{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "FrontAid CMS Schema",
  "description": "JSON Schema definition for FrontAid CMS",

  "type": "object",
  "properties": {
    ":name": {
      "title": "Name of the project model",
      "type": "string",
      "minLength": 1
    },
    ":description": {
      "title": "Description of the project model",
      "type": "string",
      "minLength": 1
    },
    ":locales": {
      "title": "Optional list of locales (the first is the default)",
      "type": "array",
      "items": {"type": "string", "pattern": "^[a-zA-Z][a-zA-Z0-9-_.]*$"},
      "minItems": 1
    }
  },
  "patternProperties": {
    "^[a-zA-Z][a-zA-Z0-9_-]*$": {"$ref": "#/definitions/nodeOrField"}
  },
  "required": [
    ":name"
  ],
  "additionalProperties": false,
  "allOf": [
    {"$ref": "#/definitions/enforceProp"}
  ],

  "definitions": {

    "enforceProp": {
      "$comment": "Enforce at least one custom property.",
      "if": {"required": [":name", ":description"]},
      "then": {
        "minProperties": 3
      },
      "else": {
        "if": {"required": [":name"]},
        "then": {"minProperties": 2},
        "else": {
          "if": {"required": [":description"]},
          "then": {"minProperties": 2},
          "else": {"minProperties": 1}
        }
      }
    },

    "nodeOrField": {
      "oneOf": [
        {"$ref": "#/definitions/object"},
        {"$ref": "#/definitions/listObject"},
        {"$ref": "#/definitions/line"},
        {"$ref": "#/definitions/text"},
        {"$ref": "#/definitions/image"}
      ]
    },

    "object": {
      "title": "Node",
      "type": "object",
      "properties": {
        ":name": {"type": "string"},
        ":description": {"type": "string"}
      },
      "patternProperties": {
        "^[a-zA-Z][a-zA-Z0-9_-]*$": {"$ref": "#/definitions/nodeOrField"}
      },
      "additionalProperties": false,
      "allOf": [
        {"$ref": "#/definitions/enforceProp"}
      ]
    },

    "listObject": {
      "title": "List node",
      "type": "object",
      "properties": {
        ":name": {"type": "string"},
        ":description": {"type": "string"},
        ":items": {
          "type": "object",
          "minProperties": 1,
          "$comment": "Only custom properties allowed here",
          "patternProperties": {
            "^[a-zA-Z][a-zA-Z0-9_-]*$": {"$ref": "#/definitions/nodeOrField"}
          },
          "allOf": [
            {"$ref": "#/definitions/enforceProp"}
          ],
          "additionalProperties": false
        }
      },
      "required": [":items"],
      "additionalProperties": false
    },

    "line": {
      "title": "Short single-line text",
      "type": "object",
      "properties": {
        ":name": {"type": "string"},
        ":description": {"type": "string"},
        ":type": {"const": "line"},
        ":richtext": {"type": "boolean"}
      },
      "required": [":type"],
      "additionalProperties": false
    },

    "text": {
      "title": "Default text field",
      "type": "object",
      "properties": {
        ":name": {"type": "string"},
        ":description": {"type": "string"},
        ":type": {"const": "text"},
        ":richtext": {"type": "boolean"}
      },
      "required": [":type"],
      "additionalProperties": false
    },

    "image": {
      "title": "Image field",
      "type": "object",
      "properties": {
        ":name": {"type": "string"},
        ":description": {"type": "string"},
        ":type": {"const": "image"}
      },
      "required": [":type"],
      "additionalProperties": false
    }

  }
}