/**
 * This file is part of Satie music engraver <https://github.com/jnetterf/satie>.
 * Copyright (C) Joshua Netterfield <joshua.ca> 2015 - present.
 * 
 * Satie is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 * 
 * Satie is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with Satie.  If not, see <http://www.gnu.org/licenses/>.
 */

import * as invariant from "invariant";
import {isEqual} from "lodash";
import {IAny, IListInsert} from "musicxml-interfaces/operations";

import {Document, ISegment} from "./document";

import {IFactory} from "./private_factory";
import {cloneObject} from "./private_util";

export default function segmentMutator(factory: IFactory, segment: ISegment, op: IAny, doc: Document) {
    const {part, ownerType} = segment; // p[2]
    invariant(op.p.length === 6, "Invalid length for segment operation.");

    invariant(op.p[1] === "parts", "Malformed path.");
    invariant(op.p[2] === part, "Invalid fixup part.");
    invariant(op.p[3] === "voices" || op.p[3] === "staves",
        "Only voice and staff fixups are supported.");
    invariant(op.p[3] === "voices" && ownerType === "voice" ||
        op.p[3] === "staves" && ownerType === "staff", "Type/path mismatch");

    if ("li" in op && !("ld" in op)) {
        let liop = op as IListInsert<any>;
        let newModel = factory.fromSpec(liop.li);
        if (liop.li._class === "VisualCursor") {
            doc._visualCursor = newModel;
        }
        segment.splice(op.p[5] as number, 0, newModel);
    } else if ("ld" in op && !("li" in op)) {
        const existingSerializable: any = cloneObject(segment[op.p[5] as number]);
        const ld: any = cloneObject(op.ld);
        if (!isEqual(existingSerializable, ld)) {
            console.warn(
                "The element to be removed should be accurately specified in the operation.\n\n" +
                "OPERATION SPEC: " + JSON.stringify(ld, null, 2) + "\n\n" +
                "ACTUAL SPEC: " + JSON.stringify(existingSerializable, null, 2) + "\n\n" +
                "Your patch is broken."
            );
        }
        segment.splice(op.p[5] as number, 1);
    } else {
        invariant(false, "Unsupported operation type");
    }
}