{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://github.com/twitched/cascade/cascade-sequence.schema.json",
  "title": "Cascade sequence",
  "description": "A declarative UI Toolkit animation for Cascade. Steps run sequentially; the actions within a step run in parallel. Accepted by SequencePreset.FromJson / TryFromJson / PlayJson. Durations are in seconds. See AI-GUIDE.md.",
  "type": "object",
  "required": [
    "steps"
  ],
  "additionalProperties": false,
  "properties": {
    "steps": {
      "type": "array",
      "minItems": 1,
      "description": "Ordered steps; each starts when the previous finishes.",
      "items": {
        "$ref": "#/definitions/step"
      }
    }
  },
  "definitions": {
    "step": {
      "type": "object",
      "required": [
        "actions"
      ],
      "additionalProperties": false,
      "properties": {
        "actions": {
          "type": "array",
          "description": "Actions that play together (in parallel) within this step.",
          "items": {
            "$ref": "#/definitions/action"
          }
        }
      }
    },
    "action": {
      "type": "object",
      "required": [
        "verb"
      ],
      "additionalProperties": false,
      "allOf": [
        {
          "if": {
            "properties": {
              "verb": {
                "enum": [
                  "Fade",
                  "MoveX",
                  "MoveY",
                  "Scale",
                  "Rotate",
                  "Width",
                  "Height",
                  "Top",
                  "Left",
                  "Nudge"
                ]
              }
            }
          },
          "then": {
            "required": [
              "to"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "verb": {
                "enum": [
                  "MoveTo",
                  "Size"
                ]
              }
            }
          },
          "then": {
            "required": [
              "x",
              "y"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "verb": {
                "enum": [
                  "BackgroundColor",
                  "TextColor"
                ]
              }
            }
          },
          "then": {
            "required": [
              "color"
            ]
          }
        }
      ],
      "properties": {
        "verb": {
          "type": "string",
          "enum": [
            "Fade",
            "MoveX",
            "MoveY",
            "MoveTo",
            "Scale",
            "Rotate",
            "SlideIn",
            "BackgroundColor",
            "TextColor",
            "Width",
            "Height",
            "Size",
            "Top",
            "Left"
          ],
          "description": "Which property to animate. Fade/MoveX/MoveY/Scale/Rotate/Width/Height/Top/Left use 'to'; MoveTo/Size use 'x'/'y'; BackgroundColor/TextColor use 'color'; SlideIn uses 'edge'/'distance'. Width/Height/Size/Top/Left reflow layout."
        },
        "to": {
          "type": "number",
          "description": "Target value for float-target verbs. Opacity 0-1; Scale is a multiplier (1 = natural size); Rotate in degrees; others in px."
        },
        "from": {
          "type": "number",
          "description": "Explicit START value. Omitted, the action begins wherever the element already is - so \"to\": 1 on a visible element is a legitimate no-op. An entrance must state its from (e.g. \"from\": 0, \"to\": 1 to fade in). Float-target verbs only."
        },
        "x": {
          "type": "number",
          "description": "X target for MoveTo (px) / width for Size (px)."
        },
        "y": {
          "type": "number",
          "description": "Y target for MoveTo (px) / height for Size (px)."
        },
        "color": {
          "type": "string",
          "description": "Color for BackgroundColor/TextColor: '#RRGGBB', '#RRGGBBAA', or a named color.",
          "pattern": "^(#[0-9a-fA-F]{6}([0-9a-fA-F]{2})?|[a-zA-Z]+)$"
        },
        "edge": {
          "type": "string",
          "enum": [
            "Left",
            "Right",
            "Top",
            "Bottom"
          ],
          "description": "Edge to slide in from (SlideIn)."
        },
        "distance": {
          "type": "number",
          "minimum": 0,
          "default": 48,
          "description": "How far (px) the element starts off-rest for SlideIn."
        },
        "duration": {
          "type": "number",
          "minimum": 0,
          "maximum": 600,
          "default": 0.3,
          "description": "Duration in SECONDS (0.3 = 300 ms). Capped at 600 (10 min); longer is treated as a generation error."
        },
        "delay": {
          "type": "number",
          "minimum": 0,
          "maximum": 600,
          "default": 0,
          "description": "Delay in seconds before this action starts. Capped at 600 (10 min)."
        },
        "ease": {
          "type": "string",
          "enum": [
            "Linear",
            "InSine",
            "OutSine",
            "InOutSine",
            "InQuad",
            "OutQuad",
            "InOutQuad",
            "InCubic",
            "OutCubic",
            "InOutCubic",
            "OutQuart",
            "OutExpo",
            "OutCirc",
            "InBack",
            "OutBack",
            "InOutBack",
            "OutElastic",
            "OutBounce"
          ],
          "default": "OutCubic",
          "description": "Easing curve. Ignored when 'spring' is set."
        },
        "spring": {
          "type": "string",
          "enum": [
            "Gentle",
            "Snappy",
            "Bouncy"
          ],
          "description": "Use a physics spring instead of an easing curve. Overrides 'ease'."
        }
      }
    }
  }
}