export type NodePlatform = "windows" | "mac" | "alpine" | "linux";
export type NodeArch = "x86" | "x64" | "arm" | "arm64";

const platforms: NodePlatform[] = ["windows", "mac", "alpine", "linux"],
  architectures: NodeArch[] = ["x86", "x64", "arm", "arm64"];

export { platforms, architectures };

export interface NexeTarget {
  version: string;
  platform: NodePlatform | string;
  arch: NodeArch | string;
}

const prettyPlatform: { [key: string]: NodePlatform } = {
  win32: "windows",
  windows: "windows",
  win: "windows",
  darwin: "mac",
  macos: "mac",
  mac: "mac",
  linux: "linux",
  static: "alpine",
  alpine: "alpine",
};

const prettyArch: { [key: string]: NodeArch } = {
  x86: "x86",
  arm6: "arm",
  arm64: "arm64",
  arm6l: "arm",
  arm: "arm",
  arm7: "arm",
  arm7l: "arm",
  amd64: "x64",
  ia32: "x86",
  x32: "x86",
  x64: "x64",
};

function isVersion(x: string) {
  if (!x) {
    return false;
  }
  return /^[\d]+$/.test(x.replace(/v|\.|\s+/g, ""));
}

function isPlatform(x: string): x is NodePlatform {
  return x in prettyPlatform;
}

function isArch(x: string): x is NodeArch {
  return x in prettyArch;
}

class Target implements NexeTarget {
  constructor(
    public arch: NodeArch,
    public platform: NodePlatform,
    public version: string
  ) { }
  toJSON() {
    return this.toString();
  }
  toString() {
    return `${this.platform}-${this.arch}-${this.version}`;
  }
}

export function targetsEqual(a: NexeTarget, b: NexeTarget) {
  return (
    a.arch === b.arch && a.platform === b.platform && a.version === b.version
  );
}

export function getTarget(
  target: string | Partial<NexeTarget> = ""
): NexeTarget {
  const currentArch = process.arch;
  let arch =
    currentArch in prettyArch
      ? prettyArch[process.arch]
      : (process.arch as NodeArch),
    platform = prettyPlatform[process.platform],
    version = process.version.slice(1);

  if (typeof target !== "string") {
    target = `${target.platform}-${target.arch}-${target.version}`;
  }

  target
    .toLowerCase()
    .split("-")
    .forEach((x) => {
      if (isVersion(x)) {
        version = x.replace(/v/g, "");
      }
      if (isPlatform(x)) {
        platform = prettyPlatform[x];
      }
      if (isArch(x)) {
        arch = prettyArch[x];
      }
    });

  return new Target(arch, platform, version);
}