#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <linux/fb.h>
#include <linux/spi/spidev.h>
#include "gpio.h"
#include "lcd.h"
#include "elog.h"


#define USE_FB

#define BK_GPIO             98      //PD2
#define DC_GPIO             99      //PD3, 96+3=99
#define RST_GPIO            100     //PD4, 96+4=100

#if 1
    #define LOGD  log_d
    #define LOGE  log_e
#else
    #define LOGD  printf
    #define LOGE  printf
#endif

#define BIT(x)              (1<<x)
#define SWAP16(a)           ((uint16_t)((a<<8)|(a>>8)))

#ifdef USE_FB
    #define DEV_PATH        "/dev/fb0"
    typedef struct fb_fix_screeninfo fb_finfo_t;
    typedef struct fb_var_screeninfo fb_vinfo_t;
#else
    #define DEV_PATH        "/dev/spidev1.0"
#endif


typedef struct {
    int  x;
    int  y;
    int  w;
    int  h;
}lcd_rect_t;
typedef struct {
    int         width;
    int         height;
    int         color;
    int         rotate;

    int         fd;
#ifdef USE_FB
    uint16_t    *buf;
#else
    int         io;
    uint8_t     *buf;
#endif
    
    int         buflen;
}lcd_handle_t;
static lcd_handle_t lcdHandle={0};
static int ssd1309_init(lcd_handle_t *h);
static void ssd1309_refresh(lcd_handle_t *h);

static int lcd_hw_init(lcd_handle_t *h)
{
    h->fd = open(DEV_PATH, O_RDWR);
    if (h->fd < 0) {
        LOGE("___ open %s failed\n", DEV_PATH);
        return -1;
    }
    
#ifdef USE_FB
    fb_vinfo_t vinfo;
    if (ioctl(h->fd, FBIOGET_VSCREENINFO, &vinfo)) {
        LOGE("___ get screen info failed\n");
        return -1;
    }
    h->buflen = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;
    h->buf = (uint16_t *)mmap(0, h->buflen, PROT_READ | PROT_WRITE, MAP_SHARED, h->fd, 0);
    if ((int)h->buf == -1) {
        LOGE("Error: failed to map framebuffer device to memory\n");
        return -1;
    }
    memset(h->buf, 0, h->buflen);
#else
    h->io = gpio_init(DC_GPIO, GPIO_OUT);
    h->buflen = h->width*h->height/8;
    h->buf = (uint8_t*)calloc(1, h->buflen);
    if (!h->buf) {
        LOGE("malloc buffer falied\n");
        return -1;
    }
    
    #if 0
    uint8_t mode = SPI_MODE_0;
    if (ioctl(fd, SPI_IOC_WR_MODE, &mode) == -1) {
        LOGE("Can't set SPI mode\n");
        return -1;
    }
    
    uint32_t speed = 8000000;
    if (ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed) == -1) {
        LOGE("Can't set max speed\n");
        return -1;
    }
    #endif
    
    ssd1309_init(h);
#endif

    return 0;
}
static int lcd_hw_write(lcd_handle_t *h, void *data, int len)
{
    int r;
    struct spi_ioc_transfer tr = {
        .tx_buf = (unsigned long)data,
        .rx_buf = 0,
        .len = len,
        .speed_hz = 8000000,
        .bits_per_word = 8,
    };
 
    r = ioctl(h->fd, SPI_IOC_MESSAGE(1), &tr);
    if (r < 1) {
        LOGE("Can't send spi message");
    }
    
    return 0;
}
static void lcd_write_reg(lcd_handle_t *h, uint8_t reg)
{
#ifndef USE_FB
    gpio_set(h->io, 0);
    lcd_hw_write(h, &reg, 1);
#endif
}
static int ssd1309_reset(void)
{
    int fd = gpio_init(RST_GPIO, GPIO_OUT);
    gpio_set(fd, 0);
    usleep(100*1000);
    gpio_set(fd, 1);
    gpio_deinit(fd);
    return 0;
}
static void ssd1309_on(lcd_handle_t *h, int flag)
{
    if(flag) {
        lcd_write_reg(h,0x8D);
	    lcd_write_reg(h,0x14);
	    lcd_write_reg(h,0xAF);
    }
    else {
        lcd_write_reg(h,0x8D);
	    lcd_write_reg(h,0x10);
	    lcd_write_reg(h,0xAE);
    }

}
static int ssd1309_init(lcd_handle_t *h)
{
    ssd1309_reset();

    lcd_write_reg(h,0xFD);
	lcd_write_reg(h,0x12);
	lcd_write_reg(h,0xAE);//--turn off oled panel
	lcd_write_reg(h,0xd5);//--set display clock divide ratio/oscillator frequency
	lcd_write_reg(h,0xA0);
	lcd_write_reg(h,0xA8);//--set multiplex ratio(1 to 64)
	lcd_write_reg(h,0x3f);//--1/64 duty
	lcd_write_reg(h,0xD3);//-set display offset	Shift Mapping RAM Counter (0x00~0x3F)
	lcd_write_reg(h,0x00);//-not offset
	lcd_write_reg(h,0x40);//--set start line address  Set Mapping RAM Display Start Line (0x00~0x3F)
	lcd_write_reg(h,0xA1);//--Set SEG/Column Mapping     0xa0左右反置 0xa1正常
	lcd_write_reg(h,0xC8);//Set COM/Row Scan Direction   0xc0上下反置 0xc8正常
	lcd_write_reg(h,0xDA);//--set com pins hardware configuration
	lcd_write_reg(h,0x12);
	lcd_write_reg(h,0x81);//--set contrast control register
	lcd_write_reg(h,0x7F);// Set SEG Output Current Brightness
	lcd_write_reg(h,0xD9);//--set pre-charge period
	lcd_write_reg(h,0x82);//Set Pre-Charge as 15 Clocks & Discharge as 1 Clock
	lcd_write_reg(h,0xDB);//--set vcomh
	lcd_write_reg(h,0x34);//Set VCOM Deselect Level
	lcd_write_reg(h,0xA4);// Disable Entire Display On (0xa4/0xa5)
	lcd_write_reg(h,0xA6);// Disable Inverse Display On (0xa6/a7)

    ssd1309_refresh(h);
    ssd1309_on(h,1);
	
	return 0;
}
static void ssd1309_refresh(lcd_handle_t *h)
{
#ifndef USE_FB
	int i,n,offset;
    
	for(i=0;i<8;i++) {
	   lcd_write_reg(h,0xb0+i); 			//设置行起始地址
	   lcd_write_reg(h,0x00);   			//设置低列起始地址
	   lcd_write_reg(h,0x10);   			//设置高列起始地址

       gpio_set(h->io, 1);
       offset = i*128;
	   for(n=0;n<128;n++) {
          lcd_hw_write(h, &h->buf[offset+n], 1);
	   }
  	}
#endif
}
static int lcd_hw_deinit(lcd_handle_t *h)
{
#ifdef USE_FB
    munmap(h->buf, h->buflen);
#else
    gpio_deinit(h->io);
    free(h->buf);
#endif
    close(h->fd);
    
    return 0;
}

static inline int set_point(lcd_handle_t *h, int x, int y, int data)
{
    int pos,bit;

    if(h->rotate==180) {
        x = h->width-1-x;
        y = h->height-1-y;
    }

#ifdef USE_FB
    h->buf[y*h->width+x] = (uint16_t)data;
#else
    pos = y / 8;                                            /* get y page */
    bit = y % 8;                                            /* get y point */
    if (data) {                                             /* if 1  */
        h->buf[pos*h->width+x] |= BIT(bit);         		/* set 1 */
    }
    else {
        h->buf[pos*h->width+x] &= ~BIT(bit);        		/* set 0 */
    }
#endif
	
	return 0;
}
static int get_color_bits(int color)
{
    if(color==COLOR_WB) {
        return 1;
    }
    else if(color==COLOR_RGB8) {
        return 8;
    }
    else if(color==COLOR_RGB565) {
        return 16;
    }
    else {
        return 32;
    }
}

////////////////////////////////////////////////////////////
void lcd_init(int width, int height, int color)
{
    lcd_handle_t *h=&lcdHandle;
    h->width  = width;
    h->height = height;
    h->color  = color;
    h->rotate = 0;

    lcd_hw_init(h);
}

void lcd_deinit(void)
{
    lcd_handle_t *h=&lcdHandle;
    lcd_hw_deinit(h);
}


void lcd_rotate(int rotate)
{
    lcd_handle_t *h=&lcdHandle;

    if(rotate==0 || rotate==180) {
        h->rotate = rotate;
    }
}


int lcd_get_rotate(void)
{
    lcd_handle_t *h=&lcdHandle;
    return h->rotate;
}


void lcd_set_backlight(int on)
{
    lcd_handle_t *h=&lcdHandle;
}


void lcd_fill(int color)
{
    lcd_handle_t *h=&lcdHandle;
    
    lcd_fill_rect(0, 0, h->width, h->height, color);
}


void lcd_draw_line(int x1, int y1, int x2, int y2, int color)
{
    int incx = 0, incy = 0;
    int  delta_x = 0, delta_y = 0;
    int  distance = 0;
    int  t = 0;
    int  x = 0, y = 0;
    int  x_temp = 0, y_temp = 0;
    lcd_handle_t *h=&lcdHandle;

    /* 画斜线（Bresenham算法） */
    delta_x = x2 - x1;
    delta_y = y2 - y1;
    if(delta_x > 0) {
        //斜线(从左到右)
        incx = 1;
    }
    else if(delta_x == 0) {
        //垂直斜线(竖线)
        incx = 0;
    }
    else {
        //斜线(从右到左)
        incx = -1;
        delta_x = -delta_x;
    }
    
    if(delta_y > 0) {
        //斜线(从左到右)
        incy = 1;
    }
    else if(delta_y == 0) {
        //水平斜线(水平线)
        incy = 0;
    }
    else {
        //斜线(从右到左)
        incy = -1;
        delta_y = -delta_y;
    }           
    
    /* 计算画笔打点距离(取两个间距中的最大值) */
    if(delta_x > delta_y) {
        distance = delta_x;
    }
    else {
        distance = delta_y;
    }
    
    /* 开始打点 */
    x = x1;
    y = y1;
    //第一个点无效，所以t的次数加一
    for(t = 0; t <= distance + 1;t++) {
        set_point(h, x, y, color);
    
        /* 判断离实际值最近的像素点 */
        x_temp += delta_x;  
        if(x_temp > distance) {
            //x方向越界，减去距离值，为下一次检测做准备
            x_temp -= distance;     
            //在x方向递增打点
            x += incx;
        }
        y_temp += delta_y;
        if(y_temp > distance) {
            //y方向越界，减去距离值，为下一次检测做准备
            y_temp -= distance;
            //在y方向递增打点
            y += incy;
        }
    }
}



void lcd_draw_rect(int x, int y, int w, int h, int color)
{
    int  x2,y2;

    x2 = x + w;
    y2 = y + h;
    lcd_draw_line(x,y,x2,y,color);
    lcd_draw_line(x,y,x,y2,color);
    lcd_draw_line(x,y2,x2,y2,color);
    lcd_draw_line(x,y,x2,y2,color);
}


void lcd_fill_rect(int x, int y, int w, int h, int color)
{
    int i,j;
    lcd_handle_t *h2=&lcdHandle;

    for(i=x; i<x+w; i++) {
        for(j=y; j<y+h; j++) {
            set_point(h2, i, j, color);
        }
    }
}


void lcd_refresh(void)
{
    lcd_handle_t *h=&lcdHandle;
#ifndef USE_FB
    ssd1309_refresh(h);
#endif
}


int lcd_draw_char(lcd_handle_t *hd, int x, int y, int w, int h, uint8_t *c, int font, int color, int bgcolor, int vert)
{
    uint8_t tmp;
    font_data_t fdata;
    int i,j,x0=x,y0=y,x1=x+w,y1=y+h;
    
    fdata = font_data(font, c);
    if(h>fdata.height) {
        if(vert==VERTICAL_CENTER) {
            y0 += (h-fdata.height)/2;
        }
        else if (vert==VERTICAL_BOTTOM) {
            y0 += h-fdata.height;
        }
        y = y0;
    }
    
    for(i=0; i<fdata.dlen; i++)  {
        tmp = fdata.data[i];
        for(j=0; j<8; j++)  {
            if((x<x1 && x<hd->width) && (y<y1 && y<hd->height)) 
            {
                if(tmp&0x01) {
                    set_point(hd, x, y, color);
                }
                else {
                    set_point(hd, x, y, bgcolor);
                }
            }
            tmp >>= 1;
            y++;

            if((y-y0)>=fdata.height) {
                y=y0; x++;
                break;
            }
        }
    }

    return fdata.width;
}


void lcd_draw_string(int x, int y, int w, int h, char *str, int font, int color, int bgcolor, int hori, int vert)
{
    int r,sw,xmax=x+w;
    lcd_rect_t rect;
    uint8_t *pstr=(uint8_t*)str;
    lcd_handle_t *h2=&lcdHandle;

   sw = font_width_str(font, pstr);
    if(sw>w) {
        sw = w;
    }
    
    if(hori==HORIZONTAL_LEFT) {
        rect.x = x;
    }
    else if(hori==HORIZONTAL_RIGHT) {
        rect.x = x+w-sw;
    }
    else if(hori==HORIZONTAL_CENTER) {
        rect.x = x+(w-sw)/2;
    }
    else {
        return;
    }
    
    if(rect.x+sw>=h2->width) {
        rect.w = h2->width-rect.x;
    }
    else {
        rect.w = sw;
    }
    rect.y = y;
    rect.h = h;

    while(*pstr)  {
        r = lcd_draw_char(h2, rect.x, rect.y, rect.w, rect.h, pstr, font, color, bgcolor, vert);
        rect.x += r;
        pstr = font_next(pstr);
        if(!pstr || x>=xmax) {
            break;
        }
    }
}