goodwe-addon/goodwe_controller/DECISIONS/UX-54-forecast-tab.md

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

**Status: DONE 2026-10-26 (owner go 2026-10-26: "Day curve", "New tab").**

## Decision

A tab beside Home and Batteries shows today and tomorrow, per 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.

- **Blocks are Home's.** Today's are the `runs` of the same plan Home draws
  (grid, give, monthly cycle). Tomorrow's come from the same builders
  (`homeview.runs_for()`). The words are the plan lines'. A block is on the tab
  exactly where Home has one, so the UX-53 gate is followed too.
- **Tomorrow is read ahead.** Home sizes a block from the battery's level now
  and draws none when there is no room or energy (`room()` and `plan_need()`
  in `homeview.mode_runs()`, the leg sizing in `trade_runs()`). For a day that
  has not started that level says nothing, so tomorrow's blocks are built with
  `ahead` (Home never passes it): `mode_runs()` reads each block at the level
  the curve has when it starts, with its own filter and `MIN_KWH`, so there is
  no give block where the battery is at the floor and no grid block where it
  is at its planned level. Where the curve has no level yet, a charge is read
  from the floor and a give from the ceiling. The blocks and the curve follow
  each other and are taken to a fixed point. The gate (`mode_gate`, UX-53) is
  not bypassed.
- **Modes off has no curve** (no forecast is read, no house profile kept), so
  `trade_runs(ahead=f)` reads each leg at Home's own count
  (`dayview._counted()`): the level now, plus what the blocks before it put in,
  less what they take out. No sun is read and the house only takes, so no give
  block where the emptiest battery is at the floor by that count, and control
  does not give there. A charge is read from the floor: a full battery covers
  the house before the cheap hour, and control charges it back then. Walked
  every 15 minutes on a cloudy day, the packs moved by control and a 400 W
  house (`test_ux54.py` part 7, cases A-D, one price quarter per leg),
  control charges and gives in exactly the quarters the tab has a block.
- **A block lasts as long as control acts.** A cheap run is sized for all the
  batteries charging together, so a slower one is still below
  `modetrade.charge_to()` when it ends, and control plans the next cheap slots
  (`Controller._price_runs()`). `dayview._levels()` asks the same functions,
  `modetrade.energy()` and `priceruns.plan()`, with the packs at the curve's
  level, and draws the grid block to where control stops. Each battery's block
  then ends where the curve has it at its own level, and a give block where
  it reaches the floor: the curve puts a point at both (`daycurve.curve()`
  cuts the step there), and the block ends at the first point where the level
  the tab shows (0.1 %) is there. What is proven: control walked every 15
  minutes through tomorrow with its own model of the packs, not the curve's
  levels (`_mode_roles()` each quarter; the house from the profile, the sun
  at 100 % trust, a GIVE role counted only where control's own discharge
  envelope `packshare.envelope()` is open, the cut-out at the floor), charges
  and gives in exactly the quarters the tab has a block in 13 cases
  (`test_ux54.py` part 7, `own_walk()`), e.g. 25/45 % with the peak guard:
  control gives 17:00-20:15, the block is 17:00-20:06; 30/80 % with a 7 kW
  evening house, B held to its rating: control 17:00-19:45, the block
  17:00-19:32. The floor point is placed in one cut, where the battery runs
  out at the rate it gives (`_floor_cut()`, checked to the second against
  times worked out by hand), so a build stays small: at most 14 floor cuts
  and 28 level points per battery and day in those cases. With a cut-out under
  the floor, or a house or sun that differs from the forecast and profile,
  control differs (Limits).
- **The sun** is what `solarfc` reads. An hourly split (Solcast
  `detailedForecast`, Open-Meteo `wh_period`) is used as given. A daily total
  (Forecast.Solar, and any other state-only sensor, the owner's three "today
  remaining" and three "tomorrow") is spread over the 06:00-20:00 bell, and the
  tab says so.
- **The house** is `HouseProfile.estimator()`, never below the night median, as
  the plan reads it.
- **The level did not exist** (the plan holds targets and run blocks only), so
  `daycurve.curve()` derives it: each battery has the role `modetrade.decide()`
  gives (follow the house, hold, give, charge from the grid, rest), spare solar
  goes to Solar first batteries first, a shortfall is met by those that may
  give, shared as control shares it (by what each holds above the floor,
  `packshare.weights()`, each at most its rating, the rest passed on), both
  at `dayplan.EFF`, inside the plan's floor and ceiling, from the
  level now. Spare solar is `trust x max(0, sun - house)` and what is stored
  loses `EFF`, the plan's own `trust x EFF x max(0, sun - house)` (10 kWh of
  sun, 2 kWh of house, 70 %: 5.32 kWh stored). A shortfall is not scaled by
  trust. The tab says it counts on `solar_trust_pct`. Grid charging goes to
  `modetrade.charge_to()`. It is an estimate.
- **Measured solar** is kept per local hour in memory (`SolarToday`), from the
  reading the control cycle already takes; nothing is read back.
- **On request.** `GET forecast` builds the tab (`Controller.forecast_payload()`
  reads `/status`' plan first, so today's blocks are the very ones Home has). No
  Home Assistant call, nothing cached, nothing in the cycle but one in-memory
  add. The page asks every 30 s while the tab shows.
- **Not known yet is a note, not an empty chart:** modes off, no forecast set,
  forecast missing or old, learning, no tomorrow forecast, a monthly cycle, no
  level reading, control stopped, shadow.

## What does not change

No decision, command, timing or option key. The one write in the control path
is `SolarToday.add()` after the solar read, in a `try`, in memory.

## Limits

- Prices are planned about a day ahead (`priceruns.HORIZON`), so a block of
  tomorrow later than 24 h from now, or one that needs prices not yet
  published, appears as the day comes near. The tab says so.
- Today's blocks are Home's. UX-77: Home draws today's grid block to where
  control will stop charging, as the tab does for tomorrow's: the cheap run
  rolls on at its end while a battery is short (`cheaproll.roll_end()`, the
  same loop as `dayview._levels()`), the level read at the charge power the
  peak limit leaves (peak aim less the house, else the rating) and shared by
  room left to full as control shares it (`packshare.weights()`, re-read as
  the levels move), and each battery's block ends at its own stop. The curve stops charging at its level
  (`charge_to()`) and giving at the floor.
- Today, a give run in the plan on a battery that is empty now has no block on
  Home (no energy to give). The tab equals Home, and says so: "The add-on plans
  to give power. No block shows while a battery has no energy to give." The
  curve gives in that run if the sun fills the battery first.
- With no forecast for tomorrow the curve stops at the first hour of the sun,
  `solarfc.BELL_FROM_H` (06:00): `Forecast.between()` has no answer past it. The
  note names that hour from the constant.
- Tomorrow shows price blocks only. A monthly cycle is drawn today, where the
  curve then stops for that battery.
- The curve uses the arbitrage floor and ceiling, as the plan does, not the
  battery's own cut-out level. Control stops a pack at its cut-out, so with a
  cut-out under the floor a battery in a give run covers the house below the
  floor; Home draws no block there either. The house profile is a median per
  hour, net of the solar the house used.
- Modes off: the count knows no sun and no house. A battery at the floor that
  the sun fills before a give gets no block until then (the tab says "The
  add-on plans to give power. No block shows while a battery has no energy to
  give."), and a small charge may be used by the house before the give. The
  other way round, a charge is drawn even when the sun fills the batteries
  before it: at the ceiling control then takes none (a cheap quarter at 13:00
  on a sunny day: the tab draws the charge, control charges nothing at 95 %
  or 100 %).
  A leg is the verdict's as it stands now, one price period, as on Home; with
  several equal prices in a row control takes the next one as each passes.
- Measured solar starts when the add-on starts; the tab says from when.
- Clock changes: the tab walks local hours with `dayplan._hour_slices()`,
  which steps in UTC (SAFETY-123), and keys measured solar by the start of
  the local hour taken back from the UTC instant, so the spring day has 23
  hours, the autumn day 25 (two of them 02:00), and a request always returns
  (`test_ux54_dst.py`, every quarter of both change days, with and without
  tzdata). The solar bell is spread over hours from local midnight, so on
  those two days it is an hour off the clock (SAFETY-123, not changed here).

## Found, not changed

`dayplan.plan()` reads the forecast hour by hour with `Forecast.between(s, e)`.
For a state-only forecast `between()` takes its start as the moment the "left
today" figure was read, so each later hour is spread over what is left of the
bell from that hour: on the owner's shape 14.4 kWh left gives 57 kWh over the
hours to midnight (`test_ux54.py` part 1). The plan's sun is overcounted for
those sites. It does not show on a site whose batteries are all Solar first
(no level is planned for them). The tab measures both ends from now
(`dayview.sun_kwh()`), which keeps the total and gives the same hours for an
hourly split. A card should fix the plan.