/**
 * @file st7305_rlcd.c
 * @brief ST7305 反射式 LCD 驱动实现(纯 C)
 *
 * 移植自微雪官方 custom_lcd_display.cc。
 * 关键逻辑(初始化序列、横屏 LUT、像素打包)100% 保留,
 * 只是把 C++ class 改成模块级全局变量 + 函数。
 */

#include "st7305_rlcd.h"

#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"
#include "esp_heap_caps.h"
#include "driver/gpio.h"

static const char *TAG = "st7305";

/* ===========================================================
 * 模块内部状态(等价于原来 C++ 类的成员变量)
 * =========================================================== */

/* SPI 设备句柄:用 ESP-IDF 的 esp_lcd panel io 框架来管 SPI 通信 */
static esp_lcd_panel_io_handle_t s_io_handle = NULL;

/* 显存:每 8 像素打包成 1 字节,所以显存大小 = W*H/8 = 400*300/8 = 15000 字节。
 * 这个 buffer 放在 PSRAM 里(8MB PSRAM 完全够)。 */
#define DISPLAY_BUFFER_LEN   ((ST7305_RLCD_WIDTH * ST7305_RLCD_HEIGHT) / 8)
static uint8_t *s_disp_buffer = NULL;

/* 横屏 LUT:把 (x,y) 像素坐标映射到 (字节索引, 位掩码)。
 * ST7305 的显存布局很奇怪(2列×4行打包),没有 LUT 的话
 * 每次画一个像素都要重新算一遍位运算,LUT 让它变成 O(1) 查表。
 * 索引方式:pixel_index = x * HEIGHT + y(跟官方一致) */
static uint16_t *s_pixel_index_lut = NULL;   /* 大小: W*H 个 uint16 */
static uint8_t  *s_pixel_bit_lut   = NULL;   /* 大小: W*H 个 uint8  */

/* ===========================================================
 * SPI 底层:发命令 / 发数据
 * 用 esp_lcd panel io 框架,它会自动管 DC 引脚
 *   (DC=0 表示命令, DC=1 表示数据)
 * =========================================================== */
static void send_command(uint8_t cmd)
{
    /* 用 -1 作为 dis_flags 表示"不带参数的命令" */
    esp_lcd_panel_io_tx_param(s_io_handle, cmd, NULL, 0);
}

static void send_data(uint8_t data)
{
    esp_lcd_panel_io_tx_param(s_io_handle, -1, &data, 1);
}

static void send_buffer(uint8_t *data, int len)
{
    esp_lcd_panel_io_tx_color(s_io_handle, -1, data, len);
}

/* ===========================================================
 * 硬件复位(官方 RLCD_Reset 翻译)
 * =========================================================== */
static void hardware_reset(void)
{
    /* RST 引脚高 → 低 → 高 的脉冲,跟官方时序一致 */
    gpio_set_level(ST7305_RLCD_PIN_RST, 1);
    vTaskDelay(pdMS_TO_TICKS(50));
    gpio_set_level(ST7305_RLCD_PIN_RST, 0);
    vTaskDelay(pdMS_TO_TICKS(20));
    gpio_set_level(ST7305_RLCD_PIN_RST, 1);
    vTaskDelay(pdMS_TO_TICKS(50));
}

/* ===========================================================
 * ST7305 初始化序列(官方 RLCD_Init 完整翻译)
 * 这 50+ 条寄存器命令是从微雪官方代码原样复制来的,
 * 不要随便改顺序或值 —— 它们是微雪调好的参数。
 * 每条命令的中文注释参考 ST7305 datasheet 和官方命名。
 * =========================================================== */
static void init_display(void)
{
    /* NVM Load Control - 从非易失存储加载设置 */
    send_command(0xD6);
    send_data(0x17);
    send_data(0x02);

    /* Booster Enable - 使能电荷泵 */
    send_command(0xD1);
    send_data(0x01);

    /* Gate Voltage Control - VGH/VGL 电压 */
    send_command(0xC0);
    send_data(0x11);
    send_data(0x04);

    /* VSHP Setting - 正向源电压(高功耗模式) */
    send_command(0xC1);
    send_data(0x69); send_data(0x69); send_data(0x69); send_data(0x69);

    /* VSLP Setting - 正向源电压(低功耗模式) */
    send_command(0xC2);
    send_data(0x19); send_data(0x19); send_data(0x19); send_data(0x19);

    /* VSHN Setting - 负向源电压(高功耗模式) */
    send_command(0xC4);
    send_data(0x4B); send_data(0x4B); send_data(0x4B); send_data(0x4B);

    /* VSLN Setting - 负向源电压(低功耗模式) */
    send_command(0xC5);
    send_data(0x19); send_data(0x19); send_data(0x19); send_data(0x19);

    /* OSC Setting - 振荡器频率控制 */
    send_command(0xD8);
    send_data(0x80);
    send_data(0xE9);

    /* Frame Rate Control - 帧率 */
    send_command(0xB2);
    send_data(0x02);

    /* Gate EQ Control (High Power Mode) - 更新周期时序 */
    send_command(0xB3);
    send_data(0xE5); send_data(0xF6); send_data(0x05); send_data(0x46);
    send_data(0x77); send_data(0x77); send_data(0x77); send_data(0x77);
    send_data(0x76); send_data(0x45);

    /* Gate EQ Control (Low Power Mode) - 更新周期时序 */
    send_command(0xB4);
    send_data(0x05); send_data(0x46); send_data(0x77); send_data(0x77);
    send_data(0x77); send_data(0x77); send_data(0x76); send_data(0x45);

    /* Gate Timing Control */
    send_command(0x62);
    send_data(0x32); send_data(0x03); send_data(0x1F);

    /* Source EQ Enable */
    send_command(0xB7);
    send_data(0x13);

    /* Gate Line Setting - 门极线数(板子相关)
     * 0x64 = 100,100*3 = 300 行,对应 300 高 */
    send_command(0xB0);
    send_data(0x64);

    /* Sleep Out - 退出睡眠(datasheet 要求 200ms 延时) */
    send_command(0x11);
    vTaskDelay(pdMS_TO_TICKS(200));

    /* Source Voltage Select - 选 VSHP1/VSLP1/VSHN1/VSLN1 */
    send_command(0xC9);
    send_data(0x00);

    /* MADCTL (Memory Data Access Control) - MX=1, DO=1 */
    send_command(0x36);
    send_data(0x48);

    /* 1-bit 单色模式 */
    send_command(0x3A);
    send_data(0x11);

    /* Gamma Mode - 单色 */
    send_command(0xB9);
    send_data(0x20);

    /* Panel Setting - 1-dot 反转,帧反转,隔行 */
    send_command(0xB8);
    send_data(0x29);

    /* Display Inversion On */
    send_command(0x21);

    /* Column Address Set - 板子相关 */
    send_command(0x2A);
    send_data(0x12);
    send_data(0x2A);

    /* Row Address Set - 板子相关 */
    send_command(0x2B);
    send_data(0x00);
    send_data(0xC7);

    /* Tearing Effect Line On */
    send_command(0x35);
    send_data(0x00);

    /* Auto Power Down Control */
    send_command(0xD0);
    send_data(0xFF);

    /* High Power Mode On */
    send_command(0x38);

    /* Display On */
    send_command(0x29);
}

/* ===========================================================
 * 横屏像素 LUT 构造(官方 InitLandscapeLUT 翻译)
 *
 * ST7305 横屏显存布局:每字节装 8 个像素,排列是 2列×4行 的块
 *
 *   一个字节(8 bit)的物理含义:
 *     Bit 7: (row 0, col 0)   Bit 6: (row 0, col 1)
 *     Bit 5: (row 1, col 0)   Bit 4: (row 1, col 1)
 *     Bit 3: (row 2, col 0)   Bit 2: (row 2, col 1)
 *     Bit 1: (row 3, col 0)   Bit 0: (row 3, col 1)
 *
 * 所以给一个逻辑坐标 (x, y),要算出:
 *   1. 它在显存里的字节索引
 *   2. 在该字节里的位掩码
 * 这就是 LUT 干的事,预计算一次,后面画像素就 O(1) 查表。
 * =========================================================== */
static void init_landscape_lut(void)
{
    const uint16_t H4 = ST7305_RLCD_HEIGHT >> 2;   /* 高度方向块数 = 300/4 = 75 */

    for (uint16_t y = 0; y < ST7305_RLCD_HEIGHT; y++) {
        /* y 方向:ST7305 是从下往上扫的,所以要反转 */
        uint16_t inv_y   = ST7305_RLCD_HEIGHT - 1 - y;
        uint16_t block_y = inv_y >> 2;             /* 在哪个 4 行块里 */
        uint8_t  local_y = inv_y & 3;              /* 块内第几行 */

        for (uint16_t x = 0; x < ST7305_RLCD_WIDTH; x++) {
            uint16_t byte_x = x >> 1;              /* 2 列共用 1 字节 */
            uint8_t  local_x = x & 1;              /* 块内第几列 */

            /* 字节索引 = 列块号 * 高度块数 + 行块号 */
            uint32_t buffer_idx = (uint32_t)byte_x * H4 + block_y;
            /* 位掩码:bit 位置 = 7 - (local_y * 2 + local_x) */
            uint8_t  bit_pos = 7 - ((local_y << 1) | local_x);
            uint8_t  bit_mask = (uint8_t)(1u << bit_pos);

            /* LUT 索引方式:x * HEIGHT + y(跟官方一致) */
            uint32_t pixel_idx = (uint32_t)x * ST7305_RLCD_HEIGHT + y;
            s_pixel_index_lut[pixel_idx] = (uint16_t)buffer_idx;
            s_pixel_bit_lut[pixel_idx]   = bit_mask;
        }
    }
}

/* ===========================================================
 * 对外 API 实现
 * =========================================================== */

esp_err_t st7305_rlcd_init(void)
{
    esp_err_t ret;

    ESP_LOGI(TAG, "Step 1: 配置 RST 引脚为输出");
    gpio_config_t gpio_conf = {
        .pin_bit_mask = (1ULL << ST7305_RLCD_PIN_RST),
        .mode         = GPIO_MODE_OUTPUT,
        .pull_up_en   = GPIO_PULLUP_ENABLE,
        .pull_down_en = GPIO_PULLDOWN_DISABLE,
        .intr_type    = GPIO_INTR_DISABLE,
    };
    gpio_config(&gpio_conf);

    ESP_LOGI(TAG, "Step 2: 初始化 SPI 总线 (SPI3, MOSI=%d, SCK=%d)",
             ST7305_RLCD_PIN_MOSI, ST7305_RLCD_PIN_SCK);
    spi_bus_config_t buscfg = {0};
    buscfg.mosi_io_num       = ST7305_RLCD_PIN_MOSI;
    buscfg.miso_io_num       = -1;                 /* 屏幕只写不读,不需要 MISO */
    buscfg.sclk_io_num       = ST7305_RLCD_PIN_SCK;
    buscfg.quadwp_io_num     = -1;
    buscfg.quadhd_io_num     = -1;
    buscfg.max_transfer_sz   = ST7305_RLCD_WIDTH * ST7305_RLCD_HEIGHT;  /* 一次传整屏 */
    ret = spi_bus_initialize(ST7305_RLCD_SPI_HOST, &buscfg, SPI_DMA_CH_AUTO);
    if (ret != ESP_OK) {
        ESP_LOGE(TAG, "SPI 总线初始化失败: %s", esp_err_to_name(ret));
        return ret;
    }

    ESP_LOGI(TAG, "Step 3: 把屏幕挂到 SPI 总线上(用 esp_lcd panel io 框架)");
    esp_lcd_panel_io_spi_config_t io_config = {0};
    io_config.dc_gpio_num       = ST7305_RLCD_PIN_DC;
    io_config.cs_gpio_num       = ST7305_RLCD_PIN_CS;
    io_config.pclk_hz           = ST7305_RLCD_SPI_HZ;
    io_config.lcd_cmd_bits      = 8;
    io_config.lcd_param_bits    = 8;
    io_config.spi_mode          = 0;
    io_config.trans_queue_depth = 7;
    ret = esp_lcd_new_panel_io_spi((esp_lcd_spi_bus_handle_t)ST7305_RLCD_SPI_HOST,
                                   &io_config, &s_io_handle);
    if (ret != ESP_OK) {
        ESP_LOGE(TAG, "panel io 创建失败: %s", esp_err_to_name(ret));
        return ret;
    }

    ESP_LOGI(TAG, "Step 4: 分配显存到 PSRAM (%d 字节)", DISPLAY_BUFFER_LEN);
    s_disp_buffer = (uint8_t *)heap_caps_malloc(DISPLAY_BUFFER_LEN, MALLOC_CAP_SPIRAM);
    if (s_disp_buffer == NULL) {
        ESP_LOGE(TAG, "显存分配失败(PSRAM?)");
        return ESP_ERR_NO_MEM;
    }

    ESP_LOGI(TAG, "Step 5: 分配像素 LUT (index=%dKB, bit=%dKB)",
             (ST7305_RLCD_WIDTH * ST7305_RLCD_HEIGHT * 2) / 1024,
             (ST7305_RLCD_WIDTH * ST7305_RLCD_HEIGHT) / 1024);
    uint32_t total_pixels = (uint32_t)ST7305_RLCD_WIDTH * ST7305_RLCD_HEIGHT;
    s_pixel_index_lut = (uint16_t *)heap_caps_malloc(total_pixels * sizeof(uint16_t),
                                                     MALLOC_CAP_SPIRAM);
    s_pixel_bit_lut   = (uint8_t  *)heap_caps_malloc(total_pixels * sizeof(uint8_t),
                                                     MALLOC_CAP_SPIRAM);
    if (!s_pixel_index_lut || !s_pixel_bit_lut) {
        ESP_LOGE(TAG, "LUT 分配失败(PSRAM?)");
        return ESP_ERR_NO_MEM;
    }

    ESP_LOGI(TAG, "Step 6: 构建横屏 LUT");
    init_landscape_lut();

    ESP_LOGI(TAG, "Step 7: 硬件复位 + 发送 ST7305 初始化序列");
    hardware_reset();
    init_display();

    ESP_LOGI(TAG, "Step 8: 清屏(全白)");
    st7305_rlcd_clear(ST7305_COLOR_WHITE);
    st7305_rlcd_flush();

    ESP_LOGI(TAG, "屏幕初始化完成 ✓");
    return ESP_OK;
}

void st7305_rlcd_set_pixel(int x, int y, uint8_t color)
{
    if (x < 0 || x >= ST7305_RLCD_WIDTH)  return;
    if (y < 0 || y >= ST7305_RLCD_HEIGHT) return;

    /* O(1) 查 LUT */
    uint32_t pixel_idx = (uint32_t)x * ST7305_RLCD_HEIGHT + y;
    uint16_t buffer_idx = s_pixel_index_lut[pixel_idx];
    uint8_t  bit_mask   = s_pixel_bit_lut[pixel_idx];

    uint8_t *p = &s_disp_buffer[buffer_idx];
    if (color == ST7305_COLOR_BLACK) {
        *p &= ~bit_mask;     /* 该位清零 = 像素亮(黑) */
    } else {
        *p |= bit_mask;      /* 该位置 1 = 像素灭(白) */
    }
}

void st7305_rlcd_flush(void)
{
    /* 官方 RLCD_Display:每次刷新都重新设置地址窗口,然后发整屏数据 */
    send_command(0x2A);   /* Column Address Set */
    send_data(0x12);
    send_data(0x2A);

    send_command(0x2B);   /* Page/Row Address Set */
    send_data(0x00);
    send_data(0xC7);

    send_command(0x2C);   /* Memory Write */
    send_buffer(s_disp_buffer, DISPLAY_BUFFER_LEN);
}

void st7305_rlcd_clear(uint8_t color)
{
    memset(s_disp_buffer, color, DISPLAY_BUFFER_LEN);
}

int st7305_rlcd_get_width(void)  { return ST7305_RLCD_WIDTH; }
int st7305_rlcd_get_height(void) { return ST7305_RLCD_HEIGHT; }