{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://beyerenrico.github.io/fieldset/spec/form-definition/1.0/meta-schema.json",
  "title": "Form Definition (Fieldset Spec 1.0)",
  "description": "Validates the structure of a Form Definition. Semantic rules are enforced by the linter (README §7).",
  "type": "object",
  "required": [
    "specVersion",
    "key",
    "title",
    "locale",
    "pages"
  ],
  "properties": {
    "$schema": {
      "type": "string",
      "pattern": "^[A-Za-z][A-Za-z0-9+.-]*:[^\\s]+$"
    },
    "specVersion": {
      "type": "string",
      "pattern": "^1\\.0\\.[0-9]+$"
    },
    "key": {
      "$ref": "#/$defs/key"
    },
    "title": {
      "type": "string",
      "minLength": 1,
      "maxLength": 200
    },
    "description": {
      "type": "string"
    },
    "locale": {
      "type": "string",
      "pattern": "^[A-Za-z]{2,3}(-[A-Za-z0-9]{2,8})*$"
    },
    "settings": {
      "type": "object",
      "properties": {
        "layout": {
          "enum": [
            "wizard",
            "scroll"
          ]
        },
        "numbering": {
          "type": "object",
          "properties": {
            "format": {
              "type": "string",
              "minLength": 1,
              "maxLength": 64
            },
            "reset": {
              "enum": [
                "never",
                "yearly",
                "monthly"
              ]
            }
          },
          "required": [
            "format"
          ],
          "patternProperties": {
            "^x-": true
          },
          "additionalProperties": false
        },
        "document": {
          "type": "object",
          "properties": {
            "design": {
              "type": "string",
              "minLength": 1,
              "maxLength": 64
            }
          },
          "patternProperties": {
            "^x-": true
          },
          "additionalProperties": false
        },
        "sendToCustomer": {
          "type": "boolean"
        }
      },
      "patternProperties": {
        "^x-": true
      },
      "additionalProperties": false
    },
    "pages": {
      "type": "array",
      "minItems": 1,
      "items": {
        "type": "object",
        "properties": {
          "id": {
            "$ref": "#/$defs/id"
          },
          "key": {
            "$ref": "#/$defs/key"
          },
          "title": {
            "type": "string",
            "minLength": 1
          },
          "description": {
            "type": "string"
          },
          "visibleIf": {
            "$ref": "#/$defs/logic"
          },
          "elements": {
            "$ref": "#/$defs/elements"
          }
        },
        "required": [
          "key",
          "title",
          "elements"
        ],
        "patternProperties": {
          "^x-": true
        },
        "additionalProperties": false
      }
    },
    "source": {
      "type": "object",
      "properties": {
        "registry": {
          "type": "string",
          "pattern": "^[A-Za-z][A-Za-z0-9+.-]*:[^\\s]+$"
        },
        "template": {
          "$ref": "#/$defs/key"
        },
        "version": {
          "type": "string",
          "pattern": "^[0-9]+\\.[0-9]+\\.[0-9]+(-[0-9A-Za-z.-]+)?$"
        }
      },
      "required": [
        "template",
        "version"
      ],
      "patternProperties": {
        "^x-": true
      },
      "additionalProperties": false
    }
  },
  "patternProperties": {
    "^x-": true
  },
  "additionalProperties": false,
  "$defs": {
    "key": {
      "type": "string",
      "pattern": "^[a-z][a-z0-9_]{0,63}$"
    },
    "id": {
      "type": "string",
      "pattern": "^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$"
    },
    "logic": {
      "description": "JsonLogic expression or boolean (spec §4)",
      "type": [
        "boolean",
        "object",
        "string",
        "number",
        "array",
        "null"
      ]
    },
    "langMap": {
      "type": "object",
      "propertyNames": {
        "pattern": "^[A-Za-z]{2,3}(-[A-Za-z0-9]{2,8})*$"
      },
      "additionalProperties": {
        "type": "string"
      }
    },
    "i18n": {
      "type": "object",
      "properties": {
        "label": {
          "$ref": "#/$defs/langMap"
        },
        "help": {
          "$ref": "#/$defs/langMap"
        },
        "placeholder": {
          "$ref": "#/$defs/langMap"
        }
      },
      "patternProperties": {
        "^x-": true
      },
      "additionalProperties": false
    },
    "numberLike": {
      "oneOf": [
        {
          "type": "number"
        },
        {
          "type": "string",
          "pattern": "^-?(0|[1-9][0-9]*)(\\.[0-9]+)?$"
        }
      ]
    },
    "option": {
      "type": "object",
      "properties": {
        "value": {
          "type": "string",
          "minLength": 1,
          "maxLength": 100
        },
        "label": {
          "type": "string",
          "minLength": 1
        },
        "i18n": {
          "type": "object",
          "properties": {
            "label": {
              "$ref": "#/$defs/langMap"
            }
          },
          "patternProperties": {
            "^x-": true
          },
          "additionalProperties": false
        }
      },
      "required": [
        "value",
        "label"
      ],
      "patternProperties": {
        "^x-": true
      },
      "additionalProperties": false
    },
    "options": {
      "type": "array",
      "minItems": 1,
      "items": {
        "$ref": "#/$defs/option"
      }
    },
    "pdf": {
      "type": "object",
      "properties": {
        "hidden": {
          "type": "boolean"
        },
        "label": {
          "type": "string"
        },
        "width": {
          "enum": [
            "full",
            "half",
            "third"
          ]
        },
        "keepTogether": {
          "type": "boolean"
        }
      },
      "patternProperties": {
        "^x-": true
      },
      "additionalProperties": false
    },
    "validation": {
      "type": "object",
      "properties": {
        "min": {
          "oneOf": [
            {
              "type": "number"
            },
            {
              "type": "string"
            }
          ]
        },
        "max": {
          "oneOf": [
            {
              "type": "number"
            },
            {
              "type": "string"
            }
          ]
        },
        "minLength": {
          "type": "integer",
          "minimum": 0
        },
        "maxLength": {
          "type": "integer",
          "minimum": 1
        },
        "pattern": {
          "type": "string",
          "minLength": 1
        },
        "step": {
          "$ref": "#/$defs/numberLike"
        },
        "accept": {
          "type": "array",
          "items": {
            "type": "string",
            "pattern": "^[a-z]+/([a-z0-9.+-]+|\\*)$"
          }
        },
        "maxFiles": {
          "type": "integer",
          "minimum": 1
        },
        "maxSizeKb": {
          "type": "integer",
          "minimum": 1
        }
      },
      "patternProperties": {
        "^x-": true
      },
      "additionalProperties": false
    },
    "elements": {
      "type": "array",
      "items": {
        "$ref": "#/$defs/element"
      }
    },
    "element": {
      "type": "object",
      "required": [
        "id",
        "type",
        "key"
      ],
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "type": {
          "enum": [
            "text",
            "textarea",
            "email",
            "phone",
            "number",
            "money",
            "date",
            "time",
            "datetime",
            "select",
            "radio",
            "multiselect",
            "checkbox",
            "toggle",
            "rating",
            "photo",
            "file",
            "signature",
            "location",
            "calculated",
            "hidden",
            "repeater",
            "section",
            "columns",
            "heading",
            "paragraph",
            "divider",
            "image",
            "page_break"
          ]
        },
        "key": {
          "$ref": "#/$defs/key"
        },
        "label": {
          "type": "string"
        },
        "help": {
          "type": "string"
        },
        "placeholder": {
          "type": "string"
        },
        "required": {
          "type": "boolean"
        },
        "visibleIf": {
          "$ref": "#/$defs/logic"
        },
        "requiredIf": {
          "$ref": "#/$defs/logic"
        },
        "readOnlyIf": {
          "$ref": "#/$defs/logic"
        },
        "default": {
          "$ref": "#/$defs/logic"
        },
        "validation": {
          "$ref": "#/$defs/validation"
        },
        "pdf": {
          "$ref": "#/$defs/pdf"
        },
        "role": {
          "type": "string",
          "pattern": "^[a-z_]+(\\.[a-z_]+)*$"
        },
        "i18n": {
          "$ref": "#/$defs/i18n"
        }
      },
      "patternProperties": {
        "^x-": true
      },
      "allOf": [
        {
          "if": {
            "properties": {
              "type": {
                "const": "text"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {},
            "required": [
              "label"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "textarea"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "rows": {
                "type": "integer",
                "minimum": 2,
                "maximum": 20
              }
            },
            "required": [
              "label"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "email"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {},
            "required": [
              "label"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "phone"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {},
            "required": [
              "label"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "number"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {},
            "required": [
              "label"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "money"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "currency": {
                "type": "string",
                "pattern": "^[A-Z]{3}$"
              },
              "scale": {
                "type": "integer",
                "minimum": 0,
                "maximum": 4
              }
            },
            "required": [
              "label",
              "currency"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "date"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {},
            "required": [
              "label"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "time"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {},
            "required": [
              "label"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "datetime"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {},
            "required": [
              "label"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "select"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "options": {
                "$ref": "#/$defs/options"
              }
            },
            "required": [
              "label",
              "options"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "radio"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "options": {
                "$ref": "#/$defs/options"
              }
            },
            "required": [
              "label",
              "options"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "multiselect"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "options": {
                "$ref": "#/$defs/options"
              }
            },
            "required": [
              "label",
              "options"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "checkbox"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {},
            "required": [
              "label"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "toggle"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {},
            "required": [
              "label"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "rating"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "max": {
                "type": "integer",
                "minimum": 3,
                "maximum": 10
              }
            },
            "required": [
              "label"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "photo"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "multiple": {
                "type": "boolean"
              }
            },
            "required": [
              "label"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "file"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "multiple": {
                "type": "boolean"
              }
            },
            "required": [
              "label"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "signature"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "signerNameFrom": {
                "$ref": "#/$defs/key"
              }
            },
            "required": [
              "label"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "location"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {},
            "required": [
              "label"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "calculated"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "expression": {
                "$ref": "#/$defs/logic"
              },
              "format": {
                "enum": [
                  "number",
                  "money",
                  "text"
                ]
              },
              "scale": {
                "type": "integer",
                "minimum": 0,
                "maximum": 10
              },
              "currency": {
                "type": "string",
                "pattern": "^[A-Z]{3}$"
              }
            },
            "required": [
              "label",
              "expression"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "hidden"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {},
            "required": []
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "repeater"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "elements": {
                "$ref": "#/$defs/elements"
              },
              "display": {
                "enum": [
                  "cards",
                  "table"
                ]
              },
              "minItems": {
                "type": "integer",
                "minimum": 0
              },
              "maxItems": {
                "type": "integer",
                "minimum": 1
              },
              "addLabel": {
                "type": "string"
              },
              "itemLabel": {
                "type": "string"
              }
            },
            "required": [
              "label",
              "elements"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "section"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "elements": {
                "$ref": "#/$defs/elements"
              },
              "collapsible": {
                "type": "boolean"
              }
            },
            "required": [
              "elements"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "columns"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "columns": {
                "type": "array",
                "minItems": 2,
                "maxItems": 4,
                "items": {
                  "type": "object",
                  "properties": {
                    "id": {
                      "$ref": "#/$defs/id"
                    },
                    "elements": {
                      "$ref": "#/$defs/elements"
                    }
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                    "elements"
                  ],
                  "patternProperties": {
                    "^x-": true
                  },
                  "additionalProperties": false
                }
              }
            },
            "required": [
              "columns"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "heading"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "text": {
                "type": "string",
                "minLength": 1
              },
              "level": {
                "type": "integer",
                "minimum": 1,
                "maximum": 3
              }
            },
            "required": [
              "text"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "paragraph"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "text": {
                "type": "string",
                "minLength": 1
              }
            },
            "required": [
              "text"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "divider"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {},
            "required": []
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "image"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {
              "src": {
                "type": "string",
                "pattern": "^(data:image/(png|jpeg|webp);base64,[A-Za-z0-9+/=]+|asset:[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12})$"
              },
              "alt": {
                "type": "string"
              }
            },
            "required": [
              "src"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "type": {
                "const": "page_break"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "properties": {},
            "required": []
          }
        }
      ],
      "unevaluatedProperties": false
    }
  }
}