const semver = require("semver");

const previousVersion = (currentVersion, releaseType) => {
  const parsedVersion = semver.parse(currentVersion);

  switch (releaseType) {
    case "major": {
      return `v${parsedVersion.major - 1}.0.0`;
    }
    case "minor": {
      return `v${parsedVersion.major}.${parsedVersion.minor - 1}.0`;
    }
    case "patch": {
      return `v${parsedVersion.major}.${parsedVersion.minor}.${
        parsedVersion.patch - 1
      }`;
    }
    case "alpha": {
      return `v${parsedVersion.major}.${parsedVersion.minor}.${
        parsedVersion.patch
      }-alpha.${parsedVersion.prerelease[1] - 1}`;
    }
    case "beta": {
      return `v${parsedVersion.major}.${parsedVersion.minor}.${
        parsedVersion.patch
      }-beta.${parsedVersion.prerelease[1] - 1}`;
    }
    case "rc": {
      return `v${parsedVersion.major}.${parsedVersion.minor}.${
        parsedVersion.patch
      }-rc.${parsedVersion.prerelease[1] - 1}`;
    }
  }
};

const [currentVersion, releaseType] = process.argv.slice(-2);
console.log(previousVersion(currentVersion, releaseType));