flakelight-php/composer-meta.nix

{
  lib,
  allVersions,
}: let
  inherit (lib) splitString split trim map substring stringToCharacters foldr elemAt filter isString;
  inherit (lib.lists) findFirstIndex;
  inherit (lib.strings) charToInt compareVersions;
in
  composerJson: let
    versionComparesForOperations = {
      "=" = i: i == 0;
      ">" = i: i > 0;
      "<" = i: i < 0;
      ">=" = i: i >= 0;
      "<=" = i: i <= 0;
    };
    isInt = c: let
      ascii = charToInt c;
      zero = charToInt "0";
      nine = charToInt "9";
    in
      ascii >= zero && ascii <= nine;

    splitConstraint = constraint: let
      trimmed = trim constraint;
      startIndex = findFirstIndex isInt 0 (stringToCharacters constraint);
    in [(substring 0 startIndex trimmed) (substring startIndex (-1) trimmed)];
    matchesSingleConstraint = constraint: version: let
      parts = splitConstraint constraint;
      cmp = elemAt parts 0;
      against = elemAt parts 1;
    in
      versionComparesForOperations.${cmp} (compareVersions version against);

    splitOrParts = expr: map trim (splitString "||" expr);
    splitAndParts = expr: filter isString (split "[, ]+" expr);

    foldAnd = foldr (a: b: a && b) true;
    foldOr = foldr (a: b: a || b) false;
    matchesAnd = expression: version: foldAnd (map (ex: matchesSingleConstraint ex version) (splitAndParts expression));
    matchesConstraint = expression: version: foldOr (map (ex: matchesAnd ex version) (splitOrParts expression));

    phpConstraint = composerJson.require.php;
    matches = matchesConstraint phpConstraint;
  in {
    inherit (composerJson) name;
    version =
      if (composerJson ? version)
      then composerJson.version
      else "0.0.0";
    phpVersions = filter matches allVersions;
  }