{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "frg-spec.schema.json",
  "title": "fRG diagram figure spec",
  "description": "A figure as rows of TeX terms and pre-built Feynman diagrams. Build it with `frg build spec.json -o figure.tex`.",
  "type": "object",
  "required": [
    "format",
    "version",
    "rows"
  ],
  "additionalProperties": false,
  "properties": {
    "$schema": {
      "type": "string"
    },
    "format": {
      "const": "frg-spec"
    },
    "version": {
      "const": 1
    },
    "style": {
      "description": "Style preset name, or style-sheet overrides (optionally based on a preset).",
      "oneOf": [
        {
          "enum": [
            "fqcd",
            "thesis",
            "journal",
            "grayscale",
            "talk"
          ]
        },
        {
          "type": "object",
          "additionalProperties": false,
          "properties": {
            "preset": {
              "enum": [
                "fqcd",
                "thesis",
                "journal",
                "grayscale",
                "talk"
              ]
            },
            "name": {
              "type": "string"
            },
            "lineWidth": {
              "type": "number"
            },
            "doubleSep": {
              "type": "number"
            },
            "arrowLength": {
              "type": "number"
            },
            "arrowWidth": {
              "type": "number"
            },
            "vertexRadius": {
              "type": "number"
            },
            "regulatorRadius": {
              "type": "number"
            },
            "loopRadius": {
              "type": "number"
            },
            "legLength": {
              "type": "number"
            },
            "gridSize": {
              "type": "number"
            },
            "vertexColor": {
              "type": "string"
            },
            "fontSize": {
              "type": "number"
            },
            "termSize": {
              "type": "number"
            },
            "rowGap": {
              "type": "number"
            },
            "colorMode": {
              "enum": [
                "color",
                "grayscale",
                "black"
              ]
            },
            "arrowOutline": {
              "type": "string"
            },
            "regulatorFill": {
              "type": "string"
            },
            "regulatorStroke": {
              "type": "string"
            }
          }
        }
      ]
    },
    "fields": {
      "type": "array",
      "description": "Extra line types, or overrides of built-in ones (same id).",
      "items": {
        "type": "object",
        "required": [
          "id",
          "name",
          "tex",
          "line",
          "color",
          "arrows"
        ],
        "properties": {
          "id": {
            "type": "string"
          },
          "name": {
            "type": "string"
          },
          "tex": {
            "type": "string"
          },
          "line": {
            "enum": [
              "single",
              "double",
              "dashed",
              "dotted",
              "wavy",
              "curly"
            ]
          },
          "color": {
            "type": "string",
            "description": "xcolor dvipsnames name (RoyalBlue, BrickRed, …) or #rrggbb."
          },
          "arrows": {
            "enum": [
              "none",
              "forward",
              "opposite"
            ]
          },
          "params": {
            "type": "object",
            "additionalProperties": {
              "type": "number"
            }
          }
        }
      }
    },
    "vertexTypes": {
      "type": "array",
      "description": "Extra vertex types, or overrides of built-in ones (same id).",
      "items": {
        "type": "object",
        "required": [
          "id",
          "name",
          "shape",
          "scale",
          "fill",
          "stroke",
          "strokeWidth"
        ],
        "properties": {
          "id": {
            "type": "string"
          },
          "name": {
            "type": "string"
          },
          "shape": {
            "enum": [
              "circle",
              "square",
              "diamond",
              "triangle",
              "hatched",
              "cross"
            ]
          },
          "scale": {
            "type": "number"
          },
          "fill": {
            "type": "string"
          },
          "stroke": {
            "type": "string"
          },
          "strokeWidth": {
            "type": "number"
          },
          "tex": {
            "type": "string"
          }
        }
      }
    },
    "regulatorKind": {
      "enum": [
        "regulator",
        "flowRegulator"
      ],
      "description": "Default regulator kind of every diagram. Regulator insertion: \"regulator\" = ∂ₜR (crossed circle), \"flowRegulator\" = (∂ₜ + 2δΦ̇/δΦ)R of the generalised flow equation with flowing fields (crossed pentagon)."
    },
    "rowGap": {
      "type": "number",
      "description": "Vertical gap between rows in pt (default 30)."
    },
    "align": {
      "enum": [
        "left",
        "center"
      ],
      "description": "Horizontal alignment of rows (default left)."
    },
    "rows": {
      "type": "array",
      "minItems": 1,
      "description": "Equation rows, top to bottom. Items in a row are laid out left to right on a common centre line.",
      "items": {
        "oneOf": [
          {
            "type": "array",
            "items": {
              "$ref": "#/$defs/item"
            }
          },
          {
            "type": "object",
            "required": [
              "items"
            ],
            "additionalProperties": false,
            "properties": {
              "items": {
                "type": "array",
                "items": {
                  "$ref": "#/$defs/item"
                }
              }
            }
          }
        ]
      }
    }
  },
  "$defs": {
    "item": {
      "oneOf": [
        {
          "type": "string",
          "description": "TeX term (math mode), e.g. \"+\", \"-\\frac{1}{2}\", \"\\partial_t\\Gamma^{(2)} =\"."
        },
        {
          "type": "object",
          "required": [
            "tex"
          ],
          "additionalProperties": false,
          "properties": {
            "tex": {
              "type": "string"
            },
            "size": {
              "type": "number"
            },
            "color": {
              "type": "string"
            }
          }
        },
        {
          "$ref": "#/$defs/diagram"
        }
      ]
    },
    "diagram": {
      "type": "object",
      "required": [
        "diagram"
      ],
      "additionalProperties": false,
      "properties": {
        "diagram": {
          "enum": [
            "propagator",
            "regulatorProp",
            "wetterich",
            "tadpole",
            "bubble",
            "fish",
            "triangle",
            "box",
            "sunset",
            "vertex4",
            "npoint",
            "exchange",
            "ring"
          ],
          "description": "propagator: Propagator [lines: line]; regulatorProp: Regulator insertion [lines: line]; wetterich: Wetterich loop (one-loop flow) [lines: loop]; tadpole: Tadpole [lines: loop]; bubble: Polarisation / self-energy [lines: upper, lower]; fish: Fish (4-point) [lines: upper, lower]; triangle: Triangle (3-point) [lines: left, right, lower]; box: Box (4-point) [lines: left, upper, right, lower]; sunset: Sunset (2-loop) [lines: upper, middle, lower]; vertex4: 4-point vertex; npoint: n-point vertex Γ⁽ⁿ⁾; exchange: Boson exchange (4-point) [lines: middle]; ring: One-loop ring (vertices with given legs), set by \"vertices\" [lines: 0, 1, …; line i runs from vertex i to i + 1]"
        },
        "field": {
          "type": "string",
          "description": "Field of every line (default \"scalar\").",
          "examples": [
            "pion",
            "sigma",
            "quark",
            "gluon",
            "ghost",
            "photon",
            "scalar",
            "aux",
            "vector",
            "diquark",
            "nucleon"
          ]
        },
        "legs": {
          "type": "string",
          "description": "Field of the external legs.",
          "examples": [
            "pion",
            "sigma",
            "quark",
            "gluon",
            "ghost",
            "photon",
            "scalar",
            "aux",
            "vector",
            "diquark",
            "nucleon"
          ]
        },
        "internal": {
          "type": "string",
          "description": "Field of all internal lines.",
          "examples": [
            "pion",
            "sigma",
            "quark",
            "gluon",
            "ghost",
            "photon",
            "scalar",
            "aux",
            "vector",
            "diquark",
            "nucleon"
          ]
        },
        "lines": {
          "type": "object",
          "description": "Field per internal line. Keys are line slots of the diagram (line, loop, upper, lower, left, right, middle; see \"frg list\") or line indices.",
          "additionalProperties": {
            "type": "string",
            "description": "Field (line type) id. Built in: pion, sigma, quark, gluon, ghost, photon, scalar, aux, vector, diquark, nucleon; or one defined under \"fields\".",
            "examples": [
              "pion",
              "sigma",
              "quark",
              "gluon",
              "ghost",
              "photon",
              "scalar",
              "aux",
              "vector",
              "diquark",
              "nucleon"
            ]
          }
        },
        "regulator": {
          "description": "Line(s) carrying the regulator insertion; \"none\", or \"each\" for the sum of copies with the regulator on each internal line.",
          "oneOf": [
            {
              "type": "string"
            },
            {
              "type": "array",
              "items": {
                "type": "string"
              }
            }
          ]
        },
        "regulatorKind": {
          "enum": [
            "regulator",
            "flowRegulator"
          ],
          "description": "Regulator insertion: \"regulator\" = ∂ₜR (crossed circle), \"flowRegulator\" = (∂ₜ + 2δΦ̇/δΦ)R of the generalised flow equation with flowing fields (crossed pentagon)."
        },
        "vertex": {
          "type": "string",
          "description": "Vertex type of the internal vertices: fullVertex, squareVertex, bareVertex, blob, hatched, counterterm, gammaN.",
          "examples": [
            "fullVertex",
            "squareVertex",
            "bareVertex",
            "blob",
            "hatched",
            "counterterm",
            "gammaN"
          ]
        },
        "reverse": {
          "type": "array",
          "items": {
            "type": "string"
          },
          "description": "Line slots (or \"legs\") whose arrows are flipped."
        },
        "labels": {
          "type": "object",
          "description": "TeX label beside a line. Keys are line slots of the diagram (line, loop, upper, lower, left, right, middle; see \"frg list\") or line indices.",
          "additionalProperties": {
            "type": "string"
          }
        },
        "momentum": {
          "type": "object",
          "description": "Momentum arrow with a TeX label beside a line. Keys are line slots of the diagram (line, loop, upper, lower, left, right, middle; see \"frg list\") or line indices.",
          "additionalProperties": {
            "type": "string"
          }
        },
        "vertices": {
          "type": "array",
          "minItems": 1,
          "description": "External legs per internal vertex, in the diagram's vertex order: a leg count, or one entry per leg. Required for \"ring\"; on other diagrams the counts must match.",
          "items": {
            "oneOf": [
              {
                "type": "integer",
                "minimum": 0
              },
              {
                "type": "array",
                "items": {
                  "oneOf": [
                    {
                      "type": "string",
                      "description": "Field (line type) id. Built in: pion, sigma, quark, gluon, ghost, photon, scalar, aux, vector, diquark, nucleon; or one defined under \"fields\".",
                      "examples": [
                        "pion",
                        "sigma",
                        "quark",
                        "gluon",
                        "ghost",
                        "photon",
                        "scalar",
                        "aux",
                        "vector",
                        "diquark",
                        "nucleon"
                      ]
                    },
                    {
                      "type": "object",
                      "required": [
                        "field"
                      ],
                      "additionalProperties": false,
                      "properties": {
                        "field": {
                          "type": "string",
                          "description": "Field (line type) id. Built in: pion, sigma, quark, gluon, ghost, photon, scalar, aux, vector, diquark, nucleon; or one defined under \"fields\".",
                          "examples": [
                            "pion",
                            "sigma",
                            "quark",
                            "gluon",
                            "ghost",
                            "photon",
                            "scalar",
                            "aux",
                            "vector",
                            "diquark",
                            "nucleon"
                          ]
                        },
                        "dir": {
                          "enum": [
                            "in",
                            "out"
                          ],
                          "description": "Arrow into or out of the vertex."
                        }
                      }
                    }
                  ]
                }
              }
            ]
          }
        }
      }
    }
  }
}