import type { CanvasNode } from "~/types/canvas";
import { clamp } from "#shared/general.util";

export type Direction = 'bottom' | 'top' | 'left' | 'right';
export type Position = { x: number, y: number };
export type Box = Position & { w: number, h: number };
export type Path = {
    path: string;
    from: Position;
    to: Position;
    side: Direction;
}

export const rotation: Record<Direction, string> = {
    top: "180",
    bottom: "0",
    left: "90",
    right: "270"
};
export const opposite: Record<Direction, Direction> = {
    top: "bottom",
    bottom: "top",
    left: "right",
    right: "left"
}

export function edgePos(side: Direction, pos: Position, offset: number): Position {
    switch (side) {
        case "left":
            return {
                x: pos.x - offset,
                y: pos.y
            };
        case "right":
            return {
                x: pos.x + offset,
                y: pos.y
            };
        case "top":
            return {
                x: pos.x,
                y: pos.y - offset
            };
        case "bottom":
            return {
                x: pos.x,
                y: pos.y + offset
            }
    }
}
export function getNode(nodes: CanvasNode[], id: string): CanvasNode | undefined
{
    return nodes.find(e => e.id === id);
}
export function posFromDir(e: { minX: number, minY: number, maxX: number, maxY: number }, t: Direction): Position {
    switch (t) {
        case "top":
            return { x: (e.minX + e.maxX) / 2, y: e.minY };
        case "right":
            return { x: e.maxX, y: (e.minY + e.maxY) / 2 };
        case "bottom":
            return { x: (e.minX + e.maxX) / 2, y: e.maxY };
        case "left":
            return { x: e.minX, y: (e.minY + e.maxY) / 2 };
    }
}
export function getBbox(node: CanvasNode): { minX: number, minY: number, maxX: number, maxY: number } {
    return { minX: node.x, minY: node.y, maxX: node.x + node.width, maxY: node.y + node.height };
}
export function getPath(from: CanvasNode, fromSide: Direction, to: CanvasNode, toSide: Direction): Path | undefined {
    if(from === undefined || to === undefined)
        return;

    const start = posFromDir(getBbox(from), fromSide), end = posFromDir(getBbox(to), toSide);
    return bezier(start, fromSide, end, toSide);
}
export function bezier(from: Position, fromSide: Direction, to: Position, toSide: Direction): Path {
    const r = Math.hypot(from.x - to.x, from.y - to.y), o = clamp(r / 2, 70, 150), a = edgePos(fromSide, from, o), s = edgePos(toSide, to, o);
    return {
        path: `M${from.x},${from.y} C${a.x},${a.y} ${s.x},${s.y} ${to.x},${to.y}`,
        from: from,
        to: to,
        side: toSide,
    };
}
export function labelCenter(from: CanvasNode, fromSide: Direction, to: CanvasNode, toSide: Direction): string {
    const start = posFromDir(getBbox(from), fromSide), end = posFromDir(getBbox(to), toSide);
    const len = Math.hypot(start.x - end.x, start.y - end.y), offset = clamp(len / 2, 70, 150), b = edgePos(fromSide, start, offset), s = edgePos(toSide, end, offset);
    const center = getCenter(start, end, b, s, 0.5);
    return `translate(${center.x}px, ${center.y}px)`;
}
export function getCenter(n: Position, i: Position, r: Position, o: Position, e: number): Position {
    const a = 1 - e, s = a * a * a, l = 3 * e * a * a, c = 3 * e * e * a, u = e * e * e;
    return {
        x: s * n.x + l * r.x + c * o.x + u * i.x,
        y: s * n.y + l * r.y + c * o.y + u * i.y
    };
}

export function gridSnap(value: number, grid: number): number
{
    return Math.round(value / grid) * grid;
}