#include "Power.h"
#include <Tactility/Logger.h>
#include <esp_adc/adc_oneshot.h>
#include <esp_adc/adc_cali.h>
#include <esp_adc/adc_cali_scheme.h>
#include <freertos/FreeRTOS.h>
#include <freertos/task.h>

static const auto* TAG = "ES3C28P_Power";

// HW: BAT+ -> R14 200K + R15 200K -> GND => BAT_ADC middle, 2x divider, to GPIO9 ADC1_CH8
// Charger TP4054 CHRG pin only drives LED, not connected to ESP32 GPIO.
// So we infer charging by voltage behavior: rising trend and high voltage.

class Es3c28pPower final : public tt::hal::power::PowerDevice {
public:
    Es3c28pPower() {
        adc_oneshot_unit_init_cfg_t init_cfg = {
            .unit_id = ADC_UNIT_1,
            .clk_src = ADC_RTC_CLK_SRC_DEFAULT,
            .ulp_mode = ADC_ULP_MODE_DISABLE,
        };
        if (adc_oneshot_new_unit(&init_cfg, &adc_handle) != ESP_OK) {
            ESP_LOGE(TAG, "ADC unit init failed");
            return;
        }
        adc_oneshot_chan_cfg_t chan_cfg = {
            .atten = ADC_ATTEN_DB_12,
            .bitwidth = ADC_BITWIDTH_12,
        };
        if (adc_oneshot_config_channel(adc_handle, ADC_CHANNEL_8, &chan_cfg) != ESP_OK) {
            ESP_LOGE(TAG, "ADC channel config failed");
            adc_oneshot_del_unit(adc_handle);
            adc_handle = nullptr;
            return;
        }
        adc_cali_curve_fitting_config_t cali_cfg = {
            .unit_id = ADC_UNIT_1,
            .atten = ADC_ATTEN_DB_12,
            .bitwidth = ADC_BITWIDTH_12,
        };
        if (adc_cali_create_scheme_curve_fitting(&cali_cfg, &cali_handle) != ESP_OK) {
            ESP_LOGW(TAG, "ADC cali scheme failed");
            cali_handle = nullptr;
        }
        ESP_LOGI(TAG, "Battery ADC GPIO9 ADC1_CH8, 2x divider, cali %s", cali_handle ? "OK" : "none");
    }

    ~Es3c28pPower() override {
        if (cali_handle) adc_cali_delete_scheme_curve_fitting(cali_handle);
        if (adc_handle) adc_oneshot_del_unit(adc_handle);
    }

    std::string getName() const override { return "ES3C28P Power"; }
    std::string getDescription() const override { return "Battery GPIO9 ADC1_CH8 + TP4054 inferred charging"; }

    bool supportsMetric(MetricType type) const override {
        switch (type) {
            case MetricType::BatteryVoltage:
            case MetricType::ChargeLevel:
            case MetricType::IsCharging:
                return adc_handle != nullptr;
            default: return false;
        }
    }

    bool getMetric(MetricType type, MetricData& data) override {
        if (!adc_handle) return false;

        int raw = 0;
        int mv = 0;
        if (adc_oneshot_read(adc_handle, ADC_CHANNEL_8, &raw) != ESP_OK) return false;
        if (cali_handle) {
            if (adc_cali_raw_to_voltage(cali_handle, raw, &mv) != ESP_OK) return false;
        } else {
            mv = (raw * 3300) / 4095;
        }
        int vbat_mv = mv * 2; // 200K/200K divider

        // Track voltage trend for charging detection
        const int now_ms = xTaskGetTickCount() * portTICK_PERIOD_MS;
        if (last_read_ms == 0) {
            last_vbat_mv = vbat_mv;
            last_read_ms = now_ms;
        }

        // Update trend every 2 seconds to avoid noise
        if (now_ms - last_read_ms > 2000) {
            // If voltage increased by at least 10mV in 2s, likely charging
            if (vbat_mv > last_vbat_mv + 10) {
                rising_count++;
                falling_count = 0;
            } else if (vbat_mv < last_vbat_mv - 10) {
                falling_count++;
                rising_count = 0;
                if (falling_count > 3) is_charging_trend = false;
            }
            last_vbat_mv = vbat_mv;
            last_read_ms = now_ms;
        }

        switch (type) {
            case MetricType::BatteryVoltage:
                data.valueAsUint32 = (uint32_t)vbat_mv;
                return true;
            case MetricType::ChargeLevel: {
                uint8_t pct;
                if (vbat_mv <= 2500) pct = 0;
                else if (vbat_mv >= 4200) pct = 100;
                else pct = (uint8_t)((vbat_mv - 2500) / 17);
                data.valueAsUint8 = pct;
                return true;
            }
            case MetricType::IsCharging: {
                // Cases:
                // 1. No battery / wall powered: vbat <500mV or >5000mV (VBUS via MOSFET) => charging true
                if (vbat_mv < 500 || vbat_mv > 5000) {
                    data.valueAsBool = true;
                    is_charging_trend = true;
                    return true;
                }
                // 2. High voltage near full with charger attached: >=4150mV => charging (charger holds at 4.2V)
                if (vbat_mv >= 4150) {
                    data.valueAsBool = true;
                    is_charging_trend = true;
                    return true;
                }
                // 3. Rising trend indicates charging
                if (rising_count >= 2) {
                    is_charging_trend = true;
                }
                // 4. If previously charging and voltage still >=4000, keep charging until drop
                if (is_charging_trend && vbat_mv >= 4000) {
                    data.valueAsBool = true;
                    return true;
                }
                data.valueAsBool = is_charging_trend;
                return true;
            }
            default: return false;
        }
    }

private:
    adc_oneshot_unit_handle_t adc_handle = nullptr;
    adc_cali_handle_t cali_handle = nullptr;
    int last_vbat_mv = 0;
    int last_read_ms = 0;
    int rising_count = 0;
    int falling_count = 0;
    bool is_charging_trend = false;
};

std::shared_ptr<tt::hal::power::PowerDevice> createPower() {
    return std::make_shared<Es3c28pPower>();
}