{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://quarka.org/schema/assistant/definitions/chart.schema.json",
  "title": "Chart definition",
  "description": "A chart rendered from a row-array variable via the shared ECharts wrapper (qahm.EChart). For pie / doughnut / hbar only the first series entry is used.",
  "type": "object",
  "additionalProperties": false,
  "required": ["source", "type", "x", "series"],
  "properties": {
    "title": { "type": "string", "description": "May be a 't:' translation reference." },
    "source": {
      "type": "string",
      "pattern": "^\\$",
      "description": "Variable reference holding the row array (must start with $)."
    },
    "type": {
      "enum": ["bar", "line", "pie", "doughnut", "hbar"],
      "description": "Chart kind. hbar = horizontal bar (rows are shown top-to-bottom in the given order)."
    },
    "x": {
      "type": "string",
      "minLength": 1,
      "description": "Row field used as the category axis label (pie/doughnut: slice name)."
    },
    "series": {
      "type": "array",
      "minItems": 1,
      "items": {
        "type": "object",
        "additionalProperties": false,
        "required": ["field"],
        "properties": {
          "field": { "type": "string", "minLength": 1, "description": "Row field holding the numeric value." },
          "label": { "type": "string", "description": "Legend label. May be a 't:' translation reference. Defaults to field." },
          "type": { "enum": ["bar", "line"], "description": "Per-series override for bar/line charts (mixed bar+line)." },
          "color": { "type": "string", "description": "Hex color (e.g. #69A4E2). Defaults to the shared theme palette. Ignored for pie / doughnut (slice colors come from the palette)." }
        }
      }
    },
    "options": {
      "type": "object",
      "description": "Renderer options (e.g. height in px). Unknown keys are ignored."
    }
  }
}