"""Exports are scoped to the most recent question's run (TODO 2026-08-11 #13).

Regression cover for the stale-figure bug: a session accumulates questions in
one chat history, and the export builders swept the WHOLE history for inline
figures — so the report for question 2 embedded question 1's volcano/Hallmark
plots, which contradicted question 2's tables. `_current_question_messages`
slices the history from the last non-empty user message onward and every
export path is built from that slice.

Small synthetic messages only — no network, no Gradio runtime.
"""

import base64
import sys
from pathlib import Path

sys.path.insert(0, str(Path(__file__).parent.parent))

from ui_formatting import _UIFormattingMixin as U  # noqa: E402

# A valid 1x1 PNG so _extract_images' base64 decode succeeds.
_PNG_B64 = base64.b64encode(
    base64.b64decode(
        "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJ"
        "AAAADUlEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg=="
    )
).decode()


def _figure_msg(caption):
    return {
        "role": "assistant",
        "content": (
            f'<div style="font-style: italic;">{caption}</div>'
            f'<img src="data:image/png;base64,{_PNG_B64}" />'
        ),
    }


def _solution_msg(text):
    return {
        "role": "assistant",
        "content": (
            '<div class="solution-header">✅ Final Solution</div>'
            f'<div class="solution-content">{text}</div>'
            "<style>.x{}</style>"
        ),
    }


def _two_question_history():
    return [
        {"role": "user", "content": "Q1: shMyc vs shCntrl DE?"},
        _figure_msg("Q1 volcano"),
        _solution_msg("Q1: MYC targets down."),
        {"role": "user", "content": "Q2: tumor vs liver met?"},
        _figure_msg("Q2 heatmap"),
        _solution_msg("Q2: bile acid up."),
    ]


class TestCurrentQuestionMessages:
    def test_slices_from_last_user_message(self):
        history = _two_question_history()
        scoped = U._current_question_messages(history)
        assert scoped == history[3:]

    def test_no_user_message_returns_all(self):
        history = [_figure_msg("orphan"), _solution_msg("s")]
        assert U._current_question_messages(history) == history

    def test_empty_history(self):
        assert U._current_question_messages([]) == []

    def test_blank_user_message_ignored(self):
        # A trailing empty user turn (e.g. a stray submit) must not create an
        # empty slice that drops the real question's figures.
        history = _two_question_history() + [{"role": "user", "content": "   "}]
        assert U._current_question_messages(history) == history[3:]

    def test_continue_resume_stays_in_slice(self):
        # Continue appends only assistant messages, so a continued run's later
        # figures stay inside the current question's slice.
        history = _two_question_history() + [_figure_msg("Q2 post-continue barplot")]
        scoped = U._current_question_messages(history)
        assert scoped[0] == history[3]
        assert scoped[-1] == history[-1]

    def test_list_content_user_message(self):
        history = [
            {"role": "user", "content": [{"type": "text", "text": "Q1"}]},
            _figure_msg("f1"),
            {"role": "user", "content": [{"type": "text", "text": "Q2"}]},
            _figure_msg("f2"),
        ]
        assert U._current_question_messages(history) == history[2:]


class TestScopedExports:
    def test_extract_images_scoped_excludes_prior_question(self):
        scoped = U._current_question_messages(_two_question_history())
        images = U._extract_images(scoped)
        captions = [c for c, _ in images]
        assert captions == ["Q2 heatmap"]

    def test_unscoped_extract_shows_the_bug_surface(self):
        # Documents why scoping matters: the full history carries both figures
        # (deduped on image data here since the test PNG is identical, but the
        # first caption wins — i.e. the stale one).
        images = U._extract_images(_two_question_history())
        assert images[0][0] == "Q1 volcano"

    def test_assessment_blocks_scoped_to_current_question(self):
        u = U()
        scoped = U._current_question_messages(_two_question_history())
        blocks = u._assessment_blocks(scoped)
        headings = {h: b for h, b, _ in blocks}
        assert headings["Question"] == "Q2: tumor vs liver met?"
        assert "bile acid" in headings["Solution"]
        assert "Q1" not in headings["Question"]