update_json.gradle

import groovy.json.JsonOutput

/**
 * Code for automatic update JSON generation
 * https://github.com/BluSunrize/ImmersiveEngineering/blob/ee3f452fe62f9efece0afa74a315ad0c341f0ec7/build.gradle#L285-L377
 * @author BluSunrize
 */
class GenerateUpdateJSON extends DefaultTask {
    static def VERSION_PREFIX = "##### Version "
    static def BUILT_SUFFIX = " - BUILT"
    static def RECOMMENDED = "-recommended"
    static def LATEST = "-latest"

    /**If the mod is in beta, no recommended release will be set*/
    boolean beta = false
    String versionScheme = '%2$s'
    String curseforgeURL
    File changelog
    File output

    static int compareVersions(String vA, String vB) {
        String[] vPartsA = vA.split("[\\D]")
        String[] vPartsB = vB.split("[\\D]")
        if (vPartsA.length==0&&vPartsB.length==0)
            return vA <=> vB
        else if (vPartsA.length==0)
            return -1
        else if (vPartsB.length==0)
            return 1

        int length = Math.min(vPartsA.length, vPartsB.length)
        for (int i = 0;i<length;i++) {
            int pA = Integer.parseInt(vPartsA[i])
            int pB = Integer.parseInt(vPartsB[i])
            if (pA!=pB) {
                return pA<=>pB
            }
        }
        if (vPartsA.length != vPartsB.length)
            return vPartsA.length <=> vPartsB.length
        return vA <=> vB
    }
    @TaskAction
    def generate() {
        if (!changelog.exists())
            println "Changelog does not exist! Aborting!"
        else {
            Map<String, Map<String, Object>> changelogForVersions = new HashMap<>()
            Map<String, String> promos = new TreeMap<>({String s1, String s2-> compareVersions(s1, s2)})
            String currentVersion = null
            String currentChangelog = ""
            changelog.eachLine {line ->
                if (line.startsWith(VERSION_PREFIX)) {
                    if (currentVersion!=null) {
                        String[] split = currentVersion.split("-")
                        if (split.length != 2) {
                            throw new IllegalArgumentException("Invalid version ${currentVersion}, expected mcversion-modversion")
                        }
                        String mcVer   = split[0]
                        String mainVer = split[1]
                        String modVersion = String.format(versionScheme, mcVer, mainVer)
                        if (!changelogForVersions.containsKey(mcVer)) {
                            if (!beta) {
                                promos.put(mcVer+RECOMMENDED, modVersion)
                            }
                            promos.put(mcVer+LATEST, modVersion)
                            changelogForVersions[mcVer] = new TreeMap<>({String s1, String s2-> compareVersions(s1, s2)})
                        }
                        changelogForVersions[mcVer][modVersion] = currentChangelog
                    }
                    if (line.endsWith(BUILT_SUFFIX)) {
                        currentVersion = line.substring(VERSION_PREFIX.length(), line.length()-BUILT_SUFFIX.length())
                    } else {
                        currentVersion = (String) null
                    }
                    currentChangelog = ""
                } else if (!line.isEmpty()) {
                    if (currentChangelog.length()==0)
                        currentChangelog += line
                    else
                        currentChangelog += "\n"+line
                }
            }
            Map<String, Object> mainMap = new TreeMap<>({String s1, String s2-> compareVersions(s1, s2)})
            mainMap.putAll(changelogForVersions)
            mainMap["homepage"] = curseforgeURL
            mainMap["promos"] = promos
            def outJson = JsonOutput.toJson(mainMap)
            outJson = JsonOutput.prettyPrint(outJson)
            File outF = output
            outF.delete()
            outF << outJson
        }
    }
}

task updateJson(type: GenerateUpdateJSON) {
    curseforgeURL = project.findProperty("${project.name}URL")
    changelog = project.file("changelog.md")
    output = project.file("changelog.json")
}