module RbSys::Mkmf

def optional_rust_toolchain(builder)
  rustup_default_cmd = "$(Q) $(CARGO_HOME)/bin/rustup default $(RB_SYS_DEFAULT_TOOLCHAIN)"
  rustup_toolchain_cmd = "$(Q) $(CARGO_HOME)/bin/rustup toolchain install $(RB_SYS_DEFAULT_TOOLCHAIN) --profile $(RB_SYS_RUSTUP_PROFILE)"
  <<~MAKE
    #{conditional_assign("RB_SYS_FORCE_INSTALL_RUST_TOOLCHAIN", force_install_rust_toolchain?(builder))}
    # Only run if the we are told to explicitly install the Rust toolchain
    #{if_neq_stmt("$(RB_SYS_FORCE_INSTALL_RUST_TOOLCHAIN)", "false")}
    #{rust_toolchain_env(builder)}
    $(CARGO):
    \t$(Q) $(MAKEDIRS) $(CARGO_HOME) $(RUSTUP_HOME)
    \t$(Q) curl --proto '=https' --tlsv1.2 --retry 10 --retry-connrefused -fsSL "https://sh.rustup.rs" | sh -s -- --no-modify-path --profile $(RB_SYS_RUSTUP_PROFILE) --default-toolchain none -y
    \t#{rustup_toolchain_cmd} || (sleep 5; #{rustup_toolchain_cmd}) || (sleep 5; #{rustup_toolchain_cmd})
    \t#{rustup_default_cmd} || (sleep 5; #{rustup_default_cmd}) || (sleep 5; #{rustup_default_cmd})
    #{install_extra_rustup_targets(builder)}
    $(RUSTLIB): $(CARGO)
    #{endif_stmt}
  MAKE
end