goodwe-addon/goodwe_controller/app/selfconfig.py

"""UX-02: reading and writing THIS add-on's own options, through the Supervisor.

WHAT THIS IS. An add-on may read and write its own options. That is not a
guess: `supervisor/api/middleware/security.py` in
`ghcr.io/home-assistant/amd64-hassio-supervisor:2026.08.0` - the version this
site runs - matches an installed app's own token against

    api_bypass = ^(?:|/addons/self/(?!security|update)[^/]+
                    |/addons/self/options/config|/info|/services.*
                    |/discovery.*|/auth)$

BEFORE it looks at `access_hassio_api` or at any role, so `GET
/addons/self/info`, `POST /addons/self/options` and `POST /addons/self/restart`
need no `hassio_role` at all. tools/supervisor_selfapi_probe.py RUNS those
compiled patterns against these exact paths rather than re-reading the regex,
because a bypass list is precisely the kind of thing that is read optimistically.

⚠️ AND THE PROBE FOUND ONE THE CARD DID NOT PREDICT, WHICH IS WHY IT WAS RUN.
`/addons/self/options/validate` - Supervisor's OWN options validator - has TWO
path segments after `self`, so `[^/]+` does not match it and it is not in the
list of literals either. An add-on cannot call it. That is not a problem for
this card, because the Supervisor's validator only knows the schema (types and
ranges) and this panel's whole reason to exist is the CROSS-FIELD rules it
structurally cannot express - but it does mean there is exactly one validator
reachable from here, `app/validate.py`, which is the one we want.

--- THE THREE THINGS THIS MODULE REFUSES TO DO ------------------------------

1. ⚠️ IT NEVER WRITES A BLOB THE SHIPPED VALIDATOR REFUSED. Not "warns and
   writes"; does not write. The reason is specific to an INGRESS panel and it
   is the failure mode that makes this card dangerous: an invalid blob plus a
   restart is exit 78, and an add-on that is not running is not serving the
   panel either. The operator would be left with no way back except the
   Supervisor UI - the surface this card exists because it is hard to read.
   So the refusal happens here, before the POST, and the edits stay on screen.

2. ⚠️ IT NEVER OVERWRITES A BLOB THAT MOVED UNDERNEATH IT. The Supervisor's
   Configuration tab CANNOT be removed (see DECISIONS/UX-02-two-config-
   surfaces.md), so there are two editors of one blob, and `POST
   /addons/self/options` REPLACES the stored user options - measured, not
   assumed: `App.options`'s setter is `self.persist[ATTR_OPTIONS] = deepcopy(
   value)`, and the effective options are `deepmerge(config defaults, persist)`.
   A key omitted from the POST therefore falls back to config.yaml's DEFAULT
   rather than to its previous value.

   This is the same shape of hazard as two writers on one actuator, and it gets
   the same discipline. `Controller.write_refusal()` (SAFETY-28) says: A NUMBER
   REACHES THE WIRE ONLY IF THE SINGLE ALLOCATOR PLACED IT, ON THIS TICK, FOR
   THIS UNIT. Here: A BLOB REACHES THE SUPERVISOR ONLY IF IT WAS DERIVED FROM
   THE BLOB THAT IS STORED RIGHT NOW. The read hands out a `fingerprint()`, the
   save hands it back, and the save re-reads and compares before writing. A
   change made in the other tab in the meantime is a REFUSAL with the changed
   keys named, not a silent clobber.

   ⚠️ THE COMPARISON IS RE-READ IMMEDIATELY BEFORE THE WRITE, not taken from
   the page load, so the window in which the other surface can slip in is one
   HTTP round trip rather than however long the operator spent typing.

3. ⚠️ IT NEVER RESTARTS AS A SIDE EFFECT OF SAVING. Applying options costs a
   restart, and `Controller.shutdown()` commands 0 W on every inverter on the
   way out (main.py, "shutting down - commanding 0 W on every inverter"). That
   is a real, if brief, loss of control of the battery, so it is its own
   deliberate action with its own confirmation - `restart()` below requires an
   explicit token in the request body, so no stray POST can spend it.

--- WHAT THIS MODULE MAY NOT GROW INTO --------------------------------------

⚠️ NOTHING HERE COMMANDS AN INVERTER, CLEARS A LATCH, OR REACHES A SAFETY
MECHANISM. The panel's configuration half talks to the Supervisor about a JSON
blob and to `validate.py` about whether that blob is startable; the only
actuator-shaped verb in the file is `restart()`, which restarts THIS ADD-ON and
whose 0 W is the existing, documented wind-down. Adding "and also set the
setpoint while we are here" would put a second writer on the actuator through
the config surface, which is the non-goal this add-on is built around.
"""

import asyncio
import hashlib
import json
import logging
import os

import aiohttp

from .configui import changed_keys
from .inverter import build_roster
from .validate import validate_startup_config, validate_unit_ranges

_LOG = logging.getLogger("goodwe.selfconfig")

SUPERVISOR_API = "http://supervisor"
SELF_INFO = f"{SUPERVISOR_API}/addons/self/info"
SELF_OPTIONS = f"{SUPERVISOR_API}/addons/self/options"
SELF_RESTART = f"{SUPERVISOR_API}/addons/self/restart"

# The word the page has to send with a restart request. It is not a password -
# ingress means Home Assistant has already authenticated the caller - it is an
# INTENT token, so that a reload, a retry or a stray fetch cannot spend a
# control interruption on the operator's behalf.
RESTART_CONFIRM = "restart"

# ⚠️ LONGER THAN hass.py's 10 s, AND FOR THE OPPOSITE REASON. `hass.py` would
# rather abandon a write and re-issue it on the next tick than hold the control
# loop. Nothing here is on the control loop - these calls are made by an
# operator standing at a screen - and a Supervisor busy with a backup can take
# a while to answer. Abandoning a `POST /addons/self/options` early would leave
# the panel unsure whether the blob was stored, which is the one state this
# module must never be in.
TIMEOUT_S = 30.0


class SupervisorUnavailable(Exception):
    """The Supervisor could not be reached, or answered with an error."""


class NotConfirmed(Exception):
    """A control interruption was asked for without the intent token.

    Its own exception rather than a `SaveRefused`, because it is not a refusal
    ABOUT a configuration - nothing was validated and nothing was compared. It
    means the request did not say what it was asking for.
    """


class SaveRefused(Exception):
    """The save did not happen, and NOTHING WAS WRITTEN.

    `kind` is `"invalid"` (the shipped validator refused the blob) or `"stale"`
    (the stored blob changed underneath). `problems` carries the validator's
    own sentences, byte for byte; `changed` names the keys that moved.
    """

    def __init__(self, kind, problems=(), changed=(), stored=None):
        self.kind = kind
        self.problems = list(problems)
        self.changed = list(changed)
        self.stored = stored
        super().__init__(f"save refused ({kind})")


def canonical(options) -> str:
    """The one textual form of an options blob, for identity only.

    Sorted keys, no insignificant whitespace, `ensure_ascii=False` so an entity
    id with a non-ASCII character is one character rather than an escape - the
    string is hashed, never displayed, so the only property that matters is
    that equal blobs produce equal text and different blobs do not.
    """
    return json.dumps(options, sort_keys=True, separators=(",", ":"),
                      ensure_ascii=False, default=str)


def fingerprint(options) -> str:
    """The compare-and-swap token for one options blob.

    ⚠️ A DIGEST, NOT A VERSION NUMBER, because there is no version to read. The
    Supervisor exposes no revision or ETag for an add-on's options, so the only
    thing the panel can hold onto between reading and writing is the CONTENT it
    read. That is enough for what this is for: the question is not "how many
    times has this changed" but "is what I am about to overwrite still what I
    was shown". Identical content is by definition safe to overwrite.
    """
    return hashlib.sha256(canonical(options).encode("utf-8")).hexdigest()


class SelfConfig:
    """The add-on's own options, read and written through the Supervisor."""

    def __init__(self, session: aiohttp.ClientSession, token: str | None = None):
        self.session = session
        self.token = token or os.environ.get("SUPERVISOR_TOKEN", "")

    @property
    def _headers(self) -> dict:
        return {"Authorization": f"Bearer {self.token}",
                "Content-Type": "application/json"}

    async def _call(self, method, url, payload=None):
        try:
            async with self.session.request(
                method, url, headers=self._headers, json=payload,
                timeout=aiohttp.ClientTimeout(total=TIMEOUT_S),
            ) as resp:
                text = await resp.text()
                if resp.status >= 400:
                    # The Supervisor's own message is carried through unedited:
                    # `{"result": "error", "message": "..."}`. A rewritten
                    # error is a second opinion about somebody else's failure.
                    try:
                        detail = (json.loads(text) or {}).get("message") or text
                    except ValueError:
                        detail = text
                    raise SupervisorUnavailable(
                        f"{method} {url} -> HTTP {resp.status}: "
                        f"{str(detail)[:400]}")
                try:
                    body = json.loads(text) if text else {}
                except ValueError as err:
                    raise SupervisorUnavailable(
                        f"{method} {url} -> unreadable answer: {err}") from None
                return body.get("data", body)
        except (aiohttp.ClientError, asyncio.TimeoutError) as err:
            raise SupervisorUnavailable(f"{method} {url} -> {err}") from None

    async def info(self) -> dict:
        """`GET /addons/self/info`.

        ⚠️ THREE OF THIS PANEL'S FOUR INGREDIENTS COME OUT OF THIS ONE CALL, and
        that is the reason the panel owns no copy of any of them. Measured on
        2026.08.0 (`supervisor/api/apps.py:info_data`):

          `options`      - `App.options`, i.e. deepmerge(config.yaml defaults,
                           the stored user options). Every key is present, which
                           is what makes a whole-blob read-modify-write safe.
          `schema`       - `App.schema_ui`, i.e. `UiOptions(...)(config.yaml
                           ["schema"])`. The field list, types, ranges and
                           enums, in config.yaml's own order.
          `translations` - `App.translations`, i.e. Supervisor's own
                           `_read_app_translations()` over translations/*.yaml,
                           which is UX-01's work reaching a second surface for
                           free.

        The fourth ingredient is `app/validate.py`, and it is not fetched.
        """
        return await self._call("GET", SELF_INFO)

    async def write_options(self, options: dict) -> None:
        """`POST /addons/self/options` - REPLACES the stored user options.

        ⚠️ CALL THIS ONLY THROUGH `save()`. On its own it is the unguarded
        write: no validation, no compare-and-swap. It is a separate method so
        that the gate above it can be read - and tested - as a gate.
        """
        await self._call("POST", SELF_OPTIONS, {"options": options})

    async def restart(self, confirm: str) -> None:
        """`POST /addons/self/restart`. Costs a control interruption.

        The add-on's own wind-down runs first: `Controller.shutdown()` commands
        0 W on every inverter before the process exits. So this is not an
        abrupt loss of control, it is a deliberate one - but it IS one, and the
        page says so before the operator presses it.
        """
        if confirm != RESTART_CONFIRM:
            raise NotConfirmed(
                "a restart interrupts control and must be confirmed")
        _LOG.warning("operator asked for a restart from the ingress panel - "
                     "the wind-down commands 0 W on every inverter first")
        await self._call("POST", SELF_RESTART)


async def problems_for(opts: dict, hass=None) -> list:
    """Every reason the SHIPPED validator would refuse to start on `opts`.

    ⚠️ THIS IS THE STARTUP GATE'S OWN COMPOSITION, NOT A SUBSET OF IT. The
    gate runs in TWO places in main.py and this is the union of both, which is
    what an operator meets:

      * `amain()` calls `validate_startup_config(opts, dev_min, dev_max)`
        UNCONDITIONALLY, before anything starts - so this does too, with the
        flat `setpoint_entity`'s device range when that entity was readable and
        None when it was not;
      * `run_control()` adds `validate_unit_ranges(roster, skip_entity=flat)`
        once every unit's own ESPHome has answered - so this does too, with the
        same `skip_entity`, so one inverter is not reported twice under two
        wordings.

    A panel that ran only half the gate would go green on a config that then
    exits 78 - which is worse than no panel, because the operator would have
    been told it was fine.

    ⚠️ AND THE DEVICE RANGES ARE READ, NOT INVENTED. `hass.limits()` is a READ
    of a Home Assistant state; nothing here writes anything to any device. When
    a device does not answer - ESPHome asleep, an entity that does not exist
    yet, or `hass=None` in a check - the range is None and the range rules are
    SKIPPED, exactly as they are at startup. That is the honest behaviour and it
    is also the conservative one: the panel then shows fewer refusals than the
    startup gate might, never more, so it cannot bless a config the gate refuses
    on a rating it could not see. It is stated on the page rather than hidden.

    `build_roster(opts, None)` builds the roster with NO Store, so this reads
    no latch and writes no state; it exists to give `validate_unit_ranges()`
    the same objects `main.py` gives it, rather than a second transcription of
    what counts as a roster entry.
    """
    problems, _unread = await problems_and_ranges(opts, hass)
    return problems


async def problems_and_ranges(opts: dict, hass=None):
    """`problems_for()`, plus WHICH setpoint entities did not report a range.

    ⚠️ THE SECOND HALF EXISTS SO THE PAGE CANNOT LOOK GREEN FOR A REASON THE
    OPERATOR CANNOT SEE. Two rules compare a configured ceiling against the
    device's own rating, and when the device is silent they are skipped rather
    than guessed at - so an unread range means the panel is showing FEWER
    refusals than the startup gate might, and it has to say so, naming the
    entity that did not answer rather than hinting at one.

    It is a separate function from `problems_for()` because the answer is about
    the CONFIGURATION UNDER TEST, not about the running roster: an operator who
    has just typed a new `setpoint_entity` must be told about THAT entity, and
    a route that asked the running controller instead would report on the old
    one. That was the first shape of this and it disagreed with itself.
    """
    flat = str(opts.get("setpoint_entity", "") or "").strip()
    units = build_roster(opts, None)
    if hass is not None:
        async def _limits(unit):
            if unit.setpoint_entity:
                unit.dev_min, unit.dev_max, _ = await hass.limits(
                    unit.setpoint_entity)
        await asyncio.gather(*(_limits(unit) for unit in units))

    dev_min = dev_max = None
    for unit in units:
        if flat and unit.setpoint_entity.strip().lower() == flat.lower():
            dev_min, dev_max = unit.dev_min, unit.dev_max
            break
    problems = list(validate_startup_config(opts, dev_min, dev_max))
    problems += validate_unit_ranges(units, skip_entity=flat)
    unread = [unit.setpoint_entity for unit in units
              if unit.setpoint_entity and unit.dev_min is None
              and unit.dev_max is None]
    return problems, unread


async def save(selfcfg: SelfConfig, proposed: dict, expect: str, *,
               hass=None) -> dict:
    """Validate, compare-and-swap, then write. Refuse rather than half-do.

    Returns `{"fingerprint": <the new one>}` on success. Raises `SaveRefused`
    with nothing written otherwise.

    THE ORDER IS DELIBERATE AND BOTH HALVES ARE PRE-WRITE GATES:

      1. VALIDATE FIRST. It is local, it costs nothing, and its refusal is
         about what is on the operator's screen - so it is the answer they can
         act on without knowing anything about the other surface.
      2. RE-READ AND COMPARE SECOND, immediately before the POST, so the
         window in which the Supervisor tab can slip a change past is one round
         trip rather than the length of an editing session.

      3. Only then write.

    ⚠️ `expect` IS REQUIRED AND THERE IS NO "FORCE" DOOR. A caller that has not
    read the current blob has nothing to compare, and a save that skips the
    comparison is the clobber this gate exists to prevent. If the operator
    genuinely wants what the other surface wrote replaced, the page reloads,
    shows them what changed, and they save again from THAT - which is a
    decision made in front of the difference rather than through it.
    """
    problems = await problems_for(proposed, hass)
    if problems:
        _LOG.warning("panel REFUSED to save: %d configuration problem(s); "
                     "nothing written. First: %s", len(problems), problems[0])
        raise SaveRefused("invalid", problems=problems)

    info = await selfcfg.info()
    stored = info.get("options") or {}
    actual = fingerprint(stored)
    if actual != expect:
        changed = changed_keys(stored, proposed)
        _LOG.warning("panel REFUSED to save: the stored options changed "
                     "underneath this page (keys: %s); nothing written",
                     ", ".join(changed) or "none this page also edited")
        raise SaveRefused("stale", changed=changed, stored=stored)

    await selfcfg.write_options(proposed)
    _LOG.info("options saved from the ingress panel; a restart is needed "
              "before they take effect")
    return {"fingerprint": fingerprint(proposed)}