from fansifter_common.adapters.sendgrid.models import (
    MergeTags,
    apply_fallback_merge_tags,
)


class TestMergeTags:
    def test_default_substitutes_to_fan(self) -> None:
        assert MergeTags().to_substitutions() == {"-firstName-": "Fan"}

    def test_none_substitutes_to_fan(self) -> None:
        assert MergeTags(first_name=None).to_substitutions() == {"-firstName-": "Fan"}

    def test_empty_string_substitutes_to_fan(self) -> None:
        assert MergeTags(first_name="").to_substitutions() == {"-firstName-": "Fan"}

    def test_whitespace_passes_through(self) -> None:
        assert MergeTags(first_name="   ").to_substitutions() == {"-firstName-": "   "}

    def test_value_passes_through(self) -> None:
        assert MergeTags(first_name="John").to_substitutions() == {
            "-firstName-": "John"
        }


class TestApplyFallbackMergeTags:
    def test_replaces_first_name(self) -> None:
        assert apply_fallback_merge_tags("Hi -firstName-!") == "Hi Fan!"

    def test_idempotent_on_html_without_tokens(self) -> None:
        assert apply_fallback_merge_tags("<p>nothing here</p>") == "<p>nothing here</p>"

    def test_replaces_multiple_occurrences(self) -> None:
        assert apply_fallback_merge_tags("-firstName- and -firstName-") == "Fan and Fan"