-9._-]*$"
        },
        "title": {
          "$ref": "#/$defs/localizedTitle"
        },
        "is_demo": {
          "type": "boolean"
        },
        "category": {
          "type": "string",
          "enum": [
            "phantom",
            "simulation",
            "in-vivo",
            "ex-vivo",
            "other"
          ]
        },
        "split": {
          "type": "string",
          "enum": [
            "train",
            "validation",
            "test",
            "unspecified"
          ]
        },
        "tags": {
          "type": "array",
          "items": {
            "type": "string"
          },
          "uniqueItems": true
        },
        "description": {
          "$ref": "#/$defs/localizedText"
        },
        "preview": {
          "type": [
            "string",
            "null"
          ],
          "description": "Relative project URL or HTTPS URL; abstract illustrations must not be described as scans."
        },
        "dimensions": {
          "type": [
            "array",
            "null"
          ],
          "items": {
            "type": "integer",
            "minimum": 1
          },
          "minItems": 3,
          "maxItems": 3,
          "description": "Array dimension lengths, ordered by axis_order."
        },
        "axis_order": {
          "type": [
            "array",
            "null"
          ],
          "items": {
            "type": "string",
            "enum": [
              "x",
              "y",
              "z"
            ]
          },
          "uniqueItems": true,
          "minItems": 3,
          "maxItems": 3,
          "description": "Array axes, not anatomical orientation; real coordinate convention belongs in documentation."
        },
        "spacing_mm": {
          "type": [
            "array",
            "null"
          ],
          "items": {
            "type": "number",
            "exclusiveMinimum": 0
          },
          "minItems": 3,
          "maxItems": 3,
          "description": "Voxel spacing in millimetres, ordered by axis_order."
        },
        "wavelength_nm": {
          "type": [
            "number",
            "null"
          ],
          "exclusiveMinimum": 0,
          "description": "Single acquisition wavelength in nanometres; extend deliberately if multi-wavelength."
        },
        "intensity_unit": {
          "$ref": "#/$defs/nullableLocalizedText"
        },
        "data_version": {
          "type": [
            "string",
            "null"
          ]
        },
        "provenance": {
          "type": "object",
          "additionalProperties": false,
          "required": [
            "source_id",
            "acquisition",
            "reconstruction",
            "standardization_reference"
          ],
          "properties": {
            "source_id": {
              "type": [
                "string",
                "null"
              ]
            },
            "acquisition": {
              "$ref": "#/$defs/nullableLocalizedText"
            },
            "reconstruction": {
              "$ref": "#/$defs/nullableLocalizedText"
            },
            "standardization_reference": {
              "$ref": "#/$defs/nullableLocalizedText"
            }
          }
        },
        "files": {
          "type": "array",
          "items": {
            "type": "object",
            "additionalProperties": false,
            "required": [
              "name",
              "format",
              "url",
              "size_bytes",
              "sha256"
            ],
            "properties": {
              "name": {
                "type": "string",
                "minLength": 1
              },
              "format": {
                "type": "string"
              },
              "url": {
                "type": [
                  "string",
                  "null"
                ]
              },
              "size_bytes": {
                "type": [
                  "integer",
                  "null"
                ],
                "minimum": 0
              },
              "sha256": {
                "type": [
                  "string",
                  "null"
                ],
                "pattern": "^[a-fA-F0-9]{64}$"
              }
            }
          }
        },
        "preview_layout": {
          "type": "object",
          "additionalProperties": false,
          "required": [
            "source_width",
            "source_height",
            "rotation_deg",
            "crop"
          ],
          "properties": {
            "source_width": {
              "type": "integer",
              "minimum": 1
            },
            "source_height": {
              "type": "integer",
              "minimum": 1
            },
            "rotation_deg": {
              "enum": [
                0,
                90
              ]
            },
            "crop": {
              "type": "array",
              "items": {
                "type": "number"
              },
              "minItems": 4,
              "maxItems": 4
            },
            "display_gamma": {
              "type": "number",
              "enum": [
                0.8,
                0.95,
                0.97,
                1
              ],
              "description": "Display-only sRGB gamma exponent; 1 is unchanged. Supported filters are defined in index.html. The original PNG and full-original view remain unfiltered."
            }
          },
          "description": "Presentation-only crop [x,y,width,height] in original pixels after clockwise rotation. Raw image is unchanged."
        }
      }
    },
    "localizedText": {
      "description": "An existing plain string, or an explicit Chinese/English text map. Missing translations fall back to Chinese, then English. The website does not automatically translate scientific content.",
      "oneOf": [
        {
          "type": "string"
        },
        {
          "type": "object",
          "additionalProperties": false,
          "minProperties": 1,
          "properties": {
            "zh": {
              "type": "string"
            },
            "en": {
              "type": "string"
            }
          }
        }
      ]
    },
    "localizedTitle": {
      "oneOf": [
        {
          "type": "string",
          "minLength": 1
        },
        {
          "type": "object",
          "additionalProperties": false,
          "minProperties": 1,
          "properties": {
            "zh": {
              "type": "string",
              "minLength": 1
            },
            "en": {
              "type": "string",
              "minLength": 1
            }
          }
        }
      ]
    },
    "nullableLocalizedText": {
      "oneOf": [
        {
          "$ref": "#/$defs/localizedText"
        },
        {
          "type": "null"
        }
      ]
    }
  }
}