#include <stdint.h>

#include "keyb.h"
#include "vga.h"
#include "map.h"
#include "data.h"
#include "game.h"

#include "player.h"

#define DIR_RIGHT 0
#define DIR_LEFT 1

#define FRAME_STANDING 0
#define FRAME_JUMPING 4
#define FRAME_DYING 5

#define WALK_CYCLE_FRAMES 4
#define WALK_DELAY 8

#define GRAVITY_OFF 0
/* XXX: subtract 1 to get the value from gravity_seq */
#define GRAVITY_DOWN 14
#define GRAVITY_UP 1

#define GRAVITY_SEQ_LEN 24

#define IS_NOT_GOING_UP(x) (gravity == GRAVITY_OFF || (x)>=GRAVITY_DOWN)

static uint16_t x, y;
static uint8_t dir, frame, delay, gravity, jump;

const uint8_t gravity_seq[GRAVITY_SEQ_LEN] = {
    6, 4, 4, 2, 2, 2, 2, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 4
};

static uint8_t bg[256];

static const Rect frames[2][6] =
{
    {
        /* walk cycle */
        { 0, 0, 144, 144 },
        { 16, 0, 144, 144 },
        { 0, 0, 144, 144 },
        { 32, 0, 144, 144 },

        /* jump */
        { 48, 0, 144, 144 },

        /* dying */
        { 128, 0, 144, 144 },
    },
    {
        /* walk cycle */
        { 64, 0, 144, 144 },
        { 80, 0, 144, 144 },
        { 64, 0, 144, 144 },
        { 96, 0, 144, 144 },

        /* jump */
        { 112, 0, 144, 144 },

        /* dying */
        { 128, 0, 144, 144 },
    },
};

void player_init(uint16_t start_x, uint8_t start_y)
{
    dir = DIR_RIGHT;
    frame = FRAME_STANDING;
    delay = 0;
    jump = 0;

    x = start_x;
    y = start_y;
    gravity = GRAVITY_OFF;
}

void player_update()
{
    uint8_t moved = 0;

    if (gravity == GRAVITY_OFF
            && !map_is_blocked(x + 4, y + 16)
            && !map_is_blocked(x + 11, y + 16))
    {
        gravity = GRAVITY_DOWN;
        frame = FRAME_JUMPING;
        moved = 1;
    }

    if (keys[KEY_UP])
    {
        if (gravity == GRAVITY_OFF && !jump)
        {
            jump = 1;
            frame = FRAME_JUMPING;
            gravity = GRAVITY_UP;
        }
    }
    else
        jump = 0;

    if (keys[KEY_RIGHT] && !keys[KEY_LEFT])
    {
        moved = 1;
        dir = DIR_RIGHT;

        /* XXX: off limits */
        if (x < MAP_W * MAP_TILE_W - 16)
        {
            if ((IS_NOT_GOING_UP(gravity) && !map_is_blocked(x + 16, y + 15))
                    || (!IS_NOT_GOING_UP(gravity)
                        && !(map_is_blocked(x + 16, y + 15)
                             && map_is_blocked(x + 16, y + 7))))
                x++;
        }
    }

    if (keys[KEY_LEFT] && !keys[KEY_RIGHT])
    {
        moved = 1;
        dir = DIR_LEFT;

        /* XXX: off limits */
        if (x)
        {
            if ((IS_NOT_GOING_UP(gravity) && !map_is_blocked(x - 1, y + 15))
                    || (!IS_NOT_GOING_UP(gravity)
                        && !(map_is_blocked(x - 1, y + 15)
                             && map_is_blocked(x - 1, y + 7))))
                x--;
        }
    }

    if (gravity != GRAVITY_OFF)
    {
        uint8_t steps = gravity_seq[gravity - 1];

        moved = 1;

        if (gravity > GRAVITY_DOWN)
        {
            /* going down! */
            for (uint8_t i = 0; i < steps; i++)
            {
                /* hit the floor */
                if ((map_is_blocked(x + 11, y + 16)
                        || map_is_blocked(x + 4, y + 16))
                        && !map_is_blocked(x + 4, y + 15)
                        && !map_is_blocked(x + 11, y + 15))
                {
                    gravity = GRAVITY_OFF;
                    frame = FRAME_STANDING;
                    break;
                }
                y++;
            }
        }
        else
        {
            /* going up! */
            if (y < steps)
                y = 0;
            else
                y -= steps;
        }

        if (gravity != GRAVITY_OFF && gravity != GRAVITY_SEQ_LEN)
            gravity++;
    }

    if (moved)
    {
        if (delay++ == WALK_DELAY)
        {
            delay = 0;
            if (frame != FRAME_JUMPING)
            {
                frame++;
                if (frame == WALK_CYCLE_FRAMES)
                    frame = FRAME_STANDING;
            }
        }
    }
    else
    {
        delay = 0;
        frame = FRAME_STANDING;
    }

    if (map_update_gold(x + (dir == DIR_LEFT ? 7 : 8), y + 15))
        add_score(10);
}

void player_erase()
{
    Rect dst = { x, y + MAP_OFFS_Y, 16, 16 };
    blit(bg, &dst);
}

void player_draw()
{
    Rect dst = { x, y + MAP_OFFS_Y, 16, 16 };

    read_buffer(bg, &dst);
    blitrc(binary_sprites_start, &frames[dir][frame], &dst);
}