// Copyright (c) Microsoft Corporation.
// Copyright (c) Microsoft Corporation.
// Licensed under the MIT license.

import * as os from "os";
import * as path from "path";
import * as util from "util";
import * as fs from "fs";

import * as toolCache from "@actions/tool-cache";
import * as core from "@actions/core";

const helmToolName = "helm";
const stableHelmVersion = "v3.8.0";
const helmAllReleasesUrl = "https://api.github.com/repos/helm/helm/releases";

export async function run() {
  let version = core.getInput("version", { required: true });

  if(version !== "latest" && version[0] !== "v"){
      version = getValidVersion(version);
  }
  if (version.toLocaleLowerCase() === "latest") {
    version = await getLatestHelmVersion();
  }

  core.debug(util.format("Downloading %s", version));
  let cachedPath = await downloadHelm(version);

  try {
    if (!process.env["PATH"].startsWith(path.dirname(cachedPath))) {
      core.addPath(path.dirname(cachedPath));
    }
  } catch {
    //do nothing, set as output variable
  }

  console.log(
    `Helm tool version: '${version}' has been cached at ${cachedPath}`
  );
  core.setOutput("helm-path", cachedPath);
}

//Returns version with proper v before it
export function getValidVersion(version: string): string {
    return "v" + version;
} 

// Downloads the helm releases JSON and parses all the recent versions of helm from it.
// Defaults to sending stable helm version if none are valid or if it fails

export async function getLatestHelmVersion(): Promise<string> {
  const helmJSONPath: string = await toolCache.downloadTool(helmAllReleasesUrl);

  try {
    const helmJSON = JSON.parse(fs.readFileSync(helmJSONPath, "utf-8"));
    for (let i in helmJSON) {
      if (isValidVersion(helmJSON[i].tag_name)) {
        return helmJSON[i].tag_name;
      }
    }
  } catch (err) {
    core.warning(
      util.format(
        "Error while fetching the latest Helm release. Error: %s. Using default Helm version %s",
        err.toString(),
        stableHelmVersion
      )
    );
    return stableHelmVersion;
  }

  return stableHelmVersion;
}

// isValidVersion checks if verison is a stable release
function isValidVersion(version: string): boolean {
  return version.indexOf("rc") == -1;
}

export function getExecutableExtension(): string {
  if (os.type().match(/^Win/)) {
    return ".exe";
  }
  return "";
}

const LINUX = "Linux";
const MAC_OS = "Darwin";
const WINDOWS = "Windows_NT";
const ARM64 = "arm64";
export function getHelmDownloadURL(version: string): string {
  const arch = os.arch();
  const operatingSystem = os.type();

  switch (true) {
    case operatingSystem == LINUX && arch == ARM64:
      return util.format(
        "https://get.helm.sh/helm-%s-linux-arm64.zip",
        version
      );
    case operatingSystem == LINUX:
      return util.format(
        "https://get.helm.sh/helm-%s-linux-amd64.zip",
        version
      );

    case operatingSystem == MAC_OS && arch == ARM64:
      return util.format(
        "https://get.helm.sh/helm-%s-darwin-arm64.zip",
        version
      );
    case operatingSystem == MAC_OS:
      return util.format(
        "https://get.helm.sh/helm-%s-darwin-amd64.zip",
        version
      );

    case operatingSystem == WINDOWS:
    default:
      return util.format(
        "https://get.helm.sh/helm-%s-windows-amd64.zip",
        version
      );
  }
}

export async function downloadHelm(version: string): Promise<string> {
  let cachedToolpath = toolCache.find(helmToolName, version);
  if (!cachedToolpath) {
    let helmDownloadPath;
    try {
      helmDownloadPath = await toolCache.downloadTool(
        getHelmDownloadURL(version)
      );
    } catch (exception) {
      throw new Error(
        util.format(
          "Failed to download Helm from location",
          getHelmDownloadURL(version)
        )
      );
    }

    fs.chmodSync(helmDownloadPath, "777");
    const unzipedHelmPath = await toolCache.extractZip(helmDownloadPath);
    cachedToolpath = await toolCache.cacheDir(
      unzipedHelmPath,
      helmToolName,
      version
    );
  }

  const helmpath = findHelm(cachedToolpath);
  if (!helmpath) {
    throw new Error(
      util.format("Helm executable not found in path", cachedToolpath)
    );
  }

  fs.chmodSync(helmpath, "777");
  return helmpath;
}

export function findHelm(rootFolder: string): string {
  fs.chmodSync(rootFolder, "777");
  var filelist: string[] = [];
  walkSync(rootFolder, filelist, helmToolName + getExecutableExtension());
  if (!filelist || filelist.length == 0) {
    throw new Error(
      util.format("Helm executable not found in path", rootFolder)
    );
  } else {
    return filelist[0];
  }
}

export var walkSync = function (dir, filelist, fileToFind) {
  var files = fs.readdirSync(dir);
  filelist = filelist || [];
  files.forEach(function (file) {
    if (fs.statSync(path.join(dir, file)).isDirectory()) {
      filelist = walkSync(path.join(dir, file), filelist, fileToFind);
    } else {
      core.debug(file);
      if (file == fileToFind) {
        filelist.push(path.join(dir, file));
      }
    }
  });
  return filelist;
};

run().catch(core.setFailed);