"""Tests for layering subtitle generation by emphasis (etapa 5 review).

Covers the pure helpers in server_tools/subtitles.py that decide which words
also get the dynamic treatment on top of the always-complete plain track, and
which clip-relative windows a plain title must be hidden (enabled="0") under.
"""

import json
from pathlib import Path

from server_tools.subtitles import (
    _load_emphasis_spans,
    _overlaps_any_span,
    _phrase_actions_path,
    _segments_in_spans,
    _word_in_spans,
    _words_in_spans,
)

SPANS = [
    {"start": 2.0, "end": 10.7, "level": 1, "text": "abertura"},
    {"start": 127.7, "end": 135.0, "level": 2, "text": "mastopexia"},
]


def test_phrase_actions_path_matches_media_stem():
    assert _phrase_actions_path("/x/y/0E6A8290.mp4") == Path(
        "/x/y/0E6A8290_phrase_actions.json"
    )


class TestLoadEmphasisSpans:
    def test_missing_file_returns_empty(self, tmp_path):
        media = tmp_path / "clip.mp4"
        media.write_bytes(b"")
        assert _load_emphasis_spans(str(media)) == []

    def test_reads_spans_from_sibling_json(self, tmp_path):
        media = tmp_path / "clip.mp4"
        media.write_bytes(b"")
        actions_path = tmp_path / "clip_phrase_actions.json"
        actions_path.write_text(
            json.dumps({"source": "clip.mp4", "actions": [], "emphasis_spans": SPANS}),
            encoding="utf-8",
        )
        assert _load_emphasis_spans(str(media)) == SPANS

    def test_corrupt_json_returns_empty(self, tmp_path):
        media = tmp_path / "clip.mp4"
        media.write_bytes(b"")
        (tmp_path / "clip_phrase_actions.json").write_text("{not json", encoding="utf-8")
        assert _load_emphasis_spans(str(media)) == []

    def test_missing_emphasis_spans_key_returns_empty(self, tmp_path):
        media = tmp_path / "clip.mp4"
        media.write_bytes(b"")
        (tmp_path / "clip_phrase_actions.json").write_text(
            json.dumps({"source": "clip.mp4", "actions": []}), encoding="utf-8"
        )
        assert _load_emphasis_spans(str(media)) == []


class TestWordInSpans:
    def test_word_fully_inside_span(self):
        assert _word_in_spans(3.0, 3.4, SPANS) is True

    def test_word_fully_outside_every_span(self):
        assert _word_in_spans(50.0, 50.4, SPANS) is False

    def test_word_straddling_span_boundary_follows_its_midpoint(self):
        # midpoint 10.6 -> inside [2.0, 10.7)
        assert _word_in_spans(10.4, 10.8, SPANS) is True
        # midpoint 10.9 -> outside
        assert _word_in_spans(10.7, 11.1, SPANS) is False

    def test_span_end_is_exclusive(self):
        assert _word_in_spans(10.7, 10.7, SPANS) is False


class TestWordsInSpans:
    WORDS = [
        {"word": "Aquela", "start": 2.03, "end": 2.69},
        {"word": "mama", "start": 2.69, "end": 2.89},
        {"word": "fora", "start": 50.0, "end": 50.2},
        {"word": "mastopexia", "start": 127.74, "end": 128.58},
    ]

    def test_no_spans_returns_nothing(self):
        assert _words_in_spans(self.WORDS, []) == []

    def test_keeps_only_words_inside_a_span(self):
        kept = _words_in_spans(self.WORDS, SPANS)
        assert [w["word"] for w in kept] == ["Aquela", "mama", "mastopexia"]

    def test_does_not_remove_words_from_the_source_list(self):
        """This is a filter for the dynamic half, not a partition — the plain
        half must still see every word, so this must never mutate `words`."""
        before = list(self.WORDS)
        _words_in_spans(self.WORDS, SPANS)
        assert self.WORDS == before


class TestOverlapsAnySpan:
    CLIP_SPANS = [(0.0, 8.64), (60.0, 67.22)]

    def test_window_inside_a_span_overlaps(self):
        assert _overlaps_any_span(1.0, 2.0, self.CLIP_SPANS) is True

    def test_window_outside_every_span_does_not_overlap(self):
        assert _overlaps_any_span(20.0, 21.0, self.CLIP_SPANS) is False

    def test_window_straddling_a_span_edge_overlaps(self):
        assert _overlaps_any_span(8.0, 9.0, self.CLIP_SPANS) is True

    def test_touching_but_not_overlapping_is_not_an_overlap(self):
        assert _overlaps_any_span(8.64, 9.0, self.CLIP_SPANS) is False

    def test_no_spans_never_overlaps(self):
        assert _overlaps_any_span(1.0, 2.0, []) is False


class TestSegmentsInSpans:
    SEGMENTS = [
        {"start": 2.0, "end": 10.67},
        {"start": 40.0, "end": 43.0},
        {"start": 127.74, "end": 134.96},
    ]

    def test_no_spans_keeps_nothing(self):
        assert _segments_in_spans(self.SEGMENTS, []) == []

    def test_keeps_only_segments_inside_a_span(self):
        kept = _segments_in_spans(self.SEGMENTS, SPANS)
        assert kept == [self.SEGMENTS[0], self.SEGMENTS[2]]