{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "funnel-chart-schema",
  "title": "Funnel Chart Schema",
  "description": "Intermediate representation for funnel chart diagrams.",
  "type": "object",
  "required": ["diagramType", "title", "data"],
  "additionalProperties": false,
  "properties": {
    "diagramType": {
      "type": "string",
      "const": "funnel",
      "description": "Identifies this JSON as a funnel chart."
    },
    "title": {
      "type": "string",
      "maxLength": 200,
      "description": "Chart title."
    },
    "subtitle": {
      "type": "string",
      "maxLength": 300,
      "description": "Optional subtitle."
    },
    "style": {
      "$ref": "schema-shared.json#/$defs/styleEnum",
      "default": "dark-professional"
    },
    "format": {
      "$ref": "schema-shared.json#/$defs/formatEnum",
      "default": "html"
    },
    "density": {
      "type": "string",
      "enum": ["compact", "normal", "spacious"],
      "default": "normal",
      "description": "Layout density. Controls stage height."
    },
    "data": {
      "type": "array",
      "description": "Funnel stages. Values should be in descending order; if not, rendering will auto-sort.",
      "items": {
        "type": "object",
        "required": ["label", "value"],
        "additionalProperties": false,
        "properties": {
          "label": {
            "$ref": "schema-shared.json#/$defs/sanitizedString",
            "maxLength": 100,
            "description": "Stage name."
          },
          "value": {
            "type": "number",
            "exclusiveMinimum": 0,
            "description": "Stage value. Must be positive."
          },
          "color": {
            "type": "string",
            "pattern": "^#[0-9a-fA-F]{6}$",
            "description": "Optional color override."
          }
        }
      },
      "minItems": 2,
      "maxItems": 8
    },
    "showConversionRate": {
      "type": "boolean",
      "default": true,
      "description": "Show conversion rate percentages between stages."
    },
    "variant": {
      "type": "string",
      "enum": ["trapezoid", "rounded"],
      "default": "trapezoid",
      "description": "Visual variant. trapezoid=straight edges, rounded=curved edges."
    },
    "legend": {
      "$ref": "schema-shared.json#/$defs/legendConfig"
    },
    "colors": {
      "$ref": "schema-shared.json#/$defs/colorsOverride"
    },
    "metadata": {
      "$ref": "schema-shared.json#/$defs/metadata"
    }
  }
}