#include "board_input.h"
#include "powerpod.h"
#include "driver/gpio.h"
#include "esp_adc/adc_oneshot.h"
#include "esp_log.h"
#include "freertos/FreeRTOS.h"
#include "freertos/idf_additions.h"
#include "freertos/queue.h"
#include <string.h>

static const char *TAG_BTN = "[BTN]";
static const char *TAG_LIPO = "[LIPO]";

#define LIPO_SAMPLE_INTERVAL_MS 10000
#define BUTTON_QUEUE_LEN 4
#define BUTTON_DEBOUNCE_MS 80
#define LIPO_ADC_FULL_SCALE_MV 3300
#define LIPO_ADC_MAX_RAW 4095

static QueueHandle_t s_button_queue;
static adc_oneshot_unit_handle_t s_adc;
static bool s_lipo1_ok;
static bool s_lipo2_ok;
static adc_channel_t s_lipo1_ch;
static adc_channel_t s_lipo2_ch;

static esp_err_t adc_init_channel(int gpio, adc_channel_t *out_ch, bool *out_ok) {
  adc_unit_t unit;
  esp_err_t err = adc_oneshot_io_to_channel(gpio, &unit, out_ch);
  if (err != ESP_OK) {
    ESP_LOGW(TAG_LIPO, "GPIO%d not an ADC channel: %s", gpio, esp_err_to_name(err));
    *out_ok = false;
    return err;
  }
  if (unit != ADC_UNIT_1) {
    ESP_LOGW(TAG_LIPO, "GPIO%d on ADC unit %d (expected ADC1)", gpio, (int)unit);
  }
  adc_oneshot_chan_cfg_t chan_cfg = {
      .atten = ADC_ATTEN_DB_12,
      .bitwidth = ADC_BITWIDTH_DEFAULT,
  };
  err = adc_oneshot_config_channel(s_adc, *out_ch, &chan_cfg);
  if (err != ESP_OK) {
    ESP_LOGW(TAG_LIPO, "ADC config GPIO%d failed: %s", gpio, esp_err_to_name(err));
    *out_ok = false;
    return err;
  }
  *out_ok = true;
  return ESP_OK;
}

static uint32_t raw_to_mv(int raw) {
  if (raw < 0) {
    return 0;
  }
  return (uint32_t)((raw * LIPO_ADC_FULL_SCALE_MV) / LIPO_ADC_MAX_RAW);
}

static void sample_one_channel(adc_channel_t ch, bool ok, uint32_t *mv_out,
                               bool *valid_out) {
  *valid_out = false;
  *mv_out = 0;
  if (!ok || s_adc == NULL) {
    return;
  }
  int raw = 0;
  if (adc_oneshot_read(s_adc, ch, &raw) == ESP_OK) {
    *valid_out = true;
    *mv_out = raw_to_mv(raw);
  }
}

void board_input_read_lipo(board_lipo_reading_t *out) {
  if (out == NULL) {
    return;
  }
  memset(out, 0, sizeof(*out));
  sample_one_channel(s_lipo1_ch, s_lipo1_ok, &out->lipo1_mv, &out->lipo1_valid);
  sample_one_channel(s_lipo2_ch, s_lipo2_ok, &out->lipo2_mv, &out->lipo2_valid);
}

static void lipo_monitor_task(void *param) {
  (void)param;

  ESP_LOGI(TAG_LIPO, "monitor task (interval %d ms)", LIPO_SAMPLE_INTERVAL_MS);

  while (1) {
    board_lipo_reading_t reading;
    board_input_read_lipo(&reading);

    ESP_LOGI(TAG_LIPO,
             "LIPO1 GPIO%d %s %lu mV  LIPO2 GPIO%d %s %lu mV",
             V_LIPO_1_GPIO, reading.lipo1_valid ? "ok" : "n/a",
             (unsigned long)reading.lipo1_mv, V_LIPO_2_GPIO,
             reading.lipo2_valid ? "ok" : "n/a",
             (unsigned long)reading.lipo2_mv);

    vTaskDelay(pdMS_TO_TICKS(LIPO_SAMPLE_INTERVAL_MS));
  }
}

static void IRAM_ATTR button_isr(void *arg) {
  (void)arg;
  uint8_t one = 1;
  BaseType_t wake = pdFALSE;
  if (s_button_queue != NULL) {
    xQueueSendFromISR(s_button_queue, &one, &wake);
    if (wake) {
      portYIELD_FROM_ISR();
    }
  }
}

static void button_task(void *param) {
  (void)param;
  uint8_t evt;

  while (1) {
    if (xQueueReceive(s_button_queue, &evt, portMAX_DELAY) != pdTRUE) {
      continue;
    }
    vTaskDelay(pdMS_TO_TICKS(BUTTON_DEBOUNCE_MS));
    if (gpio_get_level(TASTER_GPIO) == 0) {
      ESP_LOGI(TAG_BTN, "pressed (GPIO%d)", TASTER_GPIO);
    }
  }
}

static esp_err_t init_button(void) {
  if (V_LIPO_2_GPIO == TASTER_GPIO) {
    ESP_LOGW(TAG_BTN,
             "GPIO%d shared with V_LIPO_2 — button only, no ADC on that pin",
             TASTER_GPIO);
  }

  s_button_queue = xQueueCreate(BUTTON_QUEUE_LEN, sizeof(uint8_t));
  if (s_button_queue == NULL) {
    return ESP_ERR_NO_MEM;
  }

  gpio_config_t cfg = {
      .pin_bit_mask = 1ULL << TASTER_GPIO,
      .mode = GPIO_MODE_INPUT,
      .pull_up_en = GPIO_PULLUP_ENABLE,
      .pull_down_en = GPIO_PULLDOWN_DISABLE,
      .intr_type = GPIO_INTR_NEGEDGE,
  };
  ESP_ERROR_CHECK(gpio_config(&cfg));

  esp_err_t err = gpio_install_isr_service(0);
  if (err != ESP_OK && err != ESP_ERR_INVALID_STATE) {
    return err;
  }

  err = gpio_isr_handler_add(TASTER_GPIO, button_isr, NULL);
  if (err != ESP_OK) {
    return err;
  }

  if (xTaskCreate(button_task, "btn", 2048, NULL, 2, NULL) != pdPASS) {
    return ESP_ERR_NO_MEM;
  }

  ESP_LOGI(TAG_BTN, "ready GPIO%d (active low)", TASTER_GPIO);
  return ESP_OK;
}

static esp_err_t init_lipo_adc(void) {
  adc_oneshot_unit_init_cfg_t init_cfg = {
      .unit_id = ADC_UNIT_1,
  };
  esp_err_t err = adc_oneshot_new_unit(&init_cfg, &s_adc);
  if (err != ESP_OK) {
    ESP_LOGW(TAG_LIPO, "ADC init failed: %s", esp_err_to_name(err));
    return err;
  }

  adc_init_channel(V_LIPO_1_GPIO, &s_lipo1_ch, &s_lipo1_ok);

  if (V_LIPO_2_GPIO == TASTER_GPIO) {
    ESP_LOGW(TAG_LIPO, "LIPO2 on GPIO%d skipped (button uses same pin)",
             V_LIPO_2_GPIO);
    s_lipo2_ok = false;
  } else {
    adc_init_channel(V_LIPO_2_GPIO, &s_lipo2_ch, &s_lipo2_ok);
  }

  if (!s_lipo1_ok && !s_lipo2_ok) {
    adc_oneshot_del_unit(s_adc);
    s_adc = NULL;
    return ESP_FAIL;
  }

  if (xTaskCreate(lipo_monitor_task, "lipo_mon", 3072, NULL, 1, NULL) != pdPASS) {
    return ESP_ERR_NO_MEM;
  }

  return ESP_OK;
}

esp_err_t board_input_init(void) {
  esp_err_t err = init_button();
  if (err != ESP_OK) {
    ESP_LOGW(TAG_BTN, "init failed: %s", esp_err_to_name(err));
  }

  err = init_lipo_adc();
  if (err != ESP_OK) {
    ESP_LOGW(TAG_LIPO, "init failed: %s", esp_err_to_name(err));
  }

  return ESP_OK;
}