#include "fb.h"
#include "mbox.h"
#include "uart.h"
#include "utils.h"
#include <stdint.h>

#define MBOX_TAG_FBALLOC 0x40001
#define MBOX_TAG_FBGETPITCH 0x40008
#define MBOX_TAG_FBSETPHYS 0x48003
#define MBOX_TAG_FBSETVIRT 0x48004
#define MBOX_TAG_FBSETDEPTH 0x48005
#define MBOX_TAG_FBSETPIXORD 0x48006
#define MBOX_TAG_FBSETOFF 0x48009

/* PC Screen Font as used by Linux Console */
typedef struct {
  unsigned int magic;
  unsigned int version;
  unsigned int headersize;
  unsigned int flags;
  unsigned int numglyph;
  unsigned int bytesperglyph;
  unsigned int height;
  unsigned int width;
  unsigned char glyphs;
} __attribute__((packed)) psf_t;
extern volatile unsigned char _binary_font_psf_start;

static struct fbst fb;

unsigned char *fb_init(int width, int height)
{
  // sending many tags at once
  mbox[0]  = 35 * 4;
  mbox[1]  = MBOX_REQUEST;
  mbox[2]  = MBOX_TAG_FBSETPHYS; // set phy wh
  mbox[3]  = 8;
  mbox[4]  = 0;
  mbox[5]  = width;               // FrameBufferInfo.width
  mbox[6]  = height;               // FrameBufferInfo.height
  mbox[7]  = MBOX_TAG_FBSETVIRT; // set virt wh
  mbox[8]  = 8;
  mbox[9]  = 0;
  mbox[10] = width;              // FrameBufferInfo.virtual_width
  mbox[11] = height;              // FrameBufferInfo.virtual_height
  mbox[12] = MBOX_TAG_FBSETOFF; // set virt offset
  mbox[13] = 8;
  mbox[14] = 0;
  mbox[15] = 0;                   // FrameBufferInfo.x_offset
  mbox[16] = 0;                   // FrameBufferInfo.y.offset
  mbox[17] = MBOX_TAG_FBSETDEPTH; // set depth
  mbox[18] = 4;
  mbox[19] = 0;
  mbox[20] = 32;                   // FrameBufferInfo.depth
  mbox[21] = MBOX_TAG_FBSETPIXORD; // set pixel order
  mbox[22] = 4;
  mbox[23] = 0;
  mbox[24] = 1;                // RGB, not BGR preferably
  mbox[25] = MBOX_TAG_FBALLOC; // get framebuffer, gets alignment on request
  mbox[26] = 8;
  mbox[27] = 0;
  mbox[28] = 4096;                // FrameBufferInfo.pointer
  mbox[29] = 0;                   // FrameBufferInfo.size
  mbox[30] = MBOX_TAG_FBGETPITCH; // get pitch
  mbox[31] = 4;
  mbox[32] = 0;
  mbox[33] = 0; // FrameBufferInfo.pitch
  mbox[34] = MBOX_TAG_LAST;

  if (mbox_call(MBOX_CH_PROP, mbox) == 0 && mbox[20] == 32 && mbox[28] != 0) {
    mbox[28] &= 0x3FFFFFFF; // convert GPU address to ARM address
    fb.width  = mbox[5];   // get actual physical width
    fb.height = mbox[6];   // get actual physical height
    fb.pitch  = mbox[33];  // get number of bytes per line
    fb.isrgb  = mbox[24];  // get the actual channel order
    fb.fbp    = (void *)((unsigned long)mbox[28]);
  } else {
    puts("Unable to set framebuffer!\r\n");
    return 0;
  }

  return fb.fbp;
}

struct fbst * fb_get(){
  return &fb;
}

void fb_print(int x, int y, char *s)
{
  // get our font
  psf_t *font = (psf_t *)&_binary_font_psf_start;
  // draw next character if it's not zero
  while (*s) {
    // get the offset of the glyph. Need to adjust this to support unicode table
    unsigned char *glyph =
        (unsigned char *)&_binary_font_psf_start + font->headersize +
        (*((unsigned char *)s) < font->numglyph ? *s : 0) * font->bytesperglyph;
    // calculate the offset on screen
    int offs = (y * fb.pitch) + (x * 4);
    // variables
    int line, mask, bytesperline = (font->width + 7) / 8;
    // handle carrige return
    if (*s == '\r') {
      x = 0;
    } else
      // new line
      if (*s == '\n') {
        x = 0;
        y += font->height;
      } else {
        // display a character
        for (unsigned int j = 0; j < font->height; j++) {
          // display one row
          line = offs;
          mask = 1 << (font->width - 1);
          for (unsigned int i = 0; i < font->width; i++) {
            // if bit set, we use white color, otherwise black
            *((unsigned int *)(fb.fbp + line)) = ((int)*glyph) & mask ? 0xFFFFFF : 0;
            mask >>= 1;
            line += 4;
          }
          // adjust to next line
          glyph += bytesperline;
          offs += fb.pitch;
        }
        x += (font->width + 1);
      }
    // next character
    s++;
  }
}