"""IMP-56 (#90) u9 — Step 13 ``text_path_stamper`` wiring tests.

Verifies that :func:`src.phase_z2_pipeline.render_slide` stamps each
rendered ``text-line`` opening tag with
``data-text-path="{slot_key}.{line_index}"`` via the u8 stamper
(``src.text_path_stamper.stamp_zone_html``). This is the wiring unit
companion to the u8 module-level tests at
``tests/test_text_path_stamper.py``.

Coverage axes (Stage 2 plan u9 + Stage 1 binding contract) :

  - happy path : real ``bim_current_problems_paired`` template emits
    ``text-line`` divs for list-valued slots; the stamper attaches
    ``data-text-path`` with matching ``{slot_key}.{line_index}``.
  - non-list slots skipped : ``title`` / ``row_*_left_label`` (scalars)
    do NOT receive ``data-text-path`` attributes.
  - empty list slots emit no stamps : rows whose body list is empty
    contribute zero stamps.
  - deterministic : repeated calls produce byte-identical HTML
    (no nondeterministic mutation of ``slot_payload`` between renders).
  - empty zone : the ``__empty__`` template_id short-circuit emits no
    ``data-text-path`` (the stamper short-circuits on empty stamps).

Fully synthetic slot_payload — no real Phase Z run, no
``v4_full32_result.yaml`` dependency. Uses the real
``bim_current_problems_paired`` family template only to exercise the
genuine Jinja2 + slide_base render path.
"""
from __future__ import annotations

import re

import pytest

from src.phase_z2_pipeline import render_slide


# ─── Fixture helpers ────────────────────────────────────────────────


def _layout_css() -> dict:
    """Minimal valid layout_css for a single-zone slide.

    Mirrors tests/phase_z2/test_slide_base_embedded_mode.py shape.
    """
    return {"areas": '"primary"', "cols": "1fr", "rows": "1fr"}


def _paired_slot_payload(
    *,
    left_lines: list[str] | None = None,
    right_lines: list[str] | None = None,
) -> dict:
    """Build a slot_payload for the bim_current_problems_paired family.

    Only row_1 is populated by default; rows 2-4 stay empty so the
    template short-circuits to zero text-line divs for them.
    """
    left_lines = left_lines if left_lines is not None else ["L1a", "L1b"]
    right_lines = right_lines if right_lines is not None else ["R1a"]
    payload: dict = {
        "title": "Synthetic Title",
        "row_1_left_label": "left pill 1",
        "row_1_left_body": [{"text": t, "indent": 0} for t in left_lines],
        "row_1_right_label": "right pill 1",
        "row_1_right_body": [{"text": t, "indent": 0} for t in right_lines],
    }
    for r in (2, 3, 4):
        payload[f"row_{r}_left_label"] = f"left pill {r}"
        payload[f"row_{r}_left_body"] = []
        payload[f"row_{r}_right_label"] = f"right pill {r}"
        payload[f"row_{r}_right_body"] = []
    return payload


def _zone(template_id: str, slot_payload: dict) -> dict:
    return {
        "position": "primary",
        "template_id": template_id,
        "slot_payload": slot_payload,
    }


def _render(zones: list[dict]) -> str:
    return render_slide(
        slide_title="t",
        slide_footer=None,
        zones_data=zones,
        layout_preset="single",
        layout_css=_layout_css(),
        gap_px=14,
        embedded_mode="embedded",
    )


# ─── Case 1 : happy path — list-valued slots stamped ─────────────────


def test_render_slide_stamps_text_path_per_line():
    """Each list-valued slot line gets data-text-path={slot}.{index}."""
    payload = _paired_slot_payload(
        left_lines=["left line A", "left line B"],
        right_lines=["right line A"],
    )
    html = _render([_zone("bim_current_problems_paired", payload)])

    # left body 2 lines + right body 1 line = 3 stamps in row 1.
    assert 'data-text-path="row_1_left_body.0"' in html
    assert 'data-text-path="row_1_left_body.1"' in html
    assert 'data-text-path="row_1_right_body.0"' in html
    # row 2-4 are empty → no stamps for those slot_keys.
    assert "row_2_left_body" not in html
    assert "row_3_right_body" not in html


def test_stamps_preserve_class_attribute():
    """data-text-path injected before existing class attribute, both present."""
    payload = _paired_slot_payload(left_lines=["only left"], right_lines=[])
    html = _render([_zone("bim_current_problems_paired", payload)])

    # The original class="text-line..." must survive verbatim alongside
    # the injected data-text-path attribute on the same opening tag.
    assert re.search(
        r'<div\s+data-text-path="row_1_left_body\.0"\s+class="text-line[^"]*">',
        html,
    ) is not None


# ─── Case 2 : non-list slots are NOT stamped ─────────────────────────


def test_non_list_slots_not_stamped():
    """Scalar slot values (title, *_label) get no data-text-path."""
    payload = _paired_slot_payload(left_lines=["x"], right_lines=["y"])
    html = _render([_zone("bim_current_problems_paired", payload)])

    # Scalar slots present in slot_payload as strings — must not receive
    # data-text-path stamps (u8 contract: scalar slots skipped silently
    # because they render outside text-line divs).
    assert 'data-text-path="title' not in html
    assert 'data-text-path="row_1_left_label' not in html
    assert 'data-text-path="row_1_right_label' not in html


# ─── Case 3 : empty list slots contribute no stamps ──────────────────


def test_empty_list_slots_no_stamps():
    """Empty list slot yields zero stamps; template emits zero text-line divs."""
    payload = _paired_slot_payload(left_lines=[], right_lines=[])
    html = _render([_zone("bim_current_problems_paired", payload)])

    # No row 1 lines at all (both bodies empty) → no row_1_*_body stamps.
    assert "data-text-path" not in html


# ─── Case 4 : deterministic — repeated render produces same HTML ─────


def test_render_with_stamp_is_deterministic():
    """Same slot_payload → byte-identical HTML across two render_slide calls.

    Guards against the wiring layer accidentally mutating slot_payload
    between renders (the stamper itself only reads slot_payload; it
    operates on rendered_partial). Also guards against double-stamping.
    """
    payload_1 = _paired_slot_payload()
    payload_2 = _paired_slot_payload()
    html_1 = _render([_zone("bim_current_problems_paired", payload_1)])
    html_2 = _render([_zone("bim_current_problems_paired", payload_2)])

    assert html_1 == html_2
    # Counts must match — no double-stamp side effect on shared module state.
    assert html_1.count("data-text-path=") == html_2.count("data-text-path=")
    # 2 left + 1 right = 3 stamps for the default fixture.
    assert html_1.count("data-text-path=") == 3


# ─── Case 5 : __empty__ short-circuit emits no stamps ────────────────


def test_empty_template_short_circuit_no_stamps():
    """``template_id=__empty__`` short-circuits before stamping; no stamps."""
    html = _render([_zone("__empty__", {})])
    assert "data-text-path" not in html


# ─── Case 6 : slot_payload preserved (raw_content invariant) ─────────


def test_render_does_not_mutate_slot_payload():
    """Stamping must not mutate slot_payload list/dict contents.

    The stamper operates on rendered_partial HTML; the source
    slot_payload should be byte-identical before and after render_slide.
    Locks the raw_content preservation invariant at the wiring layer.
    """
    payload = _paired_slot_payload(
        left_lines=["preserved A", "preserved B"],
        right_lines=["preserved C"],
    )
    # Snapshot key list/dict identities and content.
    snapshot_left = list(payload["row_1_left_body"])
    snapshot_left_text = [item["text"] for item in snapshot_left]
    snapshot_right_text = [item["text"] for item in payload["row_1_right_body"]]

    _ = _render([_zone("bim_current_problems_paired", payload)])

    assert [item["text"] for item in payload["row_1_left_body"]] == snapshot_left_text
    assert [item["text"] for item in payload["row_1_right_body"]] == snapshot_right_text
    # Scalar slots untouched too.
    assert payload["title"] == "Synthetic Title"