contra-renderer/www/js/moves/promenade.ts

import { DanceRole } from "../danceCommon.js";
import { HandTo, SemanticPosition, DancerDistance, HandConnection, PositionKind } from "../interpreterCommon.js";
import { Move } from "../libfigureMapper.js";
import { SemanticAnimationKind } from "../lowLevelMove.js";
import { Hand } from "../rendererConstants.js";
import { ISingleVariantMoveInterpreter, LowLevelMovesForAllDancers, MoveInterpreter, PartialLowLevelMove, SemanticPositionsForAllDancers, SingleVariantMoveInterpreter, moveInterpreters } from "./_moveInterpreter.js";

const moveName: Move["move"] = "promenade";

class PromenadeSingleVariant extends SingleVariantMoveInterpreter<Promenade, typeof moveName> {
  moveAsLowLevelMoves(): LowLevelMovesForAllDancers {
    if (this.move.parameters.dir !== "across") {
      // TODO "along" would be the bicycle chain? Not sure what left/right diagonal means here.
      throw "Promenade not across the set is unsupported."
    }

    // TODO How to know?
    const twirlAfterPromenade = true;
    const twirlBeats = twirlAfterPromenade ? this.move.beats / 2 : 0;
    const promenadeBeats = this.move.beats - twirlBeats;

    return this.handleCirclePairedMove(this.move.parameters.who, ({ startPos }) => {
      const handTo = startPos.which.isOnLeftLookingAcross() ? HandTo.DancerRight : HandTo.DancerLeft;
      const startingPos: SemanticPosition = {
        ...startPos,
        facing: startPos.which.facingAcross(),
        dancerDistance: DancerDistance.Compact,
        hands: new Map<Hand, HandConnection>([
          [Hand.Left, { hand: Hand.Left, to: handTo }],
          [Hand.Right, { hand: Hand.Right, to: handTo }],
        ]),
      };

      const endSetOffset = this.move.progression
        ? (startPos.setOffset ?? 0) + (startPos.which.isLeft() ? +0.5 : -0.5)
        : startPos.setOffset;
      const beforeTwirlPos: SemanticPosition & { kind: PositionKind.Circle } = {
        ...startingPos,
        which: startPos.which.swapAcross(),
        facing: startPos.which.facingAcross(),
        setOffset: endSetOffset,
      };
      const endPos: SemanticPosition = {
        ...beforeTwirlPos,
        which: beforeTwirlPos.which.swapUpAndDown(),
        facing: beforeTwirlPos.which.facingAcross(),
        dancerDistance: undefined,
      };

      const maybeTwirl: [] | [PartialLowLevelMove] = (twirlAfterPromenade ? [{
        beats: twirlBeats,
        endPosition: endPos,
        movementPattern: {
          kind: SemanticAnimationKind.CourtesyTurn,
          clockwise: this.move.parameters.turn, // TODO or ! this?
        }
      }] : [])

      return this.combine([{
        beats: promenadeBeats,
        endPosition: beforeTwirlPos,
        movementPattern: {
          kind: SemanticAnimationKind.Promenade,
          swingRole: startPos.which.isOnLeftLookingAcross() ? DanceRole.Lark : DanceRole.Robin,
          twirl: true,
          passBy: this.move.parameters.turn ? Hand.Left : Hand.Right,
        }
      }, ...maybeTwirl], startingPos);
    });
  }
}

class Promenade extends MoveInterpreter<typeof moveName> {
  buildSingleVariantMoveInterpreter(startingPos: SemanticPositionsForAllDancers): ISingleVariantMoveInterpreter {
    return new PromenadeSingleVariant(this, startingPos);
  }
}

moveInterpreters.set(moveName, Promenade);