import * as core from '@actions/core'
import * as exec from '@actions/exec'
import * as fs from 'fs'
import * as github from '@actions/github'
import * as tc from '@actions/tool-cache'
import retry = require('async-retry')
import semver = require('semver')

const NEXTFLOW_REPO = {owner: 'nextflow-io', repo: 'nextflow'}

async function all_nf_releases(ok) {
  return await ok.paginate(
    ok.rest.repos.listReleases,
    NEXTFLOW_REPO,
    response => response.data
  )
}

async function latest_stable_release_data(ok) {
  const {data: stable_release} = await ok.rest.repos.getLatestRelease(
    NEXTFLOW_REPO
  )

  return stable_release
}

async function release_data(version, ok) {
  // Setup tag-based filtering
  let filter = r => {
    return semver.satisfies(r.tag_name, version, true)
  }

  // Check if the user passed a 'latest*' tag, and override filtering
  // accordingly
  if (version.includes('latest')) {
    if (version.includes('-everything')) {
      // No filtering
      filter = r => {
        return true
      }
    } else if (version.includes('-edge')) {
      filter = r => {
        return r.tag_name.endsWith('-edge')
      }
    } else {
      // This is special: passing 'latest' or 'latest-stable' allows us to use
      // the latest stable GitHub release direct from the API
      const stable_release = await latest_stable_release_data(ok)
      return stable_release
    }
  }

  // Get all the releases
  const all_releases = await all_nf_releases(ok)

  let matching_releases = all_releases.filter(filter)

  matching_releases.sort(function (x, y) {
    semver.compare(x.tag_name, y.tag_name, true)
  })

  return matching_releases[0]
}

function nextflow_bin_url(release, get_all) {
  const release_assets = release.assets
  const all_asset = release_assets.filter(a => {
    return a.browser_download_url.endsWith('-all')
  })[0]
  const regular_asset = release_assets.filter(a => {
    return a.name == 'nextflow'
  })[0]

  const dl_asset = get_all ? all_asset : regular_asset

  return dl_asset.browser_download_url
}

async function install_nextflow(url, version) {
  core.debug(`Downloading Nextflow from ${url}`)
  const nf_dl_path = await retry(
    async bail => {
      return await tc.downloadTool(url)
    },
    {
      onRetry: err => {
        core.debug(`Download of ${url} failed, trying again. Error ${err}`)
      }
    }
  )

  const temp_install_dir = fs.mkdtempSync(`nxf-${version}`)
  const nf_path = `${temp_install_dir}/nextflow`

  fs.renameSync(nf_dl_path, nf_path)
  fs.chmodSync(nf_path, '0711')

  return temp_install_dir
}

async function run() {
  // Set environment variables
  core.exportVariable('CAPSULE_LOG', 'none')

  // Read in the arguments
  const token = core.getInput('token')
  const version = core.getInput('version')
  const get_all = core.getBooleanInput('all')

  let resolved_version = ''

  // Setup the API
  let octokit = {}
  try {
    octokit = github.getOctokit(token)
  } catch (e: any) {
    core.setFailed(
      `Could not authenticate to GitHub Releases API with provided token\n${e.message}`
    )
  }

  // Get the release info for the desired release
  let release: any = {}
  try {
    release = await release_data(version, octokit)
    resolved_version = release.tag_name
    core.info(`Input version '${version}' resolved to Nextflow ${release.name}`)
  } catch (e: any) {
    core.setFailed(
      `Could not retrieve Nextflow release matching ${version}.\n${e.message}`
    )
  }

  // Get the download url for the desired release
  let url = ''
  try {
    url = nextflow_bin_url(release, get_all)
    core.info(`Preparing to download from ${url}`)
  } catch (e: any) {
    core.setFailed(`Could not parse the download URL\n${e.message}`)
  }
  try {
    // Download Nextflow and add it to path
    let nf_path = ''
    nf_path = tc.find('nextflow', resolved_version)

    if (!nf_path) {
      core.debug(`Could not find Nextflow ${resolved_version} in cache`)
      const nf_install_path = await install_nextflow(url, resolved_version)

      nf_path = await tc.cacheDir(nf_install_path, 'nextflow', resolved_version)
      core.debug(`Added Nextflow to cache: ${nf_path}`)

      fs.rmdirSync(nf_install_path, {recursive: true})
    } else {
      core.debug(`Using cached version of Nextflow: ${nf_path}`)
    }

    core.addPath(nf_path)

    core.info(`Downloaded \`nextflow\` to ${nf_path} and added to PATH`)
  } catch (e: any) {
    core.setFailed(e.message)
  }

  // Run Nextflow so it downloads its dependencies
  try {
    const nf_exit_code = await exec.exec('nextflow', ['help'])
  } catch (e: any) {
    core.warning(
      'Nextflow appears to have installed correctly, but an error was thrown while running it.'
    )
  }
}

run()