"""Integration: Containerfile stage-1 (frontend) asset coverage pin (phase 23).

HERMETIC — no podman, no network, no database: this suite parses the
``Containerfile`` and ``frontend/`` as plain text and pins the image-build
coverage that the TODO L6 bug ("Fix Containerfile build not working")
demonstrated can silently rot in two independent ways:

* the stage-1 ``cp`` line only copies the pages that existed when it was
  written (``document.html`` / ``login.html`` + their scripts +
  ``markdown.js`` were all missing from the image), and
* absolute module imports (``import … from "/assets/header.js"``) break
  the esbuild bundle, so a "fixed" stage 1 can still ship a broken page.

The pins (each is one test, per the phase-23 task file):

1. every ``frontend/*.html`` page is copied into stage 1's ``/out``
   — exactly (a new page without a ``cp`` entry fails; a ``cp`` of a
   deleted page also fails);
2. every local ``assets/`` / ``/assets/`` ``src=``/``href=`` reference in
   the pages is produced by a stage-1 line (``esbuild … --outfile`` or
   ``cp``) — the missing-``markdown.js``-style gap cannot reappear;
3. the set of ``type="module"`` page scripts the HTML references equals
   the set of inputs esbuild ``--bundle``s in stage 1;
4. ``header.js`` is imported relatively by every page script and loaded
   by NO direct ``<script>`` tag (single-evaluation design pin,
   owner-confirmed 2026-08-24);
5. ``markdown.js`` is a classic script: stage-1 minify line WITHOUT
   ``--bundle``, and no top-level ``import``/``export`` in the source
   (the source-level assumption that makes that build line safe);
6. the frontend stage pins a concrete ``esbuild@X.Y.Z`` (no floating
   version — the exact pinned 0.25.5 is what the diagnosis reproduced
   against).
"""

from __future__ import annotations

import re
from pathlib import Path

REPO_ROOT = Path(__file__).resolve().parents[2]
FRONTEND = REPO_ROOT / "frontend"
ASSETS = FRONTEND / "assets"
CONTAINERFILE = REPO_ROOT / "Containerfile"

# A local asset reference: src="assets/…" or src/href="/assets/…"
# (data: URIs, "#main" anchors, and same-origin page links never match).
_ASSET_REF_RE = re.compile(r"""(?:src|href)\s*=\s*["']((?:/)?assets/[^"']+)["']""")
_SCRIPT_TAG_RE = re.compile(r"<script\b[^>]*>", re.IGNORECASE)
_MODULE_ATTR_RE = re.compile(r"""type\s*=\s*["']module["']""", re.IGNORECASE)
_SRC_ATTR_RE = re.compile(r"""src\s*=\s*["']([^"']+)["']""")
_TOP_LEVEL_MODULE_RE = re.compile(r"^\s*(?:import\b|export\b)", re.MULTILINE)


def _stage1_lines() -> list[str]:
    """The physical lines of the ``frontend`` build stage (FROM … up to,
    but not including, the next FROM)."""
    assert CONTAINERFILE.is_file(), f"missing Containerfile: {CONTAINERFILE}"
    lines = CONTAINERFILE.read_text(encoding="utf-8").splitlines()
    start = next(
        i
        for i, ln in enumerate(lines)
        if re.match(r"^FROM\s+\S+\s+AS\s+frontend\b", ln, re.IGNORECASE)
    )
    end = len(lines)
    for j in range(start + 1, len(lines)):
        if re.match(r"^FROM\s", lines[j], re.IGNORECASE):
            end = j
            break
    return lines[start:end]


def _is_esbuild_invocation(ln: str) -> bool:
    """True if the line actually RUNS esbuild (not just mentions it in a
    comment or in the npm install line)."""
    stripped = ln.lstrip()
    return not stripped.startswith("#") and bool(re.search(r"(?:^|&&)\s*esbuild\b", ln))


def _esbuild_outputs(stage1: list[str]) -> dict[str, bool]:
    """basename of every asset a stage-1 esbuild line writes → was it
    ``--bundle``d? (Only lines with an ``--outfile`` count.)"""
    outputs: dict[str, bool] = {}
    for ln in stage1:
        if not _is_esbuild_invocation(ln):
            continue
        m = re.search(r"--outfile=(\S+)", ln)
        assert m, f"stage-1 esbuild line without --outfile: {ln.strip()}"
        assert m.group(1).startswith("/out/assets/"), (
            f"stage-1 asset must be written under /out/assets (the served "
            f"/assets/ URL space), got {m.group(1)}"
        )
        outputs[m.group(1).rsplit("/", 1)[-1]] = "--bundle" in ln
    return outputs


def _esbuild_bundle_inputs(stage1: list[str]) -> set[str]:
    """Basenames of the inputs to every stage-1 ``esbuild … --bundle``."""
    inputs: set[str] = set()
    for ln in stage1:
        if _is_esbuild_invocation(ln) and "--bundle" in ln:
            m = re.search(r"esbuild\s+(\S+)", ln)
            assert m, f"stage-1 esbuild --bundle line without an input: {ln.strip()}"
            inputs.add(m.group(1).rsplit("/", 1)[-1])
    return inputs


def _cp_produced_basenames(stage1: list[str]) -> set[str]:
    """Basenames written into the image by stage-1 ``cp`` lines (the last
    argument is the destination; a ``/``-suffixed one is a directory)."""
    produced: set[str] = set()
    for ln in stage1:
        m = re.search(r"\bcp\s+(.+?)(?:\s*\\)?\s*$", ln)
        if not m:
            continue
        args = m.group(1).split()
        assert len(args) >= 2, f"malformed cp line in stage 1: {ln.strip()}"
        dest = args[-1]
        if dest.endswith("/"):
            produced.update(a.rsplit("/", 1)[-1] for a in args[:-1])
        else:  # single-file rename: the image sees the destination name
            produced.add(dest.rsplit("/", 1)[-1])
    return produced


def _local_asset_basenames() -> set[str]:
    """Every local assets/ reference (basenames) across all frontend pages."""
    refs: set[str] = set()
    for html in sorted(FRONTEND.glob("*.html")):
        text = html.read_text(encoding="utf-8")
        refs.update(m.group(1).rsplit("/", 1)[-1] for m in _ASSET_REF_RE.finditer(text))
    return refs


def _module_script_basenames() -> set[str]:
    """Basenames of the ``<script type="module" src=…>`` page scripts."""
    names: set[str] = set()
    for html in sorted(FRONTEND.glob("*.html")):
        for tag in _SCRIPT_TAG_RE.findall(html.read_text(encoding="utf-8")):
            if _MODULE_ATTR_RE.search(tag):
                m = _SRC_ATTR_RE.search(tag)
                assert m, f"{html.name}: module <script> without src: {tag}"
                names.add(m.group(1).rsplit("/", 1)[-1])
    return names


# ---------- 1. page coverage ----------


def test_every_html_page_is_copied_into_stage1() -> None:
    """Every ``frontend/*.html`` page is copied into stage 1's ``/out`` —
    and the ``cp`` set is EXACTLY the pages on disk: a new page without a
    matching cp entry (image 404s) and a cp of a deleted page (stale build
    step) both fail here."""
    stage1 = _stage1_lines()
    on_disk = {p.name for p in FRONTEND.glob("*.html")}
    assert on_disk, "frontend/ contains no .html pages — test is blind"

    copied: set[str] = set()
    for ln in stage1:
        if ".html" not in ln:
            continue
        m = re.search(r"\bcp\s+(.+?)(?:\s*\\)?\s*$", ln)
        if not m:
            continue
        args = m.group(1).split()
        dest = args[-1]
        assert dest.rstrip("/") == "/out", f"pages must be copied into /out, got {dest}"
        copied.update(a.rsplit("/", 1)[-1] for a in args[:-1] if a.endswith(".html"))

    missing = on_disk - copied
    extra = copied - on_disk
    assert not missing, (
        f"pages missing from stage 1's cp line (404 in the image): {sorted(missing)}"
    )
    assert not extra, (
        f"stage 1 copies pages that no longer exist in frontend/: {sorted(extra)}"
    )


# ---------- 2. asset-reference coverage ----------


def test_every_local_asset_reference_is_produced() -> None:
    """Every local assets/… src/href in the pages is produced by a stage-1
    line — esbuild ``--outfile=/out/assets/<name>`` or a ``cp`` of it.
    This is what catches a missing-markdown.js-style gap: a page that
    references an asset stage 1 never builds is a 404 in the image."""
    stage1 = _stage1_lines()
    produced = set(_esbuild_outputs(stage1)) | _cp_produced_basenames(stage1)
    refs = _local_asset_basenames()
    assert refs, "no local assets/ references found in the pages — test is blind"
    missing = refs - produced
    assert not missing, (
        f"local assets referenced by the pages but not produced by stage 1 "
        f"(404 in the image): {sorted(missing)}"
    )


# ---------- 3. page-module ⇄ bundle-input parity ----------


def test_page_module_scripts_are_bundled() -> None:
    """The set of ``type="module"`` page scripts the HTML references
    (basenames) EQUALS the set of inputs esbuild ``--bundle``s in stage 1
    (today: app.js, sources.js, document.js, login.js). A new page script
    without a bundle entry would 404 in the image; a bundle input whose
    page no longer references it is dead build weight."""
    stage1 = _stage1_lines()
    html_modules = _module_script_basenames()
    bundled = _esbuild_bundle_inputs(stage1)
    assert html_modules, "no module page scripts found in the pages — test is blind"
    assert html_modules == bundled, (
        f"page module scripts {sorted(html_modules)} != esbuild bundle inputs "
        f"{sorted(bundled)} — stage 1 must bundle exactly the pages' modules"
    )


# ---------- 4. single-evaluation design pin ----------


def test_header_module_is_imported_not_directly_loaded() -> None:
    """Owner-confirmed design (2026-08-24, A4-2): NO page loads header.js
    with a direct ``<script>`` tag — in the image the bundled page script
    already contains the header code, so a raw header.js tag would evaluate
    the module TWICE (duplicate sign-out listener, double init). Every page
    script imports it relatively instead (``from "./header.js"``) — a
    hoisted import that guarantees evaluation order in dev AND in the
    bundle, and the only form esbuild can resolve."""
    htmls = sorted(FRONTEND.glob("*.html"))
    assert htmls, "no frontend pages — test is blind"
    for html in htmls:
        text = html.read_text(encoding="utf-8")
        for tag in _SCRIPT_TAG_RE.findall(text):
            m = _SRC_ATTR_RE.search(tag)
            assert m is None or m.group(1).rsplit("/", 1)[-1] != "header.js", (
                f"{html.name}: direct header.js <script> tag — double-evaluation "
                f"trap in the image: {tag}"
            )
    page_scripts = _module_script_basenames()
    assert page_scripts, "no module page scripts found — test is blind"
    for name in sorted(page_scripts):
        js_path = ASSETS / name
        assert js_path.is_file(), f"page script missing: {js_path}"
        body = js_path.read_text(encoding="utf-8")
        # Phase 76: the shell's router (router.js) is NOT a view module
        # — the shell's shared header boots via the chat module (app.js,
        # which imports header.js), and the view modules the router
        # lazy-imports (tuning.js, …) import header.js themselves, so
        # the single-evaluation contract holds without the router
        # importing it (it owns the view switch, not the header).
        if name == "router.js":
            assert 'from "./header.js"' not in body, (
                "router.js must not import the header module — the chat "
                "module boots the shell's ONE header"
            )
            continue
        assert re.search(r"""from\s+["']\./header\.js["']""", body), (
            f"{name}: must import the shared header module relatively "
            f'("from \\"./header.js\\"")'
        )
        assert '"/assets/header.js"' not in body, (
            f"{name}: absolute header import breaks the esbuild stage-1 bundle"
        )


# ---------- 5. markdown.js is a classic script ----------


def test_markdown_js_is_a_produced_classic_script() -> None:
    """markdown.js ships minified WITHOUT --bundle (it is a classic global
    script — window.markdownRender — loaded by index.html and
    document.html), and the source has no top-level import/export: that
    source-level fact is exactly what makes the no-bundle build line safe.
    Pinning both sides keeps the assumption honest."""
    stage1 = _stage1_lines()
    outputs = _esbuild_outputs(stage1)
    assert "markdown.js" in outputs, (
        "markdown.js has no stage-1 esbuild --outfile line — index.html and "
        "document.html would 404 the renderer in the image"
    )
    assert outputs["markdown.js"] is False, (
        "markdown.js must NOT be --bundled: it is a classic global script, and "
        "bundling it would strip the window-level globals the pages rely on"
    )
    md_path = ASSETS / "markdown.js"
    assert md_path.is_file(), f"missing {md_path}"
    hits = _TOP_LEVEL_MODULE_RE.findall(md_path.read_text(encoding="utf-8"))
    assert not hits, f"markdown.js has top-level module syntax: {hits!r}"


# ---------- 6. pinned esbuild ----------


def test_esbuild_stays_pinned() -> None:
    """The frontend stage installs esbuild at a CONCRETE X.Y.Z. The phase-23
    diagnosis was reproduced against the exact pinned 0.25.5; a floating
    version (latest, ^, ~, or no spec) would let an upstream release change
    the bundle behavior with no diff to see."""
    stage1 = _stage1_lines()
    install_lines = [ln for ln in stage1 if re.search(r"\bnpm\s+(?:install|i|add)\b", ln)]
    assert install_lines, "no npm install line in the frontend stage"
    pinned = [
        v for ln in install_lines for v in re.findall(r"\besbuild@(\d+\.\d+\.\d+)\b", ln)
    ]
    assert pinned, (
        "the frontend stage must pin esbuild@X.Y.Z — a floating esbuild is how "
        "the bundle behavior rots silently"
    )
    for ln in install_lines:
        for m in re.finditer(r"\besbuild(@\S*)?", ln):
            spec = m.group(1) or ""
            assert re.fullmatch(r"@\d+\.\d+\.\d+", spec), (
                f"esbuild must be installed with a concrete pin, got "
                f"{m.group(0)!r} in: {ln.strip()}"
            )