{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "bar-chart-schema",
  "title": "Bar Chart Schema",
  "description": "Intermediate representation for bar chart diagrams. LLM extracts data from natural language into this format, then rendering pipeline generates HTML/SVG from it.",
  "type": "object",
  "required": ["diagramType", "title", "series"],
  "additionalProperties": false,
  "properties": {
    "diagramType": {
      "type": "string",
      "const": "bar",
      "description": "Identifies this JSON as a bar chart. Must always be 'bar'."
    },
    "title": {
      "type": "string",
      "maxLength": 200,
      "description": "Chart title, displayed at the top of the rendered page.",
      "examples": ["Quarterly Revenue 2025", "Monthly Active Users Comparison"]
    },
    "subtitle": {
      "type": "string",
      "maxLength": 300,
      "description": "Optional subtitle shown below the title, typically describing the unit or scope.",
      "examples": ["In tens of thousands (CNY)", "Comparison across product lines"]
    },
    "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 xychart-beta syntax (experimental).",
      "default": "html"
    },
    "density": {
      "type": "string",
      "enum": ["compact", "normal", "spacious"],
      "description": "Layout density. compact=tighter spacing; normal=standard; spacious=generous spacing.",
      "default": "normal"
    },
    "direction": {
      "type": "string",
      "enum": ["vertical", "horizontal"],
      "description": "Bar orientation. vertical=bars grow upward (default). horizontal=bars grow rightward.",
      "default": "vertical"
    },
    "variant": {
      "type": "string",
      "enum": ["grouped", "stacked"],
      "description": "Multi-series arrangement. grouped=bars side by side (default). stacked=bars on top of each other.",
      "default": "grouped"
    },
    "series": {
      "type": "array",
      "description": "Data series. Each series contains data points with labels and values. Multiple series are displayed as grouped or stacked bars.",
      "items": {
        "$ref": "#/$defs/seriesItem"
      },
      "minItems": 1,
      "maxItems": 8
    },
    "axis": {
      "type": "object",
      "description": "Axis configuration for both X and Y axes.",
      "additionalProperties": false,
      "properties": {
        "x": {
          "$ref": "schema-shared.json#/$defs/axisConfig",
          "description": "X-axis configuration (category axis)."
        },
        "y": {
          "$ref": "schema-shared.json#/$defs/axisConfig",
          "description": "Y-axis configuration (value axis)."
        }
      }
    },
    "legend": {
      "$ref": "schema-shared.json#/$defs/legendConfig",
      "description": "Legend configuration. Auto-generated from series names if not provided."
    },
    "colors": {
      "$ref": "schema-shared.json#/$defs/colorsOverride",
      "description": "Optional color overrides for the style's environment colors (background, text, etc.). Does NOT affect data bar colors — use series[].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."
    }
  },
  "$defs": {
    "seriesItem": {
      "type": "object",
      "required": ["name", "data"],
      "additionalProperties": false,
      "description": "A data series containing named data points.",
      "properties": {
        "name": {
          "$ref": "schema-shared.json#/$defs/sanitizedString",
          "maxLength": 100,
          "description": "Series name displayed in the legend.",
          "examples": ["Revenue", "Users", "Revenue"]
        },
        "color": {
          "type": "string",
          "pattern": "^#[0-9a-fA-F]{6}$",
          "description": "Optional color override for all bars in this series. Must be 6-digit hex (#RRGGBB). If omitted, uses the chart palette."
        },
        "data": {
          "type": "array",
          "description": "Data points in this series. Each has a label and numeric value.",
          "items": {
            "$ref": "schema-shared.json#/$defs/dataPoint"
          },
          "minItems": 2,
          "maxItems": 30
        }
      }
    }
  }
}