{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://gamut.style/schema/v0.1/theme.schema.json",
  "title": "GAMUT Theme Format v0.1",
  "type": "object",
  "required": ["format", "id", "version", "name", "mode", "license", "core"],
  "properties": {
    "$schema": { "type": "string" },
    "format": { "const": "gamut/0.1" },
    "id": {
      "type": "string",
      "pattern": "^[a-z0-9][a-z0-9-]*\\/[a-z0-9][a-z0-9-]*$",
      "description": "Immutable namespaced id: author-slug/theme-slug"
    },
    "version": {
      "type": "string",
      "pattern": "^\\d+\\.\\d+\\.\\d+$"
    },
    "name": { "type": "string", "minLength": 1, "maxLength": 80 },
    "mode": { "enum": ["dark", "light"] },
    "author": {
      "type": "object",
      "properties": {
        "name": { "type": "string" },
        "url": { "type": "string", "format": "uri" }
      }
    },
    "license": { "type": "string", "description": "SPDX identifier; CC0-1.0 recommended" },
    "tags": { "type": "array", "items": { "type": "string" }, "maxItems": 20 },
    "description": { "type": "string", "maxLength": 300 },
    "companion": {
      "type": "string",
      "description": "Optional id of the paired light/dark counterpart theme"
    },

    "palette": {
      "type": "object",
      "additionalProperties": { "$ref": "#/$defs/color" }
    },

    "core": {
      "type": "object",
      "required": [
        "bg", "bgAlt", "surface", "muted", "fgAlt", "fg", "fgBright", "bgInverse",
        "accent0", "accent1", "accent2", "accent3", "accent4", "accent5", "accent6", "accent7"
      ],
      "additionalProperties": false,
      "properties": {
        "bg": { "$ref": "#/$defs/colorOrRef" },
        "bgAlt": { "$ref": "#/$defs/colorOrRef" },
        "surface": { "$ref": "#/$defs/colorOrRef" },
        "muted": { "$ref": "#/$defs/colorOrRef" },
        "fgAlt": { "$ref": "#/$defs/colorOrRef" },
        "fg": { "$ref": "#/$defs/colorOrRef" },
        "fgBright": { "$ref": "#/$defs/colorOrRef" },
        "bgInverse": { "$ref": "#/$defs/colorOrRef" },
        "accent0": { "$ref": "#/$defs/colorOrRef" },
        "accent1": { "$ref": "#/$defs/colorOrRef" },
        "accent2": { "$ref": "#/$defs/colorOrRef" },
        "accent3": { "$ref": "#/$defs/colorOrRef" },
        "accent4": { "$ref": "#/$defs/colorOrRef" },
        "accent5": { "$ref": "#/$defs/colorOrRef" },
        "accent6": { "$ref": "#/$defs/colorOrRef" },
        "accent7": { "$ref": "#/$defs/colorOrRef" }
      }
    },

    "ui": {
      "type": "object",
      "description": "Tier 2 roles. All optional; spec defines Tier 1 fallbacks.",
      "propertyNames": {
        "enum": [
          "surfaceRaised", "border", "borderFocus", "selectionBg", "selectionFg",
          "cursor", "cursorText", "findMatchBg", "hoverBg", "disabledFg",
          "tooltipBg", "scrollbar", "link", "linkVisited", "error", "warning",
          "success", "info", "diffAdded", "diffRemoved", "diffChanged",
          "badgeBg", "badgeFg", "shadow"
        ]
      },
      "additionalProperties": { "$ref": "#/$defs/styledColorOrRef" }
    },

    "syntax": {
      "type": "object",
      "description": "Tier 3 roles. All optional; spec defines Tier 1 fallbacks.",
      "propertyNames": {
        "enum": [
          "keyword", "function", "type", "class", "variable", "property",
          "parameter", "decorator", "tag", "attribute", "namespace", "string",
          "stringEscape", "number", "constant", "comment", "commentDoc",
          "operator", "punctuation", "regex", "markupHeading", "markupBold"
        ]
      },
      "additionalProperties": { "$ref": "#/$defs/styledColorOrRef" }
    },

    "ansi": {
      "type": "object",
      "propertyNames": {
        "enum": [
          "black", "red", "green", "yellow", "blue", "magenta", "cyan", "white",
          "brightBlack", "brightRed", "brightGreen", "brightYellow",
          "brightBlue", "brightMagenta", "brightCyan", "brightWhite"
        ]
      },
      "additionalProperties": { "$ref": "#/$defs/colorOrRef" }
    },

    "metrics": {
      "type": "object",
      "description": "Computed at publish time; validators recompute and must match.",
      "required": ["computedWith", "contrast", "separation", "cvd", "badges"],
      "properties": {
        "computedWith": { "type": "string" },
        "contrast": {
          "type": "object",
          "required": ["method", "fgBg", "minAccentBg"],
          "properties": {
            "method": { "const": "APCA-4g" },
            "fgBg": { "type": "number" },
            "minAccentBg": { "type": "number" },
            "matrix": { "type": "object" }
          }
        },
        "separation": {
          "type": "object",
          "required": ["method", "minAccentPair"],
          "properties": {
            "method": { "const": "deltaE-OK" },
            "minAccentPair": { "type": "number" }
          }
        },
        "cvd": {
          "type": "object",
          "required": ["method", "protanopia", "deuteranopia", "tritanopia"],
          "properties": {
            "method": { "const": "machado-2009" },
            "protanopia": { "$ref": "#/$defs/cvdResult" },
            "deuteranopia": { "$ref": "#/$defs/cvdResult" },
            "tritanopia": { "$ref": "#/$defs/cvdResult" }
          }
        },
        "coherence": {
          "type": "object",
          "properties": {
            "accentLightnessRange": { "type": "number" },
            "accentChromaRange": { "type": "number" },
            "hueSpreadDegrees": { "type": "number" }
          }
        },
        "badges": {
          "type": "array",
          "items": {
            "enum": [
              "aa-readable", "aaa-readable", "distinct-accents",
              "cvd-safe", "coherent", "conventional-hues"
            ]
          }
        }
      }
    }
  },

  "$defs": {
    "color": {
      "type": "object",
      "required": ["oklch", "hex"],
      "properties": {
        "oklch": {
          "type": "array",
          "prefixItems": [
            { "type": "number", "minimum": 0, "maximum": 1 },
            { "type": "number", "minimum": 0 },
            { "type": "number", "minimum": 0, "exclusiveMaximum": 360 }
          ],
          "minItems": 3,
          "maxItems": 3
        },
        "hex": { "type": "string", "pattern": "^#[0-9a-f]{6}$" },
        "alpha": { "type": "number", "minimum": 0, "maximum": 1 }
      }
    },
    "paletteRef": {
      "type": "string",
      "pattern": "^\\$[a-zA-Z][a-zA-Z0-9_-]*$",
      "description": "Reference to a Tier 0 palette entry, e.g. \"$ember\""
    },
    "colorOrRef": {
      "oneOf": [ { "$ref": "#/$defs/color" }, { "$ref": "#/$defs/paletteRef" } ]
    },
    "styledColorOrRef": {
      "oneOf": [
        { "$ref": "#/$defs/paletteRef" },
        {
          "allOf": [ { "$ref": "#/$defs/color" } ],
          "properties": {
            "style": {
              "type": "array",
              "items": { "enum": ["italic", "bold", "underline"] }
            }
          }
        }
      ]
    },
    "cvdResult": {
      "type": "object",
      "required": ["minAccentPair", "safe"],
      "properties": {
        "minAccentPair": { "type": "number" },
        "safe": { "type": "boolean" }
      }
    }
  }
}