"""Integration: the themed favicon route — ``GET /favicon.svg`` (phase
177, task 02, D2; A2/A3 owner-confirmed) + the template pins (task 03,
D3 — the route is the SINGLE source; the static file is deleted).

The route's contract, driven through the real app (TestClient + the
house ``db`` fixture — the ``test_ui_settings_api`` pattern):

* **default state** (no ``ui_settings`` row): 200 ``image/svg+xml`` +
  ``Cache-Control: no-cache``, the body byte-identical to the golden
  art (``FAVICON_GOLDEN`` from ``tests.unit.test_theming`` — ONE
  source, so the route and the renderer can never serve different
  bytes), the CSP header present (the ``SecurityHeadersMiddleware``
  pass-through — no new header wiring was needed);
* **themed state**: a set row's ``surface``/``brand``/``brand_ink``
  land in their exact SVG attribute roles (asserted by PARSING the
  attributes — the ``test_theming`` unit-pin idiom, not substring) and
  none of the other 14 built-ins appears in the body;
* **no process cache**: a row update is visible on the very next
  request — the palette is re-read per request (the runtime-change
  contract; a theme change never needs a restart to reach the tab
  icon);
* **DB-failure state**: ``effective_settings`` raising (a DB blip / a
  pre-migration boot) → 200 with the built-in golden bytes (NEVER 500
  — the never-break contract) + the fallback log line;
* **HEAD parity**: the same headers as GET, an empty body (the
  phase-76 static-file parity idiom — the pre-phase static file
  answered both methods);
* **routes-first**: a file named ``favicon.svg`` in the static dir
  could NOT shadow the route (the registration position holds);
* **task 03 (template pins)**: all five served page bodies link the
  EXACT bare ``<link … href="/favicon.svg">`` (NO ``?v=`` — the href
  is not under ``/assets/``, so ``CachingMiddleware``'s
  ``_ASSET_REF_RE`` can never touch it; the pin keeps that contract
  explicit against a future regex drift) and contain no
  ``/assets/favicon.svg`` reference; ``GET /assets/favicon.svg``
  404s (the file is deleted); a tree scan of ``frontend/`` finds zero
  remaining ``/assets/favicon.svg`` references.

The route is deliberately OUTSIDE ``/api/*`` (no per-response
byte-budget line — AGENTS rule 10 is ``/api/*``-only) and carries NO
auth dependency (the favicon is chrome — public like the login page):
every test below is the anonymous ``client``.

Real Postgres (``podman compose up -d db``); no LLM involved.

Requires:  podman compose up -d db
"""
from __future__ import annotations

import logging
import xml.etree.ElementTree as ET
from collections.abc import Iterator
from pathlib import Path

import pytest
from fastapi.testclient import TestClient
from sqlalchemy import text, update
from sqlalchemy.orm import Session

from app.config import get_settings
from app.core import theming
from app.models import UiSettings
from tests.unit.test_theming import FAVICON_GOLDEN

# Phase 177 (task 03, D3): the template pins — every page links the
# BARE route; the static file is gone.

#: The EXACT favicon link tag every template must carry (bare — no
#: ``?v=``: the href is not under ``/assets/``).
FAVICON_LINK_TAG = (
    '<link rel="icon" type="image/svg+xml" href="/favicon.svg">'
)

#: The five L8 pages — the shell + the four standalone pages.
PAGE_PATHS: tuple[str, ...] = (
    "/",
    "/document.html",
    "/login.html",
    "/shared.html",
    "/doc-edit.html",
)

#: The frontend tree root (the house tree-scan idiom).
FRONTEND = Path(__file__).resolve().parents[2] / "frontend"


@pytest.fixture(autouse=True)
def clean_state(db: Session) -> Iterator[None]:
    """The single ui_settings row is global state — wiped so every
    test starts from the state it asserts (the house DELETE reset
    pattern, ``test_ui_settings_api``)."""
    db.execute(text("DELETE FROM ui_settings"))
    db.commit()
    yield
    db.execute(text("DELETE FROM ui_settings"))
    db.commit()


def _assert_roles(
    svg_text: str, *, surface: str, brand: str, brand_ink: str
) -> None:
    """The three hexes in their EXACT SVG attribute roles — asserted by
    PARSING the attributes (the ``test_theming`` unit-pin idiom, not
    substring) — the geometry invariants along the way (the hexagon
    ``d`` path, the three element order), and none of the other 14
    built-in hexes anywhere in the body (a themed favicon must not
    leak a built-in color)."""
    ns = "{http://www.w3.org/2000/svg}"
    root = ET.fromstring(svg_text)
    assert root.tag == f"{ns}svg"
    hexagon, circle, spokes = list(root)
    assert hexagon.tag == f"{ns}path"
    assert hexagon.get("d") == "M32 4 55 18v28L32 60 9 46V18Z"
    assert hexagon.get("fill") == surface
    assert hexagon.get("stroke") == brand
    assert circle.tag == f"{ns}circle"
    assert circle.get("fill") == brand
    assert spokes.tag == f"{ns}path"
    assert spokes.get("stroke") == brand_ink
    for key, value in theming.BUILTIN_COLORS.items():
        if value not in (surface, brand, brand_ink):
            assert value not in svg_text, (
                f"built-in {key} ({value}) must not appear in a themed favicon"
            )


def test_default_state_serves_the_golden_bytes(
    client: TestClient, db: Session
) -> None:
    """No ui_settings row: the BUILT-IN palette renders — 200
    ``image/svg+xml`` + ``Cache-Control: no-cache``, the body
    byte-identical to the golden art (the D1 contract through the
    wire), and the CSP header is present on the response (the
    ``SecurityHeadersMiddleware`` pass-through — no header change was
    needed; the phase-123 ``img-src 'self' data:`` carve-out is part
    of the policy that covers task 04's ``data:`` preview)."""
    assert (
        db.execute(text("SELECT count(*) FROM ui_settings")).scalar() == 0
    ), "the test starts from a row-missing state"
    r = client.get("/favicon.svg")
    assert r.status_code == 200
    assert r.headers["content-type"] == "image/svg+xml"
    assert r.headers["cache-control"] == "no-cache"
    assert r.text == FAVICON_GOLDEN
    assert "content-security-policy" in r.headers
    assert "default-src 'self'" in r.headers["content-security-policy"]
    assert "img-src 'self' data:" in r.headers["content-security-policy"]


def test_themed_state_carries_the_three_roles(
    client: TestClient, db: Session
) -> None:
    """A set row (distinct ``surface``/``brand``/``brand_ink``): the
    three hexes land in their exact SVG attribute roles (parsed, not
    substring) and none of the other 14 built-ins appears in the
    body; the header contract (no-cache + content-type) is unchanged
    by the palette."""
    db.add(
        UiSettings(
            id=1, surface="#102030", brand="#4f46e5", brand_ink="#a5b4fc"
        )
    )
    db.commit()
    r = client.get("/favicon.svg")
    assert r.status_code == 200
    assert r.headers["content-type"] == "image/svg+xml"
    assert r.headers["cache-control"] == "no-cache"
    _assert_roles(
        r.text, surface="#102030", brand="#4f46e5", brand_ink="#a5b4fc"
    )


def test_themed_state_is_live_no_process_cache(
    client: TestClient, db: Session
) -> None:
    """The runtime-change contract (D2): the palette is re-read per
    request — NO process cache, so a row update is visible on the very
    next request (a theme change never needs a restart to reach the
    tab icon), and the OLD palette is gone from the body (nothing
    stale is served)."""
    db.add(
        UiSettings(
            id=1, surface="#102030", brand="#4f46e5", brand_ink="#a5b4fc"
        )
    )
    db.commit()
    r1 = client.get("/favicon.svg")
    assert r1.status_code == 200
    _assert_roles(
        r1.text, surface="#102030", brand="#4f46e5", brand_ink="#a5b4fc"
    )

    db.execute(
        update(UiSettings)
        .where(UiSettings.id == 1)
        .values(surface="#203040", brand="#0ea5e9", brand_ink="#bae6fd")
    )
    db.commit()
    r2 = client.get("/favicon.svg")
    assert r2.status_code == 200
    _assert_roles(
        r2.text, surface="#203040", brand="#0ea5e9", brand_ink="#bae6fd"
    )
    for old in ("#102030", "#4f46e5", "#a5b4fc"):
        assert old not in r2.text


def test_db_failure_serves_the_builtin_art_with_200(
    client: TestClient,
    db: Session,
    monkeypatch: pytest.MonkeyPatch,
    caplog: pytest.LogCaptureFixture,
) -> None:
    """A DB blip / pre-migration boot (``effective_settings`` raising):
    the handler's fallback serves the BUILT-IN golden bytes with 200
    (NEVER 500 — the never-break contract) and logs the failure via
    ``logger.exception`` (the ``caching.py`` DB-blip pattern)."""

    def _boom(_session: Session) -> dict[str, str]:
        raise RuntimeError("db blip (test)")

    monkeypatch.setattr(theming, "effective_settings", _boom)
    with caplog.at_level(logging.ERROR, logger="app"):
        r = client.get("/favicon.svg")
    assert r.status_code == 200
    assert r.headers["content-type"] == "image/svg+xml"
    assert r.headers["cache-control"] == "no-cache"
    assert r.text == FAVICON_GOLDEN
    assert any(
        "favicon: theme read failed" in record.message for record in caplog.records
    ), "the fallback path must log the failure (logger.exception)"


def test_head_parity_matches_get(client: TestClient, db: Session) -> None:
    """``HEAD /favicon.svg``: 200 with the SAME headers as GET
    (content-type, no-cache, the CSP pass-through) and an empty body
    (the phase-76 static-file parity idiom — the pre-phase static
    file answered both methods, the dynamic route keeps that)."""
    r = client.head("/favicon.svg")
    assert r.status_code == 200
    assert r.headers["content-type"] == "image/svg+xml"
    assert r.headers["cache-control"] == "no-cache"
    assert "content-security-policy" in r.headers
    assert r.content == b""


def test_route_wins_over_the_static_mount(client: TestClient) -> None:
    """Routes-first: a file named ``favicon.svg`` in the static dir
    could NOT shadow the route — the file is created with
    SHADOW-ATTEMPT bytes (and deleted again in the ``finally``), and
    the response is still the golden art (the registration position —
    after the router includes, before the static catch-all mount —
    holds)."""
    shadow = Path(get_settings().static_dir).resolve() / "favicon.svg"
    assert not shadow.exists(), (
        "the test must start without a static-dir favicon.svg"
    )
    shadow.write_text("SHADOW ATTEMPT", encoding="utf-8")
    try:
        r = client.get("/favicon.svg")
        assert r.status_code == 200
        assert r.text == FAVICON_GOLDEN
        assert "SHADOW ATTEMPT" not in r.text
    finally:
        shadow.unlink()


def test_route_is_public_no_auth_dependency(client: TestClient) -> None:
    """The favicon is chrome — public like the login page: the
    anonymous (unsigned-in) client gets 200, and the route carries no
    ``/api/`` prefix (deliberately outside ``/api/*`` — no
    per-response byte-budget line, AGENTS rule 10's scope)."""
    assert client.get("/api/whoami").json() == {
        "authenticated": False,
        "role": "anonymous",
    }
    r = client.get("/favicon.svg")
    assert r.status_code == 200


# ---------- Phase 177 (task 03, D3): the template pins ----------


@pytest.mark.parametrize("path", PAGE_PATHS)
def test_served_page_links_the_bare_route(
    client: TestClient, path: str
) -> None:
    """Each of the five served page bodies carries the EXACT bare
    favicon link (task 03, D3 — ``href="/favicon.svg"``) and contains
    NO ``/assets/favicon.svg`` reference of any kind. The link stays
    BARE — no ``?v=`` (the href is not under ``/assets/``, so
    ``CachingMiddleware``'s ``_ASSET_REF_RE`` can never touch it;
    the pin keeps that contract explicit against a future regex
    drift)."""
    r = client.get(path)
    assert r.status_code == 200
    assert FAVICON_LINK_TAG in r.text, f"{path}: favicon link pin missing"
    assert "/assets/favicon.svg" not in r.text
    assert "/favicon.svg?v=" not in r.text, (
        f"{path}: the favicon link must stay bare (no ?v= version token)"
    )


def test_the_static_favicon_file_is_gone(client: TestClient) -> None:
    """The single-source decision (task 03, D3): ``frontend/assets/
    favicon.svg`` no longer exists — on disk AND over the wire (the
    static catch-all 404s it). Nothing is lost: the built-in bytes
    stay pinned by ``FAVICON_GOLDEN`` in ``test_theming`` (task 01's
    golden constant is the durable contract), and ``GET
    /favicon.svg`` still serves the golden art (the route is the
    single source now)."""
    assert not (FRONTEND / "assets" / "favicon.svg").exists()
    r = client.get("/assets/favicon.svg")
    assert r.status_code == 404
    r = client.get("/favicon.svg")
    assert r.status_code == 200
    assert r.text == FAVICON_GOLDEN


def test_tree_scan_has_zero_assets_favicon_references() -> None:
    """A tree scan of ``frontend/`` (the house idiom — every file,
    markup + scripts + styles, comments included): ZERO remaining
    references to ``/assets/favicon.svg`` (the deletion is complete —
    no template, script, or stylesheet still asks for the retired
    URL)."""
    files = [
        p
        for p in sorted(FRONTEND.rglob("*"))
        if p.is_file()
    ]
    assert files, "frontend/ contains no files — test is blind"
    for path in files:
        assert "/assets/favicon.svg" not in path.read_text(encoding="utf-8"), (
            f"/assets/favicon.svg survived in {path.relative_to(FRONTEND)}"
        )