#include "drawing.h"
#include "display_spec.h"
#include "font.h"

extern uint8_t LCD_displayMap[LCD_WIDTH * LCD_HEIGHT / 8];

// This function sets a pixel on displayMap to your preferred
// color. 1=Black, 0= white.
void LCD_setPixel(int x, int y, enum Color bw)
{
    // First, double check that the coordinate is in range.
    if ((x >= 0) && (x < LCD_WIDTH) && (y >= 0) && (y < LCD_HEIGHT)) {
        uint8_t shift = y % 8;

        if (bw) // If black, set the bit.
            LCD_displayMap[x + (y / 8) * LCD_WIDTH] |= 1 << shift;
        else   // If white clear the bit.
            LCD_displayMap[x + (y / 8) * LCD_WIDTH] &= ~(1 << shift);
    }
}

// setLine draws a line from x0,y0 to x1,y1 with the set color.
// This function was grabbed from the SparkFun ColorLCDShield
// library.
void LCD_setLine(int x0, int y0, int x1, int y1, enum Color bw)
{
    int dy = y1 - y0; // Difference between y0 and y1
    int dx = x1 - x0; // Difference between x0 and x1
    int stepx, stepy;

    if (dy < 0) {
        dy = -dy;
        stepy = -1;
    }
    else
        stepy = 1;

    if (dx < 0) {
        dx = -dx;
        stepx = -1;
    }
    else
        stepx = 1;

    dy <<= 1; // dy is now 2*dy
    dx <<= 1; // dx is now 2*dx
    LCD_setPixel(x0, y0, bw); // Draw the first pixel.

    if (dx > dy) {
        int fraction = dy - (dx >> 1);
        while (x0 != x1) {
            if (fraction >= 0) {
                y0 += stepy;
                fraction -= dx;
            }
            x0 += stepx;
            fraction += dy;
            LCD_setPixel(x0, y0, bw);
        }
    }
    else {
        int fraction = dx - (dy >> 1);
        while (y0 != y1) {
            if (fraction >= 0) {
                x0 += stepx;
                fraction -= dy;
            }
            y0 += stepy;
            fraction += dx;
            LCD_setPixel(x0, y0, bw);
        }
    }
}

// setRect will draw a rectangle from x0,y0 top-left corner to
// a x1,y1 bottom-right corner. Can be filled with the fill
// parameter, and colored with bw.
// This function was grabbed from the SparkFun ColorLCDShield
// library.
void LCD_setRect(int x0, int y0, int x1, int y1, bool fill, enum Color bw)
{
    // check if the rectangle is to be filled
    if (fill == 1) {
        int xDiff;

        if (x0 > x1)
            xDiff = x0 - x1; //Find the difference between the x vars
        else
            xDiff = x1 - x0;

        while (xDiff > 0) {
            LCD_setLine(x0, y0, x0, y1, bw);

            if (x0 > x1)
                x0--;
            else
                x0++;

            xDiff--;
        }
    }
    else {
        // best way to draw an unfilled rectangle is to draw four lines
        LCD_setLine(x0, y0, x1, y0, bw);
        LCD_setLine(x0, y1, x1, y1, bw);
        LCD_setLine(x0, y0, x0, y1, bw);
        LCD_setLine(x1, y0, x1, y1, bw);
    }
}

// setCircle draws a circle centered around x0,y0 with a defined
// radius. The circle can be black or white. And have a line
// thickness ranging from 1 to the radius of the circle.
// This function was grabbed from the SparkFun ColorLCDShield
// library.
void LCD_setCircle(int x0, int y0, int radius, enum Color bw, int lineThickness)
{
    for (int r = 0; r < lineThickness; r++) {
        int f = 1 - radius;
        int ddF_x = 0;
        int ddF_y = -2 * radius;
        int x = 0;
        int y = radius;

        LCD_setPixel(x0, y0 + radius, bw);
        LCD_setPixel(x0, y0 - radius, bw);
        LCD_setPixel(x0 + radius, y0, bw);
        LCD_setPixel(x0 - radius, y0, bw);

        while (x < y) {
            if (f >= 0) {
                y--;
                ddF_y += 2;
                f += ddF_y;
            }
            x++;
            ddF_x += 2;
            f += ddF_x + 1;

            LCD_setPixel(x0 + x, y0 + y, bw);
            LCD_setPixel(x0 - x, y0 + y, bw);
            LCD_setPixel(x0 + x, y0 - y, bw);
            LCD_setPixel(x0 - x, y0 - y, bw);
            LCD_setPixel(x0 + y, y0 + x, bw);
            LCD_setPixel(x0 - y, y0 + x, bw);
            LCD_setPixel(x0 + y, y0 - x, bw);
            LCD_setPixel(x0 - y, y0 - x, bw);
        }
        radius--;
    }
}

static void LCD_setCharEx(struct Utf8Char character, int x, int y, enum Color color, struct TextStyle style)
{
    const struct FontGraphic *symbol = Font_GetSymbol(character);

    uint8_t column; // temp byte to store character's column bitmap
    for (int i = 0; i < 5; i++) // 5 columns (x) per character
    {
        column = symbol->columns[i];
        for (int j = 0; j < 8; j++) // 8 rows (y) per character
        {
            bool bit = column & (1 << j);

            if (style.size == FONT_NORMAL) {
                if (bit) {// test bits to set pixels
                    LCD_setPixel(x + i, y + j, color);
                }
                else if (style.bg) {
                    LCD_setPixel(x + i, y + j, !color);
                }
            }
            else if (style.size == FONT_DOUBLE) {
                if (bit) {// test bits to set pixels
                    LCD_setPixel(x + i * 2, y + j * 2, color);
                    LCD_setPixel(x + i * 2 + 1, y + j * 2, color);
                    LCD_setPixel(x + i * 2, y + j * 2 + 1, color);
                    LCD_setPixel(x + i * 2 + 1, y + j * 2 + 1, color);
                }
                else if (style.bg) {
                    LCD_setPixel(x + i * 2, y + j * 2, !color);
                    LCD_setPixel(x + i * 2 + 1, y + j * 2, !color);
                    LCD_setPixel(x + i * 2, y + j * 2 + 1, !color);
                    LCD_setPixel(x + i * 2 + 1, y + j * 2 + 1, !color);
                }
            }
            else if (style.size == FONT_BOLD) {
                if (bit) {// test bits to set pixels
                    LCD_setPixel(x + i, y + j, color);
                    LCD_setPixel(x + i + 1, y + j, color);
                }
                else if (style.bg) {
                    LCD_setPixel(x + i, y + j, !color);
                    LCD_setPixel(x + i + 1, y + j, !color);
                }
            }
        }
    }
}

// setStr draws a string of characters, calling setChar with
// progressive coordinates until it's done.
// This function was grabbed from the SparkFun ColorLCDShield
// library.
void LCD_setStr(const char *dString, int x, int y, enum Color bw)
{
    LCD_setStrEx(dString, x, y, bw, (struct TextStyle) {});
}

static const int char_widths[] = {
    [FONT_NORMAL] = 5,
    [FONT_DOUBLE] = 10,
    [FONT_BOLD] = 6
};

static const int char_spacings[] = {
    [FONT_NORMAL] = 1,
    [FONT_DOUBLE] = 2,
    [FONT_BOLD] = 1
};

static const int char_heights[] = {
    [FONT_NORMAL] = 8,
    [FONT_DOUBLE] = 16,
    [FONT_BOLD] = 8
};

// setStr draws a string of characters, calling setChar with
// progressive coordinates until it's done.
// This function was grabbed from the SparkFun ColorLCDShield
// library. AND HEAVILY MODIFIED
void LCD_setStrEx(const char *dString, int x, int y, enum Color color, struct TextStyle style)
{
    struct Utf8Char uchar;
    struct Utf8Iterator iter;
    Utf8Iterator_Init(&iter, dString);

    int charw = char_widths[style.size];
    int charh = char_heights[style.size];
    int spacingx = char_spacings[style.size] + style.spacing_x;
    int spacingy = style.spacing_y;

    if (style.align != ALIGN_LEFT) {
        int line_len = 0;
        int skip = style.skip;
        while ((uchar = Utf8Iterator_Next(&iter)).uint) {
            if (skip > 0) {
                skip -= 1;
                continue;
            }
            if (uchar.bytes[0] == '\n') {
                break;
            }
            line_len++;
        }
        if (style.align == ALIGN_CENTER) {
            x -= ((charw + spacingx) * line_len) / 2 - spacingx/2;
        } else {
            // right
            x -= ((charw + spacingx) * line_len) - spacingx;
        }
    }

    const int x0 = x;
    Utf8Iterator_Init(&iter, dString);

    int limit = style.limit;
    int skip = style.skip;
    bool wrap;
    while ((uchar = Utf8Iterator_Next(&iter)).uint) {
        if (skip > 0) {
            skip -= 1;
            continue;
        }

        wrap = uchar.bytes[0] == '\n';

        if (!wrap) LCD_setCharEx(uchar, x, y, color, style);

        if (limit > 0) {
            limit -= 1;
            if (limit == 0) return;
        }

        if (!wrap) {
            x += charw;
            if (style.bg) {
                for (int i = y; i < y + charh; i++) {
                    for (int j = x; j < x + spacingx; j++) {
                        LCD_setPixel(j, i, !color);
                    }
                }
            }
        }

        x += spacingx;
        if (wrap || x > (LCD_WIDTH - charw)) {
            if (style.nowrap) break;
            if (style.wrap_to_0) {
                x = 0;
            } else {
                x = x0;
            }
            y += charh + spacingy;
        }

        // no more characters could be seen
        if (y >= LCD_HEIGHT) {
            break;
        }
    }
}

// This function will draw an array over the screen. (For now) the
// array must be the same size as the screen, covering the entirety
// of the display.
void LCD_setBitmap(const uint8_t *bitArray)
{
    for (int i = 0; i < (LCD_WIDTH * LCD_HEIGHT / 8); i++) {
        LCD_displayMap[i] = bitArray[i];
    }
}

// This function clears the entire display either white (0) or
// black (1).
// The screen won't actually clear until you call updateDisplay()!
void LCD_clearDisplay(enum Color bw)
{
    for (int i = 0; i < (LCD_WIDTH * LCD_HEIGHT / 8); i++) {
        if (bw)
            LCD_displayMap[i] = 0xFF;
        else
            LCD_displayMap[i] = 0;
    }
}

void LCD_invertDisplayData()
{
    /* Indirect, swap bits in displayMap option: */
    for (int i = 0; i < (LCD_WIDTH * LCD_HEIGHT / 8); i++) {
        LCD_displayMap[i] ^= 0xFF;
    }
}