"""Unit: the additive PDF strip view (phase 163, task 04 — D4, LOCKED A1/A6).

Frontend source-contract pins + node behavioral runs (the
``test_document_viewer.py`` house pattern) over ``document.js``'s
``renderDocument`` — the ONE shared core (Sources modal AND
/document.html):

* the MODE branch — ``page_urls`` + ``page_strip_mode === "additive"``
  falls through to the text-doc rendering (Summary panel + content,
  the pre-148 branch reused) wrapped in a ``.doc-views`` container
  with the ``.doc-view-toggle`` group above it (Text pressed by
  default, LOCKED A6); ``page_urls`` with the mode ABSENT or
  ``"primary"`` keeps the phase-148 strip-only branch VERBATIM (append
  the strip to ``contentEl`` + return — no toggle, no wrapper, no
  Summary panel); falsy ``page_urls`` is untouched;
* the toggle semantics — ``role="group"`` + ``aria-label="Document
  view"``, two ``<button type="button">`` labeled ``Text`` / ``Pages``
  (fixed strings, no doc-derived text), ``aria-pressed`` true/false
  initial state, and a click mutating ONLY the two ``aria-pressed``
  states + the wrapper's ``data-view`` attribute (CSS-driven show/
  hide — the strip node stays mounted, no re-render, no refetch);
* the never-build-HTML rule — createElement + properties/textContent
  only in the new code path (the module's ONE innerHTML stays the
  escape-first markdown render); the strip imgs keep
  ``loading = "lazy"`` (the hidden strip never fetches);
* the ``.doc-view-toggle`` CSS — the house ghost-pill idiom, the
  pressed state as text + style (never color alone, B5), ≥44px
  targets, and the ``data-view`` show/hide contract.
"""
from __future__ import annotations

import json
import re
import shutil
import subprocess
from pathlib import Path

import pytest

FRONTEND = Path(__file__).resolve().parents[2] / "frontend"
DOCUMENT_JS = FRONTEND / "assets" / "document.js"
STYLES_CSS = FRONTEND / "assets" / "styles.css"

HAVE_NODE = shutil.which("node") is not None


def _read(path: Path) -> str:
    return path.read_text(encoding="utf-8")


def _fn(js: str, name: str) -> str:
    """The source of a top-level function via balanced-brace counting
    (the ``test_document_viewer.py`` pattern)."""
    start = js.find(f"function {name}(")
    assert start != -1, f"{name}() must exist in document.js"
    i = js.find("(", start)
    depth = 0
    close = i
    while i < len(js):
        if js[i] == "(":
            depth += 1
        elif js[i] == ")":
            depth -= 1
            if depth == 0:
                close = i
                break
        i += 1
    brace = js.find("{", close)
    depth = 0
    for j in range(brace, len(js)):
        if js[j] == "{":
            depth += 1
        elif js[j] == "}":
            depth -= 1
            if depth == 0:
                return js[start : j + 1]
    raise AssertionError(f"unbalanced braces in {name}()")


def _code(js: str) -> str:
    """The source with comments stripped (the never-build-HTML pins)."""
    return re.sub(r"//.*?$|/\*.*?\*/", "", js, flags=re.S | re.M)


def _prose_rule(js: str) -> str:
    """The phase-165 prose rule (the PROSE_FORMATS const + isProseDoc,
    module scope) — renderDocument's prose gate, needed beside the
    extracted functions for the node runs."""
    start = js.index("const PROSE_FORMATS")
    end = js.index("}", js.index("function isProseDoc")) + 1
    return js[start:end]


def _run_node(script: str) -> str:
    proc = subprocess.run(
        ["node", "-e", script], capture_output=True, text=True, timeout=60
    )
    assert proc.returncode == 0, f"node failed: {proc.stderr}"
    return proc.stdout


# ---------------------------------------------------------------------------
# Source pins — the renderDocument mode branch
# ---------------------------------------------------------------------------


def test_render_document_branches_on_strip_mode() -> None:
    """The mode branch (LOCKED A2 — the tolerant read): the additive
    flag keys on the EXACT ``doc.page_strip_mode === "additive"``
    string (absent / "primary" / anything else ⇒ primary), and the
    primary/absent strip branch stays the phase-148 shape — append
    ``docPagesStrip`` to ``contentEl`` and RETURN — evaluated BEFORE
    any wrapper/toggle construction."""
    render = _fn(_read(DOCUMENT_JS), "renderDocument")
    assert 'doc.page_strip_mode === "additive"' in render, (
        "only the exact additive string switches on the toggle"
    )
    gate_i = render.find('const additive = stripEligible && doc.page_strip_mode === "additive";')
    primary_i = render.find("if (stripEligible && !additive) {")
    strip_i = render.find("contentEl.appendChild(docPagesStrip(doc, pageUrls));")
    return_i = render.find("return;", strip_i)
    wrapper_i = render.find('views.className = "doc-views";')
    assert -1 < gate_i < primary_i < strip_i < return_i < wrapper_i, (
        "the primary/absent branch (strip into contentEl + return) precedes "
        "the additive wrapper — its DOM stays the phase-148 shape verbatim"
    )
    # The wrapper + toggle: ONE .doc-views container, the toggle BEFORE
    # it, both into contentEl; the text view lands in the wrapper.
    append_i = render.find("contentEl.append(docViewToggle(views), views);")
    assert wrapper_i < append_i, "the wrapper is built, then appended after its toggle"
    assert 'views.setAttribute("data-view", "text");' in render, (
        "LOCKED A6 — Text is the default view"
    )
    # The strip mounts ONCE inside the wrapper, after the text view —
    # never rebuilt on a flip (no docPagesStrip call outside the two
    # branches).
    assert render.count("docPagesStrip(doc, pageUrls)") == 2
    mount_i = render.rfind("views.appendChild(docPagesStrip(doc, pageUrls));")
    assert mount_i > render.find('slot.appendChild(pre);') or mount_i > render.rfind(
        "slot.appendChild(wrap);"
    ), "the strip mounts AFTER the text view inside the wrapper"
    # The non-additive path is untouched: slot === contentEl (the
    # pre-148 appends keep their exact shape through the slot var).
    assert "let slot = contentEl;" in render


def test_primary_absent_branch_builds_no_toggle() -> None:
    """The primary/absent branch is toggle-free by construction: the
    strip-branch block (from the ``pageUrls`` read to its ``return``)
    contains NO ``doc-view-toggle`` / ``doc-views`` construction — the
    strip-only DOM stays byte-identical to pre-phase-163."""
    render = _fn(_read(DOCUMENT_JS), "renderDocument")
    primary_start = render.find("if (stripEligible && !additive)")
    branch = render[render.find("const pageUrls =") : render.find("return;", primary_start)]
    assert "doc-view-toggle" not in branch
    assert "doc-views" not in branch
    assert branch.count("appendChild") == 1, (
        "the primary branch is exactly the phase-148 append + return"
    )


def test_toggle_never_builds_html_and_labels_are_fixed() -> None:
    """The never-build-HTML rule: the toggle builders use
    createElement + properties/textContent only — no innerHTML /
    outerHTML — and the labels are the FIXED strings ``Text`` /
    ``Pages`` (no doc-derived text inside the toggle). The module's
    ONE innerHTML (the escape-first markdown render) survives."""
    js = _read(DOCUMENT_JS)
    toggle = _fn(js, "docViewToggle")
    btn = _fn(js, "viewToggleButton")
    for body in (toggle, btn):
        code = _code(body)
        assert "innerHTML" not in code and "outerHTML" not in code
    assert 'document.createElement("div")' in toggle
    assert 'group.setAttribute("role", "group")' in toggle
    assert 'group.setAttribute("aria-label", "Document view")' in toggle
    assert 'document.createElement("button")' in btn
    assert 'btn.type = "button"' in btn
    assert 'btn.className = "doc-view-btn"' in btn
    assert 'viewToggleButton("Text")' in toggle
    assert 'viewToggleButton("Pages")' in toggle
    # The module-wide XSS contract: exactly one innerHTML, the
    # renderMarkdown line.
    whole = _code(js)
    assert whole.count("innerHTML") == 1
    assert "outerHTML" not in whole


def test_strip_imgs_stay_lazy() -> None:
    """The phase-148 lazy-img pin re-runs green: the strip builder is
    UNMODIFIED — every page ``<img>`` keeps ``loading = "lazy"`` (the
    additive default view never fetches the strip)."""
    strip = _fn(_read(DOCUMENT_JS), "docPagesStrip")
    assert 'img.loading = "lazy";' in strip


def test_view_toggle_css() -> None:
    """styles.css: the ``.doc-view-toggle`` group (the chat-column
    reading width, the pill pair adjacent) + the ``.doc-view-btn``
    ghost pill (≥44px target, ink-soft text — AA) + the PRESSED state
    (``[aria-pressed="true"]`` — brand fill + font-weight 700: text +
    style, never color alone, B5) + the CSS-driven view swap
    (``.doc-views .doc-pages`` hidden by default; ``[data-view=
    "pages"]`` hides the Summary panel / .doc-md / .doc-raw /
    .doc-prose (phase 165, task 01) / .doc-image and shows the strip as
    the grid — one grouped declaration). Provenance comment above the
    block (house style)."""
    css = _read(STYLES_CSS)
    toggle_i = css.find(".doc-view-toggle {")
    assert toggle_i != -1, "styles.css must style .doc-view-toggle"
    comment_start = css.rfind("/*", 0, toggle_i)
    assert -1 < comment_start < toggle_i and "phase 163" in css[comment_start:toggle_i]
    btn_i = css.find(".doc-view-btn {")
    pressed_i = css.find('.doc-view-btn[aria-pressed="true"]')
    assert toggle_i < btn_i < pressed_i
    btn_rule = css[btn_i : css.find("}", btn_i)]
    for decl in ("min-height: 44px", "color: var(--ink-soft)", "border: 1px solid var(--line)"):
        assert decl in btn_rule
    pressed_rule = css[pressed_i : css.find("}", pressed_i)]
    assert "background: var(--brand)" in pressed_rule
    assert "font-weight: 700" in pressed_rule, (
        "the pressed state is text weight + fill — never color alone (B5)"
    )
    # The CSS-driven swap: hidden strip by default; pages hides the
    # text view and shows the strip. The hide list is ONE grouped
    # declaration (phase 165: .doc-prose joins it — defensive today,
    # load-bearing if the owner ever adds "pdf" to PROSE_FORMATS).
    assert '.doc-views .doc-pages { display: none; }' in css
    expected = ",\n".join(
        f'.doc-views[data-view="pages"] {sel}'
        for sel in (".doc-summary", ".doc-md", ".doc-raw", ".doc-prose", ".doc-image")
    ) + " { display: none; }"
    assert css.count(expected) == 1, (
        "the text-view hide list is exactly ONE grouped declaration "
        "over .doc-summary/.doc-md/.doc-raw/.doc-prose/.doc-image"
    )
    assert '.doc-views[data-view="pages"] .doc-pages { display: grid; }' in css


# ---------------------------------------------------------------------------
# Node behavioral runs — the real renderDocument over a minimal fake DOM
# ---------------------------------------------------------------------------

_FAKE_DOM = """
function makeEl(tag) {
  return {
    tag, className: "", textContent: "", attrs: {}, children: [], handlers: {},
    setAttribute(k, v) { this.attrs[k] = String(v); },
    getAttribute(k) { return k in this.attrs ? this.attrs[k] : null; },
    appendChild(c) { this.children.push(c); return c; },
    append(...cs) { this.children.push(...cs); },
    replaceChildren(...cs) { this.children = cs; },
    addEventListener(ev, fn) { this.handlers[ev] = fn; },
    click() { this.handlers.click(); },
  };
}
globalThis.document = { createElement: (t) => makeEl(t) };
function fmtDate(x) { return "DATE:" + x; }
function metaBadge(cls, text, title) {
  const s = makeEl("span");
  s.className = cls;
  s.textContent = text;
  if (title !== undefined) s.setAttribute("title", title);
  return s;
}
function copyPathButton() { return makeEl("button"); }
function originAnchor() { return makeEl("a"); }
async function docAdminReady() { return false; }
function wireDateEdit() {}
function wireSummaryEdit() {}
function renderMarkdown(s) { return s; }
function docImageBlock() { return makeEl("div"); }
function describe(el) {
  return {
    tag: el.tag,
    className: el.className,
    attrs: el.attrs,
    text: el.textContent,
    children: el.children.map(describe),
  };
}
"""


def _render_script() -> str:
    js = _read(DOCUMENT_JS)
    parts = [_prose_rule(js)] + [
        _fn(js, n)
        for n in ("renderDocument", "docViewToggle", "viewToggleButton", "docPagesStrip")
    ]
    return _FAKE_DOM + "\n".join(parts)


@pytest.mark.skipif(not HAVE_NODE, reason="node not available")
def test_additive_doc_renders_text_views_and_toggle() -> None:
    """Behavioral (node, fake DOM): an ADDITIVE doc renders the TEXT
    doc exactly as a non-qualifying one — Summary panel + content —
    inside ``.doc-views`` (data-view="text"), with the toggle group
    FIRST in the content slot: role=group, aria-label="Document
    view", the two ``doc-view-btn`` buttons labeled Text/Pages, Text
    aria-pressed="true" (LOCKED A6), and the strip MOUNTED inside the
    wrapper (figures + lazy imgs) after the text view."""
    out = _run_node(
        _render_script()
        + """
const doc = {
  title: "Letumdei", path: "book.pdf", source: "Library", format: "pdf",
  summary: "A book.", content: "BODY TEXT", created_at: "c", indexed_at: "i",
  chunks: 9, page_urls: ["/api/documents/x/pages/1", "/api/documents/x/pages/2"],
  page_strip_mode: "additive",
};
const contentEl = makeEl("div");
renderDocument(doc, { titleEl: makeEl("h1"), metaEl: makeEl("div"), contentEl });
console.log(JSON.stringify(describe(contentEl)));
"""
    )
    content = json.loads(out)
    assert [c["className"] for c in content["children"]] == [
        "doc-view-toggle",
        "doc-views",
    ], "the toggle group sits above the .doc-views wrapper"
    toggle, views = content["children"]
    assert toggle["attrs"]["role"] == "group"
    assert toggle["attrs"]["aria-label"] == "Document view"
    labels = [c["text"] for c in toggle["children"]]
    assert labels == ["Text", "Pages"]
    assert [c["attrs"]["aria-pressed"] for c in toggle["children"]] == ["true", "false"], (
        "Text pressed by default (LOCKED A6)"
    )
    for c in toggle["children"]:
        assert c["tag"] == "button"
    assert views["attrs"]["data-view"] == "text"
    assert [c["className"] for c in views["children"]] == [
        "doc-summary",
        "doc-raw",
        "doc-pages",
    ], "additive = Summary panel + text content + the mounted strip"
    # pre.textContent — a text node, never parsed as HTML
    assert views["children"][1]["text"] == "BODY TEXT"
    strip = views["children"][2]
    assert len(strip["children"]) == 2, "one figure per page_urls entry"


@pytest.mark.skipif(not HAVE_NODE, reason="node not available")
def test_primary_and_absent_modes_keep_the_strip_only_dom() -> None:
    """Behavioral: mode "primary" AND an absent mode (the pre-163
    stamped row — the live Letumdei pre-sync shape) keep the phase-148
    DOM byte-identically: the content slot holds EXACTLY the
    ``.doc-pages`` strip — no wrapper, no toggle, no Summary panel,
    no text block."""
    out = _run_node(
        _render_script()
        + """
const results = [];
for (const mode of ["primary", undefined]) {
  const doc = {
    title: "Manual", path: "m.pdf", source: "Library", format: "pdf",
    summary: "A manual.", content: "SHOULD NOT SHOW", created_at: "c",
    indexed_at: "i", chunks: 4,
    page_urls: ["/api/documents/y/pages/1"],
  };
  if (mode !== undefined) doc.page_strip_mode = mode;
  const contentEl = makeEl("div");
  renderDocument(doc, { titleEl: makeEl("h1"), metaEl: makeEl("div"), contentEl });
  results.push(describe(contentEl));
}
console.log(JSON.stringify(results));
"""
    )
    primary, absent = json.loads(out)
    for content in (primary, absent):
        assert len(content["children"]) == 1
        assert content["children"][0]["className"] == "doc-pages"
        classes = json.dumps(content)
        assert "doc-view-toggle" not in classes
        assert "doc-views" not in classes
        assert "doc-summary" not in classes
        assert "doc-raw" not in classes, "the strip replaces the text block (primary class)"


@pytest.mark.skipif(not HAVE_NODE, reason="node not available")
def test_text_doc_dom_is_untouched() -> None:
    """Behavioral: a doc with no page_urls is UNTOUCHED — Summary
    panel + content appended straight to the content slot, no
    wrapper, no toggle (the byte-identity property for every
    non-PDF)."""
    out = _run_node(
        _render_script()
        + """
const doc = {
  title: "Note", path: "n.pdf", source: "Library", format: "pdf",
  summary: "S.", content: "TEXT", created_at: "c", indexed_at: "i", chunks: 1,
};
const contentEl = makeEl("div");
renderDocument(doc, { titleEl: makeEl("h1"), metaEl: makeEl("div"), contentEl });
console.log(JSON.stringify(describe(contentEl)));
"""
    )
    content = json.loads(out)
    assert [c["className"] for c in content["children"]] == ["doc-summary", "doc-raw"]


@pytest.mark.skipif(not HAVE_NODE, reason="node not available")
def test_toggle_flips_view_without_rerender_or_refetch() -> None:
    """Behavioral: the toggle handler mutates ONLY the two
    aria-pressed states + the wrapper's data-view. Clicking Pages
    flips data-view to "pages"; clicking back to Text reverses; the
    strip node STAYS MOUNTED the whole time (same object, no
    re-append — the flip-flop fetches nothing) and the wrapper's
    children never change count."""
    out = _run_node(
        _render_script()
        + """
const doc = {
  title: "Book", path: "b.pdf", source: "Library", format: "pdf",
  summary: "S.", content: "TEXT", created_at: "c", indexed_at: "i", chunks: 2,
  page_urls: ["/api/documents/z/pages/1", "/api/documents/z/pages/2"],
  page_strip_mode: "additive",
};
const contentEl = makeEl("div");
renderDocument(doc, { titleEl: makeEl("h1"), metaEl: makeEl("div"), contentEl });
const toggle = contentEl.children[0];
const views = contentEl.children[1];
const [textBtn, pagesBtn] = toggle.children;
const stripBefore = views.children[2];
const countBefore = views.children.length;
pagesBtn.click();
const afterPages = {
  view: views.getAttribute("data-view"),
  pressed: toggle.children.map((b) => b.getAttribute("aria-pressed")),
};
textBtn.click();
const afterText = {
  view: views.getAttribute("data-view"),
  pressed: toggle.children.map((b) => b.getAttribute("aria-pressed")),
  stripSame: views.children[2] === stripBefore,
  countSame: views.children.length === countBefore,
};
console.log(JSON.stringify({ afterPages, afterText }));
"""
    )
    res = json.loads(out)
    assert res["afterPages"] == {"view": "pages", "pressed": ["false", "true"]}
    assert res["afterText"] == {
        "view": "text",
        "pressed": ["true", "false"],
        "stripSame": True,
        "countSame": True,
    }, "the strip node persists across flips — no re-render, no refetch"