#define __BSD_VISIBLE 1
#include <azur/azur.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include "chaos-drop.h"

#if defined(AZUR_TOOLKIT_SDL)
#include <SDL2/SDL.h>
#include <azur/gl/gl.h>
#include <memory>
#include "backend/linux/programs.h"

static uint16_t vram[VWIDTH * VHEIGHT];
std::unique_ptr<ProgramTexture> shader_texture = nullptr;
static GLuint tex_vram;

static void view_update(void)
{
    SDL_Window *window = azur_sdl_window();
    int width, height;
    SDL_GetWindowSize(window, &width, &height);

    /* Transform from pixel coordinates within the winfow to GL coordinates */
    glm::mat3 tr_pixel2gl(
         2.0f / width,                0.0f,                       0.0f,
         0.0f,                       -2.0f / height,              0.0f,
        -1.0f,                        1.0f,                       1.0f);

    glUseProgram(shader_texture->prog);
    shader_texture->set_uniform("u_transform", tr_pixel2gl);
}

static void init(void)
{
    shader_texture = std::make_unique<ProgramTexture>();
    view_update();
    memset(vram, 0x55, sizeof vram);

    glGenTextures(1, &tex_vram);
    glBindTexture(GL_TEXTURE_2D, tex_vram);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, VWIDTH, VHEIGHT, 0, GL_RGB,
        GL_UNSIGNED_SHORT_5_6_5, vram);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
}

static void quit(void)
{
}

static int platform_update(struct input *input)
{
    SDL_Event e;
    *input = (struct input){};

    while(SDL_PollEvent(&e)) {
//        ImGui_ImplSDL2_ProcessEvent(&e);
//        render_needed = std::max(render_needed, 1);

        if(e.type == SDL_QUIT)
            return 1;
        if(e.type == SDL_WINDOWEVENT &&
                e.window.event == SDL_WINDOWEVENT_SIZE_CHANGED) {
            view_update();
        }
    }

    Uint8 const *state = SDL_GetKeyboardState(NULL);
    input->up = state[SDL_SCANCODE_UP];
    input->down = state[SDL_SCANCODE_DOWN];
    input->left = state[SDL_SCANCODE_LEFT];
    input->right = state[SDL_SCANCODE_RIGHT];
    input->roll_left = state[SDL_SCANCODE_F1];
    input->roll_right = state[SDL_SCANCODE_F2];
    return 0;
}

static void platform_render(void)
{
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, VWIDTH, VHEIGHT, 0, GL_RGB,
        GL_UNSIGNED_SHORT_5_6_5, vram);

    SDL_Window *window = azur_sdl_window();

    shader_texture->vertices.clear();
    shader_texture->add_texture(0, 0, 3*VWIDTH, 3*VHEIGHT);
    shader_texture->draw();

    SDL_GL_SwapWindow(window);
}

static void draw_text(int x, int y, char const *str, int size)
{
    // TODO: SDL: Text rendering
}

static int text_size(char const *str, int length)
{
    // TODO: SDL: Text rendering
    return 0;
}

#elif defined(AZUR_TOOLKIT_GINT)

#include <azur/gint/render.h>
#include <gint/gint.h>
#include <gint/keyboard.h>
#include <gint/display.h>
#include <gint/drivers/r61524.h>
#include <libprof.h>
#define vram gint_vram

static int platform_update(struct input *input)
{
    key_event_t e;

    while((e = pollevent()).type != KEYEV_NONE) {
        if(e.type == KEYEV_UP)
            continue;

        if(e.key == KEY_EXIT)
            return 1;
        if(e.key == KEY_MENU)
            gint_osmenu();
        if(e.key == KEY_OPTN)
            input->OPTN = true;
        if(e.key == KEY_F1)
            input->roll_left = true;
        if(e.key == KEY_F2)
            input->roll_right = true;
        if(e.key == KEY_EXE && keydown(KEY_VARS))
            input->RESET_LEVEL = true;
        if(e.key == KEY_MINUS && keydown(KEY_VARS))
            input->PREV_LEVEL = true;
        if(e.key == KEY_PLUS && keydown(KEY_VARS))
            input->NEXT_LEVEL = true;
    }

    input->left = keydown(KEY_LEFT);
    input->right = keydown(KEY_RIGHT);
    input->up = keydown(KEY_UP);
    input->down = keydown(KEY_DOWN);
    return 0;
}

static void platform_render(void)
{
    azrp_update();
}

static void init(void)
{
    prof_init();
    azrp_config_scale(2);
    cd_raytrace_configure();
    azrp_shader_clear_configure();
    azrp_shader_image_p8_configure();
}

static void quit(void)
{
    prof_quit();
}

static uint8_t const font_glyph_width[96] = {
    3,1,3,5,5,4,5,2,2,2,3,5,2,5,2,3,
    4,4,4,4,4,4,4,4,4,4,2,2,3,4,3,4,
    5,4,4,4,4,4,4,4,4,1,4,4,4,5,4,4,
    4,4,4,4,5,4,5,5,5,5,4,2,3,2,5,4,
    2,4,4,4,4,4,4,4,4,1,2,4,3,5,4,4,
    4,4,4,4,4,4,5,5,5,4,4,3,1,3,5,4,
};

/* Very bad text renderer */
static void draw_text(int x, int y, char const *str, int size)
{
    extern bopti_image_t img_font;

    for(int i = 0; str[i] && i < size; i++) {
        if(str[i] < 32 || str[i] >= 0x7f)
            continue;

        int row = (str[i] - 32) >> 4;
        int col = (str[i] - 32) & 15;
        int gw = font_glyph_width[str[i] - 32];
        azrp_subimage(x, y, &img_font, 7 * col + 1, 9 * row + 1, gw, 8,
            DIMAGE_NONE);
        x += gw + 1;
    }
}

static int text_size(char const *str, int length)
{
    int total = 0;

    for(int i = 0; str[i] && i < length; i++) {
        if(str[i] < 32 || str[i] >= 0x7f)
            continue;
        total += font_glyph_width[str[i] - 32] + 1;
    }

    return total - (total > 0);
}

#endif

mat3 operator *(mat3 const &A, mat3 const &B)
{
    mat3 C;

    C.x11 = A.x11 * B.x11 + A.x12 * B.x21 + A.x13 * B.x31;
    C.x12 = A.x11 * B.x12 + A.x12 * B.x22 + A.x13 * B.x32;
    C.x13 = A.x11 * B.x13 + A.x12 * B.x23 + A.x13 * B.x33;

    C.x21 = A.x21 * B.x11 + A.x22 * B.x21 + A.x23 * B.x31;
    C.x22 = A.x21 * B.x12 + A.x22 * B.x22 + A.x23 * B.x32;
    C.x23 = A.x21 * B.x13 + A.x22 * B.x23 + A.x23 * B.x33;

    C.x31 = A.x31 * B.x11 + A.x32 * B.x21 + A.x33 * B.x31;
    C.x32 = A.x31 * B.x12 + A.x32 * B.x22 + A.x33 * B.x32;
    C.x33 = A.x31 * B.x13 + A.x32 * B.x23 + A.x33 * B.x33;

    return C;
}

vec3 operator * (mat3 const &M, vec3 const &u)
{
    vec3 v;

    v.x = M.x11 * u.x + M.x12 * u.y + M.x13 * u.z;
    v.y = M.x21 * u.x + M.x22 * u.y + M.x23 * u.z;
    v.z = M.x31 * u.x + M.x32 * u.y + M.x33 * u.z;

    return v;
}

__attribute__((unused))
 static void print_text(int x, int y, char const *fmt, ...)
{
    static char str[128];
    va_list args;
    va_start(args, fmt);
    vsnprintf(str, sizeof str, fmt, args);
    va_end(args);
    draw_text(x, y, str, strlen(str));
}

void render_centered_text(char const *str)
{
    /* Count lines */
    int lines = 1;
    for(int i = 0; str[i]; i++)
        lines += str[i] == '\n';

    static int const line_height = 10;
    int y = (VHEIGHT - line_height * lines) / 2;

    /* Draw each line centered */
    char const *line = str;
    char const *endline;
    while(*line) {
        endline = strchrnul(line, '\n');
        int w = text_size(line, endline - line);
        draw_text((VWIDTH - w) / 2, y, line, endline - line);
        line = endline + (*endline != 0);
        y += line_height;
    }
}

static struct camera *camera = NULL;
static struct world *world = NULL;
static int reset_frames = 0;
static bool debug = false;

#ifdef AZUR_TOOLKIT_GINT
extern struct level level_1_1, level_1_2, level_1_3;
extern struct level level_2_1, level_2_2, level_2_3;
extern struct level level_3_1, level_3_2, level_3_3;
static struct level const *levels[] = {
    &level_1_1, &level_1_2, &level_1_3,
    &level_2_1, &level_2_2, &level_2_3,
};
#else
/* Basic basic level */
static struct level const lv_test = {
    .name = "<Test>",
    .finish = num(1024),
    .mirror_count = 1,
    .mirrors = (struct element_mirror[]){
        { .begin = 256, .end = 768 },
    },
    .plane_count = 2,
    .planes = (struct element_plane[]){
        { .y = 384, .shape = 0b01010'10101'01010'10101'01010,
          .type = ELEMENT_PLANE_DAMAGE, .data = 0 },
        { .y = 384+64, .shape = 0b11111'10001'10001'10001'11111,
          .type = ELEMENT_PLANE_DAMAGE, .data = 0 },
    },
    .text_count = 1,
    .texts = (struct element_text[]){
        { .begin = 32, .end = 256,
          .str = "Red stuff bad!\nDon't touch the red stuff!", },
    },
};
static struct level const *levels[] = { &lv_test };
#endif

static int current_level = 0;

void load_level_number(int number)
{
    int total_number = sizeof levels / sizeof levels[0];

    if(number < 0)
        number = 0;
    if(number > total_number)
        number = total_number - 1;

    current_level = number;
}

bool is_final_level(int number)
{
    int total_number = sizeof levels / sizeof levels[0];
    return number >= total_number - 1;
}

void world_reset(struct world *world)
{
    world->neon_position = 0;
    world->depth = 0;
    world->neon_period = 64;
    world->mirror = NULL;
    world->plane = NULL;
    world->text = NULL;
    world->mirror_index = 0;
    world->plane_index = 0;
    world->text_index = 0;
}

void world_level_transition(struct world *world)
{
    world->depth = world->depth % num(world->neon_period);
    world->mirror = NULL;
    world->plane = NULL;
    world->text = NULL;
    world->mirror_index = 0;
    world->plane_index = 0;
    world->text_index = 0;
}

void render(void)
{
    struct level const *level = levels[current_level];

#ifdef AZUR_TOOLKIT_GINT
    azrp_perf_clear();
    if(reset_frames > 0) {
        reset_frames--;
        azrp_clear(0xffff);
    }
    else {
        cd_raytrace(camera, world);
        if(world->text)
            render_centered_text(world->text->str);
        draw_text(1, 1, level->name, strlen(level->name));
    }
    platform_render();

    if(debug) {
        drect(0, DHEIGHT-20, DWIDTH-1, DHEIGHT-1, C_WHITE);
        dprint(4, 209, C_BLACK, "render:%4d+%4dus",
            prof_time(azrp_perf_render) - prof_time(azrp_perf_r61524),
            prof_time(azrp_perf_r61524));
        r61524_display(gint_vram, DHEIGHT-20, 20, R61524_DMA_WAIT);
    }
#else
    if(reset_frames > 0) {
        reset_frames--;
        memset(vram, 0xff, sizeof vram);
    }
    else {
        render_fragment(camera, world, vram, 0, VHEIGHT);
        if(world->text)
            render_centered_text(world->text->str);
        draw_text(1, 1, level->name, strlen(level->name));
    }
    platform_render();
#endif
}

int update(void)
{
    struct input input = {};
    if(platform_update(&input))
        return 1;

    /* Debug contros */
    if(input.OPTN)
        debug = !debug;
    if(input.RESET_LEVEL) {
        world_reset(world);
        reset_frames = 2;
    }
    if(input.NEXT_LEVEL && !is_final_level(current_level)) {
        world_level_transition(world);
        load_level_number(current_level+1);
        reset_frames = 2;
    }
    if(input.PREV_LEVEL && current_level > 0) {
        world_level_transition(world);
        load_level_number(current_level-1);
        reset_frames = 2;
    }
    if(reset_frames > 0)
        return 0;

    static num const mv_speed = 0.45;
    static num const wall = WORLD_SIZE * 0.45; /* margin */
    static float const rot_speed = 0.01;
    static float const rot_snap = 0.6;
    static float const rot_max = 0.2;
    static num const fall_speed = 2;
    static float const barrel_snap = 0.5;

    if(input.left) {
        camera->pos -= mv_speed * camera->right;
        camera->yaw = fmaxf(camera->yaw - rot_speed, -rot_max);
    }
    else if(input.right) {
        camera->pos += mv_speed * camera->right;
        camera->yaw = fminf(camera->yaw + rot_speed, rot_max);
    }
    else {
        camera->yaw *= rot_snap;
    }

    if(input.up) {
        camera->pos += mv_speed * camera->up;
        camera->pitch = fmaxf(camera->pitch - rot_speed, -rot_max);
    }
    else if(input.down) {
        camera->pos -= mv_speed * camera->up;
        camera->pitch = fminf(camera->pitch + rot_speed, rot_max);
    }
    else {
        camera->pitch *= rot_snap;
    }

    camera->pos.x = clamp(camera->pos.x, -wall, wall);
    camera->pos.z = clamp(camera->pos.z, -wall, wall);

    if(input.roll_left && !camera_rolling(camera)) {
        camera->roll_quadrant = (camera->roll_quadrant + 4 - 1) % 4;
    }
    else if(input.roll_right && !camera_rolling(camera)) {
        camera->roll_quadrant = (camera->roll_quadrant + 1) % 4;
    }

    camera_roll(camera, barrel_snap);
    camera_update_angles(camera);

    world->depth += fall_speed;
    world->neon_position += world->neon_period - num16(fall_speed);
    world->neon_position %= world->neon_period;

    // Remove old world elements

    struct world *w = world;

    if(w->mirror && w->depth > w->mirror->end)
        w->mirror = NULL;
    if(w->plane && w->depth > w->plane->y - num(4)) {
        /* Apply plane effect */
        if((w->plane->type == ELEMENT_PLANE_DAMAGE ||
            w->plane->type == ELEMENT_PLANE_INVIS)
           && plane_collides(num16(camera->pos.x), num16(camera->pos.z),
                    w->plane->shape)) {
            world_reset(w);
            reset_frames = 2;
        }
        else if(w->plane->type == ELEMENT_PLANE_ARROW &&
                camera->roll_quadrant != w->plane->data) {
            world_reset(w);
            reset_frames = 2;
        }
        w->plane = NULL;
    }
    if(w->text && w->depth > w->text->end)
        w->text = NULL;

    // Load incoming world elements

    struct level const *level = levels[current_level];

    if(!w->mirror && w->mirror_index < level->mirror_count
            && level->mirrors[w->mirror_index].begin < w->depth + num(64)) {
        w->mirror = &level->mirrors[w->mirror_index++];
    }
    if(!w->plane && w->plane_index < level->plane_count
            && level->planes[w->plane_index].y < w->depth + num(64)) {
        w->plane = &level->planes[w->plane_index++];
    }
    if(!w->text && w->text_index < level->text_count
            && level->texts[w->text_index].begin < w->depth + num(64)) {
        w->text = &level->texts[w->text_index++];
    }

    // End of level

    if(!w->mirror && !w->plane && !w->text && w->depth >= level->finish
        && !reset_frames) {
        if(is_final_level(current_level)) {
            // TODO: Main menu
            return 1;
        }
        else {
            world_level_transition(w);
            load_level_number(current_level + 1);
        }
    }

    return 0;
}

int main(void)
{
    if(azur_init("Chaos Drop!", 3*VWIDTH, 3*VHEIGHT))
        return 1;

    struct camera c = {};
    camera = &c;
    /* TODO: Why do I need such a low FOV?! */
    camera_set_fov(camera, 80.0);
    camera_update_angles(camera);

    struct world w = {};
    load_level_number(0);
    world_reset(&w);
    world = &w;

    init();
    int rc = azur_main_loop(render, 30, update, -1, AZUR_MAIN_LOOP_TIED);
    quit();
    return rc;
}