import * as c from './constants'
import * as semver from 'semver'
import {
  downloadExtractAndCacheJDK,
  getTaggedRelease,
  getMatchingTags
} from './utils'
import {downloadTool} from '@actions/tool-cache'
import {spawnSync} from 'child_process'

const LIBERICA_GH_USER = 'bell-sw'
const LIBERICA_RELEASES_REPO = 'LibericaNIK'
const LIBERICA_JDK_TAG_PREFIX = 'jdk-'
const LIBERICA_VM_PREFIX = 'bellsoft-liberica-vm-'

export async function setUpLiberica(
  javaVersion: string,
  version: string
): Promise<string> {
  const resolvedJavaVersion = await findLatestLibericaJavaVersion(javaVersion)
  const downloadUrl = await findLibericaURL(resolvedJavaVersion, version)
  const toolName = determineToolName(javaVersion, version)
  return downloadExtractAndCacheJDK(
    async () => downloadTool(downloadUrl),
    toolName,
    javaVersion
  )
}

export async function findLatestLibericaJavaVersion(
  javaVersion: string
): Promise<string> {
  const matchingRefs = await getMatchingTags(
    LIBERICA_GH_USER,
    LIBERICA_RELEASES_REPO,
    `${LIBERICA_JDK_TAG_PREFIX}${javaVersion}`
  )
  const noMatch = '0.0.1'
  let bestMatch = noMatch
  const prefixLength = `refs/tags/${LIBERICA_JDK_TAG_PREFIX}`.length
  const patternLength = javaVersion.length
  for (const matchingRef of matchingRefs) {
    const version = matchingRef.ref.substring(prefixLength)
    if (
      semver.valid(version) &&
      // pattern '17.0.1' should match '17.0.1+12' but not '17.0.10'
      (version.length <= patternLength ||
        !isDigit(version.charAt(patternLength))) &&
      semver.compareBuild(version, bestMatch) == 1
    ) {
      bestMatch = version
    }
  }
  if (bestMatch === noMatch) {
    throw new Error(
      `Unable to find the latest version for JDK${javaVersion}. Please make sure the java-version is set correctly. ${c.ERROR_HINT}`
    )
  }
  return bestMatch
}

export async function findLibericaURL(
  javaVersion: string,
  version: string
): Promise<string> {
  const release = await getTaggedRelease(
    LIBERICA_GH_USER,
    LIBERICA_RELEASES_REPO,
    LIBERICA_JDK_TAG_PREFIX + javaVersion
  )
  const platform = determinePlatformPart()
  const assetPrefix = `${LIBERICA_VM_PREFIX}${determineToolVersionPart(
    version
  )}openjdk${javaVersion}`
  const assetSuffix = `-${platform}${c.GRAALVM_FILE_EXTENSION}`
  for (const asset of release.assets) {
    if (
      asset.name.startsWith(assetPrefix) &&
      asset.name.endsWith(assetSuffix)
    ) {
      return asset.browser_download_url
    }
  }
  throw new Error(
    `Unable to find asset for java-version: ${javaVersion}, version: ${version}, platform: ${platform}`
  )
}

function determineToolVersionPart(version: string) {
  return version === 'std' || version === '' ? '' : `${version}-`
}

function determineToolName(javaVersion: string, version: string) {
  return `${LIBERICA_VM_PREFIX}${determineToolVersionPart(
    version
  )}openjdk${javaVersion}-${determinePlatformPart()}`
}

function determinePlatformPart() {
  if (isMuslBasedLinux()) {
    return `linux-${c.JDK_ARCH}-musl`
  } else {
    return `${c.JDK_PLATFORM}-${c.GRAALVM_ARCH}`
  }
}

function isMuslBasedLinux() {
  if (c.IS_LINUX) {
    const output = spawnSync('ldd', ['--version']).stderr.toString('utf8')
    if (output.indexOf('musl') > -1) {
      return true
    }
  }
  return false
}

function isDigit(c: string) {
  return c.charAt(0) >= '0' && c.charAt(0) <= '9'
}