#ifndef _BM_CAIRO_H_
#define _BM_CAIRO_H_

#include "internal.h"
#include <string.h>
#include <assert.h>
#include <cairo/cairo.h>

#ifndef MAX
#  define MAX(a,b) (((a)>(b))?(a):(b))
#endif

struct cairo {
    cairo_t *cr;
    cairo_surface_t *surface;
};

struct cairo_color {
    float r, g, b, a;
};

struct cairo_paint {
    struct cairo_color fg;
    struct cairo_color bg;
    cairo_font_extents_t fe;
};

struct cairo_result {
    cairo_text_extents_t te;
};

static size_t blen = 0;
static char *buffer = NULL;

__attribute__((unused)) BM_LOG_ATTR(3, 4) static bool
bm_cairo_get_text_extents(struct cairo *cairo, struct cairo_result *result, const char *fmt, ...)
{
    assert(cairo && result && fmt);
    memset(result, 0, sizeof(struct cairo_result));

    va_list args;
    va_start(args, fmt);
    bool ret = bm_vrprintf(&buffer, &blen, fmt, args);
    va_end(args);

    if (!ret)
        return false;

    cairo_text_extents(cairo->cr, buffer, &result->te);
    return true;
}

__attribute__((unused)) BM_LOG_ATTR(8, 9) static bool
bm_cairo_draw_line(struct cairo *cairo, struct cairo_paint *paint, struct cairo_result *result, uint32_t xoff, uint32_t w, int32_t x, int32_t y, const char *fmt, ...)
{
    assert(cairo && paint && result && fmt);
    memset(result, 0, sizeof(struct cairo_result));

    va_list args;
    va_start(args, fmt);
    bool ret = bm_vrprintf(&buffer, &blen, fmt, args);
    va_end(args);

    if (!ret)
        return false;

    cairo_text_extents_t te;
    cairo_text_extents(cairo->cr, buffer, &te);

    cairo_set_source_rgba(cairo->cr, paint->bg.r, paint->bg.b, paint->bg.g, paint->bg.a);
    cairo_rectangle(cairo->cr, x - xoff, y, (w > 0 ? w : te.width) + xoff, paint->fe.height);
    cairo_fill(cairo->cr);

    cairo_set_source_rgba(cairo->cr, paint->fg.r, paint->fg.b, paint->fg.g, paint->fg.a);
    cairo_move_to(cairo->cr, x, y + paint->fe.descent + paint->fe.height * 0.5);
    cairo_show_text(cairo->cr, buffer);

    memcpy(&result->te, &te, sizeof(te));
    return true;
}

__attribute__((unused)) static void
bm_cairo_color_from_menu_color(const struct bm_menu *menu, enum bm_color color, struct cairo_color *c)
{
    assert(menu);
    c->r = (float)menu->colors[color].r / 255.0f;
    c->g = (float)menu->colors[color].g / 255.0f;
    c->b = (float)menu->colors[color].b / 255.0f;
    c->a = 1.0f;
}

__attribute__((unused)) static uint32_t
bm_cairo_paint(struct cairo *cairo, uint32_t width, uint32_t height, const struct bm_menu *menu)
{
    assert(cairo && menu);

    struct cairo_color c;
    bm_cairo_color_from_menu_color(menu, BM_COLOR_BG, &c);
    cairo_set_source_rgb(cairo->cr, c.r, c.g, c.b);
    cairo_rectangle(cairo->cr, 0, 0, width, height);
    cairo_fill(cairo->cr);

    cairo_select_font_face(cairo->cr, menu->font.name, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
    cairo_set_font_size(cairo->cr, menu->font.size);

    struct cairo_paint paint;
    memset(&paint, 0, sizeof(paint));
    cairo_font_extents(cairo->cr, &paint.fe);

    struct cairo_result result;
    memset(&result, 0, sizeof(result));

    if (menu->title) {
        bm_cairo_color_from_menu_color(menu, BM_COLOR_TITLE_FG, &paint.fg);
        bm_cairo_color_from_menu_color(menu, BM_COLOR_TITLE_BG, &paint.bg);
        bm_cairo_draw_line(cairo, &paint, &result, 0, 0, result.te.x_advance, 4, "%s", menu->title);
    }

    bm_cairo_color_from_menu_color(menu, BM_COLOR_FILTER_FG, &paint.fg);
    bm_cairo_color_from_menu_color(menu, BM_COLOR_FILTER_BG, &paint.bg);
    bm_cairo_draw_line(cairo, &paint, &result, 0, width, result.te.x_advance, 4, "%s%s", (menu->title ? " " : ""), (menu->filter ? menu->filter : ""));

    uint32_t displayed = 1;
    uint32_t lines = MAX(height / paint.fe.height, menu->lines);
    if (lines > 1) {
        uint32_t count, cl = 1;
        struct bm_item **items = bm_menu_get_filtered_items(menu, &count);
        for (uint32_t i = (menu->index / (lines - 1)) * (lines - 1); i < count && cl < lines; ++i) {
            bool highlighted = (items[i] == bm_menu_get_highlighted_item(menu));

            if (highlighted) {
                bm_cairo_color_from_menu_color(menu, BM_COLOR_HIGHLIGHTED_FG, &paint.fg);
                bm_cairo_color_from_menu_color(menu, BM_COLOR_HIGHLIGHTED_BG, &paint.bg);
            } else if (bm_menu_item_is_selected(menu, items[i])) {
                bm_cairo_color_from_menu_color(menu, BM_COLOR_SELECTED_FG, &paint.fg);
                bm_cairo_color_from_menu_color(menu, BM_COLOR_SELECTED_BG, &paint.bg);
            } else {
                bm_cairo_color_from_menu_color(menu, BM_COLOR_ITEM_FG, &paint.fg);
                bm_cairo_color_from_menu_color(menu, BM_COLOR_ITEM_BG, &paint.bg);
            }

            bm_cairo_draw_line(cairo, &paint, &result, 0, width, 0, 4 + paint.fe.height * cl++,
                    "%s%s", (highlighted ? ">> " : "   "), (items[i]->text ? items[i]->text : ""));

            ++displayed;
        }
    } else {
        uint32_t count;
        struct bm_item **items = bm_menu_get_filtered_items(menu, &count);

        uint32_t cl = width / 4;
        if (menu->wrap || menu->index > 0) {
            bm_cairo_draw_line(cairo, &paint, &result, 0, 0, cl, 4, "<");
            cl += result.te.x_advance + 4;
        }

        for (uint32_t i = menu->index; i < count && cl < width; ++i) {
            bool highlighted = (items[i] == bm_menu_get_highlighted_item(menu));

            if (highlighted) {
                bm_cairo_color_from_menu_color(menu, BM_COLOR_HIGHLIGHTED_FG, &paint.fg);
                bm_cairo_color_from_menu_color(menu, BM_COLOR_HIGHLIGHTED_BG, &paint.bg);
            } else if (bm_menu_item_is_selected(menu, items[i])) {
                bm_cairo_color_from_menu_color(menu, BM_COLOR_SELECTED_FG, &paint.fg);
                bm_cairo_color_from_menu_color(menu, BM_COLOR_SELECTED_BG, &paint.bg);
            } else {
                bm_cairo_color_from_menu_color(menu, BM_COLOR_ITEM_FG, &paint.fg);
                bm_cairo_color_from_menu_color(menu, BM_COLOR_ITEM_BG, &paint.bg);
            }

            bm_cairo_draw_line(cairo, &paint, &result, 0, 0, cl, 4, "%s", (items[i]->text ? items[i]->text : ""));
            cl += result.te.x_advance + 4;
            displayed += (cl < width);
        }

        if (menu->wrap || menu->index + 1 < count) {
            bm_cairo_color_from_menu_color(menu, BM_COLOR_FILTER_FG, &paint.fg);
            bm_cairo_color_from_menu_color(menu, BM_COLOR_FILTER_BG, &paint.bg);
            bm_cairo_get_text_extents(cairo, &result, ">");
            bm_cairo_draw_line(cairo, &paint, &result, 4, result.te.x_advance + 4, width - result.te.x_advance - 4, 4, ">");
        }
    }

    return displayed;
}

#endif /* _BM_CAIRO_H */

/* vim: set ts=8 sw=4 tw=0 :*/