/**
 * @file ssd1306_oled.c
 * @author xushenghao
 * @brief SSD1306 OLED display driver
 * @version 0.1
 * @note PB13-SCK PB12-SDA
 */
#include "ssd1306_oled.h"

#include "ssd1306_oled.h"

static i2c_t *ssd1306_oled;
static uint8_t buffer[SSD1306_WIDTH * SSD1306_HEIGHT / 8]; // 定义屏幕缓冲区

static void ssd1306_write_command(uint8_t command)
{
    uint8_t data[2];
    data[0] = SSD1306_CMD_SET_LOW_COLUMN; // Co = 0, D/C# = 0
    data[1] = command;
    ssd1306_oled->interface.start(ssd1306_oled);
    ssd1306_oled->interface.write_byte(ssd1306_oled, SSD1306_I2C_ADDRESS);
    ssd1306_oled->interface.wait_ack(ssd1306_oled);
    ssd1306_oled->interface.write_byte(ssd1306_oled, data[0]);
    ssd1306_oled->interface.wait_ack(ssd1306_oled);
    ssd1306_oled->interface.write_byte(ssd1306_oled, data[1]);
    ssd1306_oled->interface.wait_ack(ssd1306_oled);
    ssd1306_oled->interface.stop(ssd1306_oled);
}

static void ssd1306_write_data(uint8_t data)
{
    uint8_t buffer[2];
    buffer[0] = SSD1306_CMD_SET_START_LINE; // Co = 0, D/C# = 1
    buffer[1] = data;
    ssd1306_oled->interface.start(ssd1306_oled);
    ssd1306_oled->interface.write_byte(ssd1306_oled, SSD1306_I2C_ADDRESS);
    ssd1306_oled->interface.wait_ack(ssd1306_oled);
    ssd1306_oled->interface.write_byte(ssd1306_oled, buffer[0]);
    ssd1306_oled->interface.wait_ack(ssd1306_oled);
    ssd1306_oled->interface.write_byte(ssd1306_oled, buffer[1]);
    ssd1306_oled->interface.wait_ack(ssd1306_oled);
    ssd1306_oled->interface.stop(ssd1306_oled);
}

static void ssd1306_test(void)
{
}

void ssd1306_init(void)
{
    i2c_gpio_group_t gpios;
    gpios.scl = gpio_create(SSD1306_SCK_PORT, SSD1306_SCK_PIN);
    gpios.sda = gpio_create(SSD1306_SDA_PORT, SSD1306_SDA_PIN);

    ssd1306_oled = i2c_create(gpios, 0);

    ssd1306_write_command(SSD1306_CMD_DISPLAY_OFF);
    ssd1306_write_command(SSD1306_CMD_SET_DISPLAY_CLOCK_DIV);
    ssd1306_write_command(0x80);
    ssd1306_write_command(SSD1306_CMD_SET_MULTIPLEX);
    ssd1306_write_command(SSD1306_HEIGHT - 1);
    ssd1306_write_command(SSD1306_CMD_SET_DISPLAY_OFFSET);
    ssd1306_write_command(0x00);
    ssd1306_write_command(SSD1306_CMD_SET_START_LINE | 0x00);
    ssd1306_write_command(SSD1306_CMD_CHARGE_PUMP);
    ssd1306_write_command(0x14);
    ssd1306_write_command(SSD1306_CMD_MEMORY_MODE);
    ssd1306_write_command(0x00);
    ssd1306_write_command(SSD1306_CMD_SEG_REMAP | 0x01);
    ssd1306_write_command(SSD1306_CMD_COM_SCAN_DEC);
    ssd1306_write_command(SSD1306_CMD_SET_COM_PINS);
    ssd1306_write_command(0x12);
    ssd1306_write_command(SSD1306_CMD_SET_CONTRAST);
    ssd1306_write_command(0xCF);
    ssd1306_write_command(SSD1306_CMD_SET_PRECHARGE);
    ssd1306_write_command(0xF1);
    ssd1306_write_command(SSD1306_CMD_SET_VCOM_DETECT);
    ssd1306_write_command(0x40);
    ssd1306_write_command(SSD1306_CMD_DISPLAY_ALL_ON_RESUME);
    ssd1306_write_command(SSD1306_CMD_NORMAL_DISPLAY);
    ssd1306_write_command(SSD1306_CMD_DISPLAY_ON);

    ssd1306_test();
}

void ssd1306_display_on(void)
{
    ssd1306_write_command(SSD1306_CMD_DISPLAY_ON);
}

void ssd1306_display_off(void)
{
    ssd1306_write_command(SSD1306_CMD_DISPLAY_OFF);
}

void ssd1306_clear(void)
{
    for (uint16_t i = 0; i < SSD1306_WIDTH * SSD1306_HEIGHT / 8; i++)
    {
        ssd1306_write_data(0x00);
    }
}

/**
 * @brief 在SSD1306屏幕上绘制一个像素点
 *
 * 在SSD1306 OLED显示屏上绘制一个像素点，如果指定位置超出屏幕范围，则不执行任何操作。
 *
 * @param x 像素点的x坐标
 * @param y 像素点的y坐标
 * @param color 像素点的颜色，非零值表示绘制像素点，零值表示清除像素点
 */
void ssd1306_draw_pixel(uint8_t x, uint8_t y, uint8_t color)
{
    if (x >= SSD1306_WIDTH || y >= SSD1306_HEIGHT)
    {
        return;
    }

    if (color)
    {
        buffer[x + (y / 8) * SSD1306_WIDTH] |= (1 << (y % 8));
    }
    else
    {
        buffer[x + (y / 8) * SSD1306_WIDTH] &= ~(1 << (y % 8));
    }
}

/**
 * @brief 更新SSD1306 OLED显示屏的内容
 *
 * 此函数将缓冲区中的数据写入SSD1306 OLED显示屏，从而更新显示内容。
 *
 * 首先，通过发送命令设置列地址和页地址，然后将缓冲区中的数据逐行写入显示屏。
 *
 * @note 在调用此函数之前，需要将需要显示的数据写入缓冲区。
 */
void ssd1306_update_screen(void)
{
    for (uint8_t i = 0; i < SSD1306_HEIGHT / 8; i++)
    {
        ssd1306_write_command(SSD1306_CMD_COLUMN_ADDR);
        ssd1306_write_command(0);
        ssd1306_write_command(SSD1306_WIDTH - 1);
        ssd1306_write_command(SSD1306_CMD_PAGE_ADDR);
        ssd1306_write_command(i);
        ssd1306_write_command(i);

        for (uint8_t j = 0; j < SSD1306_WIDTH; j++)
        {
            ssd1306_write_data(buffer[j + i * SSD1306_WIDTH]);
        }
    }
}