{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://unovis.dev/schema/chart-spec.v0.1.json",
  "title": "Unovis ChartSpec",
  "description": "The @unovis/mcp chart spec contract, version 0.1. While the major is 0, breaking changes bump the minor; from 1.0 on, additions are non-breaking and only the major breaks.",
  "type": "object",
  "properties": {
    "specVersion": {
      "type": "string",
      "pattern": "^\\d+\\.\\d+$",
      "description": "ChartSpec contract version as major.minor (see SPEC_VERSION). While the major is 0, breaking changes bump the minor; from 1.0 on, minors are additive and only the major breaks"
    },
    "container": {
      "type": "string",
      "enum": [
        "xy",
        "single"
      ]
    },
    "width": {
      "type": "number",
      "exclusiveMinimum": 0
    },
    "height": {
      "type": "number",
      "exclusiveMinimum": 0
    },
    "theme": {
      "type": "string",
      "enum": [
        "light",
        "dark"
      ]
    },
    "title": {
      "type": "string"
    },
    "containerConfig": {
      "type": "object",
      "additionalProperties": {}
    },
    "components": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "type": {
            "type": "string",
            "enum": [
              "Line",
              "Area",
              "GroupedBar",
              "StackedBar",
              "Scatter",
              "Timeline",
              "Boxplot",
              "XYLabels",
              "Plotband",
              "Plotline",
              "Donut",
              "NestedDonut",
              "RadialBar",
              "Sankey",
              "Heatmap",
              "Treemap",
              "ChordDiagram",
              "Graph",
              "TopoJSONMap"
            ]
          },
          "config": {
            "type": "object",
            "additionalProperties": {}
          }
        },
        "required": [
          "type",
          "config"
        ],
        "additionalProperties": false
      },
      "minItems": 1
    },
    "xAxis": {
      "type": "object",
      "properties": {
        "label": {
          "type": "string"
        },
        "gridLine": {
          "type": "boolean"
        },
        "numTicks": {
          "type": "number"
        },
        "tickFormat": {
          "anyOf": [
            {
              "type": "object",
              "properties": {
                "$field": {
                  "type": "string"
                },
                "as": {
                  "type": "string",
                  "enum": [
                    "number",
                    "string",
                    "date"
                  ]
                }
              },
              "required": [
                "$field"
              ],
              "additionalProperties": false,
              "description": "d => coerce(d[field])"
            },
            {
              "type": "object",
              "properties": {
                "$index": {
                  "type": "boolean",
                  "const": true
                }
              },
              "required": [
                "$index"
              ],
              "additionalProperties": false,
              "description": "(d, i) => i"
            },
            {
              "type": "object",
              "properties": {
                "$const": {}
              },
              "additionalProperties": false,
              "description": "() => value"
            },
            {
              "type": "object",
              "properties": {
                "$dateTickFormat": {
                  "type": "boolean",
                  "const": true
                }
              },
              "required": [
                "$dateTickFormat"
              ],
              "additionalProperties": false,
              "description": "Locale-aware date tick formatter"
            },
            {
              "type": "object",
              "properties": {
                "$numTickFormat": {
                  "type": "boolean",
                  "const": true
                }
              },
              "required": [
                "$numTickFormat"
              ],
              "additionalProperties": false,
              "description": "Locale-aware number tick formatter"
            },
            {
              "type": "object",
              "properties": {
                "$lookup": {
                  "type": "array",
                  "items": {
                    "type": [
                      "string",
                      "number"
                    ]
                  }
                }
              },
              "required": [
                "$lookup"
              ],
              "additionalProperties": false,
              "description": "(d, i) => values[i % values.length]"
            },
            {
              "type": "object",
              "properties": {
                "$format": {
                  "type": "object",
                  "properties": {
                    "field": {
                      "type": "string"
                    },
                    "prefix": {
                      "type": "string"
                    },
                    "suffix": {
                      "type": "string"
                    }
                  },
                  "required": [
                    "field"
                  ],
                  "additionalProperties": false
                }
              },
              "required": [
                "$format"
              ],
              "additionalProperties": false,
              "description": "d => prefix + formatNumber(d[field]) + suffix"
            },
            {
              "type": "object",
              "properties": {
                "$mapField": {
                  "type": "object",
                  "properties": {
                    "field": {
                      "type": "string"
                    },
                    "mapping": {
                      "type": "object",
                      "additionalProperties": {
                        "type": "string"
                      }
                    },
                    "fallback": {
                      "type": "string"
                    }
                  },
                  "required": [
                    "field",
                    "mapping"
                  ],
                  "additionalProperties": false
                }
              },
              "required": [
                "$mapField"
              ],
              "additionalProperties": false,
              "description": "d => mapping[String(d[field])] ?? fallback"
            }
          ]
        },
        "domainLine": {
          "type": "boolean"
        },
        "tickTextAngle": {
          "type": "number"
        },
        "tickValues": {
          "type": "array",
          "items": {
            "type": "number"
          }
        }
      },
      "additionalProperties": {}
    },
    "yAxis": {
      "$ref": "#/properties/xAxis"
    },
    "colors": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "locale": {
      "type": "string",
      "description": "BCP-47 locale for date/number formatting (default en-US)"
    },
    "legend": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "name": {
            "type": "string"
          },
          "color": {
            "type": "string"
          },
          "paletteIndex": {
            "type": "integer"
          }
        },
        "required": [
          "name"
        ],
        "additionalProperties": false
      }
    },
    "data": {}
  },
  "required": [
    "container",
    "width",
    "height",
    "theme",
    "components"
  ],
  "additionalProperties": false
}