#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <math.h>
#include <wchar.h>
#include <inttypes.h>
#include <sys/ioctl.h>
#include <linux/fb.h>

#include "vt.h"
#include "fbtools.h"
#include "fb-gui.h"

static int ys =  3;
static int xs = 10;

/* ---------------------------------------------------------------------- */
/* shadow framebuffer -- internals                                        */

static int32_t s_lut_transp[256], s_lut_red[256], s_lut_green[256], s_lut_blue[256];

static unsigned char **shadow;
static unsigned int  *sdirty,swidth,sheight;

static cairo_t *context;
static cairo_surface_t *surface;
static unsigned char *framebuffer;
static cairo_font_extents_t extents;

static void shadow_lut_init_one(int32_t *lut, int bits, int shift)
{
    int i;
    
    if (bits > 8)
	for (i = 0; i < 256; i++)
	    lut[i] = (i << (bits + shift - 8));
    else
	for (i = 0; i < 256; i++)
	    lut[i] = (i >> (8 - bits)) << shift;
}

static void shadow_lut_init(gfxstate *gfx)
{
    shadow_lut_init_one(s_lut_transp, gfx->tlen, gfx->toff);
    shadow_lut_init_one(s_lut_red,    gfx->rlen, gfx->roff);
    shadow_lut_init_one(s_lut_green,  gfx->glen, gfx->goff);
    shadow_lut_init_one(s_lut_blue,   gfx->blen, gfx->boff);
}

static void shadow_render_line(gfxstate *gfx, int line,
                               unsigned char *dest, char unsigned *buffer)
{
    uint8_t  *ptr  = (void*)dest;
    uint16_t *ptr2 = (void*)dest;
    uint32_t *ptr4 = (void*)dest;
    int x;

    switch (gfx->bits_per_pixel) {
    case 15:
    case 16:
	for (x = 0; x < swidth; x++) {
	    ptr2[x] =
                s_lut_red[buffer[x*4+2]] |
		s_lut_green[buffer[x*4+1]] |
		s_lut_blue[buffer[x*4+0]];
	}
	break;
    case 24:
	for (x = 0; x < swidth; x++) {
	    ptr[3*x+2] = buffer[4*x+2];
	    ptr[3*x+1] = buffer[4*x+1];
	    ptr[3*x+0] = buffer[4*x+0];
	}
	break;
    case 32:
	for (x = 0; x < swidth; x++) {
	    ptr4[x] = s_lut_transp[255] |
		s_lut_red[buffer[x*4+2]] |
		s_lut_green[buffer[x*4+1]] |
		s_lut_blue[buffer[x*4+0]];
	}
	break;
    }
}

/* ---------------------------------------------------------------------- */
/* shadow framebuffer -- management interface                             */

void shadow_render(gfxstate *gfx)
{
    unsigned int offset = 0;
    int i;

    if (!console_visible)
	return;
    for (i = 0; i < sheight; i++, offset += gfx->stride) {
	if (0 == sdirty[i])
	    continue;
	shadow_render_line(gfx, i, gfx->mem + offset, shadow[i]);
	sdirty[i] = 0;
    }
    if (gfx->flush_display)
        gfx->flush_display(false);
}

void shadow_clear_lines(int first, int last)
{
    int i;

    for (i = first; i <= last; i++) {
	memset(shadow[i],0,4*swidth);
	sdirty[i]++;
    }
}

void shadow_clear(void)
{
    shadow_clear_lines(0, sheight-1);
}

void shadow_set_dirty_range(int y, int h)
{
    int i;

    if (y < 0)
        y = 0;
    for (i = y; i < y + h && i < sheight; i++)
	sdirty[i]++;
}

void shadow_set_dirty(void)
{
    shadow_set_dirty_range(0, sheight);
}

void shadow_init(gfxstate *gfx)
{
    int i;

    /* init shadow fb */
    swidth  = gfx->hdisplay;
    sheight = gfx->vdisplay;
    shadow  = malloc(sizeof(unsigned char*) * sheight);
    sdirty  = malloc(sizeof(unsigned int)   * sheight);
    memset(sdirty,0, sizeof(unsigned int)   * sheight);
    framebuffer = malloc(swidth*sheight*4);
    for (i = 0; i < sheight; i++)
	shadow[i] = framebuffer + i*swidth*4;
    shadow_clear();
    surface = cairo_image_surface_create_for_data(framebuffer,
                                                  CAIRO_FORMAT_RGB24,
                                                  swidth, sheight,
                                                  swidth * 4);
    context = cairo_create(surface);

    /* init rendering */
    switch (gfx->bits_per_pixel) {
    case 15:
    case 16:
    case 24:
    case 32:
        shadow_lut_init(gfx);
	break;
    default:
	fprintf(stderr, "Oops: %i bit/pixel ???\n",
		gfx->bits_per_pixel);
	exit(1);
    }
}

void shadow_fini(void)
{
    if (!shadow)
	return;
    free(shadow);
    free(sdirty);
    free(framebuffer);
}

/* ---------------------------------------------------------------------- */
/* shadow framebuffer -- drawing interface                                */

void shadow_draw_line(int x1, int x2, int y1,int y2)
{
    cairo_set_source_rgb(context, 1, 1, 1);
    cairo_set_line_width(context, 1);

    cairo_move_to(context, x1 + 0.5, y1 + 0.5);
    cairo_line_to(context, x2 + 0.5, y2 + 0.5);
    cairo_stroke(context);

    shadow_set_dirty_range(y1, (y2 - y1) + 1);
}

void shadow_draw_rect(int x1, int x2, int y1, int y2)
{
    cairo_set_source_rgb(context, 1, 1, 1);
    cairo_set_line_width(context, 1);

    cairo_move_to(context, x1 + 0.5, y1 + 0.5);
    cairo_line_to(context, x2 + 0.5, y1 + 0.5);
    cairo_line_to(context, x2 + 0.5, y2 + 0.5);
    cairo_line_to(context, x1 + 0.5, y2 + 0.5);
    cairo_line_to(context, x1 + 0.5, y1 + 0.5);
    cairo_stroke(context);

    shadow_set_dirty_range(y1, (y2 - y1) + 1);
}

void shadow_draw_rgbdata(int x, int y, int pixels, unsigned char *rgb)
{
    unsigned char *dest = shadow[y] + 4*x;
    int i;

    for (i = 0; i < pixels; i++) {
        dest[0] = rgb[2];
        dest[1] = rgb[1];
        dest[2] = rgb[0];
        dest += 4;
        rgb += 3;
    }
    sdirty[y]++;
}

void shadow_merge_rgbdata(int x, int y, int pixels, int weight,
			  unsigned char *rgb)
{
    unsigned char *dest = shadow[y] + 4*x;
    int i;

    weight = weight * 256 / 100;

    for (i = 0; i < pixels; i++) {
        dest[0] += rgb[2] * weight >> 8;
        dest[1] += rgb[1] * weight >> 8;
        dest[2] += rgb[0] * weight >> 8;
        dest += 4;
        rgb += 3;
    }
    sdirty[y]++;
}


void shadow_darkify(int x1, int x2, int y1,int y2, int percent)
{
    cairo_rectangle(context, x1, y1,
                    x2 - x1 + 1,
                    y2 - y1 + 1);
    cairo_set_source_rgba(context, 0, 0, 0, 1 - (percent * 0.01));
    cairo_fill(context);
}

int shadow_draw_string(int x, int y, char *str, int align)
{
    cairo_text_extents_t te;

    cairo_text_extents(context, str, &te);
    switch(align) {
    case -1: /* left */
	break;
    case 0: /* center */
	x -= te.x_advance / 2;
	break;
    case 1: /* right */
	x -= te.x_advance;
	break;
    }

    cairo_move_to(context, x, y + extents.ascent);
    cairo_show_text(context, str);
    return 0;
}

void shadow_draw_text_box(int x, int y, int percent, char *lines[], unsigned int count)
{
    unsigned int i, len, max, x1, x2, y1, y2;

    if (!console_visible)
	return;

    max = 0;
    for (i = 0; i < count; i++) {
	len = strlen(lines[i]);
	if (max < len)
	    max = len;
    }

    x1 = x;
    x2 = x + max * extents.max_x_advance;
    y1 = y;
    y2 = y + count * extents.height;

    x += xs; x2 += 2*xs;
    y += ys; y2 += 2*ys;

    shadow_darkify(x1, x2, y1, y2, percent);
    shadow_draw_rect(x1, x2, y1, y2);
    for (i = 0; i < count; i++) {
	shadow_draw_string(x, y, lines[i], -1);
	y += extents.height;
    }
}

cairo_font_extents_t *shadow_font_init(char *font)
{
    char fontname[64];
    int fontsize, rc;

    rc = sscanf(font, "%63[^-]-%d", fontname, &fontsize);
    if (rc != 2) {
        rc = sscanf(font, "%63[^:]:size=%d", fontname, &fontsize);
        if (rc != 2) {
            strncpy(fontname, font, sizeof(fontname));
            fontsize = 16;
        }
    }

    cairo_select_font_face(context, fontname,
                           CAIRO_FONT_SLANT_NORMAL,
                           CAIRO_FONT_WEIGHT_NORMAL);
    cairo_set_font_size(context, fontsize);
    cairo_font_extents(context, &extents);
    return &extents;
}