MapComplete/src/UI/History/HistoryUtils.ts

import * as all_layers from "../../assets/generated/themes/personal.json"
import ThemeConfig from "../../Models/ThemeConfig/ThemeConfig"
import { OsmObject } from "../../Logic/Osm/OsmObject"

export class HistoryUtils {

    public static readonly personalTheme = new ThemeConfig(<any> all_layers, true)
    private static ignoredLayers = new Set<string>(["fixme"])
    public static determineLayer(properties: Record<string, string>){
        return this.personalTheme.getMatchingLayer(properties, this.ignoredLayers)
    }

    public static tagHistoryDiff(step: OsmObject, history: OsmObject[]): {
        key: string,
        value?: string,
        oldValue?: string,
        step: OsmObject
    }[] {
        const previous = history[step.version - 2]
        if (!previous) {
            return Object.keys(step.tags).filter(key => !key.startsWith("_") && key !== "id").map(key => ({
                key, value: step.tags[key], step
            }))
        }
        const previousTags = previous.tags
        return Object.keys(step.tags).filter(key => !key.startsWith("_") )
            .map(key => {
                const value = step.tags[key]
                const oldValue = previousTags[key]
                return {
                    key, value, oldValue, step
                }
            }).filter(ch => ch.oldValue !== ch.value)
    }

    public static fullHistoryDiff(histories: OsmObject[][], onlyShowUsername?: Set<string>){
        const allDiffs: {key: string, oldValue?: string, value?: string}[] = [].concat(...histories.map(
            history => {
                const filtered = history.filter(step => !onlyShowUsername || onlyShowUsername?.has(step.tags["_last_edit:contributor"] ))
                const diffs: {
                    key: string;
                    value?: string;
                    oldValue?: string
                }[][] = filtered.map(step => HistoryUtils.tagHistoryDiff(step, history))
                return [].concat(...diffs)
            }
        ))
        return allDiffs
    }

}