import { regEx } from '../../../util/regex.ts';
import type {
  NugetBracketRange,
  NugetExactRange,
  NugetFloatingRange,
  NugetRange,
  NugetVersion,
} from './types.ts';

const versionRegex = regEx(
  /^(?<major>\d+)(?:\s*\.\s*(?<minor>\d+)(?:\s*\.\s*(?<patch>\d+)(?:\s*\.\s*(?<revision>\d+))?)?)?\s*(?:-(?<prerelease>[-a-zA-Z0-9]+(?:\.[-a-zA-Z0-9]+)*))?(?:\+(?<metadata>[-a-zA-Z0-9]+(?:\.[-a-zA-Z0-9]+)*))?$/,
);

export function parseVersion(input: string): NugetVersion | null {
  const groups = versionRegex.exec(input?.trim())?.groups;
  if (!groups) {
    return null;
  }

  const { major, minor, patch, revision, prerelease, metadata } = groups;

  // istanbul ignore if: never happens by design
  if (!major) {
    return null;
  }

  const res: NugetVersion = {
    type: 'nuget-version',
    major: Number.parseInt(major, 10),
  };

  if (minor) {
    res.minor = Number.parseInt(minor, 10);
  }

  if (patch) {
    res.patch = Number.parseInt(patch, 10);
  }

  if (revision) {
    res.revision = Number.parseInt(revision, 10);
  }

  if (prerelease) {
    res.prerelease = prerelease;
  }

  if (metadata) {
    res.metadata = metadata;
  }

  return res;
}

const floatingRangeRegex = regEx(
  /^(?:(?:(?<floating_major>\d*\*)|(?<major>\d+)(?:\.(?:(?<floating_minor>\d*\*)|(?<minor>\d+)(?:\.(?:(?<floating_patch>\d*\*)|(?<patch>\d+)(?:\.(?:(?<floating_revision>\d*\*)|(?<revision>\d+)))?))?))?)(?:-(?<floating_prerelease>\*|[-a-zA-Z0-9]+(?:\.[-a-zA-Z0-9]+)*\.?\*))?)$/,
);

function parseFloatingComponent(input: string): number {
  const [int] = input.split('*');
  return int ? 10 * Number.parseInt(int, 10) : 0;
}

export function parseFloatingRange(input: string): NugetFloatingRange | null {
  const groups = floatingRangeRegex.exec(input)?.groups;
  if (!groups) {
    return null;
  }

  let res: NugetFloatingRange = {
    type: 'nuget-floating-range',
    major: 0,
  };

  const {
    major,
    floating_major,
    minor,
    floating_minor,
    patch,
    floating_patch,
    revision,
    floating_revision,
    floating_prerelease,
  } = groups;

  if (floating_prerelease) {
    res.prerelease = groups.floating_prerelease as `${string}*`;
  }

  if (floating_major) {
    return {
      ...res,
      major: parseFloatingComponent(floating_major),
      floating: 'major',
    };
  }

  const majorNum = Number.parseInt(major, 10);
  if (!Number.isNaN(majorNum)) {
    res = { ...res, major: majorNum };
  }

  if (floating_minor) {
    return {
      ...res,
      minor: parseFloatingComponent(floating_minor),
      floating: 'minor',
    };
  }

  const minorNum = Number.parseInt(minor, 10);
  if (!Number.isNaN(minorNum)) {
    res = { ...res, minor: minorNum };
  }

  if (floating_patch) {
    return {
      ...res,
      patch: parseFloatingComponent(floating_patch),
      floating: 'patch',
    };
  }

  const patchNum = Number.parseInt(patch, 10);
  if (!Number.isNaN(patchNum)) {
    res = { ...res, patch: patchNum };
  }

  if (floating_revision) {
    return {
      ...res,
      revision: parseFloatingComponent(floating_revision),
      floating: 'revision',
    };
  }

  const revisionNum = Number.parseInt(revision, 10);
  if (!Number.isNaN(revisionNum)) {
    res = { ...res, revision: revisionNum };
  }

  if (res.prerelease) {
    return res;
  }

  return null;
}

const exactRangeRegex = regEx(/^\s*\[\s*(?<version>[^,]+)\s*\]\s*$/);

export function parseExactRange(input: string): NugetExactRange | null {
  const versionStr = exactRangeRegex.exec(input)?.groups?.version;
  if (!versionStr) {
    return null;
  }

  const version = parseVersion(versionStr);
  if (!version) {
    return null;
  }

  return {
    type: 'nuget-exact-range',
    version,
  };
}

const maxBracketRangeRegex = regEx(
  /^\s*(?<left_bracket>\(|\[)\s*,\s*(?<max_version>[^\s\])]+)\s*(?<right_bracket>\)|\])\s*$/,
);

const minBracketRangeRegex = regEx(
  /^\s*(?<left_bracket>\(|\[)\s*(?<min_version>[^\s,]+)\s*,\s*(?<right_bracket>\)|\])\s*$/,
);

const bracketRangeRegex = regEx(
  /^\s*(?<left_bracket>\(|\[)\s*(?<min_version>[^\s,]+)\s*,\s*(?<max_version>[^\s\])]+)\s*(?<right_bracket>\)|\])\s*$/,
);

export function parseBracketRange(input: string): NugetBracketRange | null {
  const maxGroups = maxBracketRangeRegex.exec(input)?.groups;
  if (maxGroups) {
    const { max_version, left_bracket, right_bracket } = maxGroups;

    const max = parseVersion(max_version);
    if (!max) {
      return null;
    }

    return {
      type: 'nuget-bracket-range',
      max,
      minInclusive: left_bracket === '[',
      maxInclusive: right_bracket === ']',
    };
  }

  const minGroups = minBracketRangeRegex.exec(input)?.groups;
  if (minGroups) {
    const { min_version, left_bracket, right_bracket } = minGroups;

    const min = parseVersion(min_version) ?? parseFloatingRange(min_version);
    if (!min) {
      return null;
    }

    return {
      type: 'nuget-bracket-range',
      min,
      minInclusive: left_bracket === '[',
      maxInclusive: right_bracket === ']',
    };
  }

  const groups = bracketRangeRegex.exec(input)?.groups;
  if (groups) {
    const { min_version, max_version, left_bracket, right_bracket } = groups;

    const min = parseVersion(min_version) ?? parseFloatingRange(min_version);
    if (!min) {
      return null;
    }

    const max = parseVersion(max_version);
    if (!max) {
      return null;
    }

    return {
      type: 'nuget-bracket-range',
      min,
      max,
      minInclusive: left_bracket === '[',
      maxInclusive: right_bracket === ']',
    };
  }

  return null;
}

export function parseRange(input: string): NugetRange | null {
  return (
    parseExactRange(input) ??
    parseBracketRange(input) ??
    parseFloatingRange(input)
  );
}