"""Unit tests for the snippet serialize/parse helpers (pure functions, no DB)."""
from scribe.services import snippets as s


def test_compose_title_with_and_without_usage():
    assert s.compose_title("debounce", "rate-limit a callback") == "debounce — rate-limit a callback"
    assert s.compose_title("  debounce  ", "") == "debounce"
    assert s.compose_title("debounce") == "debounce"


def test_compose_tags_lowercases_language_and_dedups():
    assert s.compose_tags("Python", ["util", "python"]) == ["python", "snippet", "util"]
    assert s.compose_tags("", None) == ["snippet"]
    assert s.compose_tags("vue", ["snippet"]) == ["vue", "snippet"]


def test_compose_body_includes_fields_and_fence():
    body = s.compose_body(
        code="return 1", language="python", signature="f() -> int",
        when_to_use="always", repo="scribe", path="a.py", symbol="f",
    )
    assert "**When to use:** always" in body
    assert "**Signature:** `f() -> int`" in body
    assert "`scribe` · `a.py` · `f`" in body
    assert "```python\nreturn 1\n```" in body
    assert body.rstrip().endswith("```")


def test_compose_body_bare_code_only():
    body = s.compose_body(code="x = 1")
    assert body.strip() == "```\nx = 1\n```"


def test_parse_round_trips_a_composed_snippet():
    title = s.compose_title("useDebouncedRef", "debounce a reactive ref")
    body = s.compose_body(
        code="const x = 1", language="ts", signature="useDebouncedRef(v, ms)",
        when_to_use="debounce a reactive ref", repo="scribe",
        path="frontend/src/composables/x.ts", symbol="useDebouncedRef",
    )
    got = s.parse_snippet_fields(title, body, ["ts", "snippet"])
    assert got["name"] == "useDebouncedRef"
    assert got["when_to_use"] == "debounce a reactive ref"
    assert got["signature"] == "useDebouncedRef(v, ms)"
    assert got["language"] == "ts"
    assert got["code"] == "const x = 1"
    assert got["repo"] == "scribe"
    assert got["path"] == "frontend/src/composables/x.ts"
    assert got["symbol"] == "useDebouncedRef"


def test_parse_is_tolerant_of_plain_body():
    got = s.parse_snippet_fields("just a name", "no structure here", None)
    assert got["name"] == "just a name"
    assert got["when_to_use"] == ""
    assert got["signature"] == ""
    assert got["code"] == ""  # never raises on an unstructured body


def test_parse_falls_back_to_tag_for_language():
    got = s.parse_snippet_fields("n — u", "```\ncode\n```", ["ruby", "snippet"])
    assert got["language"] == "ruby"


def test_parse_does_not_promote_a_caller_tag_to_language():
    # compose_tags puts the language FIRST, so a leading "snippet" marker means
    # no language was recorded — the tags after it are the caller's own and must
    # not be mistaken for one (which would also corrupt the code fence on the
    # next update).
    tags = s.compose_tags("", ["auth"])
    assert tags == ["snippet", "auth"]
    got = s.parse_snippet_fields("n — u", s.compose_body(code="x = 1"), tags)
    assert got["language"] == ""


def test_caller_tag_survives_an_update_round_trip_without_a_language():
    # Regression: the tag used to be read back as the language, then dropped
    # from the extra-tag set on re-compose — so it silently disappeared.
    tags = s.compose_tags("", ["auth"])
    fields = s.parse_snippet_fields("n — u", s.compose_body(code="x = 1"), tags)
    extra = [t for t in tags if t not in (s.SNIPPET_TAG, fields["language"])]
    assert s.compose_tags(fields["language"], extra) == ["snippet", "auth"]


def test_compose_body_multi_location_renders_bullet_list():
    body = s.compose_body(
        code="x = 1",
        locations=[
            {"repo": "scribe", "path": "a.py", "symbol": "f"},
            {"repo": "web", "path": "b.ts", "symbol": "g"},
        ],
    )
    assert "**Locations:**" in body
    assert "- `scribe` · `a.py` · `f`" in body
    assert "- `web` · `b.ts` · `g`" in body
    assert "**Location:**" not in body.replace("**Locations:**", "")


def test_compose_body_single_location_via_list_uses_singular_label():
    body = s.compose_body(
        code="x = 1", locations=[{"repo": "scribe", "path": "a.py", "symbol": "f"}],
    )
    assert "**Location:** `scribe` · `a.py` · `f`" in body
    assert "**Locations:**" not in body


def test_normalize_locations_drops_empty_and_dedups():
    got = s._normalize_locations([
        {"repo": "scribe", "path": "a.py", "symbol": "f"},
        {"repo": "", "path": "", "symbol": ""},          # dropped (empty)
        {"repo": "scribe", "path": "a.py", "symbol": "f"},  # dropped (dup)
        {"repo": "web", "path": "", "symbol": ""},
    ])
    assert got == [
        {"repo": "scribe", "path": "a.py", "symbol": "f"},
        {"repo": "web", "path": "", "symbol": ""},
    ]


def test_parse_round_trips_multi_location():
    body = s.compose_body(
        code="const x = 1", language="ts",
        locations=[
            {"repo": "scribe", "path": "a.ts", "symbol": "f"},
            {"repo": "web", "path": "b.ts", "symbol": "g"},
        ],
    )
    got = s.parse_snippet_fields("n — u", body, ["ts", "snippet"])
    assert got["locations"] == [
        {"repo": "scribe", "path": "a.ts", "symbol": "f"},
        {"repo": "web", "path": "b.ts", "symbol": "g"},
    ]
    # repo/path/symbol mirror the first location for back-compat.
    assert (got["repo"], got["path"], got["symbol"]) == ("scribe", "a.ts", "f")


def test_parse_legacy_single_location_line_still_works():
    # A body written by the pre-multi-location serializer.
    body = "**Location:** `scribe` · `a.py` · `f`\n\n```py\nx = 1\n```\n"
    got = s.parse_snippet_fields("n — u", body, None)
    assert got["locations"] == [{"repo": "scribe", "path": "a.py", "symbol": "f"}]
    assert (got["repo"], got["path"], got["symbol"]) == ("scribe", "a.py", "f")


def test_merge_snippet_fields_unions_locations_and_tags():
    target_fields = {"language": "py", "locations": [{"repo": "a", "path": "a.py", "symbol": "f"}]}
    src1 = ({"language": "py", "locations": [{"repo": "b", "path": "b.py", "symbol": "g"}]},
            ["py", "snippet", "helper"])
    src2 = ({"language": "py", "locations": [{"repo": "a", "path": "a.py", "symbol": "f"}]},  # dup loc
            ["snippet"])
    locs, extra = s.merge_snippet_fields(target_fields, ["py", "snippet", "core"], [src1, src2])
    # target location first, then unique source locations; dup dropped.
    assert locs == [
        {"repo": "a", "path": "a.py", "symbol": "f"},
        {"repo": "b", "path": "b.py", "symbol": "g"},
    ]
    # extra tags unioned, language + "snippet" markers excluded.
    assert extra == ["core", "helper"]


def test_snippet_to_dict_includes_parsed_fields():
    class FakeNote:
        title = "debounce — rate-limit"
        body = "```js\ncode\n```\n"
        tags = ["js", "snippet"]

        def to_dict(self):
            return {"id": 1, "title": self.title, "note_type": "snippet", "tags": self.tags}

    data = s.snippet_to_dict(FakeNote())
    assert data["snippet"]["name"] == "debounce"
    assert data["snippet"]["language"] == "js"
    assert data["snippet"]["code"] == "code"