/*
 * Rotary Thermostat — CrowPanel 2.1" HMI Rotary Display.
 *
 * Boot ordering here is not arbitrary. Reading top to bottom:
 *
 *  1. Relay off, first, before anything can fail. A PCF8574 does not reset
 *     when the ESP32 does, so if we got here from a panic while the contact
 *     was closed, the furnace is still running right now. Nothing else in
 *     this function matters as much as the next few milliseconds.
 *  2. WiFi before the display (PRD 8.2). The radio's PSRAM allocations and
 *     the RGB panel's bandwidth demands do not mix well the other way round.
 *  3. Display, then LVGL, then UI.
 *  4. Control loop last, once everything it reports on exists.
 */

#include "control.h"
#include "cst826.h"
#include "display.h"
#include "encoder.h"
#include "esp_log.h"
#include "esp_system.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "i2c_bus.h"
#include "lvgl_port.h"
#include "pcf8574.h"
#include "relay.h"
#include "settings.h"
#include "ui_manager.h"
#include "wifi_manager.h"
#include "zigbee_client.h"

static const char *TAG = "main";

/*
 * Set to 1 to draw colour bars and stop before LVGL.
 *
 * This is the PRD phase-2 check. It proves the ST7701S init sequence, the RGB
 * bus and the timings on their own, with no LVGL in the picture to blame.
 */
#define BRINGUP_TEST_PATTERN    0

void app_main(void)
{
    ESP_LOGI(TAG, "Rotary Thermostat starting");

    /* ---- 1. Make the furnace safe ------------------------------------- */

    ESP_ERROR_CHECK(i2c_bus_init());

    /*
     * The scan is the cheap sanity check from PRD 8.1: finding the PCF8574 at
     * 0x21 and the CST826 at 0x15 proves the board is alive and the I2C pins
     * are right, independently of the display.
     */
    i2c_bus_scan();

    if (pcf8574_init() != ESP_OK) {
        /*
         * Without the expander there is no way to guarantee the relay is open,
         * and no way to open it if it is closed. Continuing would mean running
         * a heating controller that cannot turn the heat off. Reboot and try
         * again rather than pretend.
         */
        ESP_LOGE(TAG, "expander init failed — cannot control the relay, "
                      "restarting in 5s");
        vTaskDelay(pdMS_TO_TICKS(5000));
        esp_restart();
    }

    /* pcf8574_init() already pushed the all-high shadow, which de-asserts the
     * relay. This is belt and braces, and it is cheap. */
    relay_emergency_off();
    ESP_LOGI(TAG, "relay de-asserted");

    /* ---- 2. Settings and network -------------------------------------- */

    settings_init();

    /* Non-blocking: returns as soon as the driver is started. */
    wifi_manager_init();

    /*
     * Give the association a few seconds before bringing the panel up. Not
     * required for correctness — everything downstream tolerates no network —
     * but PRD 8.2 wants WiFi up first, and it means the first frame drawn
     * usually already has real readings on it.
     */
    if (wifi_manager_wait_connected(6000)) {
        ESP_LOGI(TAG, "network up before display init");
    } else {
        ESP_LOGW(TAG, "no network yet — continuing, it will connect in the "
                      "background");
    }

    zigbee_client_init();

    /* ---- 3. Display ---------------------------------------------------- */

    if (display_init() != ESP_OK) {
        /*
         * A blind thermostat is still a thermostat. It has a setpoint from
         * NVS, sensors over MQTT and a relay; losing the screen should not
         * lose the heat.
         */
        ESP_LOGE(TAG, "display init failed — continuing headless");
    } else {
#if BRINGUP_TEST_PATTERN
        display_test_pattern();
        ESP_LOGW(TAG, "BRINGUP_TEST_PATTERN is set — stopping here");
        while (1) {
            vTaskDelay(pdMS_TO_TICKS(1000));
        }
#endif
        cst826_init();

        if (lvgl_port_init() == ESP_OK) {
            ui_manager_init();
        } else {
            ESP_LOGE(TAG, "LVGL port failed — continuing headless");
        }
    }

    if (encoder_init() != ESP_OK) {
        ESP_LOGE(TAG, "encoder init failed — setpoint fixed at stored value");
    }

    /* ---- 4. Arm the heat ----------------------------------------------- */

    ESP_ERROR_CHECK(relay_init());
    ESP_ERROR_CHECK(control_init());

    ESP_LOGI(TAG, "running");

    /*
     * Everything from here is task-driven. This loop only reports, at a
     * cadence slow enough to be readable in a terminal left open on the bench.
     */
    while (1) {
        vTaskDelay(pdMS_TO_TICKS(60000));

        control_state_t st;
        relay_status_t rs;
        control_get_state(&st);
        relay_status(&rs);

        ESP_LOGI(TAG, "temp %.1fC set %.1fC | %s | heat %s | %s | wifi %s mqtt %s",
                 st.governing_temp_c, st.effective_setpoint_c,
                 (st.governing_room >= 0)
                     ? zigbee_client_room_name(st.governing_room) : "none",
                 rs.heat_on ? "ON" : "off",
                 control_source_str(st.source),
                 wifi_manager_is_connected() ? "up" : "down",
                 zigbee_client_is_connected() ? "up" : "down");
    }
}