{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "pie-chart-schema",
  "title": "Pie Chart Schema",
  "description": "Intermediate representation for pie/donut chart diagrams. LLM extracts data from natural language into this format, then rendering pipeline generates HTML/SVG from it.",
  "type": "object",
  "required": ["diagramType", "title", "data"],
  "additionalProperties": false,
  "properties": {
    "diagramType": {
      "type": "string",
      "const": "pie",
      "description": "Identifies this JSON as a pie chart. Must always be 'pie'."
    },
    "title": {
      "type": "string",
      "maxLength": 200,
      "description": "Chart title, displayed at the top of the rendered page.",
      "examples": ["Browser Market Share", "Revenue by Category"]
    },
    "subtitle": {
      "type": "string",
      "maxLength": 300,
      "description": "Optional subtitle shown below the title, typically describing the scope or time period.",
      "examples": ["2025 global data", "Q1-Q4 Breakdown"]
    },
    "style": {
      "$ref": "schema-shared.json#/$defs/styleEnum",
      "description": "Visual style preset. Each style has its own template and design rules.",
      "default": "dark-professional"
    },
    "format": {
      "$ref": "schema-shared.json#/$defs/formatEnum",
      "description": "Output format. HTML is the default (single-file with inline SVG and CSS). SVG outputs standalone SVG. Mermaid uses pie title syntax.",
      "default": "html"
    },
    "variant": {
      "type": "string",
      "enum": ["pie", "donut"],
      "description": "Chart variant. pie=full pie sectors. donut=annular ring with optional center text.",
      "default": "pie"
    },
    "data": {
      "type": "array",
      "description": "Data items. Each has a label, numeric value, and optional color override. 2-12 items allowed; for more than 12, merge smallest items into 'Other'.",
      "items": {
        "type": "object",
        "required": ["label", "value"],
        "additionalProperties": false,
        "properties": {
          "label": {
            "$ref": "schema-shared.json#/$defs/sanitizedString",
            "maxLength": 100,
            "description": "Category label displayed in the legend and optionally on the slice.",
            "examples": ["Chrome", "Safari"]
          },
          "value": {
            "type": "number",
            "exclusiveMinimum": 0,
            "description": "Numeric value for this slice. Must be positive (no negative values in pie charts)."
          },
          "color": {
            "type": "string",
            "pattern": "^#[0-9a-fA-F]{6}$",
            "description": "Optional color override for this slice. Must be 6-digit hex (#RRGGBB). If omitted, uses the chart palette."
          }
        }
      },
      "minItems": 2,
      "maxItems": 12
    },
    "donut": {
      "type": "object",
      "description": "Donut-specific configuration. Only effective when variant is 'donut'.",
      "additionalProperties": false,
      "properties": {
        "innerRadiusRatio": {
          "type": "number",
          "minimum": 0.1,
          "maximum": 0.9,
          "default": 0.6,
          "description": "Ratio of inner radius to outer radius. 0.6 means the hole is 60% of the pie radius."
        },
        "centerText": {
          "$ref": "schema-shared.json#/$defs/sanitizedString",
          "maxLength": 50,
          "description": "Text displayed in the center of the donut (e.g., 'Total', 'Total').",
          "examples": ["Total", "Total"]
        },
        "centerValue": {
          "$ref": "schema-shared.json#/$defs/sanitizedString",
          "maxLength": 30,
          "description": "Value displayed in the center of the donut (e.g., '1,234').",
          "examples": ["1,234", "100%"]
        }
      }
    },
    "legend": {
      "type": "object",
      "description": "Legend configuration for the pie chart.",
      "additionalProperties": false,
      "properties": {
        "visible": {
          "type": "boolean",
          "description": "Whether to show the legend.",
          "default": true
        },
        "position": {
          "type": "string",
          "enum": ["right", "bottom"],
          "description": "Legend placement. 'right' places it beside the pie; 'bottom' places it below.",
          "default": "right"
        }
      }
    },
    "colors": {
      "$ref": "schema-shared.json#/$defs/colorsOverride",
      "description": "Optional color overrides for the style's environment colors (background, text, etc.). Does NOT affect slice colors — use data[].color for that."
    },
    "metadata": {
      "$ref": "schema-shared.json#/$defs/metadata",
      "description": "Optional metadata. author field is for internal tracking only and MUST NOT be rendered into the output."
    }
  }
}