//阅读器应用

#include "stdio.h"

#include "sys.h"
#include "systick.h"

#include "key.h"
#include "lcd.h"

#include "GameEngine.h"
#include "SD.h"

#include "APP_Reader.h"

/**************************************** 私有定义 ****************************************/

typedef struct
{
    FSIZE_t page_ptr;
    uint32_t page_size;
} Page; //页结构定义

typedef struct
{
    uint8_t font_size;
    uint32_t page_num;
    uint32_t page_amount;
} Save; //存档结构定义

/*****************************************************************************************/

/**************************************** 全局变量 ****************************************/

FIL file;          //文件
char filename[32]; //文件名
char filepath[32]; //文件路径

FIL page_file;          //分页文件
char page_filepath[32]; //分页文件名
char page_filename[32]; //分页文件路径

FIL save_file;          //存档文件
char save_filepath[32]; //存档文件名
char save_filename[32]; //存档文件路径

uint32_t page_amount = 1;            //页数
uint8_t current_font_size = FONT_24; //当前字体设置
uint32_t current_page = 1;           //当前页码

/*****************************************************************************************/

/**************************************** 私有函数 ****************************************/

uint8_t APP_Reader_ReadPage(uint8_t font_size, uint32_t page_num);
uint8_t APP_Reader_SplitPages(uint8_t font_size);
uint8_t APP_Reader_Menu(void);
uint8_t APP_Reader_SaveWrite(void);
uint8_t APP_Reader_SaveRead(void);
void APP_Reader_Msg(uint8_t *head, uint8_t *content);
void APP_Reader_Msg_NoBlock(uint8_t *head, uint8_t *content);

/*****************************************************************************************/

/**
  * @brief  启动阅读器
  */
void APP_Reader_Launcher(void)
{
    //GUI 选取文件
    uint8_t ret;
    if ((ret = SD_SelectFile(filename, "txt")) != SD_OK)
    {
        if (ret == SD_ERROR)
            APP_Reader_Msg("警告", "选取文件出错！\n\n请按任意键返回");

        return;
    }

    SD_GetPath(filepath, filename);

    //打开文件
    if (f_open(&file, filepath, FA_OPEN_EXISTING | FA_READ) != FR_OK)
    {
        APP_Reader_Msg("警告", "打开文件出错！\n\n请按任意键返回");

        return;
    }

    //读存档
    uint8_t is_saved = 0;
    if (APP_Reader_SaveRead() == 0)
        is_saved = 1;

    uint32_t save_page_amount = page_amount;

    //分页
    if (APP_Reader_SplitPages(current_font_size) != 0)
    {
        APP_Reader_Msg("警告", "分页出错！\n\n请按任意键返回");

        return;
    }

    if (is_saved == 0 || save_page_amount != page_amount)
        current_page = 1;

    //开始阅读
    f_open(&page_file, page_filepath, FA_OPEN_EXISTING | FA_READ); //打开分页文件
    while (1)
    {
        GE_Draw_ClrAll(WHITE);

        if (APP_Reader_ReadPage(current_font_size, current_page) != 0)
        {
            GE_Draw_ClrAll(WHITE);
            APP_Reader_Msg("警告", "发生错误！\n\n请按任意键返回");

            return;
        }

        switch (KEY_GetKeyWait())
        {
        case JOY_L_UP: //设置菜单
        {
            if (APP_Reader_Menu() != 0)
                return;
        }
        break;

        case JOY_D_DOWN: //向后翻页
        {
            if (current_page == page_amount)
                APP_Reader_Msg("提示", "已到最后一页！");
            else
                current_page++;
        }
        break;

        case JOY_U_DOWN: //向前翻页
        {
            if (current_page == 1)
                APP_Reader_Msg("提示", "已到第一页！");
            else
                current_page--;
        }
        }
    }
}

/**
  * @brief  显示某一页
  * @param  font_size: 字体大小
  * @param  page_num: 页码，从 1 开始
  * @retval 成功返回 0，失败返回 1
  */
uint8_t APP_Reader_ReadPage(uint8_t font_size, uint32_t page_num)
{
    FRESULT f_res;
    uint32_t br;
    uint32_t page_br;
    Page page;

    //读分页信息
    f_res = f_lseek(&page_file, (page_num - 1) * sizeof(Page));
    f_res = f_read(&page_file, &page, sizeof(Page), &page_br);

    //读取文件
    uint8_t buffer[1500];

    f_res = f_lseek(&file, page.page_ptr);
    f_res = f_read(&file, buffer, page.page_size, &br);

    if (f_res != FR_OK)
        return 1;

    *((uint8_t *)buffer + page.page_size) = '\0';

    GE_Font_Print(0, 0, BORDER_MAX, BORDER_MAX, font_size, BLACK, WHITE, TRUE, buffer);

    GE_Font_Print(
        1,
        223,
        BORDER_MAX,
        BORDER_MAX,
        FONT_16,
        BLUE,
        WHITE,
        TRUE,
        "页数:%d/%d  %.1f%%",
        page_num,
        page_amount,
        (float)page_num / (float)page_amount * 100.0);

    GE_Draw_Disp();

    return 0;
}

/**
  * @brief  对文本文件分页
  * @param  font_size: 字体大小
  * @retval 成功返回 0，失败返回 1
  */
uint8_t APP_Reader_SplitPages(uint8_t font_size)
{
    APP_Reader_Msg_NoBlock("提示", "正在分页中...\n\n请稍等");

    uint32_t br;
    FRESULT f_res;
    char ch;
    uint8_t x, y;
    Page page;
    FSIZE_t fptr = 0;

    uint32_t page_bw;

    uint8_t x_max, y_max;
    if (font_size == FONT_16)
    {
        x_max = 40;
        y_max = 13;
    }
    else
    {
        x_max = 26;
        y_max = 9;
    }

    strcpy(page_filename, filename);
    strcat(page_filename, ".page");

    SD_GetPath(page_filepath, page_filename);

    f_res = f_open(&page_file, page_filepath, FA_CREATE_ALWAYS | FA_WRITE);

    page_amount = 1;
    f_lseek(&file, 0);
    page.page_size = 0;

    while (1)
    {
        x = 0;
        y = 0;

        while (1)
        {
            if (f_res != FR_OK)
                return 1;

            f_res = f_read(&file, &ch, 1, &br); //读一个字符
            page.page_size++;

            if (br == 0) //分页完毕
            {
                page.page_ptr = fptr;
                f_res = f_write(&page_file, &page, sizeof(Page), &page_bw);

                f_res = f_close(&page_file);

                if (f_res != FR_OK)
                    return 1;
                else
                    return 0;
            }

            if (ch <= 0x80) //ASCII 字符
            {
                if (ch == '\r' || ch == '\0') //忽略的字符
                    continue;

                if ((x + 1 > x_max) || (ch == '\n'))
                {
                    x = 0;
                    y++;

                    if (y + 1 > y_max)
                    {
                        if (ch != '\n')
                            f_res = f_lseek(&file, file.fptr - 1);

                        page.page_size--;
                        break;
                    }
                }

                if (ch != '\n')
                    x++;
            }
            else //GBK 字符
            {
                f_res = f_lseek(&file, file.fptr + 1);
                page.page_size++;

                if (x + 2 > x_max)
                {
                    x = 0;
                    y++;

                    if (y + 1 > y_max)
                    {
                        f_res = f_lseek(&file, file.fptr - 2);
                        page.page_size -= 2;
                        break;
                    }
                }

                x += 2;
            }
        }

        page_amount++;                                              //页数增加
        page.page_ptr = fptr;                                       //本页起始指针
        f_res = f_write(&page_file, &page, sizeof(Page), &page_bw); //写入分页文件
        page.page_size = 0;                                         //页大小归零
        fptr = file.fptr;                                           //下页起始指针
    }
}

/**
  * @brief  设置菜单
  * @retval 返回阅读器返回 0，结束阅读返回 1
  */
uint8_t APP_Reader_Menu(void)
{
    uint8_t content[3][GE_GUI_MENUBOX_CONTENT_LEN] = {"字体设置", "退出阅读器", "返回"};

    GE_Draw_Fill(50, 50, 220, 140, WHITE);
    switch (GE_GUI_MenuBox(50, 50, 220, 140, "菜单", 3, content, NULL))
    {
    case 0: //返回
    {
        KEY_ClearKey();
    }
    break;

    case 1: //字体设置
    {
        GE_Draw_Fill(50, 50, 220, 140, WHITE);

        uint8_t content[2][GE_GUI_MENUBOX_CONTENT_LEN] = {"大号字体", "小号字体"};
        if (GE_GUI_MenuBox(50, 50, 220, 140, "字体设置", 2, content, NULL) == 1)
        {
            if (current_font_size == FONT_24)
            {
                APP_Reader_Msg("提示", "您正在使用大号字体！");
                current_page--;
            }
            else
            {
                float read_pos = (float)current_page / (float)page_amount;
                current_font_size = FONT_24;
                f_close(&page_file);
                APP_Reader_SplitPages(current_font_size);
                f_open(&page_file, page_filepath, FA_OPEN_EXISTING | FA_READ);
                current_page = (float)page_amount * read_pos;
            }
        }
        else
        {
            if (current_font_size == FONT_16)
            {
                APP_Reader_Msg("提示", "您正在使用小号字体！");
                current_page--;
            }
            else
            {
                float read_pos = (float)current_page / (float)page_amount;
                current_font_size = FONT_16;
                f_close(&page_file);
                APP_Reader_SplitPages(current_font_size);
                f_open(&page_file, page_filepath, FA_OPEN_EXISTING | FA_READ);
                current_page = (float)page_amount * read_pos;
            }
        }
    }
    break;

    case 2: //退出
    {
        //关闭文件
        f_close(&page_file);
        f_close(&file);

        APP_Reader_SaveWrite();

        return 1;
    }
    break;

    case 3: //返回
    {
    }
    }

    return 0;
}

/**
  * @brief  读存档
  * @retval 有存档返回 0，无存档返回 1
  */
uint8_t APP_Reader_SaveRead(void)
{
    uint32_t save_br;
    Save save;

    strcpy(save_filename, filename);
    strcat(save_filename, ".save");

    SD_GetPath(save_filepath, save_filename);

    if (f_open(&save_file, save_filepath, FA_OPEN_EXISTING | FA_READ) != FR_OK ||
        f_read(&save_file, &save, sizeof(Save), &save_br) != FR_OK)
    {
        f_close(&save_file);

        return 1;
    }

    f_close(&save_file);

    if (save.font_size == FONT_16)
        current_font_size = FONT_16;
    else if (save.font_size == FONT_24)
        current_font_size = FONT_24;
    else
        return 1;

    current_page = save.page_num;
    page_amount = save.page_amount;

    return 0;
}

/**
  * @brief  写存档
  * @retval 成功返回 0，失败返回 1
  */
uint8_t APP_Reader_SaveWrite(void)
{
    uint32_t save_bw;
    Save save;

    save.font_size = current_font_size;
    save.page_num = current_page;
    save.page_amount = page_amount;

    strcpy(save_filename, filename);
    strcat(save_filename, ".save");

    SD_GetPath(save_filepath, save_filename);
    f_open(&save_file, save_filepath, FA_CREATE_ALWAYS | FA_WRITE);
    f_write(&save_file, &save, sizeof(Save), &save_bw);
    f_close(&save_file);

    return 0;
}

/**
  * @brief  消息框，任意键按下后退出
  * @param  head: 标题
  * @param  content: 内容
  */
void APP_Reader_Msg(uint8_t *head, uint8_t *content)
{
    GE_Draw_Fill(60, 75, 200, 90, WHITE);
    GE_GUI_MsgBox(60, 75, 200, 90, head, content, NULL);
    KEY_WaitKey(JOY_L);
}

/**
  * @brief  消息框，任意键按下后退出
  * @param  head: 标题
  * @param  content: 内容
  */
void APP_Reader_Msg_NoBlock(uint8_t *head, uint8_t *content)
{
    GE_Draw_Fill(60, 75, 200, 90, WHITE);
    GE_GUI_MsgBox(60, 75, 200, 90, head, content, NULL);
}