/** @internal */
declare const _debug_: Debug;
import type { Debug } from '../debug/debug.js';
import type { Mat } from '../mat/mat.js';
import { getLargestVertex } from '../mat/get-largest-vertex.js';
import { createNewCpTrees } from '../mat/create-new-cp-trees.js';
import { cull } from './cull.js';
import { addDebugInfo } from './add-debug-info.js';
import { clone } from '../cp-node/fs/clone.js';
import { getSatCulls } from './get-sat-culls.js';


/**
 * Apply and returns an enhanced version of the Scale Axis Transform (SAT) to
 * the given MAT. The returned SAT is guaranteed to be a subset of the MAT and
 * preserves topology at any scale.
 * 
 * Typically the MAT contains too many branches caused by minute details on the
 * boundary of the shape. The SAT is a simplification of the MAT that preserves
 * less detail the higher the applied scale factor. The severity at which noise
 * are removed depends on the local scale of the shape.
 * 
 * @param mat the Medial Axis Transform (MAT) on which to apply the SAT
 * @param s the scale factor >= 1 (e.g. 1.3)
 */
function toScaleAxis(
        mat: Mat,
        s: number): Mat {

    let timingStart = 0;
    if (typeof _debug_ !== 'undefined') {
        timingStart = performance.now();
    }

    const cpNode = getLargestVertex(clone(mat.cpNode));
    const culls = getSatCulls(cpNode, s);

    cull(culls, cpNode);

    const sat: Mat = {
        cpNode: cpNode,
        meta: {
            ...mat.meta,
            cpTrees: createNewCpTrees(cpNode)
        }
    };


    addDebugInfo(timingStart);

    return sat;
}


export { toScaleAxis }