thermostat-hw/main/api/ha_data.h

/*
 * The data contract between "fetching" and "drawing".
 *
 * ha_data_t is plain data with no ESP-IDF or network dependency, and
 * ha_parse_json() is a pure function. That is what lets the desktop simulator
 * run the real UI: sim/ supplies a JSON snapshot or a LAN fetch, the firmware
 * supplies esp_http_client, and both hand the identical struct to the
 * identical drawing code.
 *
 * The UI layer must never see HTTP, cJSON or an entity ID -- only this.
 */
#ifndef HA_DATA_H
#define HA_DATA_H

#include <stdbool.h>
#include <stdint.h>

#include "ha_config.h"

/* Five days across the bottom strip. HA returns six; the sixth is dropped. */
#define HA_FORECAST_DAYS 5

/* Derived from HA_LIGHT_LIST so the two can never disagree. */
#define HA_LIGHT_COUNT_X(a, b, c, d) +1
#define HA_LIGHT_COUNT (0 HA_LIGHT_LIST(HA_LIGHT_COUNT_X))

/*
 * A reading that may not exist.
 *
 * Sensors go unavailable routinely -- a dead anemometer, a flat battery, an
 * integration reloading -- and a float alone cannot say so. Every consumer has
 * to check `valid` before touching `value`; there is deliberately no sentinel
 * to accidentally render as a real number.
 */
typedef struct {
    float value;
    bool  valid;
} ha_value_t;

typedef enum {
    HA_LIGHT_OFF = 0,
    HA_LIGHT_ON,
    HA_LIGHT_UNAVAILABLE,   /* entity exists but HA cannot reach the device */
} ha_light_state_t;

typedef struct {
    ha_light_state_t state;
    /* 0-255 as HA reports it. Only meaningful when state is HA_LIGHT_ON and
     * the entity is dimmable; -1 otherwise. */
    int16_t brightness;
} ha_light_status_t;

typedef struct {
    const char *entity_id;
    const char *label;
    bool dimmable;
} ha_light_cfg_t;

/*
 * Which way a reading has moved over the last hour.
 *
 * UNKNOWN is deliberately 0 so a freshly wiped ha_data_t renders no arrow --
 * after boot there is no history, and "no arrow" is the honest display until
 * at least HA_TREND_MIN_AGE_MS of samples exist.
 */
typedef enum {
    HA_TREND_UNKNOWN = 0,
    HA_TREND_FLAT,
    HA_TREND_RISING,
    HA_TREND_FALLING,
} ha_trend_t;

enum {
    HA_TREND_CH_INDOOR = 0,
    HA_TREND_CH_OUTDOOR,
    HA_TREND_CH_PRESSURE,
    HA_TREND_CHANNELS,
};

/* Generated from HA_LIGHT_LIST; index-aligned with ha_data_t.lights. */
extern const ha_light_cfg_t HA_LIGHTS[HA_LIGHT_COUNT];

typedef struct {
    char       day[4];        /* "Mon" -- derived from the ISO date, see below */
    char       condition[24]; /* met.no condition slug, e.g. "partlycloudy" */
    ha_value_t high_f;
    ha_value_t low_f;
} ha_forecast_day_t;

typedef struct {
    /* Weather station */
    ha_value_t outdoor_temp_f;
    ha_value_t outdoor_humidity;
    ha_value_t indoor_temp_f;
    ha_value_t indoor_humidity;
    ha_value_t dew_point_f;
    ha_value_t pressure_inhg;
    ha_value_t rain_today_in;
    ha_value_t rain_rate_inhr;
    ha_value_t wind_mph;
    ha_value_t gust_mph;
    ha_value_t wind_dir_deg;

    /* Forecast / sun. These strings arrive pre-formatted in local time --
     * HA owns the timezone, so the device needs no clock and no SNTP. */
    char condition[24];
    char sunrise[12];       /* "6:05 AM" */
    char sunset[12];        /* "7:45 PM" */
    char clock[12];         /* "10:21 AM" */
    char date[16];          /* "Tue Aug 4" */
    bool sun_up;

    ha_light_status_t lights[HA_LIGHT_COUNT];

    ha_forecast_day_t forecast[HA_FORECAST_DAYS];
    uint8_t forecast_count;   /* 0 when no forecast has been fetched yet */

    /*
     * Filled by the CALLER after parsing, from ha_trend_feed/compute --
     * the parser wipes them to UNKNOWN. Local ring-buffer history, not an HA
     * query: an /api/history call returns hundreds of points per entity,
     * which is silly when the device already sees every reading each poll.
     */
    ha_trend_t trend_indoor;
    ha_trend_t trend_outdoor;
    ha_trend_t trend_pressure;
} ha_data_t;

/*
 * Parse the reply to the state template into `out`.
 *
 * Zeroes `out` first, so a field missing from the response reads as invalid
 * rather than keeping a previous poll's value. Returns false only when the
 * body is not parseable JSON -- individual missing or unavailable sensors are
 * normal and leave their ha_value_t invalid.
 *
 * Does not touch the forecast fields; those come from ha_parse_forecast_json()
 * on a slower poll and would otherwise be wiped every minute.
 */
bool ha_parse_json(const char *json, ha_data_t *out);

/*
 * Parse a weather/get_forecasts service response into out->forecast.
 * Fills at most HA_FORECAST_DAYS entries and sets forecast_count.
 */
bool ha_parse_forecast_json(const char *json, ha_data_t *out);

/*
 * "light" or "switch" for entity_id -- the HA service domain to call. The
 * patio plug is a switch, and calling light.turn_on on it silently does
 * nothing.
 */
const char *ha_service_domain(const char *entity_id);

/* Human-readable form of a met.no condition slug ("partlycloudy" ->
 * "Partly Cloudy"). Returns the slug unchanged if unrecognised, so an
 * unhandled condition shows up on screen as the thing to go add. */
const char *ha_condition_label(const char *slug);

/* As above, abbreviated for the forecast strip's narrow columns
 * ("partlycloudy" -> "Partly"). */
const char *ha_condition_short(const char *slug);

/* Compass point for a bearing in degrees ("NNE"). */
const char *ha_wind_cardinal(float degrees);

/*
 * Trend tracking. Feed one sample per poll; compute compares the newest
 * sample against the one closest to an hour old. Timestamps come from the
 * caller (lv_tick_get() or xTaskGetTickCount-derived ms) so this file stays
 * free of LVGL and FreeRTOS. Wrap-safe on uint32 ms.
 *
 * compute returns UNKNOWN until the oldest usable sample is at least
 * HA_TREND_MIN_AGE_MS old -- "trending" over 90 seconds is noise.
 */
#define HA_TREND_WINDOW_MS  (60u * 60u * 1000u)
#define HA_TREND_MIN_AGE_MS (5u * 60u * 1000u)

void ha_trend_feed(int channel, float value, uint32_t now_ms);
ha_trend_t ha_trend_compute(int channel, float threshold_per_hour, uint32_t now_ms);

#endif