UX-54: a Forecast tab with the sun, the house and each battery's level, per hour

A new tab beside Home and Batteries for today and tomorrow: the solar
forecast, the solar measured so far, the house's expected use and each
battery's expected level, with the plan's own charge and give blocks under it.

- Blocks are Home's: today's are the plan's `runs`, tomorrow's come from the
  same builders (`homeview.runs_for()`), in the plan lines' words.
- The sun is what solarfc reads; a daily total is spread over the bell and the
  tab says so. The house is HouseProfile.estimator(), as the plan reads it.
- The level is new: `daycurve.curve()` gives each battery the role
  `modetrade.decide()` gives it and moves it hour by hour inside the plan's
  floor and ceiling. It is an estimate and counts on `solar_trust_pct`.
- Built on request (`GET forecast`), no Home Assistant call. Measured solar is
  kept per hour in memory from the reading control already takes.
- A part not known yet is a note: modes off, no forecast, learning, no
  forecast for tomorrow, a monthly cycle, no level, stopped, shadow.

No decision, command, timing or option key changes. Found, not changed:
`dayplan.plan()` over-counts a state-only forecast (DECISIONS/UX-54).

Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Bdqr7PiaHcBnzPituu2yTC

goodwe_controller/app/daycurve.py

@@ -0,0 +1,216 @@
+"""UX-54: the expected battery level through the day, for the Forecast tab.
+
+Pure: batteries, the sun and the house's use in; a level per battery over
+time out. Display only: nothing here is read by control, and it never
+decides a block. The blocks are the plan's (`homeview.mode_runs()`); this
+only says where the level goes, hour by hour, if the add-on does what the
+plan says.
+
+Each step gives every battery a role, as `modetrade.decide()` does (the
+names are modetrade's): in a grid block it charges (CHARGE) and the others
+rest (REST, no charge); else it follows the house (HOUSE) if it is Solar
+first or no price plan is on; inside a give run it covers the house (GIVE);
+else it holds (HOLD, may charge from spare solar, gives nothing). Spare
+solar (sun less the house's use) goes to Solar first batteries first, then
+the rest, by room. A shortfall comes from the batteries that may give,
+those in a give run first, by what they hold above the floor. Charging and
+giving lose `dayplan.EFF`, as the plan counts. A level stays inside the
+floor and ceiling the plan uses, and a battery already outside them does
+not move further out.
+
+`SolarToday` keeps the site's measured solar per hour, in memory, from the
+reading the control cycle already has. It is shown and never read back
+(TEL-11 keeps site solar out of control).
+"""
+
+import math
+from datetime import datetime, timedelta, timezone
+from dataclasses import dataclass
+
+from .dayplan import EFF, _hour_slices, _local
+from .modetrade import CHARGE, GIVE, HOLD, HOUSE, REST
+
+EPS = 1e-9
+GAP_S = 60.0                # a longer gap between readings is not counted
+MIN_COVER = 0.5             # share of the elapsed hour a reading must cover
+
+
+@dataclass(frozen=True)
+class Batt:
+    """One battery that is on, with a level and a capacity."""
+    name: str
+    capacity_kwh: float
+    rating_kw: float
+    soc: float                  # % now
+    solar_first: bool           # Solar first: follows the house all day
+    priced: bool                # a price plan is on and its mode is a price mode
+    grid: tuple = ()            # ((start, end, to_pct), ...) grid blocks
+    give: tuple = ()            # ((start, end), ...) give runs
+    stop_at: datetime | None = None    # a monthly cycle starts: no level after
+
+
+def _role(b, t, charging, own):
+    """The battery's role at instant `t`; `own`: it charges from the grid;
+    `charging`: some battery does. Returns `(role, may_charge, may_give)`."""
+    in_give = any(s <= t < e for s, e in b.give)
+    if own:
+        return CHARGE, False, False
+    if charging:
+        return REST, False, b.solar_first or not b.priced or in_give
+    if b.solar_first or not b.priced:
+        return HOUSE, True, True
+    if in_give:
+        return GIVE, True, True
+    return HOLD, True, False
+
+
+def _spread(amount, caps, weights):
+    """Split `amount` over the keys of `caps` by `weights`, none over its
+    cap. Returns `(taken, left)`: what each took and what no one could."""
+    got = {k: 0.0 for k in caps}
+    left = float(amount)
+    live = {k for k, c in caps.items() if c > EPS and weights.get(k, 0.0) > 0}
+    while left > EPS and live:
+        total = sum(weights[k] for k in live)
+        used, full = 0.0, set()
+        for k in live:
+            part = left * weights[k] / total
+            room = caps[k] - got[k]
+            if part >= room - EPS:
+                part = room
+                full.add(k)
+            got[k] += part
+            used += part
+        left -= used
+        if not full:
+            break
+        live -= full
+    return got, max(0.0, left)
+
+
+def curve(batts, start, end, sun_kwh, use_kwh, *, floor_pct, ceiling_pct):
+    """`{name: [(t, pct), ...]}` from `start` (each battery's level now) to
+    `end`, a point at every hour edge and every block edge. A battery's list
+    stops where `sun_kwh(a, b)` is None (the sun is not known) or its
+    `stop_at` comes. `sun_kwh` and `use_kwh` give kWh for the span `[a, b)`."""
+    floor, ceil = float(floor_pct), float(ceiling_pct)
+    cuts = {end}
+    for a, _b, _h in _hour_slices(start, end):
+        cuts.add(a)
+    for b in batts:
+        for s, e, *_ in b.grid + b.give:
+            cuts.update(x for x in (s, e) if start < x < end)
+    cuts.add(start)
+    ts = sorted(cuts)
+    level = {b.name: float(b.soc) for b in batts}
+    out = {b.name: [(start, level[b.name])] for b in batts}
+    alive = {b.name for b in batts}
+    for a, z in zip(ts, ts[1:]):
+        if not alive:
+            break
+        sun = sun_kwh(a, z)
+        if sun is None:
+            break
+        for b in batts:
+            if b.name in alive and b.stop_at is not None and a >= b.stop_at:
+                alive.discard(b.name)
+        net = sun - use_kwh(a, z)
+        hrs = (z - a).total_seconds() / 3600.0
+        want = {}                                # name -> grid target %
+        for b in batts:
+            if b.name in alive:
+                for s, e, to in b.grid:
+                    if s <= a < e and level[b.name] < to - EPS:
+                        want[b.name] = float(to)
+        roles = {b.name: _role(b, a, bool(want), b.name in want)
+                 for b in batts if b.name in alive}
+        by = {b.name: b for b in batts}
+        for n, to in want.items():              # charging from the grid
+            b = by[n]
+            room = (to - level[n]) / 100.0 * b.capacity_kwh
+            level[n] += min(b.rating_kw * hrs * EFF, room) \
+                / b.capacity_kwh * 100.0
+        if net > EPS:
+            caps = {n: min(by[n].rating_kw * hrs,
+                           max(0.0, ceil - level[n]) / 100.0
+                           * by[n].capacity_kwh / EFF)
+                    for n, r in roles.items() if r[1]}
+            first = {n: c for n, c in caps.items() if by[n].solar_first}
+            rest = {n: c for n, c in caps.items() if n not in first}
+            left = net
+            for grp in (first, rest):
+                got, left = _spread(left, grp, dict(grp))
+                for n, v in got.items():
+                    level[n] += v * EFF / by[n].capacity_kwh * 100.0
+        elif net < -EPS:
+            caps = {n: min(by[n].rating_kw * hrs,
+                           max(0.0, level[n] - floor) / 100.0
+                           * by[n].capacity_kwh * EFF)
+                    for n, r in roles.items() if r[2]}
+            first = {n: c for n, c in caps.items() if roles[n][0] == GIVE}
+            rest = {n: c for n, c in caps.items() if n not in first}
+            left = -net
+            for grp in (first, rest):
+                got, left = _spread(left, grp, dict(grp))
+                for n, v in got.items():
+                    level[n] -= v / EFF / by[n].capacity_kwh * 100.0
+        for b in batts:
+            if b.name in alive:
+                out[b.name].append((z, level[b.name]))
+    return out
+
+
+# --------------------------------------------------------------------------- #
+# Measured solar, per local hour
+# --------------------------------------------------------------------------- #
+class SolarToday:
+    """The site's solar power, averaged per local hour of one local day. In
+    memory only: a restart starts it again, and `first` says from when it
+    has counted. Display only."""
+
+    def __init__(self):
+        self.day = None
+        self.first = None
+        self._hours = {}            # hour start (UTC) -> [W x s, seconds]
+        self._last = None           # (time, W)
+
+    def add(self, now: datetime, w) -> None:
+        """One reading (`None`: no reading, which ends the interval)."""
+        day = _local(now).date()
+        if day != self.day:
+            self.day, self.first, self._hours, self._last = day, None, {}, None
+        try:
+            ok = w is not None and math.isfinite(float(w))
+        except (TypeError, ValueError):
+            ok = False
+        if not ok:
+            self._last = None
+            return
+        w = max(0.0, float(w))
+        if self.first is None:
+            self.first = now
+        if self._last is not None and now > self._last[0]:
+            dt = min(GAP_S, (now - self._last[0]).total_seconds())
+            key = _hour_start(self._last[0])
+            row = self._hours.setdefault(key, [0.0, 0.0])
+            row[0] += (self._last[1] + w) / 2.0 * dt
+            row[1] += dt
+        self._last = (now, w)
+
+    def kwh(self, start: datetime, end: datetime, now: datetime):
+        """kWh for the hour `[start, end)` up to `now`: the mean power it was
+        read at over the part of the hour that has passed, or None when the
+        readings cover under half of that part (or none has passed)."""
+        if self.day != _local(now).date():
+            return None
+        over = (min(end, now) - start).total_seconds()
+        row = self._hours.get(start)
+        if over <= 0 or row is None or row[1] < MIN_COVER * over:
+            return None
+        return row[0] / row[1] * over / 3.6e6
+
+
+def _hour_start(t: datetime) -> datetime:
+    lt = _local(t)
+    return lt.replace(minute=0, second=0, microsecond=0).astimezone(
+        timezone.utc)

goodwe_controller/app/dayview.py

@@ -0,0 +1,251 @@
+"""UX-54: the Forecast tab, built on request (`GET forecast`). Reads only.
+
+Two days, today and tomorrow, per local hour: the solar forecast, the solar
+measured so far, the house's expected use, and each battery's expected level
+with its blocks.
+
+It follows the add-on, as Home does (UX-53), and decides nothing:
+* the blocks are Home's own: today's are the `runs` of `/status`'s plan, and
+  tomorrow's come from the same builders (`homeview.runs_for()`), so a block
+  is on the tab exactly where the plan has one, with the plan's words;
+* the sun is `solarfc.Forecast.between()` and the house's use is
+  `dayplan.HouseProfile.estimator()` read as `dayplan.plan()` reads it;
+* the level is `daycurve.curve()`, fed the blocks, the give runs, the packs
+  and the plan's levels (`modetrade.charge_to()`), floor and ceiling.
+A part that is not known yet is a plain note (`home_words.day`), never an
+empty chart. DECISIONS/UX-54-forecast-tab.md has the record.
+"""
+
+from datetime import datetime, timedelta
+
+from . import arbitrage, dayplan, homeview as hv, modetrade
+from .daycurve import Batt, curve
+from .packmode import SOLAR_FIRST
+from .price import brussels
+
+BLOCKS = ("grid", "give", "cycle")      # the kinds a battery's blocks carry
+
+
+def _hours_between(a, b) -> float:
+    return (b - a).total_seconds() / 3600.0
+
+
+def build(c, status: dict, now: datetime, lang: str = "en") -> dict:
+    """The tab's JSON. `status` is the `/status` payload just built, whose
+    plan holds today's blocks."""
+    with hv.in_lang(lang):
+        return _build(c, status, now)
+
+
+def sun_kwh(fc, now, a, b):
+    """kWh the forecast gives in `[a, b)`, `a` at or after `now`, or None.
+    Both ends are measured from `now`: `Forecast.between()` reads its start
+    as the moment the "left today" figure was taken, so a span that starts
+    later would be spread over what is left of the bell, not over its own
+    hours (state-only forecasts, DECISIONS/UX-54-forecast-tab.md)."""
+    hi, lo = fc.between(now, b), fc.between(now, a)
+    return None if hi is None or lo is None else max(0.0, hi - lo)
+
+
+def _times(run):
+    return (datetime.fromisoformat(run["start"]),
+            datetime.fromisoformat(run["end"]))
+
+
+def _build(c, status, now):
+    plan, rows = status.get("plan"), status.get("batteries")
+    if not plan or rows is None:
+        return {"ok": False}
+    d0, d1 = hv.local_day(now)
+    n0, n1 = hv.local_day(d1 + timedelta(hours=2))
+    shadow = bool(c.shadow)
+    key = plan.get("verdict_key")
+    running = key not in ("held", "stopped")
+    modes_on = bool(getattr(c, "modes_on", False))
+    floor, ceil = arbitrage.soc_bounds(c.o)
+    fc = getattr(c, "solar_fc", None)
+    hp = getattr(c, "house_profile", None)
+    est = hp.estimator() if hp is not None and fc is not None else None
+    trust = max(0.0, min(1.0, float(getattr(c, "solar_trust_pct", 70))
+                         / 100.0))
+
+    # Why a part is not known (None: nothing is missing).
+    missing = ("modes_off" if not modes_on
+               else "not_set" if c.fc_entity is None
+               else "no_forecast" if fc is None
+               else "learning" if est is None else None)
+
+    # The blocks of each day: today's from Home, tomorrow's by its builders.
+    runs = [plan["runs"], hv.runs_for(c, n0, n1, now, shadow) if running
+            else []]
+    blocks = [[[r for r in rs if r["battery"] == i and r["kind"] in BLOCKS]
+               for i in range(len(c.inverters))] for rs in runs]
+
+    # The level curve of every battery that is on and known.
+    notes_b = {}
+    levels = {}
+    if running and missing is None:
+        levels = _levels(c, est, fc, trust, now, n1, runs, floor, ceil,
+                         notes_b)
+    # Prices are planned about a day ahead (`priceruns.HORIZON`), so tomorrow's
+    # blocks may be missing now and appear later.
+    priced = bool(plan.get("has_prices")) and (
+        any(c.pack_mode(i).use and c.pack_mode(i).mode in hv.PRICE_MODES
+            for i in c.inverters) if modes_on else arbitrage.enabled(c.o))
+    days = []
+    for k, (a, z) in enumerate(((d0, d1), (n0, n1))):
+        days.append(_day(c, k, a, z, now, fc, est, trust, levels, blocks[k],
+                         rows, shadow, running, key, missing, notes_b, status,
+                         priced))
+    return {"ok": True, "running": running, "shadow": shadow,
+            "now_h": round(_hours_between(d0, now), 3),
+            "updated": None if fc is None else hv.hhmm(fc.at),
+            "days": days}
+
+
+def _levels(c, est, fc, trust, now, end, runs, floor, ceil, notes_b):
+    """`{name: [(t, pct), ...]}` from `daycurve.curve()` for the batteries
+    that are on, have a level and are not in their monthly cycle."""
+    packs = {p.name: p for p in c._mode_packs()}
+    targets = c.plan_targets()
+    rp = getattr(c, "mode_runs", None)
+    plan_on = rp is not None and rp.on
+    house_w, base_w = est
+    batts = []
+    for i, inv in enumerate(c.inverters):
+        pm = c.pack_mode(inv)
+        if not pm.use:
+            continue
+        if inv.soc is None or not inv.capacity_kwh:
+            notes_b[inv.name] = hv.day_note("no_level", name=inv.name)
+            continue
+        mine = [r for rs in runs for r in rs
+                if r["battery"] == i and r["kind"] in BLOCKS]
+        cyc = [_times(r)[0] for r in mine if r["kind"] == "cycle"]
+        if cyc and min(cyc) <= now:
+            notes_b[inv.name] = hv.day_note("cycle", name=inv.name)
+            continue
+        if cyc:
+            notes_b[inv.name] = hv.day_note("cycle", name=inv.name)
+        to = modetrade.charge_to(packs[inv.name], ceil, targets)
+        grid = tuple((*_times(r), to) for r in mine
+                     if r["kind"] == "grid" and to is not None)
+        priced = plan_on and pm.mode != SOLAR_FIRST
+        give = tuple((g.start, g.end) for g in rp.give) if priced else ()
+        batts.append(Batt(inv.name, float(inv.capacity_kwh),
+                          inv.max_w / 1000.0, float(inv.soc),
+                          pm.mode == SOLAR_FIRST, priced, grid, give,
+                          min(cyc) if cyc else None))
+
+    def sun(a, z):
+        kwh = sun_kwh(fc, now, a, z)
+        return None if kwh is None else kwh * trust
+
+    def use(a, z):
+        return sum(max(house_w(h), base_w) * _hours_between(s, e) / 1000.0
+                   for s, e, h in dayplan._hour_slices(a, z))
+    if not batts:
+        return {}
+    return curve(batts, now, end, sun, use, floor_pct=floor, ceiling_pct=ceil)
+
+
+def _day(c, k, d0, d1, now, fc, house, trust, levels, blocks, rows, shadow,
+         running, key, missing, notes_b, status, priced):
+    day = (fc.today, fc.tomorrow)[k] if fc is not None else None
+    solar = getattr(c, "solar_today", None)
+    names = [inv.name for inv in c.inverters]
+    hours = []
+    for s, e, h in dayplan._hour_slices(d0, d1):
+        f = None
+        if fc is not None and e > now and (k == 0 or fc.tomorrow is not None):
+            f = sun_kwh(fc, now, max(s, now), e)
+        got = solar.kwh(s, e, now) if k == 0 and solar is not None \
+            and s < now else None
+        use = None if house is None else max(house[0](h), house[1]) \
+            * _hours_between(s, e) / 1000.0
+        row = {"start_h": round(_hours_between(d0, s), 3),
+               "end_h": round(_hours_between(d0, e), 3), "label": hv.hhmm(s),
+               "forecast_kwh": None if f is None else round(f, 3),
+               "measured_kwh": None if got is None else round(got, 3),
+               "house_kwh": None if use is None else round(use, 3),
+               "levels": []}
+        hours.append((s, row))
+    batts = []
+    for i, inv in enumerate(c.inverters):
+        row = rows[i] if i < len(rows) else {}
+        pts = [(t, v) for t, v in levels.get(inv.name, ()) if d0 <= t <= d1]
+        mine = blocks[i]
+        batts.append({
+            "name": inv.name, "capacity_kwh": inv.capacity_kwh,
+            "off": row.get("use") is False,
+            "levels": [[round(_hours_between(d0, t), 3), round(v, 1)]
+                       for t, v in pts],
+            "blocks": [{x: r[x] for x in ("kind", "from", "to", "start_h",
+                                          "end_h", "what", "why", "amount")}
+                       for r in mine],
+            "line": _line(c, inv, row, mine, running, key, shadow)})
+        at = {t: v for t, v in pts}
+        for s, hr in hours:
+            hr["levels"].append(None if s not in at else round(at[s], 1))
+    has_levels = any(b["levels"] for b in batts)
+    fcs = [h["forecast_kwh"] for _s, h in hours]
+    notes = []
+    if missing is not None:
+        notes.append(hv.day_note(missing))
+    if not running:
+        notes.append(hv.why_words(key))
+    if shadow:
+        notes.append(hv.why_words("shadow"))
+    line = ""
+    if fc is not None:
+        if k == 0:
+            line = hv.line_solar(fc.today.kwh, fc.today.kwh * trust,
+                                 hv.hhmm(fc.at))
+        elif fc.tomorrow is not None:
+            line = hv.day_note("tomorrow_total",
+                               kwh=hv._kwh(fc.tomorrow.kwh),
+                               count=hv._kwh(fc.tomorrow.kwh * trust))
+        if day is not None and not day.periods:
+            notes.append(hv.day_note("estimate"))
+        if k == 1 and fc.tomorrow is None:
+            notes.append(hv.day_note("no_tomorrow"))
+    if k == 0 and solar is not None and solar.first is not None \
+            and solar.day == brussels(now).date() \
+            and _hours_between(d0, solar.first) > 0.5:
+        notes.append(hv.day_note("measured_from", at=hv.hhmm(solar.first)))
+    if has_levels:
+        notes.append(hv.day_note("trust", pct=round(trust * 100)))
+    if k == 1 and _tomorrow_line(status):
+        notes.append(_tomorrow_line(status))
+    if k == 1 and running and priced:
+        notes.append(hv.day_note("ahead"))
+    notes += [notes_b[n] for n in names if n in notes_b]
+    return {"key": ("today", "tomorrow")[k], "date": brussels(d0).date()
+            .isoformat(),
+            "length_h": int(round(_hours_between(d0, d1))),
+            "line": line, "notes": list(dict.fromkeys(notes)),
+            "sun": {"forecast": any(x is not None for x in fcs),
+                    "estimate": day is not None and not day.periods,
+                    "measured": any(h["measured_kwh"] is not None
+                                    for _s, h in hours),
+                    "house": house is not None},
+            "hours": [h for _s, h in hours], "batteries": batts}
+
+
+def _tomorrow_line(status) -> str:
+    """Home's own line about tomorrow's prices, for the tomorrow tab."""
+    return (status.get("plan") or {}).get("tomorrow_line") or ""
+
+
+def _line(c, inv, row, mine, running, key, shadow) -> str:
+    """What to say for a battery with no block: the plan's own words."""
+    if not running:
+        return hv.why_words(key)
+    if row.get("use") is False:
+        return hv.why_words("off")
+    if mine:
+        return ""
+    if getattr(c, "modes_on", False) and row.get("mode_choice") in \
+            hv.PRICE_MODES:
+        return hv.day_note("no_blocks")
+    return hv.run_house_what(shadow) + " " + hv.run_house_why(shadow)

goodwe_controller/app/homeview.py

@@ -16,6 +16,7 @@ them, so nothing here invents a plan. Every sentence is in the words
 section at the bottom and is held to STYLE.md by test_messages.py.
 """
 
+import contextlib
 from datetime import datetime, timedelta, timezone
 
 from . import arbitrage, messages, peakguard, uitext
@@ -612,6 +613,19 @@ def region_of(opts):
             if rid in REGION_PRESETS else None}
 
 
+def runs_for(c, day0, day1, now, shadow):
+    """UX-54: the price blocks of the window `[day0, day1)`, by the same
+    builders `build_plan()` uses for today: the batteries' price runs with
+    modes on, the verdict's legs with them off. Nothing is decided here."""
+    if getattr(c, "modes_on", False):
+        return mode_runs(c, day0, day1, now, shadow)[0]
+    fresh = c.fresh_tariff_plan(now)
+    verdict, _why = trade_verdict(c, fresh, now)
+    if verdict is None:
+        return []
+    return trade_runs(c, fresh, verdict, day0, day1, now, shadow)[0]
+
+
 def build_plan(c, now, shadow, running, held=False, settled=True):
     day0, day1 = local_day(now)
     fresh = c.fresh_tariff_plan(now)
@@ -1001,6 +1015,16 @@ def state_of(c, level, shadow, waiting=False):
     return "running"
 
 
+@contextlib.contextmanager
+def in_lang(lang):
+    """UX-54: build sentences in `lang` for the length of a `with` block."""
+    _LANG[0] = uitext.lang_of(lang)
+    try:
+        yield
+    finally:
+        _LANG[0] = "en"
+
+
 def build(c, *, level: str, checks: list, now: datetime | None = None,
           lang: str = "en", held: bool | None = None,
           waiting: bool = False) -> dict:
@@ -1329,6 +1353,11 @@ def run_house_amount() -> str:
     return _t("run.house_amount")
 
 
+def day_note(key, **values) -> str:
+    """UX-54: one sentence of the Forecast tab (`home_words.day`)."""
+    return _t("day." + key, **values)
+
+
 def line_solar(fc_kwh, count_kwh, at) -> str:
     return _t("solar.line", kwh=_kwh(fc_kwh), count=_kwh(count_kwh), at=at)
 
@@ -1502,6 +1531,9 @@ def _samples() -> list:
     out += [("plan", today_words(k)) for k in words["today"]]
     out += [("plan", line_solar(9.2, 6.4, "10:15")),
             ("plan", _t("solar.no_forecast")), ("plan", _t("solar.learning"))]
+    out += [("plan", day_note(k, pct=70, name="Battery A", at="08:15",
+                              kwh="9.2 kWh", count="6.4 kWh"))
+            for k in words["day"]]
     out += [("plan", line_no_trade(k)) for k in
             ("not_covered", "no_prices", "peak", "not_firm", "not_worth",
              "no_level")]

goodwe_controller/app/main.py

@@ -64,7 +64,8 @@ from .clamp import (
     shortfall_note, write_clamp_note,
 )
 from . import freshness
-from . import homeview
+from . import dayview, homeview
+from .daycurve import SolarToday
 from . import messages
 from .freeze import (
     FreezeWatchdog, FreezeWatchdogConfig, looks_frozen, rail_unreachable, rail_w,
@@ -1261,6 +1262,9 @@ class Controller:
         # UX-13 P1: today's prices as the Home chart has seen them. Display
         # only; nothing reads it back into a decision.
         self.home_prices = homeview.DayPrices()
+        # UX-54: the site's measured solar per hour, for the Forecast tab.
+        # In memory, display only; nothing reads it back into a decision.
+        self.solar_today = SolarToday()
         # TARIFF-11. When the most recent cycle() STARTED. `arb_at < cycle_at`
         # is the exact, derived statement of "the latest cycle did not get as
         # far as the arbitrage step", which is the fact the *Arbitrage* row
@@ -3381,6 +3385,11 @@ class Controller:
             *(self.hass.state(entity) for entity in roster))
         self.pv_w, self.pv_why, self.pv_parts = pv_read.total(
             list(zip(roster, states)), pv_read.inverted(self.o))
+        # UX-54: kept for the Forecast tab only. It must never cost a cycle.
+        try:
+            self.solar_today.add(datetime.now(timezone.utc), self.pv_w)
+        except Exception:                               # noqa: BLE001
+            _LOG.debug("measured solar not kept", exc_info=True)
 
     def _peak_fc_unit_log(self, fault) -> None:
         """SAFETY-118. One WARNING when the peak forecast's unit cannot be read
@@ -7635,6 +7644,21 @@ class Controller:
             out["home_error"] = True
         return out
 
+    def forecast_payload(self, lang: str = "en") -> dict:
+        """UX-54: the Forecast tab's data. Built on request, from what the
+        control cycle already holds; no Home Assistant call. Today's blocks are
+        Home's own, so `status_payload()` is built first and read."""
+        try:
+            return dayview.build(self, self.status_payload(lang=lang),
+                                 datetime.now(timezone.utc), lang)
+        except Exception:                               # noqa: BLE001
+            if not getattr(self, "_forecast_failed", False):
+                self._forecast_failed = True
+                _LOG.exception("The Forecast tab could not be built")
+            else:
+                _LOG.debug("The Forecast tab failed again", exc_info=True)
+            return {"ok": False}
+
     async def handle_action(self, what: str, *, unit=None, value=None):
         now = datetime.now(timezone.utc)
         if what in ("pack_use", "pack_mode", "pack_sell"):

goodwe_controller/app/static/app.css

@@ -246,3 +246,29 @@ select.sel:disabled{opacity:.6}
 .simple .card .lbl{font-weight:600;font-size:15px}
 .simple .inv .hd{border-bottom:0}
 .simple .inv .f{border-top:0;padding-top:0}
+/* UX-54: the Forecast screen */
+.fcline{text-align:right}
+.fcnote{background:var(--info-bg);border-radius:10px;padding:8px 10px;margin:0 0 8px}
+.fcbars{display:flex;align-items:flex-end;gap:2px;height:110px}
+.fcol{flex:1;position:relative;height:100%;min-width:0}
+.fcol i{position:absolute;display:block}
+.fcol .sun{bottom:0;left:0;right:0;background:var(--solar);border-radius:3px 3px 0 0;opacity:.85}
+.fcol .sun.est{opacity:.5}
+.fcol .got{bottom:0;left:30%;right:30%;background:repeating-linear-gradient(135deg,var(--ink) 0 3px,var(--card) 3px 5px);border:1px solid var(--ink);border-bottom:0}
+.fcol .use{left:-1px;right:-1px;height:3px;background:var(--house)}
+.fcols{position:absolute;inset:0;display:flex;gap:0}
+.fcols>i{flex:1;min-width:0;display:block}
+.lvlchart{position:relative;height:110px;margin:18px 0 4px}
+.lvlchart svg{position:absolute;inset:0;width:100%;height:100%;display:block}
+.lvlchart .yl{position:absolute;right:2px;font-size:10px;color:var(--faint);pointer-events:none}
+.fcnow{position:absolute;top:-4px;bottom:0;width:2px;background:var(--ink);opacity:.7;pointer-events:none}
+.fcnow span{position:absolute;top:-15px;left:-10px;font-size:10px}
+.legend i.sun{background:var(--solar)}
+.legend i.got{background:repeating-linear-gradient(135deg,var(--ink) 0 2px,var(--card) 2px 4px);border:1px solid var(--ink)}
+.legend i.use{height:3px;background:var(--house)}
+.legend i.lv{height:3px;background:var(--batt)}
+table.fct{width:100%;border-collapse:collapse;font-size:12px;font-variant-numeric:tabular-nums}
+table.fct th,table.fct td{padding:4px 3px;text-align:right;border-bottom:1px solid var(--line)}
+table.fct th:first-child,table.fct td:first-child{text-align:left}
+table.fct th{color:var(--muted);font-weight:600}
+.ymax{position:absolute;top:-2px;left:2px;font-size:10px;color:var(--faint);pointer-events:none}

goodwe_controller/app/static/app.js

@@ -448,6 +448,175 @@
     });
   }
 
+  /* ---------------- Forecast (UX-54) ---------------- */
+  // Today and tomorrow, per hour: the solar forecast and what was measured,
+  // the house's expected use, and each battery's expected level with its
+  // blocks. The data is built by app/dayview.py when the tab asks (GET
+  // forecast), the sentences in the page's language. A part that is not
+  // known yet comes as a note, so no chart is ever drawn empty.
+  // The SVG namespace, read off the page's own icons: the page names no URL.
+  const SVGNS = document.querySelector("svg").namespaceURI;
+  function sv(tag, attrs) {
+    const e = document.createElementNS(SVGNS, tag);
+    for (const k in attrs || {}) e.setAttribute(k, attrs[k]);
+    return e;
+  }
+  let FC = null;
+  let fcDay = 0;
+  let fcBusy = false;
+  let fcTimer = null;
+  const fmtKwh = (x) => dec(Number(x).toFixed(1));
+  const hoursOf = (d) => d.length_h || d.hours.length || 24;
+  function endLabel(d, i) { return i + 1 < d.hours.length ? d.hours[i + 1].label : "24:00"; }
+  function hourTip(d, i) {
+    const x = d.hours[i];
+    const lines = [];
+    if (x.forecast_kwh != null) lines.push(t("forecast.forecast") + ": " + fmtKwh(x.forecast_kwh) + " kWh");
+    if (x.measured_kwh != null) lines.push(t("forecast.measured") + ": " + fmtKwh(x.measured_kwh) + " kWh");
+    if (x.house_kwh != null) lines.push(t("forecast.house") + ": " + fmtKwh(x.house_kwh) + " kWh");
+    d.batteries.forEach((b, j) => { if (x.levels[j] != null) lines.push(b.name + ": " + dec(Math.round(x.levels[j]).toString()) + " %"); });
+    return [x.label + " " + t("plan.time_to") + " " + endLabel(d, i)].concat(lines);
+  }
+  function hourItem(tag, cls, d, i, kids) {
+    const tip = hourTip(d, i);
+    const e = h(tag, { class: cls, tabindex: "-1", role: "img", "aria-label": tip.join(". "), "data-tip": JSON.stringify(tip) }, kids);
+    return e;
+  }
+  function renderSun(d) {
+    const card = $("#fc-sun");
+    const any = d.sun.forecast || d.sun.measured || d.sun.house;
+    card.hidden = !any;
+    if (!any) return;
+    const mx = Math.max(0.5, ...d.hours.map((x) => Math.max(x.forecast_kwh || 0, x.measured_kwh || 0, x.house_kwh || 0)));
+    const pct = (v) => Math.max(0, Math.min(100, v / mx * 100)) + "%";
+    const bars = $("#fc-bars");
+    bars.setAttribute("aria-label", t("forecast.sun"));
+    bars.replaceChildren(...d.hours.map((x, i) => hourItem("div", "fcol", d, i, [
+      x.forecast_kwh != null ? h("i", { class: "sun" + (d.sun.estimate ? " est" : ""), style: "height:" + pct(x.forecast_kwh) }) : null,
+      x.measured_kwh != null ? h("i", { class: "got", style: "height:" + pct(x.measured_kwh) }) : null,
+      x.house_kwh != null ? h("i", { class: "use", style: "bottom:calc(" + pct(x.house_kwh) + " - 1px)" }) : null])));
+    roving(bars);
+    const chart = $("#fc-sunchart");
+    chart.querySelectorAll(".fcnow, .ymax").forEach((e) => e.remove());
+    chart.append(h("span", { class: "ymax", "aria-hidden": "true" }, fmtKwh(mx)));
+    if (fcDay === 0) chart.append(nowMark(d));
+    const used = [["sun", d.sun.forecast, "forecast"], ["got", d.sun.measured, "measured"], ["use", d.sun.house, "house"]];
+    $("#fc-legend").replaceChildren(...used.filter((u) => u[1]).map((u) => h("span", {}, h("i", { class: u[0], "aria-hidden": "true" }), t("forecast." + u[2]))));
+  }
+  function nowMark(d) {
+    return h("div", { class: "fcnow", "aria-hidden": "true", style: "left:" + Math.max(0, Math.min(100, FC.now_h / hoursOf(d) * 100)) + "%" }, h("span", {}, t("plan.now")));
+  }
+  function levelChart(d, b, bi) {
+    const L = hoursOf(d), W = L * 10;
+    const x = (hr) => hr * 10;
+    const box = h("div", { class: "chart" });
+    const area = h("div", { class: "lvlchart" });
+    const svg = sv("svg", { viewBox: "0 0 " + W + " 100", preserveAspectRatio: "none", "aria-hidden": "true", focusable: "false" });
+    [0, 50, 100].forEach((p) => svg.append(sv("line", { x1: 0, x2: W, y1: 100 - p, y2: 100 - p, stroke: "var(--line)", "stroke-width": 1, "vector-effect": "non-scaling-stroke" })));
+    const fill = { grid: "var(--accent)", give: "var(--house)", cycle: "var(--warn)" };
+    for (const r of b.blocks) {
+      if (r.end_h <= r.start_h) continue;
+      svg.append(sv("rect", { x: x(r.start_h), y: 0, width: x(r.end_h) - x(r.start_h), height: 100, fill: fill[r.kind] || "var(--mid)", opacity: 0.18 }));
+    }
+    const pts = b.levels.map((p) => x(p[0]) + "," + (100 - p[1]));
+    svg.append(sv("polygon", { points: x(b.levels[0][0]) + ",100 " + pts.join(" ") + " " + x(b.levels[b.levels.length - 1][0]) + ",100", fill: "var(--batt)", opacity: 0.12 }));
+    svg.append(sv("polyline", { points: pts.join(" "), fill: "none", stroke: "var(--batt)", "stroke-width": 2.5, "stroke-linejoin": "round", "vector-effect": "non-scaling-stroke" }));
+    area.append(svg);
+    [["100", 0], ["50", 50], ["0", 100]].forEach((y) => area.append(h("span", { class: "yl", "aria-hidden": "true", style: "top:" + y[1] + "%;transform:translateY(" + (y[1] === 100 ? "-100%" : y[1] === 0 ? "0" : "-50%") + ")" }, y[0] + " %")));
+    area.append(h("div", { class: "fcols", role: "group", "aria-label": b.name }, ...d.hours.map((hx, i) => hourItem("i", "", d, i, null))));
+    roving(area.querySelector(".fcols"));
+    if (fcDay === 0) area.append(nowMark(d));
+    box.append(area);
+    // The blocks under the chart, drawn as Home draws them.
+    if (b.blocks.length) {
+      const lane = h("div", { class: "lane", role: "group", "aria-label": b.name });
+      for (const r of b.blocks) {
+        if (r.end_h <= r.start_h) continue;
+        lane.append(chartItem("b", r.kind, "left:" + (r.start_h / L * 100) + "%;width:" + ((r.end_h - r.start_h) / L * 100) + "%",
+                              b.name + ", " + r.from + " " + t("plan.time_to") + " " + r.to, [r.what, r.why, r.amount]));
+      }
+      box.append(lane);
+      roving(lane);
+    }
+    box.append(h("div", { class: "axis", "aria-hidden": "true" }, h("span", {}, "00:00"), h("span", {}, "06:00"), h("span", {}, "12:00"), h("span", {}, "18:00"), h("span", {}, "24:00")));
+    return box;
+  }
+  function batteryCardFc(d, b, bi) {
+    const drawn = b.levels.length > 1;
+    const list = b.blocks.map((r) => h("li", {}, h("strong", {}, r.from + " " + t("plan.time_to") + " " + r.to + ": "), tipText([r.what, r.why, r.amount])));
+    return h("div", { class: "card" },
+      h("div", { class: "row spread" }, h("h2", {}, b.name),
+        h("span", { class: "tiny muted" }, (b.capacity_kwh ? fmtKwh(b.capacity_kwh) + " kWh · " : "") + t("forecast.levels"))),
+      drawn ? levelChart(d, b, bi) : null,
+      list.length ? h("ul", { class: "plain small" }, ...list) : null,
+      b.line ? h("p", { class: "small muted", style: "margin:6px 0 0" }, b.line) : null);
+  }
+  function renderTable(d) {
+    const more = $("#fc-more");
+    const any = d.sun.forecast || d.sun.measured || d.sun.house;
+    more.hidden = !any;
+    if (!any) return;
+    const lv = d.batteries.filter((b) => b.levels.length > 1);
+    const head = h("tr", {}, h("th", { scope: "col" }, t("forecast.hour")),
+      d.sun.forecast ? h("th", { scope: "col" }, t("forecast.solar")) : null,
+      d.sun.measured ? h("th", { scope: "col" }, t("forecast.got")) : null,
+      d.sun.house ? h("th", { scope: "col" }, t("forecast.use")) : null,
+      ...lv.map((b) => h("th", { scope: "col" }, b.name + " %")));
+    const cell = (v, f) => h("td", {}, v == null ? "–" : f(v));
+    const rows = d.hours.map((x) => h("tr", {},
+      h("td", {}, x.label),
+      d.sun.forecast ? cell(x.forecast_kwh, fmtKwh) : null,
+      d.sun.measured ? cell(x.measured_kwh, fmtKwh) : null,
+      d.sun.house ? cell(x.house_kwh, fmtKwh) : null,
+      ...lv.map((b) => cell(x.levels[d.batteries.indexOf(b)], (v) => dec(Math.round(v).toString())))));
+    $("#fc-table").replaceChildren(h("thead", {}, head), h("tbody", {}, ...rows));
+  }
+  function renderForecast() {
+    const loading = $("#fc-loading");
+    if (!FC || FC.ok !== true) {
+      loading.hidden = false; loading.textContent = FC ? t("offline.name") : t("forecast.loading");
+      $("#fc-notes").replaceChildren(); $("#fc-sun").hidden = true; $("#fc-batts").replaceChildren(); $("#fc-more").hidden = true; $("#fc-line").textContent = "";
+      return;
+    }
+    loading.hidden = true;
+    const d = FC.days[fcDay];
+    $("#fc-line").textContent = d.line || "";
+    $("#fc-notes").replaceChildren(...d.notes.map((n) => h("p", { class: "fcnote small" }, n)));
+    renderSun(d);
+    $("#fc-batts").replaceChildren(...d.batteries.map((b, i) => batteryCardFc(d, b, i)));
+    renderTable(d);
+    document.querySelectorAll("#fc-day button").forEach((b) => {
+      const on = Number(b.dataset.d) === fcDay;
+      b.setAttribute("aria-checked", String(on)); b.tabIndex = on ? 0 : -1;
+    });
+  }
+  async function loadForecast() {
+    if (fcBusy) return;
+    fcBusy = true;
+    try {
+      const r = await fetch("forecast?lang=" + LANG, { cache: "no-store" });
+      if (!r.ok) throw new Error("forecast " + r.status);
+      FC = await r.json();
+    } catch (e) { FC = { ok: false }; }
+    finally { fcBusy = false; }
+    renderForecast();
+  }
+  document.querySelectorAll("#fc-day button").forEach((b, i, all) => {
+    b.addEventListener("click", () => { fcDay = Number(b.dataset.d); renderForecast(); });
+    b.addEventListener("keydown", (e) => {
+      const j = { ArrowRight: i + 1, ArrowLeft: i - 1 + all.length }[e.key];
+      if (j === undefined) return;
+      e.preventDefault(); fcDay = j % all.length; renderForecast(); all[fcDay].focus();
+    });
+  });
+  // Every 30 s while the screen shows: the data moves slowly, and each load
+  // is built on request.
+  function scheduleForecast() {
+    const on = !document.hidden && $("#t-fc").getAttribute("aria-selected") === "true";
+    if (on && !fcTimer) { loadForecast(); fcTimer = setInterval(loadForecast, 30000); }
+    if (!on && fcTimer) { clearInterval(fcTimer); fcTimer = null; }
+  }
+
   /* ---------------- control buttons ---------------- */
   // The action is a toggle, so the page reads the live state first and sends
   // nothing when control is already where the person asked it to be.
@@ -511,11 +680,13 @@
   }
   addEventListener("hashchange", fromHash);
 
-  /* ---------------- polling: every 3 s while Home or Batteries shows ---------------- */
+  /* ---------------- polling: every 3 s while Home, Batteries or Forecast shows ---------------- */
   let timer = null;
   function schedule() {
+    scheduleForecast();
     const live = !document.hidden && ($("#t-home").getAttribute("aria-selected") === "true" ||
-                                      $("#t-batt").getAttribute("aria-selected") === "true");
+                                      $("#t-batt").getAttribute("aria-selected") === "true" ||
+                                      $("#t-fc").getAttribute("aria-selected") === "true");
     if (live && !timer) { refresh(); timer = setInterval(refresh, 3000); }
     if (!live && timer) { clearInterval(timer); timer = null; }
   }

goodwe_controller/app/static/index.html

@@ -18,6 +18,7 @@
 <nav class="tabs" role="tablist" id="tabs" data-t-label="tabs.label">
   <button class="tab" role="tab" id="t-home" aria-controls="s-home" aria-selected="true" data-hash="home"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true"><path d="M3 11l9-7 9 7v9a1 1 0 0 1-1 1h-5v-6H9v6H4a1 1 0 0 1-1-1z"/></svg><span data-t="tabs.home"></span><span class="badge" id="attn-badge" hidden></span></button>
   <button class="tab" role="tab" id="t-batt" aria-controls="s-batt" aria-selected="false" data-hash="batteries" tabindex="-1"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true"><rect x="3" y="7" width="16" height="10" rx="2"/><path d="M21 11v2"/><rect x="5.5" y="9.5" width="7" height="5" fill="currentColor" stroke="none"/></svg><span data-t="tabs.batteries"></span></button>
+  <button class="tab" role="tab" id="t-fc" aria-controls="s-fc" aria-selected="false" data-hash="forecast" tabindex="-1"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true"><path d="M3 20h18M4 16l5-6 4 4 7-9"/></svg><span data-t="tabs.forecast"></span></button>
   <button class="tab" role="tab" id="t-set" aria-controls="s-set" aria-selected="false" data-hash="settings" tabindex="-1"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true"><path d="M4 6h10M18 6h2M4 12h4M12 12h8M4 18h12M20 18h0"/><circle cx="16" cy="6" r="2"/><circle cx="10" cy="12" r="2"/><circle cx="18" cy="18" r="2"/></svg><span data-t="tabs.settings"></span></button>
   <button class="tab" role="tab" id="t-wiz" aria-controls="s-wiz" aria-selected="false" data-hash="setup" tabindex="-1"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true"><path d="M14 7l3 3M5 19l9.5-9.5 3 3L8 22H5z"/><path d="M19 2v4M17 4h4"/></svg><span data-t="tabs.setup"></span></button>
 </nav>
@@ -114,6 +115,32 @@
   </details>
 </section>
 
+<section class="screen" id="s-fc" role="tabpanel" aria-labelledby="t-fc" hidden>
+  <div class="row spread" style="margin-bottom:8px">
+    <div class="seg" role="radiogroup" id="fc-day" data-t-label="forecast.day">
+      <button type="button" role="radio" aria-checked="true" data-d="0" data-t="forecast.today"></button>
+      <button type="button" role="radio" aria-checked="false" data-d="1" tabindex="-1" data-t="forecast.tomorrow"></button>
+    </div>
+    <span class="tiny muted grow fcline" id="fc-line"></span>
+  </div>
+  <div id="fc-notes" aria-live="polite"></div>
+  <p class="small muted" id="fc-loading" data-t="forecast.loading"></p>
+  <div class="card" id="fc-sun" hidden>
+    <div class="row spread"><h2 data-t="forecast.sun"></h2><span class="tiny muted" data-t="forecast.unit"></span></div>
+    <div class="chart" id="fc-sunchart">
+      <div class="fcbars" id="fc-bars" role="group"></div>
+      <div class="axis" aria-hidden="true"><span>00:00</span><span>06:00</span><span>12:00</span><span>18:00</span><span>24:00</span></div>
+    </div>
+    <div class="legend" id="fc-legend"></div>
+    <p class="tiny muted" style="margin:6px 0 0" data-t="plan.description"></p>
+  </div>
+  <div id="fc-batts"></div>
+  <details class="grp" id="fc-more" hidden>
+    <summary><span class="grow"><strong data-t="forecast.table"></strong></span><span class="chev" aria-hidden="true">&#8250;</span></summary>
+    <div class="body"><table class="fct" id="fc-table"></table></div>
+  </details>
+</section>
+
 <section class="screen" id="s-set" role="tabpanel" aria-labelledby="t-set" hidden>
   <div class="row spread" style="margin-bottom:6px">
     <h2 style="margin:0" data-s="name"></h2>

goodwe_controller/app/ui_text/en.json

@@ -45,7 +45,7 @@
   },
   "home": {
     "app": {"name": "Battery add-on"},
-    "tabs": {"home": "Home", "batteries": "Batteries", "settings": "Settings", "setup": "Setup", "label": "Screens"},
+    "tabs": {"home": "Home", "batteries": "Batteries", "forecast": "Forecast", "settings": "Settings", "setup": "Setup", "label": "Screens"},
     "now": {"name": "Now", "description": "Updated every 3 seconds.", "solar": "Solar", "house": "House", "grid": "Grid", "batteries": "Batteries"},
     "plan": {
       "name": "Today's plan",
@@ -68,6 +68,24 @@
       "no_prices": {"description": "No prices for today, so the chart shows only the plan."},
       "list": "The plan in words"
     },
+    "forecast": {
+      "name": "Forecast",
+      "day": "Day",
+      "today": "Today",
+      "tomorrow": "Tomorrow",
+      "sun": "Solar and house",
+      "unit": "kWh per hour",
+      "forecast": "Solar forecast",
+      "measured": "Solar measured",
+      "house": "House use",
+      "levels": "Battery level",
+      "table": "Hour by hour",
+      "hour": "Hour",
+      "solar": "Solar",
+      "got": "Measured",
+      "use": "House",
+      "loading": "Loading the forecast."
+    },
     "peak": {"name": "Peak limit", "this_month": "This month's peak", "limit": "Limit", "none": "None recorded yet", "unreadable": "Cannot be read now"},
     "attention": {"name": "Needs attention", "nothing": "Nothing to look at", "to_look": "to look at", "details": "Details", "alarm": "Alarm", "warning": "Warning", "info": "Info"},
     "control": {"name": "Control", "stop": "Stop control", "start": "Start control", "maint_start": "Start a battery cycle now", "maint_abort": "Stop the battery cycle", "docs": "Add-on documentation", "more": "More actions"},
@@ -425,6 +443,21 @@
       "known": "Tomorrow's prices are in.",
       "unknown": "Tomorrow's prices usually arrive after 13:00."
     },
+    "day": {
+      "modes_off": "Battery modes are off. No forecast is read and no level is planned.",
+      "not_set": "No solar forecast is set up. Without one, no battery level is planned.",
+      "no_forecast": "The solar forecast is missing or too old. The levels return when it is back.",
+      "learning": "The add-on is learning your house's use. The levels start after one full day.",
+      "no_tomorrow": "There is no solar forecast for tomorrow yet. The levels stop at sunrise.",
+      "estimate": "The forecast gives one total for the day. The add-on spreads it over the hours.",
+      "trust": "The levels count on {pct} % of the forecast.",
+      "cycle": "{name} does its monthly cycle. Its level is not shown from the start.",
+      "no_level": "{name} has no level reading yet. Its levels are not shown.",
+      "measured_from": "Measured solar is counted from {at}, when the add-on started.",
+      "tomorrow_total": "Solar expected tomorrow: {kwh}, we count on {count}.",
+      "no_blocks": "No charge or give blocks planned.",
+      "ahead": "The add-on plans prices about a day ahead. Blocks for later hours appear as they come near."
+    },
     "region": {
       "preset": "Levies and VAT: {region}, {year} figures.",
       "own": "Levies and VAT: your own figure."

goodwe_controller/app/ui_text/nl.json

@@ -42,7 +42,7 @@
   "applies": {"restart": {"name": "Geldt na een herstart"}, "now": {"name": "Geldt meteen"}},
   "home": {
     "app": {"name": "Batterij-add-on"},
-    "tabs": {"home": "Start", "batteries": "Batterijen", "settings": "Instellingen", "setup": "Installatie", "label": "Schermen"},
+    "tabs": {"home": "Start", "batteries": "Batterijen", "forecast": "Prognose", "settings": "Instellingen", "setup": "Installatie", "label": "Schermen"},
     "now": {"name": "Nu", "description": "Elke 3 seconden bijgewerkt.", "solar": "Zonnepanelen", "house": "Huis", "grid": "Net", "batteries": "Batterijen"},
     "plan": {
       "name": "Plan voor vandaag",
@@ -65,6 +65,24 @@
       "no_prices": {"description": "Geen prijzen voor vandaag, dus de grafiek toont alleen het plan."},
       "list": "Het plan in woorden"
     },
+    "forecast": {
+      "name": "Prognose",
+      "day": "Dag",
+      "today": "Vandaag",
+      "tomorrow": "Morgen",
+      "sun": "Zon en huis",
+      "unit": "kWh per uur",
+      "forecast": "Zonneprognose",
+      "measured": "Zon gemeten",
+      "house": "Huisverbruik",
+      "levels": "Laadniveau",
+      "table": "Uur per uur",
+      "hour": "Uur",
+      "solar": "Zon",
+      "got": "Gemeten",
+      "use": "Huis",
+      "loading": "De prognose wordt geladen."
+    },
     "peak": {"name": "Piekgrens", "this_month": "Piek van deze maand", "limit": "Grens", "none": "Nog niets gemeten", "unreadable": "Nu niet leesbaar"},
     "attention": {"name": "Vraagt aandacht", "nothing": "Niets om na te kijken", "to_look": "na te kijken", "details": "Details", "alarm": "Alarm", "warning": "Waarschuwing", "info": "Info"},
     "control": {"name": "Regeling", "stop": "Regeling stoppen", "start": "Regeling starten", "maint_start": "Nu een batterijcyclus starten", "maint_abort": "Batterijcyclus stoppen", "docs": "Documentatie van de add-on", "more": "Meer acties"},
@@ -353,6 +371,21 @@
     "period_unmeasured": "Een deel van dit kwartier is niet gemeten.",
     "prices": {"now": "Prijs nu {eur} per kWh, alles inbegrepen.", "today": "Vandaag: laagste {lo} om {lo_at}, hoogste {hi} om {hi_at}.", "none": "Geen prijzen voor vandaag."},
     "tomorrow": {"known": "De prijzen van morgen zijn binnen.", "unknown": "De prijzen van morgen komen meestal na 13:00."},
+    "day": {
+      "modes_off": "Batterijmodi staan uit. Er wordt geen prognose gelezen en geen niveau gepland.",
+      "not_set": "Er is geen zonneprognose ingesteld. Zonder prognose wordt geen laadniveau gepland.",
+      "no_forecast": "De zonneprognose ontbreekt of is te oud. De niveaus komen terug als ze er weer is.",
+      "learning": "De add-on leert het verbruik van uw huis. De niveaus starten na één volle dag.",
+      "no_tomorrow": "Er is nog geen zonneprognose voor morgen. De niveaus stoppen bij zonsopgang.",
+      "estimate": "De prognose geeft één totaal voor de dag. De add-on verdeelt het over de uren.",
+      "trust": "De niveaus rekenen op {pct} % van de prognose.",
+      "cycle": "{name} doet de maandelijkse cyclus. Het niveau wordt niet getoond vanaf de start.",
+      "no_level": "{name} geeft nog geen laadniveau door. De niveaus worden niet getoond.",
+      "measured_from": "Gemeten zon telt vanaf {at}, toen de add-on startte.",
+      "tomorrow_total": "Verwachte zon morgen: {kwh}, we rekenen op {count}.",
+      "no_blocks": "Geen laad- of leverblokken gepland.",
+      "ahead": "De add-on plant prijzen ongeveer een dag vooruit. Blokken voor latere uren verschijnen als ze naderen."
+    },
     "region": {"preset": "Heffingen en btw: {region}, cijfers van {year}.", "own": "Heffingen en btw: uw eigen bedrag."},
     "peak_not_covered": "Geen piekgrens: deze meter meet geen kwartieren.",
     "control": {"shadow": "Schaduwmodus: elke omvormer blijft op 0 W.", "running": "De regeling is actief.", "stopped": "De regeling is gestopt. Elke omvormer staat op 0 W."},

goodwe_controller/app/web.py

@@ -150,6 +150,12 @@ def build_app(controller, selfcfg=None) -> web.Application:
             return web.json_response(controller.status_payload())
         return web.json_response(controller.status_payload(lang=lang))
 
+    async def forecast(request):
+        """UX-54: the Forecast tab's data, built when the tab asks. Reads only."""
+        build = getattr(controller, "forecast_payload", None)
+        lang = uitext.lang_of(request.query.get("lang"))
+        return web.json_response(build(lang=lang) if build else {"ok": False})
+
     async def action(request):
         try:
             body = await request.json()
@@ -471,6 +477,7 @@ def build_app(controller, selfcfg=None) -> web.Application:
     app.add_routes([
         web.get("/", index),
         web.get("/status", status),
+        web.get("/forecast", forecast),
         web.post("/action", action),
         web.get("/config", config_index),
         web.get("/config/model", config_model),