#!/usr/bin/env zx
$.verbose = true
/* Stolen from https://raw.githubusercontent.com/onedr0p/home-ops/main/.github/scripts/helmReleaseDiff.mjs */


/**
 * * helmReleaseDiff.mjs
 * * Runs `helm template` with your Helm values and then runs `dyff` across Flux HelmRelease manifests
 * @param --current-release   The source Flux HelmRelease to compare against the target
 * @param --incoming-release  The target Flux HelmRelease to compare against the source
 * @param --kubernetes-dir    The directory containing your Flux manifests including the HelmRepository manifests
 * * Limitations:
 * * Does not work with multiple HelmRelease maninfests in the same YAML document
 */
const CurrentRelease  = argv['current-release']
const IncomingRelease = argv['incoming-release']
const KubernetesDir   = argv['kubernetes-dir']

const dyff      = await which('dyff')
const helm      = await which('helm')
const kustomize = await which('kustomize')

async function helmRelease(releaseFile) {
    const helmRelease = await fs.readFile(releaseFile, 'utf8')
    const doc = YAML.parseAllDocuments(helmRelease).map((item) => item.toJS())
    const release = doc.filter((item) =>
        item.apiVersion === 'helm.toolkit.fluxcd.io/v2beta1'
        && item.kind === 'HelmRelease'
    )
    return release[0]
}

async function helmRepositoryUrl(kubernetesDir, releaseName) {
    const files = await globby([`${kubernetesDir}/**/*.yaml`])
    for await (const file of files) {
        const contents = await fs.readFile(file, 'utf8')
        const doc = YAML.parseAllDocuments(contents).map((item) => item.toJS())
        if ('apiVersion' in doc[0] && doc[0].apiVersion === 'source.toolkit.fluxcd.io/v1beta2'
            && 'kind' in doc[0] && doc[0].kind === 'HelmRepository'
            && 'metadata' in doc[0] && 'name' in doc[0].metadata && doc[0].metadata.name === releaseName)
        {
            return doc[0].spec.url
        }
    }
}

async function kustomizeBuild(releaseBaseDir, releaseName) {
    const build = await $`${kustomize} build --load-restrictor=LoadRestrictionsNone ${releaseBaseDir}`
    const docs = YAML.parseAllDocuments(build.stdout).map((item) => item.toJS())
    const release = docs.filter((item) =>
        item.apiVersion === 'helm.toolkit.fluxcd.io/v2beta1'
        && item.kind === 'HelmRelease'
        && item.metadata.name === releaseName
    )
    return release[0]
}

async function helmRepoAdd (registryName, registryUrl) {
    await $`${helm} repo add ${registryName} ${registryUrl}`
}

async function helmTemplate (releaseName, registryName, chartName, chartVersion, chartValues) {
    const values = new YAML.Document()
    values.contents = chartValues
    const valuesFile = await $`mktemp`
    await fs.writeFile(valuesFile.stdout.trim(), values.toString())

    const manifestsFile = await $`mktemp`
    const manifests = await $`${helm} template --kube-version 1.24.8 --release-name ${releaseName} --include-crds=false ${registryName}/${chartName} --version ${chartVersion} --values ${valuesFile.stdout.trim()}`

    // Remove docs that are CustomResourceDefinition and keys which contain generated fields
    let documents = YAML.parseAllDocuments(manifests.stdout.trim())
    documents = documents.filter(doc => doc.get('kind') !== 'CustomResourceDefinition')
    documents.forEach(doc => {
        const del = (path) => doc.hasIn(path) ? doc.deleteIn(path) : false
        del(['metadata', 'labels'])
        del(['spec', 'template', 'metadata', 'annotations'])
        del(['spec', 'template', 'metadata', 'labels'])
    })

    await fs.writeFile(manifestsFile.stdout.trim(), documents.map(doc => doc.toString({directives: true})).join('\n'))
    return manifestsFile.stdout.trim()
}

// Generate current template from Helm values
const currentRelease = await helmRelease(CurrentRelease)
const currentBuild = await kustomizeBuild(path.dirname(CurrentRelease), currentRelease.metadata.name)
const currentRepositoryUrl = await helmRepositoryUrl(KubernetesDir, currentBuild.spec.chart.spec.sourceRef.name)
await helmRepoAdd(currentBuild.spec.chart.spec.sourceRef.name, currentRepositoryUrl)
const currentManifests = await helmTemplate(
    currentBuild.metadata.name,
    currentBuild.spec.chart.spec.sourceRef.name,
    currentBuild.spec.chart.spec.chart,
    currentBuild.spec.chart.spec.version,
    currentBuild.spec.values
)

// Generate incoming template from Helm values
const incomingRelease = await helmRelease(IncomingRelease)
const incomingBuild = await kustomizeBuild(path.dirname(IncomingRelease), incomingRelease.metadata.name)
const incomingRepositoryUrl = await helmRepositoryUrl(KubernetesDir, incomingBuild.spec.chart.spec.sourceRef.name)
await helmRepoAdd(incomingBuild.spec.chart.spec.sourceRef.name, incomingRepositoryUrl)
const incomingManifests = await helmTemplate(
    incomingBuild.metadata.name,
    incomingBuild.spec.chart.spec.sourceRef.name,
    incomingBuild.spec.chart.spec.chart,
    incomingBuild.spec.chart.spec.version,
    incomingBuild.spec.values
)

// Print diff using dyff
const diff = await $`${dyff} --color=off --truecolor=off between --omit-header --ignore-order-changes --detect-kubernetes=true --output=human ${currentManifests} ${incomingManifests}`
echo(diff.stdout.trim())