thi-ng/umbrella

import type { IObjectOf } from "@thi.ng/api";
import { isArray } from "@thi.ng/checks/is-array";
import type { Edge, Graph, GraphAttribs, Node } from "./api.js";

/** @internal */
let __nextID = 0;

/** @internal */
const __nextSubgraphID = () => "cluster" + __nextID++;

/** @internal */
const __wrapQ = (x: any) => `"${x}"`;

/** @internal */
const __escape = (x: any) =>
    String(x).replace(/"/g, `\\"`).replace(/\n/g, "\\n");

/** @internal */
const __formatGraphAttribs = (
    attribs: Partial<GraphAttribs>,
    acc: string[]
) => {
    for (let a in attribs) {
        let v = attribs[a];
        switch (a) {
            case "bgcolor":
            case "color":
            case "fillcolor":
            case "fontcolor":
                isArray(v) && (v = v.join(","));
                break;
            case "edge":
                acc.push(`edge[${__formatAttribs(v)}];`);
                continue;
            case "node":
                acc.push(`node[${__formatAttribs(v)}];`);
                continue;
            default:
                break;
        }
        acc.push(`${a}="${__escape(v)}";`);
    }
    return acc;
};

/** @internal */
const __formatAttribs = (attribs: Partial<Node | Edge>) => {
    const acc: string[] = [];
    for (let a in attribs) {
        let v = attribs[a];
        switch (a) {
            case "color":
            case "fillcolor":
            case "fontcolor":
                isArray(v) && (v = v.join(","));
                break;
            case "label":
                if ((<Node>attribs).ins || (<Node>attribs).outs) {
                    v = __formatPortLabel(attribs, v);
                }
                break;
            case "url":
                a = "URL";
                break;
            case "ins":
            case "outs":
            case "src":
            case "dest":
            case "srcPort":
            case "destPort":
                continue;
            default:
        }
        acc.push(`${a}="${__escape(v)}"`);
    }
    return acc.join(", ");
};

/** @internal */
const __formatPorts = (ports: IObjectOf<string>) => {
    const acc: string[] = [];
    for (let i in ports) {
        acc.push(`<${i}> ${__escape(ports[i])}`);
    }
    return `{ ${acc.join(" | ")} }`;
};

/** @internal */
const __formatPortLabel = (node: Partial<Node>, label: string) => {
    const acc: string[] = [];
    node.ins && acc.push(__formatPorts(node.ins));
    acc.push(__escape(label));
    node.outs && acc.push(__formatPorts(node.outs));
    return acc.join(" | ");
};

export const serializeNode = (id: string, n: Partial<Node>) => {
    const attribs = __formatAttribs(n);
    return attribs.length ? `"${id}"[${attribs}];` : `"${id}";`;
};

export const serializeEdge = (e: Edge, directed = true) => {
    const acc: string[] = [__wrapQ(e.src)];
    e.srcPort != null && acc.push(":", __wrapQ(e.srcPort));
    acc.push(directed ? " -> " : " -- ");
    acc.push(__wrapQ(e.dest));
    e.destPort != null && acc.push(":", __wrapQ(e.destPort));
    const attribs = __formatAttribs(e);
    attribs.length && acc.push("[", attribs, "]");
    acc.push(";");
    return acc.join("");
};

export const serializeGraph = (graph: Graph, isSub = false) => {
    const directed = graph.directed !== false;
    const acc = isSub
        ? [`subgraph ${graph.id || __nextSubgraphID()} {`]
        : [`${directed ? "di" : ""}graph ${graph.id || "g"} {`];
    if (graph.include) {
        acc.push(graph.include);
    }
    if (graph.attribs) {
        __formatGraphAttribs(graph.attribs, acc);
    }
    for (let id in graph.nodes) {
        acc.push(serializeNode(id, graph.nodes[id]));
    }
    for (let e of graph.edges) {
        acc.push(serializeEdge(e, directed));
    }
    if (graph.sub) {
        for (let sub of graph.sub) {
            acc.push(serializeGraph(sub, true));
        }
    }
    acc.push("}");
    return acc.join("\n");
};