{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://docs.tatrman.org/model/layout.schema.json",
  "title": "Tatrman layout (format 1)",
  "description": "One named picture of a schema: the cards it shows and, optionally, where they sit. The YAML serialization of the Tatrman layout document; the same document is also written as a TTR `.ttrg` graph block. See https://docs.tatrman.org/model/layout-files/ and the shared test vectors in layout-vectors/.",
  "type": "object",
  "required": ["layout", "name", "model", "objects"],
  "additionalProperties": false,
  "properties": {
    "layout": {
      "description": "The format version. A reader that meets a higher version refuses the file: \"layout format N is newer than this reader\".",
      "const": 1
    },
    "name": {
      "description": "The layout's name — the `.ttrg` graph-name rule; a writer also uses it as the file stem.",
      "type": "string",
      "pattern": "^[A-Za-z_][A-Za-z0-9_]*$"
    },
    "model": {
      "description": "The schema the cards come from. `md` and `cnc` are admitted, untested.",
      "enum": ["er", "db", "md", "cnc"]
    },
    "objects": {
      "description": "The cards shown — entities (er), tables and views (db). A writer lists full qnames, sorted alphabetically (see the vectors' README); a reader resolves any form the resolution rule accepts.",
      "type": "array",
      "items": { "$ref": "#/$defs/objectRef" }
    },
    "positions": {
      "description": "Manual positions, keyed by a ref that is also in `objects`. Absent or empty means auto layout.",
      "type": "object",
      "propertyNames": { "$ref": "#/$defs/objectRef" },
      "additionalProperties": { "$ref": "#/$defs/point" }
    },
    "skin": {
      "description": "The notation id (`er.crow`, `db.table-classic`).",
      "type": "string",
      "minLength": 1,
      "pattern": "^[^\\u0000-\\u001F\\u007F]+$"
    },
    "collapsed": {
      "description": "Reserved: carried, not acted on in format 1.",
      "type": "array",
      "items": { "$ref": "#/$defs/objectRef" }
    }
  },
  "$defs": {
    "objectRef": {
      "description": "A model object: a full qname `<pkg>.<qname>` (`hartland.er.entity.item`, `hartland.db.dbo.item`), or a shorter form the resolution rule accepts (`er.entity.item`, `entity.item`, `item`).",
      "type": "string",
      "minLength": 1,
      "pattern": "^[^\\u0000-\\u001F\\u007F]+$"
    },
    "point": {
      "type": "object",
      "required": ["x", "y"],
      "additionalProperties": false,
      "properties": {
        "x": { "type": "number" },
        "y": { "type": "number" }
      }
    }
  }
}