#include "comp/entity.h"
#include "comp/physical.h"
#include "comp/visible.h"
#include "comp/fighter.h"
#include "comp/particle.h"
#include "aoe.h"
#include "game.h"
#include "enemies.h"

entity_t *aoe_make(uint16_t type, vec2 position, fixed_t lifetime)
{
    entity_t *e = entity_make(physical, visible, aoe);

    physical_t *p = getcomp(e, physical);
    p->x = position.x;
    p->y = position.y;

    aoe_t *aoe = getcomp(e, aoe);
    aoe->type = type;
    aoe->lifetime = lifetime;
    aoe->hits = NULL;
    aoe->hit_count = 0;

    return e;
}

void aoe_destroy(entity_t *e)
{
    aoe_t *aoe = getcomp(e, aoe);
    free(aoe->hits);
}

entity_t *aoe_make_attack(uint16_t type, entity_t *origin, vec2 dir)
{
    entity_t *e = aoe_make(type, physical_pos(origin), fix(0));
    if(e == NULL)
        return NULL;

    fighter_t *f = getcomp(origin, fighter);

    physical_t *p = getcomp(e, physical);
    visible_t *v = getcomp(e, visible);
    aoe_t *aoe = getcomp(e, aoe);

    rect hitbox = { 0 };
    fixed_t distance = fix(0.5);
    anim_t const *anim = NULL;
    bool rotate = true;
    fixed_t lifetime = fix(0);
    int plane = VERTICAL;

    if(type == AOE_HIT) {
        anim = &anims_skill_hit;
        hitbox = (rect){ -fix(4)/16, fix(3)/16, -fix(4)/16, fix(3)/16 };
        distance = fix(0.375);
    }
    else if(type == AOE_PROJECTILE || type == AOE_PROJECTILE_FAST) {
        anim = &anims_skill_projectile;
        hitbox = (rect){ -fix(1)/16, fix(1)/16, -fix(1)/16, fix(1)/16 };
        distance = fix(0.5);
        lifetime = fix(999.0);
    }
    else if(type == AOE_SLASH) {
        anim = &anims_skill_swing;
        hitbox = (rect){ -fix(10)/16, fix(10)/16, -fix(8)/16, 0 };
    }
    else if(type == AOE_IMPALE) {
        anim = &anims_skill_impale;
        hitbox = (rect){ -fix(4)/16, fix(4)/16, -fix(10)/16, 0 };
    }
    else if(type == AOE_SHOCK) {
        anim = &anims_skill_shock;
        hitbox = (rect){ -fix(23)/16, fix(24)/16, -fix(23)/16, fix(24)/16 };
        distance = fix(0);
        rotate = false;
        plane = HORIZONTAL;
    }
    else if(type == AOE_JUDGEMENT) {
        anim = &anims_skill_judgement;
        hitbox = (rect){ -fix(10)/16, fix(11)/16, -fix(6)/16, fix(6)/16 };
        distance = fix(1.5);
        rotate = false;
    }
    else if(type == AOE_BULLET) {
        anim = &anims_skill_bullet;
        hitbox = (rect){ -fix(8)/16, fix(8)/16, -fix(7)/16, fix(7)/16 };
        distance = fix(0.375);
        lifetime = fix(999.0);
    }
    else if(type == AOE_FIRE_CHARGE
         || type == AOE_WATER_CHARGE
         || type == AOE_CHEMICAL_CHARGE) {
        anim = NULL;
        hitbox = (rect){ -fix(12)/16, fix(12)/16, -fix(13)/16, fix(2)/16 };
        distance = fix(0);
        lifetime = fix(1.1);
        rotate = false;
    }

    p->x += fmul(distance, dir.x);
    p->y += fmul(distance, dir.y);
    p->facing = frdir(dir);
    p->hitbox = rotate ? rect_rotate(hitbox, UP, p->facing) : hitbox;

    v->sprite_plane = plane;

    if(lifetime)
        aoe->lifetime = lifetime;
    else if(anim)
        aoe->lifetime = anim_duration(anim);
    else
        aoe->lifetime = fix(1.0);

    aoe->repeat_delay = 0;
    aoe->origin = origin;

    if(type == AOE_HIT
    || type == AOE_SLASH
    || type == AOE_IMPALE) {
        aoe->data.generic.strength = f->ATK;
        aoe->data.generic.dir = p->facing;
    }
    else if(type == AOE_JUDGEMENT) {
        aoe->data.generic.strength = f->MAG;
        aoe->data.generic.dir = p->facing;
    }
    else if(type == AOE_PROJECTILE || type == AOE_PROJECTILE_FAST) {
        aoe->data.projectile.strength = f->ATK;
        aoe->data.projectile.direction = dir;
        if(type == AOE_PROJECTILE_FAST)
            aoe->data.projectile.speed = fix(6.0);
        else
            aoe->data.projectile.speed = fix(3.0);
        p->facing = (dir.x >= 0 ? RIGHT : LEFT);
        v->z = fix(0.5);
        v->shadow_size = 3;
    }
    else if(type == AOE_SHOCK) {
        aoe->data.shock.strength = f->ATK;
        aoe->data.shock.origin = physical_pos(origin);
        aoe->repeat_delay = fix(0.2);
    }
    else if(type == AOE_BULLET) {
        aoe->data.bullet.strength = f->MAG;
        aoe->data.bullet.dir = p->facing;
        aoe->data.bullet.v = fix(10.0);
        aoe->data.bullet.final_v = fix(4.5);
        aoe->repeat_delay = fix(0.05);
        v->z = fix(0.5);
        v->shadow_size = 4;
    }
    else if(type == AOE_FIRE_CHARGE
         || type == AOE_WATER_CHARGE
         || type == AOE_CHEMICAL_CHARGE) {
        aoe->data.charge.element = 0;
        aoe->data.charge.power = f->MAG;
        aoe->data.charge.origin = physical_pos(origin);
        aoe->repeat_delay = fix(0.2);
    }

    visible_set_anim(e, anim, 1);
    return e;
}

entity_t *aoe_make_attack_4(uint16_t type, entity_t *origin, int facing)
{
    return aoe_make_attack(type, origin, fdir(facing));
}


/* Existing record of the area hitting this entity */
static aoe_record_t *aoe_record(aoe_t *aoe, entity_t *target)
{
    for(int i = 0; i < aoe->hit_count; i++) {
        aoe_record_t *r = &aoe->hits[i];
        if(r->entity == target) return r;
    }
    return NULL;
}

static bool attack_apply(game_t *game, aoe_t *aoe, entity_t *target)
{
    fighter_t *origin_f = !aoe->origin ? NULL : getcomp(aoe->origin, fighter);
    fighter_t *target_f = getcomp(target, fighter);
    mechanical_t *target_m = getcomp(target, mechanical);
    physical_t *target_p = getcomp(target, physical);

    if(!target_f)
        return false;
    if(target_f->invulnerability_delay > 0)
        return false;

    /* No friendly fire */
    bool origin_is_monster = !aoe->origin ? true :
                             (origin_f && origin_f->enemy != NULL);
    bool target_is_monster = (target_f->enemy != NULL);
    if(origin_is_monster == target_is_monster || target_f->HP == 0)
        return false;

    /* Dash invincibility */
    if(target_m && mechanical_dashing(target))
        return false;

    /* Knockback */
    fixed_t r = (rand() & (fix(0.125)-1)) + fix(0.375);
    /* Half knockback against players */
    if(!target_f->enemy) r /= 2;

    vec2 dir = { 0, 0 };
    int damage = 0;

    if(aoe->type == AOE_HIT
    || aoe->type == AOE_SLASH
    || aoe->type == AOE_IMPALE) {
        dir = fdir(aoe->data.generic.dir);
        damage = aoe->data.generic.strength;
    }
    else if(aoe->type == AOE_PROJECTILE || aoe->type == AOE_PROJECTILE_FAST) {
        dir = aoe->data.projectile.direction;
        damage = aoe->data.projectile.strength;
        r /= 2;
        /* Projectile disappears after hitting a single target */
        aoe->lifetime = fix(0);
    }
    else if(aoe->type == AOE_SHOCK) {
        dir.x = target_p->x - aoe->data.shock.origin.x;
        dir.y = target_p->y - aoe->data.shock.origin.y;
        dir = fnormalize(dir);
        damage = aoe->data.shock.strength * 3 / 2;
        r /= 4;
        fighter_effect_stun(target, fix(0.1));
    }
    else if(aoe->type == AOE_JUDGEMENT) {
        r = fix(0);
        damage = aoe->data.generic.strength * 3;
    }
    else if(aoe->type == AOE_BULLET) {
        /* TODO: Sideways knockback */
        damage = aoe->data.bullet.strength * 3 / 2;
    }
    else if(aoe->type == AOE_FIRE_CHARGE
         || aoe->type == AOE_WATER_CHARGE
         || aoe->type == AOE_CHEMICAL_CHARGE) {
        dir.x = target_p->x - aoe->data.charge.origin.x;
        dir.y = target_p->y - aoe->data.charge.origin.y;
        dir = fnormalize(dir);
        damage = aoe->data.charge.power * 3 / 2;
        r /= 4;
        fighter_effect_stun(target, fix(0.1));
    }

    /* Inflict damage */
    damage = fighter_damage(target, damage);

    /* Apply knockback */
    if(target_m) {
        target_m->vdx += fmul(dir.x, fmul(r, KNOCKBACK_SPEED));
        target_m->vdy += fmul(dir.y, fmul(r, KNOCKBACK_SPEED));
    }

    /* Spawn damage particle */
    entity_t *particle = particle_make_damage(target, damage,
        target_f->enemy ? C_WHITE : C_RED);
    game_add_entity(game, particle);

    /* Quick screenshake for entities hit by a bullet */
    if(aoe->type == AOE_BULLET)
        game_shake(game, 3, fix(0.1));

    return true;
}

void aoe_apply(game_t *game, entity_t *entity, entity_t *e)
{
    bool was_hit = false;
    aoe_t *aoe = getcomp(entity, aoe);
    aoe_record_t *rec = aoe_record(aoe, e);
    fighter_t *e_f = getcomp(e, fighter);

    if(aoe->type == AOE_ITEM && e_f && e_f->player) {
        bool picked = player_give_item(e, aoe->data.item.type);
        if(picked) {
            game_hud_anim_backpack_item(game);
            aoe->lifetime = 0;
        }
        /* Don't bother recording the hit since the item will disappear */
        was_hit = false;
    }

    /* Don't hit entities that have been recently hit */
    if(rec && aoe->repeat_delay == 0) return;
    if(rec && aoe->lifetime > rec->lifetime - aoe->repeat_delay) return;

    if(aoe->type == AOE_HIT
    || aoe->type == AOE_PROJECTILE
    || aoe->type == AOE_PROJECTILE_FAST
    || aoe->type == AOE_SLASH
    || aoe->type == AOE_IMPALE
    || aoe->type == AOE_SHOCK
    || aoe->type == AOE_BULLET
    || aoe->type == AOE_FIRE_CHARGE
    || aoe->type == AOE_WATER_CHARGE
    || aoe->type == AOE_CHEMICAL_CHARGE)
        was_hit = attack_apply(game, aoe, e);

    if(aoe->type == AOE_JUDGEMENT) {
        fixed_t total_duration = anim_duration(&anims_skill_judgement);
        fixed_t elapsed = total_duration - aoe->lifetime;
        /* The AOE deals damage only during a part of the animation */
        if(elapsed >= fix(0.360) && elapsed < fix(0.960))
            was_hit = attack_apply(game, aoe, e);
    }

    if(!was_hit) return;

    /* Update record */
    if(!rec) {
        size_t new_size = (aoe->hit_count + 1) * sizeof *aoe->hits;
        aoe_record_t *new_hits = realloc(aoe->hits, new_size);
        if(!new_hits) return;

        aoe->hits = new_hits;
        rec = &new_hits[aoe->hit_count];
        rec->entity = e;
        aoe->hit_count++;
    }

    rec->lifetime = aoe->lifetime;
}

void aoe_update(game_t *game, entity_t *entity, fixed_t dt)
{
    physical_t *p = getcomp(entity, physical);
    aoe_t *aoe = getcomp(entity, aoe);

    if(aoe->type == AOE_PROJECTILE || aoe->type == AOE_PROJECTILE_FAST) {
        fixed_t v = aoe->data.projectile.speed;
        p->x += fmul(fmul(aoe->data.projectile.direction.x, v), dt);
        p->y += fmul(fmul(aoe->data.projectile.direction.y, v), dt);

        rect small_box = { 0, 0, 0, 0 };
        small_box = rect_translate(small_box, physical_pos(entity));

        if(map_collides(game->map, small_box))
            aoe->lifetime = 0;
    }
    else if(aoe->type == AOE_BULLET) {
        vec2 dir = fdir(aoe->data.bullet.dir);
        p->x += fmul(fmul(aoe->data.bullet.v, dir.x), dt);
        p->y += fmul(fmul(aoe->data.bullet.v, dir.y), dt);

        /* Speed update - exponential decline from initial value to final_v */
        aoe->data.bullet.v += fmul(
            aoe->data.bullet.final_v - aoe->data.bullet.v, fix(0.001));

        /* Collision of anchor with map destroys the bullet */
        rect small_box = { 0, 0, 0, 0 };
        small_box = rect_translate(small_box, physical_pos(entity));

        if(map_collides(game->map, small_box))
            aoe->lifetime = 0;
    }
}