{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://visualspec.dev/schema/1.0/modules/motion.schema.json",
  "title": "Motion",
  "description": "Temporal visual changes including keyframes, springs, paths, shared elements and driven progress.",
  "$defs": {
    "value": {
      "anyOf": [
        {
          "type": "number"
        },
        {
          "type": "string",
          "minLength": 1
        },
        {
          "type": "boolean"
        },
        {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/vector2"
        },
        {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/vector3"
        },
        {
          "$ref": "https://visualspec.dev/schema/1.0/modules/appearance.schema.json#/$defs/color"
        }
      ]
    },
    "easing": {
      "anyOf": [
        {
          "enum": [
            "linear",
            "ease",
            "ease-in",
            "ease-out",
            "ease-in-out"
          ]
        },
        {
          "type": "object",
          "properties": {
            "type": {
              "const": "cubic-bezier"
            },
            "values": {
              "type": "array",
              "items": {
                "type": "number"
              },
              "minItems": 4,
              "maxItems": 4
            }
          },
          "required": [
            "type",
            "values"
          ],
          "additionalProperties": false
        },
        {
          "type": "object",
          "properties": {
            "type": {
              "const": "cubic-bezier"
            },
            "x1": {
              "type": "number",
              "minimum": 0,
              "maximum": 1
            },
            "y1": {
              "type": "number"
            },
            "x2": {
              "type": "number",
              "minimum": 0,
              "maximum": 1
            },
            "y2": {
              "type": "number"
            }
          },
          "required": [
            "type",
            "x1",
            "y1",
            "x2",
            "y2"
          ],
          "additionalProperties": false
        },
        {
          "type": "object",
          "properties": {
            "type": {
              "const": "linear"
            },
            "points": {
              "type": "array",
              "items": {
                "type": "number"
              },
              "minItems": 2
            }
          },
          "required": [
            "type",
            "points"
          ],
          "additionalProperties": false
        },
        {
          "type": "object",
          "properties": {
            "type": {
              "const": "steps"
            },
            "count": {
              "type": "integer",
              "minimum": 1
            },
            "position": {
              "enum": [
                "start",
                "end",
                "jump-start",
                "jump-end",
                "jump-none",
                "jump-both"
              ]
            }
          },
          "required": [
            "type",
            "count"
          ],
          "additionalProperties": false
        },
        {
          "type": "object",
          "properties": {
            "type": {
              "const": "spring"
            },
            "mass": {
              "type": "number",
              "exclusiveMinimum": 0
            },
            "stiffness": {
              "type": "number",
              "exclusiveMinimum": 0
            },
            "damping": {
              "type": "number",
              "minimum": 0
            },
            "initialVelocity": {
              "type": "number"
            }
          },
          "required": [
            "type",
            "mass",
            "stiffness",
            "damping"
          ],
          "additionalProperties": false
        }
      ]
    },
    "spring": {
      "type": "object",
      "properties": {
        "mass": {
          "type": "number",
          "exclusiveMinimum": 0
        },
        "stiffness": {
          "type": "number",
          "exclusiveMinimum": 0
        },
        "damping": {
          "type": "number",
          "minimum": 0
        },
        "initialVelocity": {
          "type": "number"
        },
        "restSpeed": {
          "type": "number",
          "minimum": 0
        },
        "restDelta": {
          "type": "number",
          "minimum": 0
        }
      },
      "required": [
        "mass",
        "stiffness",
        "damping"
      ],
      "additionalProperties": false
    },
    "keyframe": {
      "type": "object",
      "properties": {
        "offset": {
          "type": "number",
          "minimum": 0,
          "maximum": 1
        },
        "value": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/motion.schema.json#/$defs/value"
        },
        "values": {
          "type": "object",
          "additionalProperties": {
            "$ref": "https://visualspec.dev/schema/1.0/modules/motion.schema.json#/$defs/value"
          }
        },
        "easing": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/motion.schema.json#/$defs/easing"
        },
        "composite": {
          "enum": [
            "replace",
            "add",
            "accumulate"
          ]
        }
      },
      "required": [
        "offset"
      ],
      "additionalProperties": false,
      "anyOf": [
        {
          "required": [
            "value"
          ]
        },
        {
          "required": [
            "values"
          ]
        }
      ]
    },
    "step": {
      "type": "object",
      "properties": {
        "type": {
          "enum": [
            "animation",
            "sequence",
            "parallel",
            "stagger",
            "wait"
          ]
        },
        "motionRef": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/id"
        },
        "each": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/duration"
        },
        "from": {
          "enum": [
            "first",
            "last",
            "center"
          ]
        },
        "seed": {
          "type": "integer",
          "minimum": 0
        },
        "duration": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/duration"
        },
        "targets": {
          "type": "array",
          "items": {
            "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/id"
          },
          "uniqueItems": true
        },
        "children": {
          "type": "array",
          "items": {
            "$ref": "https://visualspec.dev/schema/1.0/modules/motion.schema.json#/$defs/step"
          }
        }
      },
      "required": [
        "type"
      ],
      "additionalProperties": false
    },
    "track": {
      "type": "object",
      "properties": {
        "property": {
          "type": "string",
          "minLength": 1,
          "description": "Animatable visual property path, for example appearance.opacity or transform.translate."
        },
        "from": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/motion.schema.json#/$defs/value"
        },
        "to": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/motion.schema.json#/$defs/value"
        },
        "keyframes": {
          "type": "array",
          "items": {
            "$ref": "https://visualspec.dev/schema/1.0/modules/motion.schema.json#/$defs/keyframe"
          },
          "minItems": 2
        },
        "easing": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/motion.schema.json#/$defs/easing"
        },
        "composite": {
          "enum": [
            "replace",
            "add",
            "accumulate"
          ]
        }
      },
      "required": [
        "property"
      ],
      "additionalProperties": false
    },
    "driver": {
      "type": "object",
      "properties": {
        "type": {
          "enum": [
            "event",
            "state-transition",
            "gesture",
            "scroll",
            "timeline",
            "viewport",
            "visibility",
            "media-playback",
            "external-progress"
          ]
        },
        "sourceRef": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/id"
        },
        "axis": {
          "enum": [
            "x",
            "y",
            "both"
          ]
        },
        "range": {
          "type": "object",
          "properties": {
            "start": {
              "type": "number"
            },
            "end": {
              "type": "number"
            }
          },
          "required": [
            "start",
            "end"
          ],
          "additionalProperties": false
        },
        "clamp": {
          "type": "boolean"
        },
        "externalName": {
          "type": "string",
          "minLength": 1
        }
      },
      "required": [
        "type"
      ],
      "additionalProperties": false
    },
    "path": {
      "type": "object",
      "properties": {
        "data": {
          "type": "string",
          "minLength": 1
        },
        "pathRef": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/id"
        },
        "orientation": {
          "enum": [
            "auto",
            "auto-reverse",
            "fixed"
          ]
        },
        "start": {
          "type": "number",
          "minimum": 0,
          "maximum": 1
        },
        "end": {
          "type": "number",
          "minimum": 0,
          "maximum": 1
        },
        "coordinateSpace": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/coordinateSpace"
        }
      },
      "additionalProperties": false
    },
    "sharedElement": {
      "type": "object",
      "properties": {
        "entityRef": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/id"
        },
        "fromNodeRef": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/id"
        },
        "toNodeRef": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/id"
        },
        "preserve": {
          "type": "array",
          "items": {
            "enum": [
              "position",
              "size",
              "shape",
              "opacity",
              "color",
              "content"
            ]
          },
          "uniqueItems": true
        },
        "crossfade": {
          "type": "boolean"
        }
      },
      "required": [
        "entityRef",
        "fromNodeRef",
        "toNodeRef"
      ],
      "additionalProperties": false
    },
    "animation": {
      "type": "object",
      "properties": {
        "id": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/id"
        },
        "name": {
          "type": "string",
          "minLength": 1
        },
        "kind": {
          "enum": [
            "property",
            "spring",
            "decay",
            "path",
            "morph",
            "layout",
            "shared-element",
            "sequence",
            "parallel",
            "stagger",
            "transition"
          ]
        },
        "targets": {
          "type": "array",
          "items": {
            "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/id"
          },
          "uniqueItems": true
        },
        "tracks": {
          "type": "array",
          "items": {
            "$ref": "https://visualspec.dev/schema/1.0/modules/motion.schema.json#/$defs/track"
          },
          "minItems": 1
        },
        "duration": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/duration"
        },
        "delay": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/delay"
        },
        "easing": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/motion.schema.json#/$defs/easing"
        },
        "spring": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/motion.schema.json#/$defs/spring"
        },
        "decay": {
          "type": "object",
          "properties": {
            "velocity": {
              "type": "number"
            },
            "deceleration": {
              "type": "number",
              "exclusiveMinimum": 0
            }
          },
          "required": [
            "velocity",
            "deceleration"
          ],
          "additionalProperties": false
        },
        "timing": {
          "type": "object",
          "properties": {
            "duration": {
              "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/duration"
            },
            "delay": {
              "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/delay"
            },
            "endDelay": {
              "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/duration"
            },
            "iterations": {
              "anyOf": [
                {
                  "type": "number",
                  "minimum": 0
                },
                {
                  "const": "infinite"
                }
              ]
            },
            "iterationStart": {
              "type": "number",
              "minimum": 0
            },
            "direction": {
              "enum": [
                "normal",
                "reverse",
                "alternate",
                "alternate-reverse"
              ]
            },
            "fill": {
              "enum": [
                "none",
                "forwards",
                "backwards",
                "both"
              ]
            },
            "playbackRate": {
              "type": "number",
              "exclusiveMinimum": 0
            }
          },
          "additionalProperties": false
        },
        "iterations": {
          "anyOf": [
            {
              "type": "number",
              "minimum": 0
            },
            {
              "const": "infinite"
            }
          ]
        },
        "direction": {
          "enum": [
            "normal",
            "reverse",
            "alternate",
            "alternate-reverse"
          ]
        },
        "autoreverse": {
          "type": "boolean"
        },
        "fill": {
          "enum": [
            "none",
            "forwards",
            "backwards",
            "both"
          ]
        },
        "composition": {
          "enum": [
            "replace",
            "add",
            "accumulate"
          ]
        },
        "motionRefs": {
          "type": "array",
          "items": {
            "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/id"
          },
          "uniqueItems": true
        },
        "children": {
          "type": "array",
          "items": {
            "$ref": "https://visualspec.dev/schema/1.0/modules/motion.schema.json#/$defs/step"
          }
        },
        "stagger": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/duration"
        },
        "trigger": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/motion.schema.json#/$defs/driver"
        },
        "path": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/motion.schema.json#/$defs/path"
        },
        "morph": {
          "type": "object",
          "properties": {
            "fromPath": {
              "type": "string",
              "minLength": 1
            },
            "toPath": {
              "type": "string",
              "minLength": 1
            },
            "preserveTopology": {
              "type": "boolean"
            }
          },
          "required": [
            "fromPath",
            "toPath"
          ],
          "additionalProperties": false
        },
        "sharedElement": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/motion.schema.json#/$defs/sharedElement"
        },
        "essential": {
          "type": "boolean"
        },
        "interrupt": {
          "anyOf": [
            {
              "enum": [
                "cancel",
                "finish",
                "reverse",
                "retarget",
                "blend",
                "queue",
                "ignore"
              ]
            },
            {
              "type": "object",
              "properties": {
                "policy": {
                  "enum": [
                    "cancel",
                    "finish",
                    "reverse",
                    "retarget",
                    "blend",
                    "queue",
                    "ignore"
                  ]
                },
                "preserveVelocity": {
                  "type": "boolean"
                }
              },
              "required": [
                "policy"
              ],
              "additionalProperties": false
            }
          ]
        },
        "cancel": {
          "enum": [
            "restore",
            "freeze",
            "finish"
          ]
        },
        "reducedMotion": {
          "type": "object",
          "properties": {
            "strategy": {
              "enum": [
                "instant",
                "fade",
                "reduce",
                "substitute",
                "none",
                "disable",
                "replace",
                "shorten"
              ]
            },
            "duration": {
              "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/duration"
            },
            "motionRef": {
              "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/id"
            }
          },
          "additionalProperties": false
        },
        "performance": {
          "type": "object",
          "properties": {
            "preferCompositor": {
              "type": "boolean"
            },
            "frameBudget": {
              "type": "number",
              "minimum": 0
            }
          },
          "additionalProperties": false
        },
        "extensions": {
          "$ref": "https://visualspec.dev/schema/1.0/modules/common.schema.json#/$defs/extensions"
        }
      },
      "required": [
        "id"
      ],
      "additionalProperties": false
    }
  },
  "$ref": "#/$defs/animation"
}