const debug = require('../internal/debug');
const { MAX_LENGTH, MAX_SAFE_INTEGER } = require('../internal/constants');
const { safeRe: re, safeSrc: src, t } = require('../internal/re');

const parseOptions = require('../internal/parse-options');
const { compareIdentifiers } = require('../internal/identifiers');
class SemVer {
  constructor(version, options) {
    options = parseOptions(options);

    if (version instanceof SemVer) {
      if (
        version.loose === !!options.loose &&
        version.includePrerelease === !!options.includePrerelease
      ) {
        return version;
      } else {
        version = version.version;
      }
    } else if (typeof version !== 'string') {
      throw new TypeError(
        `Invalid version. Must be a string. Got type "${typeof version}".`
      );
    }

    if (version.length > MAX_LENGTH) {
      throw new TypeError(`version is longer than ${MAX_LENGTH} characters`);
    }

    debug('SemVer', version, options);
    this.options = options;
    this.loose = !!options.loose;
    // this isn't actually relevant for versions, but keep it so that we
    // don't run into trouble passing this.options around.
    this.includePrerelease = !!options.includePrerelease;

    const m = version.trim().match(options.loose ? re[t.LOOSE] : re[t.FULL]);

    if (!m) {
      throw new TypeError(`Invalid Version: ${version}`);
    }

    this.raw = version;

    // these are actually numbers
    this.major = +m[1];
    this.minor = +m[2];
    this.patch = +m[3];

    if (this.major > MAX_SAFE_INTEGER || this.major < 0) {
      throw new TypeError('Invalid major version');
    }

    if (this.minor > MAX_SAFE_INTEGER || this.minor < 0) {
      throw new TypeError('Invalid minor version');
    }

    if (this.patch > MAX_SAFE_INTEGER || this.patch < 0) {
      throw new TypeError('Invalid patch version');
    }

    // numberify any prerelease numeric ids
    if (!m[4]) {
      this.prerelease = [];
    } else {
      this.prerelease = m[4].split('.').map((id) => {
        if (/^[0-9]+$/.test(id)) {
          const num = +id;
          if (num >= 0 && num < MAX_SAFE_INTEGER) {
            return num;
          }
        }
        return id;
      });
    }

    this.build = m[5] ? m[5].split('.') : [];
    this.format();
  }

  format() {
    this.version = `${this.major}.${this.minor}.${this.patch}`;
    if (this.prerelease.length) {
      this.version += `-${this.prerelease.join('.')}`;
    }
    return this.version;
  }

  toString() {
    return this.version;
  }

  compare(other) {
    debug('SemVer.compare', this.version, this.options, other);
    if (!(other instanceof SemVer)) {
      if (typeof other === 'string' && other === this.version) {
        return 0;
      }
      other = new SemVer(other, this.options);
    }

    if (other.version === this.version) {
      return 0;
    }

    return this.compareMain(other) || this.comparePre(other);
  }

  compareMain(other) {
    if (!(other instanceof SemVer)) {
      other = new SemVer(other, this.options);
    }

    return (
      compareIdentifiers(this.major, other.major) ||
      compareIdentifiers(this.minor, other.minor) ||
      compareIdentifiers(this.patch, other.patch)
    );
  }

  comparePre(other) {
    if (!(other instanceof SemVer)) {
      other = new SemVer(other, this.options);
    }

    // NOT having a prerelease is > having one
    if (this.prerelease.length && !other.prerelease.length) {
      return -1;
    } else if (!this.prerelease.length && other.prerelease.length) {
      return 1;
    } else if (!this.prerelease.length && !other.prerelease.length) {
      return 0;
    }

    let i = 0;
    do {
      const a = this.prerelease[i];
      const b = other.prerelease[i];
      debug('prerelease compare', i, a, b);
      if (a === undefined && b === undefined) {
        return 0;
      } else if (b === undefined) {
        return 1;
      } else if (a === undefined) {
        return -1;
      } else if (a === b) {
        continue;
      } else {
        return compareIdentifiers(a, b);
      }
    } while (++i);
  }

  compareBuild(other) {
    if (!(other instanceof SemVer)) {
      other = new SemVer(other, this.options);
    }

    let i = 0;
    do {
      const a = this.build[i];
      const b = other.build[i];
      debug('build compare', i, a, b);
      if (a === undefined && b === undefined) {
        return 0;
      } else if (b === undefined) {
        return 1;
      } else if (a === undefined) {
        return -1;
      } else if (a === b) {
        continue;
      } else {
        return compareIdentifiers(a, b);
      }
    } while (++i);
  }

  // preminor will bump the version up to the next minor release, and immediately
  // down to pre-release. premajor and prepatch work the same way.
  inc(release, identifier, identifierBase) {
    if (release.startsWith('pre')) {
      if (!identifier && identifierBase === false) {
        throw new Error('invalid increment argument: identifier is empty');
      }
      // Avoid an invalid semver results
      if (identifier) {
        const r = new RegExp(
          `^${this.options.loose ? src[t.PRERELEASELOOSE] : src[t.PRERELEASE]}$`
        );
        const match = `-${identifier}`.match(r);
        if (!match || match[1] !== identifier) {
          throw new Error(`invalid identifier: ${identifier}`);
        }
      }
    }

    switch (release) {
      case 'premajor':
        this.prerelease.length = 0;
        this.patch = 0;
        this.minor = 0;
        this.major++;
        this.inc('pre', identifier, identifierBase);
        break;
      case 'preminor':
        this.prerelease.length = 0;
        this.patch = 0;
        this.minor++;
        this.inc('pre', identifier, identifierBase);
        break;
      case 'prepatch':
        // If this is already a prerelease, it will bump to the next version
        // drop any prereleases that might already exist, since they are not
        // relevant at this point.
        this.prerelease.length = 0;
        this.inc('patch', identifier, identifierBase);
        this.inc('pre', identifier, identifierBase);
        break;
      // If the input is a non-prerelease version, this acts the same as
      // prepatch.
      case 'prerelease':
        if (this.prerelease.length === 0) {
          this.inc('patch', identifier, identifierBase);
        }
        this.inc('pre', identifier, identifierBase);
        break;
      case 'release':
        if (this.prerelease.length === 0) {
          throw new Error(`version ${this.raw} is not a prerelease`);
        }
        this.prerelease.length = 0;
        break;

      case 'major':
        // If this is a pre-major version, bump up to the same major version.
        // Otherwise increment major.
        // 1.0.0-5 bumps to 1.0.0
        // 1.1.0 bumps to 2.0.0
        if (
          this.minor !== 0 ||
          this.patch !== 0 ||
          this.prerelease.length === 0
        ) {
          this.major++;
        }
        this.minor = 0;
        this.patch = 0;
        this.prerelease = [];
        break;
      case 'minor':
        // If this is a pre-minor version, bump up to the same minor version.
        // Otherwise increment minor.
        // 1.2.0-5 bumps to 1.2.0
        // 1.2.1 bumps to 1.3.0
        if (this.patch !== 0 || this.prerelease.length === 0) {
          this.minor++;
        }
        this.patch = 0;
        this.prerelease = [];
        break;
      case 'patch':
        // If this is not a pre-release version, it will increment the patch.
        // If it is a pre-release it will bump up to the same patch version.
        // 1.2.0-5 patches to 1.2.0
        // 1.2.0 patches to 1.2.1
        if (this.prerelease.length === 0) {
          this.patch++;
        }
        this.prerelease = [];
        break;
      // This probably shouldn't be used publicly.
      // 1.0.0 'pre' would become 1.0.0-0 which is the wrong direction.
      case 'pre': {
        const base = Number(identifierBase) ? 1 : 0;

        if (this.prerelease.length === 0) {
          this.prerelease = [base];
        } else {
          let i = this.prerelease.length;
          while (--i >= 0) {
            if (typeof this.prerelease[i] === 'number') {
              this.prerelease[i]++;
              i = -2;
            }
          }
          if (i === -1) {
            // didn't increment anything
            if (
              identifier === this.prerelease.join('.') &&
              identifierBase === false
            ) {
              throw new Error(
                'invalid increment argument: identifier already exists'
              );
            }
            this.prerelease.push(base);
          }
        }
        if (identifier) {
          // 1.2.0-beta.1 bumps to 1.2.0-beta.2,
          // 1.2.0-beta.fooblz or 1.2.0-beta bumps to 1.2.0-beta.0
          let prerelease = [identifier, base];
          if (identifierBase === false) {
            prerelease = [identifier];
          }
          if (compareIdentifiers(this.prerelease[0], identifier) === 0) {
            if (isNaN(this.prerelease[1])) {
              this.prerelease = prerelease;
            }
          } else {
            this.prerelease = prerelease;
          }
        }
        break;
      }
      default:
        throw new Error(`invalid increment argument: ${release}`);
    }
    this.raw = this.format();
    if (this.build.length) {
      this.raw += `+${this.build.join('.')}`;
    }
    return this;
  }
}

module.exports = SemVer;