/** Copyright Stewart Allen <sa@grid.space> -- All Rights Reserved */

import { newPolygon } from '../../../geo/polygon.js';
import { slice as gyroid_slice } from '../../../geo/gyroid.js';

export const fill_fixed = {
    hex: fillHexFull,
    grid: fillGrid,
    triangle: fillTriangle
};

export const fill = {
    hex: fillHexFull,
    grid: fillGrid,
    gyroid: fillGyroid,
    triangle: fillTriangle,
    linear: fillLinear,
    cubic: fillCubic
};

const DEG2RAD = Math.PI / 180;

function fillHexFull(target) {
    fillHex(target, true);
}

/**
 * emitter creates a hex infill pattern and sends to target
 *
 * @param {Object} target
 * @param {boolean} full continuous walls
 */
function fillHex(target, full) {
    // compute segment lengths (vert/horiz and 45)
    let spacing = target.offset();
    // let vhlen = (1 / target.density()) * (target.lineWidth() + spacing);
    let vhlen = (1 / target.density()) * target.lineWidth() * 0.5;
    let anxlen = (Math.cos(30 * DEG2RAD) * vhlen).round(7);
    let anylen = (Math.sin(30 * DEG2RAD) * vhlen).round(7);
    let bounds = target.bounds();
    let even = true;
    let evenZ = target.zIndex() % 2 === 0;
    let maxy = bounds.max.y + (vhlen + anylen * 2);
    let x, y;

    if (full || evenZ) {
        x = bounds.min.x;
        for (;;) {
            if (even && x > bounds.max.x) break;
            if (!even && x > bounds.max.x + anxlen + spacing) break;
            y = bounds.min.y;
            target.newline();
            while (y <= maxy) {
                target.emit(x,y);
                y += vhlen;
                target.emit(x,y);
                if (even) x += anxlen; else x -= anxlen;
                y += anylen;
                target.emit(x,y);
                y += vhlen;
                target.emit(x,y);
                if (even) x -= anxlen; else x += anxlen;
                y += anylen;
            }
            x += spacing;
            if (even) x += (anxlen * 2);
            even = !even;
            target.newline();
        }
    } else {
        y = bounds.min.y + vhlen;
        for (;;) {
            if (even && y > bounds.max.y) break;
            if (!even && y > bounds.max.y + anylen) break;
            x = bounds.min.x;
            target.newline();
            while (x < bounds.max.x) {
                target.emit(x,y);
                if (even) y += anylen; else y -= anylen;
                x += anxlen;
                target.emit(x,y);
                x += spacing;
                target.emit(x,y);
                if (even) y -= anylen; else y += anylen;
                x += anxlen;
                target.emit(x,y);
                x += spacing;
            }
            y += vhlen;
            if (even) y += (anylen * 2);
            even = !even;
            target.newline();
        }
    }
}

function fillGyroid(target) {
    let bounds = target.bounds();
    let height = target.zHeight();
    let span_x = bounds.max.x - bounds.min.x;
    let span_y = bounds.max.y - bounds.min.y;
    let density = target.density();
    let tile = 1 + (1 - density) * 15;
    let tile_x = span_x / tile;
    let tile_y = span_y / tile;
    let tile_z = 1 / tile;
    let gen = gyroid_slice(target.zValue() * tile_z, (1 - density) * 500);

    let polys = [];
    if (gen.dir == 'lr') {
        for (let ty=0; ty<=tile_y; ty++) {
            for (let tx=0; tx<=tile_x; tx++) {
                for (let poly of gen.polys) {
                    target.newline();
                    let points = poly.map(el => {
                        return {
                            x: el.x * tile + tx * tile + bounds.min.x,
                            y: el.y * tile + ty * tile + bounds.min.y,
                            z: 0
                        }
                    });
                    polys.push(newPolygon().setOpen(true).addObj(points));
                }
            }
            polys = connectOpenPolys(polys);
        }
    } else {
        for (let tx=0; tx<=tile_x; tx++) {
            for (let ty=0; ty<=tile_y; ty++) {
                for (let poly of gen.polys) {
                    target.newline();
                    let points = poly.map(el => {
                        return {
                            x: el.x * tile + tx * tile + bounds.min.x,
                            y: el.y * tile + ty * tile + bounds.min.y,
                            z: 0
                        }
                    });
                    polys.push(newPolygon().setOpen(true).addObj(points));
                }
            }
            polys = connectOpenPolys(polys);
        }
    }
    for (let poly of polys.filter(p => p.perimeter() > 2)) {
        target.newline();
        for (let point of poly.points) {
            target.emit(point.x, point.y);
        }
    }
}

function connectOpenPolys(noff, dist = 0.1) {
    if (noff.length <= 1) {
        return noff;
    }
    let heal = 0;
    // heal/rejoin open segments that have close endpoints
    outer: for(;; heal++) {
        let ntmp = noff, tlen = ntmp.length;
        for (let i=0; i<tlen; i++) {
            let s1 = ntmp[i];
            if (!s1 || !s1.open) continue;
            for (let j=i+1; j<tlen; j++) {
                let s2 = ntmp[j];
                if (!s2 || !s2.open) continue;
                if (s1.last().distTo2D(s2.first()) <= dist) {
                    s1.addPoints(s2.points);
                    ntmp[j] = null;
                    continue outer;
                }
                if (s1.first().distTo2D(s2.last()) <= dist) {
                    s2.addPoints(s1.points);
                    ntmp[i] = null;
                    continue outer;
                }
                if (s1.first().distTo2D(s2.first()) <= dist) {
                    s1.reverse();
                    s1.addPoints(s2.points);
                    ntmp[j] = null;
                    continue outer;
                }
                if (s1.last().distTo2D(s2.last()) <= dist) {
                    s2.reverse();
                    s1.addPoints(s2.points);
                    ntmp[j] = null;
                    continue outer;
                }
            }
        }
        break;
    }
    if (heal > 0) {
        // cull nulls
        noff = noff.filter(o => o);
    }
    return noff;
}

function fillGrid(target) {
    let bounds = target.bounds();
    let height = target.zHeight();
    let span_x = bounds.max.x - bounds.min.x;
    let span_y = bounds.max.y - bounds.min.y;
    let offset = target.offset() / 2;
    let tile = (1 / target.density()) * target.lineWidth();
    let tile_x = tile + offset;
    let tile_xc = span_x / tile_x;
    let tile_yc = span_y / tile;

    for (let tx=0; tx<=tile_xc; tx++) {
        target.newline();
        for (let ty=0; ty<=tile_yc; ty++) {
            let bx = tx * tile_x + bounds.min.x;
            let by = ty * tile + bounds.min.y;
            if ((tx + ty) % 2) {
                target.emit(bx, by);
                target.emit(bx + tile_x - offset, by + tile);
            } else {
                target.emit(bx + tile_x - offset, by);
                target.emit(bx, by + tile);
            }
        }
    }
}

function fillCubic(target) {
    let bounds = target.bounds();
    let span = Math.max(
        bounds.max.x - bounds.min.x,
        bounds.max.y - bounds.min.y
    );
    let steps = Math.floor((span / target.lineWidth()) * target.density());
    let step = span / steps;
    let ztype = Math.floor(target.zIndex() / target.repeat()) % 3;
    if (ztype === 1) {
        for (let tx=bounds.min.x; tx<=bounds.max.x; tx += step) {
            target.newline();
            target.emit(tx, bounds.min.y);
            target.emit(tx, bounds.max.y);
        }
    } else if (ztype === 0) {
        for (let ty=bounds.min.y; ty<=bounds.max.y; ty += step) {
            target.newline();
            target.emit(bounds.min.x, ty);
            target.emit(bounds.max.x, ty);
        }
    } else {
        step *- Math.sqrt(2);
        for (let tx=bounds.min.x; tx<=bounds.max.x; tx += step) {
            target.newline();
            target.emit(tx, bounds.min.y);
            target.emit(tx + 1000, bounds.max.y + 1000);
        }
        for (let ty=bounds.min.y; ty<=bounds.max.y; ty += step) {
            target.newline();
            target.emit(bounds.min.x, ty);
            target.emit(bounds.min.x + 1000, ty + 1000);
        }
    }
}

function fillLinear(target) {
    let bounds = target.bounds();
    let span = Math.max(
        bounds.max.x - bounds.min.x,
        bounds.max.y - bounds.min.y
    );
    let steps = Math.floor((span / target.lineWidth()) * target.density());
    let step = span / steps;
    let ztype = Math.floor(target.zIndex() / target.repeat()) % 2;
    if (ztype === 1) {
        for (let tx=bounds.min.x; tx<=bounds.max.x; tx += step) {
            target.newline();
            target.emit(tx, bounds.min.y);
            target.emit(tx, bounds.max.y);
        }
    } else if (ztype === 0) {
        for (let ty=bounds.min.y; ty<=bounds.max.y; ty += step) {
            target.newline();
            target.emit(bounds.min.x, ty);
            target.emit(bounds.max.x, ty);
        }
    }
}

function fillTriangle(target) {
    let bounds = target.bounds();
    let span_x = bounds.max.x - bounds.min.x;
    let span_y = bounds.max.y - bounds.min.y;
    let offset = target.offset();
    let line_w = target.lineWidth() / 2;
    let tile = (1 / target.density()) * (target.lineWidth() * 1.25);
    let tile_x = tile + offset*2 + line_w;
    let tile_xc = span_x / tile_x;
    let tile_yc = span_y / tile;

    for (let tx=0; tx<=tile_xc; tx++) {
        target.newline();
        for (let ty=0; ty<=tile_yc; ty++) {
            let bx = tx * tile_x + bounds.min.x;
            let by = ty * tile + bounds.min.y;
            if ((tx + ty) % 2) {
                target.emit(bx, by);
                target.emit(bx + tile_x - offset - line_w, by + tile);
            } else {
                target.emit(bx + tile_x - offset - line_w, by);
                target.emit(bx, by + tile);
            }
        }
    }

    for (let tx=0; tx<=tile_xc; tx++) {
        let bx = tx * tile_x + bounds.min.x;
        let xp = bx + tile_x - line_w/2 - offset/2;
        target.newline();
        target.emit(xp, bounds.min.y);
        target.emit(xp, bounds.max.y);
    }
}