{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "InfographicLayout",
  "type": "object",
  "description": "Infographic layout description with theme and node tree",
  "properties": {
    "theme": {
      "type": "object",
      "description": "Global design tokens (colors, typography, etc.)",
      "properties": {
        "colors": {
          "type": "object",
          "description": "Color tokens used across the infographic",
          "patternProperties": {
            "^[a-zA-Z_][a-zA-Z0-9_]*$": {
              "type": "string",
              "description": "Color value (e.g. hex, rgba, or implementation-defined token)"
            }
          },
          "additionalProperties": false
        },
        "typography": {
          "type": "object",
          "description": "Typography style tokens (e.g. H1, H2, Body)",
          "patternProperties": {
            "^[a-zA-Z_][a-zA-Z0-9_]*$": {
              "type": "object",
              "properties": {
                "font": {
                  "type": "string",
                  "description": "Font family name (and optionally style info, implementation-defined)"
                },
                "size": {
                  "type": "number",
                  "description": "Font size, typically in px"
                },
                "weight": {
                  "type": "string",
                  "description": "Font weight (e.g. 'normal', 'bold', '600')"
                }
              },
              "required": ["font", "size"],
              "additionalProperties": true
            }
          },
          "additionalProperties": false
        }
      },
      "additionalProperties": false
    },

    "root": {
      "$ref": "#/definitions/Node",
      "description": "Root node of the infographic layout tree"
    }
  },
  "required": ["root"],
  "additionalProperties": false,

  "definitions": {
    "Node": {
      "oneOf": [
        { "$ref": "#/definitions/Group" },
        { "$ref": "#/definitions/Stack" },
        { "$ref": "#/definitions/Text" },
        { "$ref": "#/definitions/Image" },
        { "$ref": "#/definitions/Chart" },
        { "$ref": "#/definitions/Shape" }
      ]
    },

    "Padding": {
      "oneOf": [
        {
          "type": "number",
          "description": "Uniform padding on all sides (px)"
        },
        {
          "type": "object",
          "description": "Per-side padding (px)",
          "properties": {
            "top": { "type": "number" },
            "right": { "type": "number" },
            "bottom": { "type": "number" },
            "left": { "type": "number" }
          },
          "required": ["top", "right", "bottom", "left"],
          "additionalProperties": false
        }
      ]
    },

    "OverlapConstraint": {
      "type": "object",
      "description": "Relative overlap constraint between two children in a STACK",
      "properties": {
        "sourceId": {
          "type": "string",
          "description": "ID of the element being constrained"
        },
        "targetId": {
          "type": "string",
          "description": "ID of the reference element"
        },
        "type": {
          "type": "string",
          "enum": ["FULLY_INSIDE", "NON_OVERLAP", "PARTIALLY_OVERLAP"],
          "description": "Overlap constraint type"
        },
        "minDistance": {
          "type": "number",
          "description": "Minimum distance in pixels when type is NON_OVERLAP"
        },
        "overlapPercentage": {
          "type": "number",
          "minimum": 0,
          "maximum": 100,
          "description": "Required overlap percentage (0–100) when type is PARTIALLY_OVERLAP"
        }
      },
      "required": ["sourceId", "targetId", "type"],
      "additionalProperties": false
    },

    "AlignmentConstraint": {
      "type": "object",
      "description": "Simple pairwise alignment constraint between two children in a STACK",
      "properties": {
        "sourceId": {
          "type": "string",
          "description": "ID of the element being aligned"
        },
        "targetId": {
          "type": "string",
          "description": "ID of the reference element to align to"
        },
        "type": {
          "type": "string",
          "enum": ["TOP", "BOTTOM", "LEFT", "RIGHT"],
          "description": "Which edge of source should align to the same edge of target"
        }
      },
      "required": ["sourceId", "targetId", "type"],
      "additionalProperties": false
    },

    "Group": {
      "type": "object",
      "description": "Flow layout container (row/column)",
      "properties": {
        "id": {
          "type": "string",
          "description": "Unique identifier for the group element"
        },
        "type": {
          "const": "GROUP"
        },
        "direction": {
          "type": "string",
          "enum": ["ROW", "COLUMN"],
          "description": "Layout direction of children"
        },
        "alignment": {
          "type": "object",
          "description": "Main-axis and cross-axis alignment (simplified)",
          "properties": {
            "main": {
              "type": "string",
              "enum": ["START", "CENTER", "END"],
              "description": "Alignment along the layout direction"
            },
            "cross": {
              "type": "string",
              "enum": ["START", "CENTER", "END", "STRETCH"],
              "description": "Alignment perpendicular to the layout direction"
            }
          },
          "required": ["main", "cross"],
          "additionalProperties": false
        },
        "spacing": {
          "type": "number",
          "description": "Spacing between children (px)"
        },
        "padding": {
          "$ref": "#/definitions/Padding"
        },
        "children": {
          "type": "array",
          "items": { "$ref": "#/definitions/Node" }
        }
      },
      "required": ["id", "type", "direction", "alignment", "children"],
      "additionalProperties": false
    },

    "Stack": {
      "type": "object",
      "description": "Stacked layout (children layered in z-order, like a Stack/ZStack)",
      "properties": {
        "id": {
          "type": "string",
          "description": "Unique identifier for the stack element"
        },
        "type": {
          "const": "STACK"
        },
        "alignment": {
          "type": "string",
          "enum": [
            "TOP_LEFT", "TOP_CENTER", "TOP_RIGHT",
            "CENTER_LEFT", "CENTER", "CENTER_RIGHT",
            "BOTTOM_LEFT", "BOTTOM_CENTER", "BOTTOM_RIGHT"
          ],
          "description": "Default alignment of children within the stack bounds"
        },
        "children": {
          "type": "array",
          "items": { "$ref": "#/definitions/Node" }
        },
        "overlapConstraints": {
          "type": "array",
          "description": "Overlap constraints between children in this stack",
          "items": { "$ref": "#/definitions/OverlapConstraint" }
        },
        "alignmentConstraints": {
          "type": "array",
          "description": "Pairwise alignment constraints between children in this stack",
          "items": { "$ref": "#/definitions/AlignmentConstraint" }
        }
      },
      "required": ["id", "type", "alignment", "children"],
      "additionalProperties": false
    },

    "Chart": {
      "type": "object",
      "description": "Chart placeholder node (semantics handled outside this grammar)",
      "properties": {
        "id": {
          "type": "string",
          "description": "Unique identifier for the chart element"
        },
        "type": {
          "const": "CHART"
        },
        "width": {
          "type": "number",
          "description": "Chart width (px)"
        },
        "height": {
          "type": "number",
          "description": "Chart height (px)"
        }
      },
      "required": ["id", "type", "width", "height"],
      "additionalProperties": false
    },

    "Text": {
      "type": "object",
      "description": "Text node; visual style is driven mainly by theme.typography + role",
      "properties": {
        "id": {
          "type": "string",
          "description": "Unique identifier for the text element"
        },
        "type": {
          "const": "TEXT"
        },
        "content": {
          "type": "string",
          "description": "Text content"
        },
        "role": {
          "type": "string",
          "enum": [
            "TITLE_PRIMARY",
            "TITLE_NUMBER",
            "TITLE_CONTEXT",
            "SUBTITLE",
            "CAPTION"
          ],
          "description": "Semantic role of the text, used to map to typography tokens"
        },
        "color": {
          "type": "string",
          "description": "Optional color override; if omitted, renderer may use theme colors based on role"
        },
        "maxLines": {
          "type": "integer",
          "description": "Maximum number of lines to render (truncation behavior is implementation-defined)"
        }
      },
      "required": ["id", "type", "content", "role"],
      "additionalProperties": false
    },

    "Image": {
      "type": "object",
      "description": "Image node",
      "properties": {
        "id": {
          "type": "string",
          "description": "Unique identifier for the image element"
        },
        "type": {
          "const": "IMAGE"
        },
        "src": {
          "type": "string",
          "description": "Image source (URL or asset identifier)"
        },
        "width": {
          "type": "number",
          "description": "Image width (px)"
        },
        "height": {
          "type": "number",
          "description": "Image height (px)"
        },
        "fit": {
          "type": "string",
          "enum": ["COVER", "CONTAIN", "FILL"],
          "description": "How the image fits into its bounding box"
        },
        "radius": {
          "type": "number",
          "description": "Corner radius for rounded images (px)"
        }
      },
      "required": ["id", "type", "src"],
      "additionalProperties": false
    },

    "Shape": {
      "type": "object",
      "description": "Basic geometric or path-based shape with free-form attributes",
      "properties": {
        "id": {
          "type": "string",
          "description": "Unique identifier for the shape element"
        },
        "type": {
          "type": "string",
          "enum": ["RECT", "CIRCLE", "PATH"],
          "description": "Shape type"
        },
        "attrs": {
          "type": "object",
          "description": "Implementation-defined attributes for the shape (e.g. width, height, radius, path, color, strokeColor, strokeWidth, etc.)",
          "additionalProperties": true
        }
      },
      "required": ["id", "type"],
      "additionalProperties": false
    }
  }
}