#include "comp/entity.h"
#include "comp/physical.h"
#include "comp/visible.h"
#include "comp/mechanical.h"
#include "comp/fighter.h"
#include "aoe.h"
#include "enemies.h"
#include <string.h>

/* Declare animations for an enemy */
#define ANIMS(name, I, W, A, H, D) \
    .anim_idle =    &anims_ ## name ## _ ## I, \
    .anim_walking = &anims_ ## name ## _ ## W, \
    .anim_attack =  &anims_ ## name ## _ ## A, \
    .anim_hit =     &anims_ ## name ## _ ## H, \
    .anim_death =   &anims_ ## name ## _ ## D

static enemy_t const slime_1 = {
    .name = "Slime",
    .level = 1,
    ANIMS(slime, Idle, Walking, Idle, Hit, Death),
    .hitbox = (rect){ -fix(3)/16, fix(4)/16, -fix(2)/16, fix(3)/16 },
    .limits = {
        .max_speed = fix(1),
        .friction = fix(0.6),
    },
    .stats = {
        .HP = fix(1.4),
        .ATK = fix(1.3),
        .MAG = fix(1.0),
        .DEF = fix(1.4),
    },
    .shadow_size = 4,
    .xp = 2,
    .z = 0,
};

static enemy_t const bat_2 = {
    .name = "Bat",
    .level = 2,
    ANIMS(bat, Idle, Idle, Idle, Hit, Death),
    .hitbox = (rect){ -fix(3)/16, fix(4)/16, -fix(2)/16, fix(3)/16 },
    .limits = {
        .max_speed = fix(1.8),
        .friction = fix(0.8),
    },
    .stats = {
        .HP = fix(1.5),
        .ATK = fix(1.5),
        .MAG = fix(1.3),
        .DEF = fix(1.2),
    },
    .shadow_size = 4,
    .xp = 6,
    .z = fix(0.75),
};

static enemy_t const fire_slime_4 = {
    .name = "Fire slime",
    .level = 4,
    ANIMS(fire_slime, Idle, Walking, Idle, Hit, Death),
    .hitbox = (rect){ -fix(3)/16, fix(4)/16, -fix(2)/16, fix(3)/16 },
    .limits = {
        .max_speed = fix(1),
        .friction = fix(0.6),
    },
    .stats = {
        .HP = fix(1.4),
        .ATK = fix(1.2),
        .MAG = fix(1.4),
        .DEF = fix(1.4),
    },
    .shadow_size = 4,
    .xp = 14,
    .z = 0,
};

static enemy_t const gunslinger_8 = {
    .name = "Gunslinger",
    .level = 8,
    ANIMS(gunslinger, Idle, Walking, Fire, Hit, Death),
    .hitbox = (rect){ -fix(3)/16, fix(4)/16, -fix(2)/16, fix(3)/16 },
    .limits = {
        .max_speed = fix(1.8),
        .friction = fix(0.8),
    },
    .stats = {
        .HP = fix(1.3),
        .ATK = fix(1.6),
        .MAG = fix(1.4),
        .DEF = fix(1.2),
    },
    .shadow_size = 4,
    .xp = 30,
    .z = fix(0.25),
};

static enemy_t const * const enemies[] = {
    [ENEMY_SLIME_1]       = &slime_1,
    [ENEMY_BAT_2]         = &bat_2,
    [ENEMY_FIRE_SLIME_4]  = &fire_slime_4,
    [ENEMY_GUNSLINGER_8]  = &gunslinger_8,
};

enemy_t const *enemy_data(int enemy_id)
{
    return enemies[enemy_id];
}

entity_t *enemy_make(int enemy_id)
{
    if(enemy_id < 0 || (size_t)enemy_id >= sizeof enemies / sizeof *enemies)
        return NULL;

    entity_t *e = entity_make(physical, visible, mechanical, fighter);
    if(e == NULL)
        return NULL;

    enemy_t const *data = enemies[enemy_id];

    /* These will probably be overridden by the caller */

    physical_t *p = getcomp(e, physical);
    p->x = fix(0);
    p->y = fix(0);
    p->hitbox = data->hitbox;
    p->facing = LEFT;

    visible_t *v = getcomp(e, visible);
    v->z = data->z;
    v->sprite_plane = VERTICAL;
    v->shadow_size = data->shadow_size;
    visible_set_anim(e, data->anim_idle, 1);

    mechanical_t *m = getcomp(e, mechanical);
    m->limits = &data->limits;
    m->vx = fix(0);
    m->vy = fix(0);
    m->dash = fix(0);
    m->dash_facing = LEFT;

    /* Instantiate fighter statistics */
    fighter_t *f = getcomp(e, fighter);
    memset(f, 0, sizeof *f);

    f->enemy_data = data;
    fighter_set_stats(f, &data->stats, data->level, fix(1.0));
    f->HP = f->HP_max;
    f->combo_length = 1;

    return e;
}

/* Enemy AIs */

static void move_towards_player(game_t *g, entity_t *e, fixed_t dt)
{
    physical_t *p = getcomp(e, physical);
    vec2 pos = physical_pos(e);
    vec2 direction;

    if(dist2(pos, physical_pos(g->player)) <= fix(0.25)) /* 0.5^2 */
        return;

    pfg_path_t path = pfg_bfs_inwards(&g->paths_to_player, vec_f2i(pos));
    if(path.points) {
        direction = pfc_shortcut_one(&path, pos, physical_pos(g->player),
            p->hitbox);
        pfg_path_free(&path);
    }

    if(direction.x && direction.y) {
        direction.x -= pos.x;
        direction.y -= pos.y;
    }

    mechanical_move(e, direction, dt, g->map);
    if(direction.x > 0) p->facing = RIGHT;
    else if(direction.x < 0) p->facing = LEFT;
    else if(p->x < getcomp(g->player, physical)->x) p->facing = RIGHT;
    else p->facing = LEFT;
}

static bool move_within_range_of_player(game_t *g, entity_t *e, fixed_t range,
    fixed_t dt)
{
    if(dist2(physical_pos(e), physical_pos(g->player)) <= fmul(range, range))
        return true;

    move_towards_player(g, e, dt);
    return false;
}

static bool contact_attack(game_t *g, entity_t *e)
{
    fighter_t *f = getcomp(e, fighter);
    if(f->current_attack)
        return false;

    physical_t *p = getcomp(e, physical);
    physical_t *player_p = getcomp(g->player, physical);

    vec2 dir = { player_p->x - p->x, player_p->y - p->y };
    dir = fnormalize(dir);

    entity_t *aoe = aoe_make_attack(AOE_HIT, e, dir);
    game_add_entity(g, aoe);

    f->current_attack = aoe;
    f->attack_follows_movement = true;
    visible_set_anim(e, f->enemy_data->anim_attack, 2);

    return true;
}

static bool range_attack(game_t *g, entity_t *e)
{
    fighter_t *f = getcomp(e, fighter);
    if(f->current_attack)
        return false;

    physical_t *p = getcomp(e, physical);
    physical_t *player_p = getcomp(g->player, physical);

    vec2 dir = { player_p->x - p->x, player_p->y - p->y };
    dir = fnormalize(dir);

    entity_t *aoe = aoe_make_attack(AOE_PROJECTILE, e, dir);
    game_add_entity(g, aoe);

    f->current_attack = aoe;
    f->attack_follows_movement = false;
    visible_set_anim(e, f->enemy_data->anim_attack, 2);

    return true;
}

void enemy_ai(game_t *g, entity_t *e, fixed_t dt)
{
    fighter_t *f = getcomp(e, fighter);

    if(f->enemy_data == &slime_1 || f->enemy_data == &bat_2) {
        if(move_within_range_of_player(g, e, fix(1.0), dt)) {
            contact_attack(g, e);
        }
    }

    else if(f->enemy_data == &fire_slime_4) {
    }

    else if(f->enemy_data == &gunslinger_8) {
        rect hitbox = { fix(-1/16), fix(1/16), fix(-1/16), fix(1/16) };
        bool clear = raycast_clear_hitbox(g->map, physical_pos(e),
            physical_pos(g->player), hitbox);

        if(clear)
            range_attack(g, e);
        else
            move_towards_player(g, e, dt);
    }
}