class Dependabot::Uv::LanguageVersionManager

def initialize(python_requirement_parser:)
  @python_requirement_parser = python_requirement_parser
end

def install_required_python
  # The leading space is important in the version check
  return if SharedHelpers.run_shell_command("pyenv versions").include?(" #{python_major_minor}.")
  SharedHelpers.run_shell_command(
    "tar -axf /usr/local/.pyenv/versions/#{python_version}.tar.zst -C /usr/local/.pyenv/versions"
  )
end

def installed_version
  # Use `pyenv exec` to query the active Python version
  output, _status = SharedHelpers.run_shell_command("pyenv exec python --version")
  version = output.strip.split.last # Extract the version number (e.g., "3.13.1")
  T.must(version)
end

def normalize_python_exact_version(requirement_string)
  return requirement_string if requirement_string.nil? || requirement_string.strip.empty?
  requirement_string = requirement_string.strip
  # If the requirement already has a wildcard, return nil
  return nil if requirement_string == "*"
  # If the requirement is not an exact version such as not X.Y.Z, =X.Y.Z, ==X.Y.Z, ===X.Y.Z
  # then return the requirement as is
  return requirement_string unless requirement_string.match?(/^=?={0,2}\s*\d+\.\d+(\.\d+)?(-[a-z0-9.-]+)?$/i)
  parts = requirement_string.gsub(/^=+/, "").split(".")
  case parts.length
  when 1 # Only major version (X)
    ">= #{parts[0]}.0.0 < #{parts[0].to_i + 1}.0.0" # Ensure only major version range
  when 2 # Major.Minor (X.Y)
    ">= #{parts[0]}.#{parts[1]}.0 < #{parts[0].to_i}.#{parts[1].to_i + 1}.0" # Ensure only minor version range
  when 3 # Major.Minor.Patch (X.Y.Z)
    ">= #{parts[0]}.#{parts[1]}.0 < #{parts[0].to_i}.#{parts[1].to_i + 1}.0" # Convert to >= X.Y.0
  else
    requirement_string
  end
end

def python_major_minor
  @python_major_minor ||= T.let(T.must(Version.new(python_version).segments[0..1]).join("."), T.untyped)
end

def python_requirement_string
  if user_specified_python_version
    if user_specified_python_version.start_with?(/\d/)
      parts = user_specified_python_version.split(".")
      parts.fill("*", (parts.length)..2).join(".")
    else
      user_specified_python_version
    end
  else
    python_version_matching_imputed_requirements || Language::PRE_INSTALLED_HIGHEST_VERSION.to_s
  end
end

def python_version
  @python_version ||= T.let(python_version_from_supported_versions, T.nilable(String))
end

def python_version_from_supported_versions
  requirement_string = python_requirement_string
  # If the requirement string isn't already a range (eg ">3.10"), coerce it to "major.minor.*".
  # The patch version is ignored because a non-matching patch version is unlikely to affect resolution.
  requirement_string = requirement_string.gsub(/\.\d+$/, ".*") if /^\d/.match?(requirement_string)
  requirement_string = normalize_python_exact_version(requirement_string)
  if requirement_string.nil? || requirement_string.strip.empty?
    return Language::PRE_INSTALLED_HIGHEST_VERSION.to_s
  end
  # Try to match one of our pre-installed Python versions
  requirement = T.must(Requirement.requirements_array(requirement_string).first)
  version = Language::PRE_INSTALLED_PYTHON_VERSIONS.find { |v| requirement.satisfied_by?(v) }
  return version.to_s if version
  # Otherwise we have to raise an error
  supported_versions = Language::SUPPORTED_VERSIONS.map { |v| "#{v}.*" }.join(", ")
  raise ToolVersionNotSupported.new("Python", python_requirement_string, supported_versions)
end

def python_version_matching(requirements)
  Language::PRE_INSTALLED_PYTHON_VERSIONS.find do |version|
    requirements.all? do |req|
      next req.any? { |r| r.satisfied_by?(version) } if req.is_a?(Array)
      req.satisfied_by?(version)
    end
  end.to_s
end

def python_version_matching_imputed_requirements
  compiled_file_python_requirement_markers =
    @python_requirement_parser.imputed_requirements.map do |r|
      Requirement.new(r)
    end
  python_version_matching(compiled_file_python_requirement_markers)
end

def user_specified_python_version
  @python_requirement_parser.user_specified_requirements.first
end