#include <stdbool.h>

#include <SDL.h>

#include "system/stacktrace.h"
#include "layer_picker.h"
#include "color.h"
#include "game/camera.h"
#include "math/rect.h"
#include "math/extrema.h"
#include "game/sprite_font.h"

#define LAYER_TITLE_PADDING 15.0f
#define LAYER_TITLE_SIZE 2.0f
#define SELECTOR_HEIGHT (LAYER_CELL_HEIGHT * 0.20f)

static const Color LAYER_CELL_BACKGROUND_COLORS[LAYER_PICKER_N] = {
    {1.0f, 0.0f, 0.0f, 1.0f},  // LAYER_PICKER_BOXES = 0,
    {0.0f, 1.0f, 0.0f, 1.0f},  // LAYER_PICKER_PLATFORMS,
    {0.0f, 0.0f, 1.0f, 1.0f},  // LAYER_PICKER_BACK_PLATFORMS,
    {1.0f, 1.0f, 1.0f, 1.0f},  // LAYER_PICKER_GOALS
    {1.0f, 0.2f, 0.6f, 1.0f},  // LAYER_PICKER_PLAYER
};

static const char *LAYER_CELL_TITLES[LAYER_PICKER_N] = {
    "Boxes",                   // LAYER_PICKER_BOXES = 0,
    "Platforms",               // LAYER_PICKER_PLATFORMS,
    "Back Platforms",          // LAYER_PICKER_BACK_PLATFORMS,
    "Goals",                   // LAYER_PICKER_GOALS
    "Player",                  // LAYER_PICKER_PLAYER
};

inline static float layer_picker_max_width(void)
{
    size_t max = 0;

    for (size_t i = 0; i < LAYER_PICKER_N; ++i) {
        max = max_size_t(max, strlen(LAYER_CELL_TITLES[i]));
    }

    return (float) max * FONT_CHAR_WIDTH * LAYER_TITLE_SIZE + LAYER_TITLE_PADDING * 2.0f;
}

#define LAYER_CELL_WIDTH layer_picker_max_width()
#define LAYER_CELL_HEIGHT (LAYER_TITLE_SIZE * FONT_CHAR_HEIGHT + LAYER_TITLE_PADDING * 2.0f)

inline static Vec layer_picker_position(const Camera *camera)
{
    trace_assert(camera);

    const Rect viewport = camera_view_port_screen(camera);

    Vec position = {
        .x = 0.0f,
        .y = viewport.h * 0.5f - LAYER_CELL_HEIGHT * LAYER_PICKER_N * 0.5f
    };

    return position;
}

int layer_picker_render(const LayerPicker *layer_picker,
                        Camera *camera)
{
    trace_assert(layer_picker);
    trace_assert(camera);

    const Vec position = layer_picker_position(camera);

    for (size_t i = 0; i < LAYER_PICKER_N; ++i) {
        if (camera_fill_rect_screen(
                camera,
                rect(
                    position.x,
                    LAYER_CELL_HEIGHT * (float) i + position.y,
                    LAYER_CELL_WIDTH,
                    LAYER_CELL_HEIGHT),
                LAYER_CELL_BACKGROUND_COLORS[i]) < 0) {
            return -1;
        }

        if (camera_render_text_screen(
                camera,
                LAYER_CELL_TITLES[i],
                vec(LAYER_TITLE_SIZE, LAYER_TITLE_SIZE),
                color_invert(LAYER_CELL_BACKGROUND_COLORS[i]),
                vec(position.x + LAYER_TITLE_PADDING,
                    LAYER_CELL_HEIGHT * (float) i + position.y + LAYER_TITLE_PADDING)) < 0) {
            return -1;
        }

        if (*layer_picker == i) {
            if (camera_fill_rect_screen(
                    camera,
                    rect(position.x,
                         position.y + LAYER_CELL_HEIGHT * (float) (i + 1) - SELECTOR_HEIGHT,
                         LAYER_CELL_WIDTH,
                         SELECTOR_HEIGHT),
                    color_invert(LAYER_CELL_BACKGROUND_COLORS[i])) < 0) {
                return -1;
            }
        }
    }

    return 0;
}

int layer_picker_event(LayerPicker *layer_picker,
                       const SDL_Event *event,
                       const Camera *camera,
                       bool *selected)
{
    trace_assert(layer_picker);
    trace_assert(event);
    trace_assert(camera);

    const Vec position = layer_picker_position(camera);

    switch (event->type) {
    case SDL_MOUSEBUTTONDOWN: {
        for (size_t i = 0; i < LAYER_PICKER_N; ++i) {
            const Rect cell = rect(position.x,
                                   LAYER_CELL_HEIGHT * (float) i + position.y,
                                   LAYER_CELL_WIDTH,
                                   LAYER_CELL_HEIGHT);
            if (rect_contains_point(cell, vec((float) event->button.x, (float) event->button.y))) {
                *layer_picker = i;
                *selected = true;
                return 0;
            }
        }
    } break;
    }

    return 0;
}