#include <inttypes.h>  // for PRIu32
#include "evse_state.h"
#include "evse_api.h"
#include "evse_limits.h"
#include "evse_meter.h"
#include "evse_session.h"
#include "esp_log.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_err.h"
#include "nvs.h"

// ========================
// Concurrency protection
// ========================

static portMUX_TYPE evse_mux = portMUX_INITIALIZER_UNLOCKED;

// ========================
// Runtime state (volatile)
// ========================

static bool     limit_reached       = false;
static uint32_t consumption_limit   = 0;   // Energy limit in Wh
static uint32_t charging_time_limit = 0;   // Time limit in seconds
static uint16_t under_power_limit   = 0;   // Minimum acceptable power in W

// ========================
// Limit status flag
// ========================

bool evse_get_limit_reached(void)
{
    bool val;
    portENTER_CRITICAL(&evse_mux);
    val = limit_reached;
    portEXIT_CRITICAL(&evse_mux);
    return val;
}

void evse_set_limit_reached(bool v)
{
    portENTER_CRITICAL(&evse_mux);
    limit_reached = v;
    portEXIT_CRITICAL(&evse_mux);
}

bool evse_is_limit_reached(void)
{
    return evse_get_limit_reached();
}

// ========================
// Runtime limit accessors
// ========================

uint32_t evse_get_consumption_limit(void)
{
    uint32_t val;
    portENTER_CRITICAL(&evse_mux);
    val = consumption_limit;
    portEXIT_CRITICAL(&evse_mux);
    return val;
}

void evse_set_consumption_limit(uint32_t value)
{
    bool changed = false;

    portENTER_CRITICAL(&evse_mux);
    if (consumption_limit != value)
    {
        consumption_limit = value;
        changed = true;
    }
    portEXIT_CRITICAL(&evse_mux);

    if (!changed)
        return;

    nvs_handle_t h;
    esp_err_t err = nvs_open("evse", NVS_READWRITE, &h);
    if (err == ESP_OK)
    {
        err = nvs_set_u32(h, "def_cons_lim", value);
        if (err == ESP_OK)
            err = nvs_commit(h);
        nvs_close(h);

        if (err != ESP_OK)
        {
            ESP_LOGE("EVSE_LIMITS",
                     "Failed to persist consumption limit (%" PRIu32 " Wh): %s",
                     value, esp_err_to_name(err));
        }
    }
    else
    {
        ESP_LOGE("EVSE_LIMITS",
                 "Failed to open NVS for consumption limit: %s",
                 esp_err_to_name(err));
    }
}

uint32_t evse_get_charging_time_limit(void)
{
    uint32_t val;
    portENTER_CRITICAL(&evse_mux);
    val = charging_time_limit;
    portEXIT_CRITICAL(&evse_mux);
    return val;
}

void evse_set_charging_time_limit(uint32_t value)
{
    bool changed = false;

    portENTER_CRITICAL(&evse_mux);
    if (charging_time_limit != value)
    {
        charging_time_limit = value;
        changed = true;
    }
    portEXIT_CRITICAL(&evse_mux);

    if (!changed)
        return;

    nvs_handle_t h;
    esp_err_t err = nvs_open("evse", NVS_READWRITE, &h);
    if (err == ESP_OK)
    {
        err = nvs_set_u32(h, "def_ch_time_lim", value);
        if (err == ESP_OK)
            err = nvs_commit(h);
        nvs_close(h);

        if (err != ESP_OK)
        {
            ESP_LOGE("EVSE_LIMITS",
                     "Failed to persist charging time limit (%" PRIu32 " s): %s",
                     value, esp_err_to_name(err));
        }
    }
    else
    {
        ESP_LOGE("EVSE_LIMITS",
                 "Failed to open NVS for charging time limit: %s",
                 esp_err_to_name(err));
    }
}

uint16_t evse_get_under_power_limit(void)
{
    uint16_t val;
    portENTER_CRITICAL(&evse_mux);
    val = under_power_limit;
    portEXIT_CRITICAL(&evse_mux);
    return val;
}

void evse_set_under_power_limit(uint16_t value)
{
    bool changed = false;

    portENTER_CRITICAL(&evse_mux);
    if (under_power_limit != value)
    {
        under_power_limit = value;
        changed = true;
    }
    portEXIT_CRITICAL(&evse_mux);

    if (!changed)
        return;

    nvs_handle_t h;
    esp_err_t err = nvs_open("evse", NVS_READWRITE, &h);
    if (err == ESP_OK)
    {
        err = nvs_set_u16(h, "def_un_pwr_lim", value);
        if (err == ESP_OK)
            err = nvs_commit(h);
        nvs_close(h);

        if (err != ESP_OK)
        {
            ESP_LOGE("EVSE_LIMITS",
                     "Failed to persist under-power limit (%" PRIu32 " W): %s",
                     (uint32_t)value, esp_err_to_name(err));
        }
    }
    else
    {
        ESP_LOGE("EVSE_LIMITS",
                 "Failed to open NVS for under-power limit: %s",
                 esp_err_to_name(err));
    }
}

// ========================
// Limit checking logic
// ========================

void evse_limits_check(void)
{
    // Só faz sentido durante carregamento
    if (!evse_state_is_charging(evse_get_state()))
    {
        return;
    }

    evse_session_t sess;
    if (!evse_session_get(&sess) || !sess.is_current)
    {
        // Sem sessão ativa → nada a fazer
        return;
    }

    bool reached = false;

    // 1) Limite de energia (Wh)
    if (consumption_limit > 0 && sess.energy_wh >= consumption_limit)
    {
        ESP_LOGW("EVSE_LIMITS",
                 "Energy limit reached: %" PRIu32 " Wh ≥ %" PRIu32 " Wh",
                 sess.energy_wh, consumption_limit);
        reached = true;
    }

    // 2) Limite de tempo (s)
    if (charging_time_limit > 0 && sess.duration_s >= charging_time_limit)
    {
        ESP_LOGW("EVSE_LIMITS",
                 "Charging time limit reached: %" PRIu32 " s ≥ %" PRIu32 " s",
                 sess.duration_s, charging_time_limit);
        reached = true;
    }

    // 3) Under-power (potência instantânea)
    uint32_t inst_power = evse_meter_get_instant_power();
    if (under_power_limit > 0 && inst_power < under_power_limit)
    {
        ESP_LOGW("EVSE_LIMITS",
                 "Under-power limit reached: %" PRIu32 " W < %" PRIu32 " W",
                 (uint32_t)inst_power,
                 (uint32_t)under_power_limit);
        reached = true;
    }

    if (reached)
    {
        evse_set_limit_reached(true);
    }
}