#ifndef PIXELDEFENSE_SYSTEMS_H
#define PIXELDEFENSE_SYSTEMS_H

#include <flecs.h>

#include "../components.h"

typedef struct Game Game;

/**********************************
 * Utils
 **********************************/

bool entitySetPath(const ecs_entity_t entity, const Vector2 target, Game *game);

/**********************************
 * AI systems
 **********************************/

/*
 * 0: Game (singleton)
 * 1: UnitAction
 */
void handleUnitActionsSystem(ecs_iter_t *it);

/*
 * 0: Game (singleton)
 * 1: UnitAI
 * 2: UnitAction
 */
void updateUnitAISystem(ecs_iter_t *it);

/*
 * 0: Game (singleton)
 * 1: UnitAction
 */
void updateUnitActionsSystem(ecs_iter_t *it);

/*
 * 1: Easing
 * 2: Position
 * 3: Size
 * 4: Rotation
 */
void updateEasingSystem(ecs_iter_t *it);

/**********************************
 * Animation Systems
 **********************************/


/*
 * 1: Animation
 * 2: TextureRegion
 */
void updateAnimationState(ecs_iter_t *it);
/*
 * 0:
 * 1: Animation
 * 2: TextureRegion
 */
void updateAnimation(ecs_iter_t *it);

/**********************************
 * Entity Systems
 **********************************/

/* Observer (for removing TargetPosition)
 * 0: Game (singleton) for object pool
 * 1: Path
 */
void entityPathRemove(ecs_iter_t *it);

/*
 * 0: Game (singleton) for entity map
 * 1: Position
 * 2: Size
 * 3: Velocity (only entities with velocity change position)
 * 4: SpatialGridID
 */
void entityUpdateSpatialID(ecs_iter_t *it);

/*
 * 0: Game (singleton) for collisions
 * 1: Position
 * 2: Rotation
 * 3: Velocity
 * 4: Steering
 */
void entityUpdateKinematic(ecs_iter_t *it);

/*
 * 1: Position
 * 2: Rotation
 * 3: Velocity
 * 4: TargetPosition
 * 5: Steering
 */
void entityMoveToTarget(ecs_iter_t *it);

/*
 * 0: Game (singleton) for object pool
 * 1: Path
 */
void entityFollowPath(ecs_iter_t *it);


/*
 * 1: Position
 * 2: Size
 */
void renderColliders(ecs_iter_t *it);

/*
 * 1: Position
 * 2: Rotation
 */
void renderRotationDirection(ecs_iter_t *it);

/*
 * 1: Path
 */
void renderDebugPath(ecs_iter_t *it);

/**********************************
 * Event Systems
 **********************************/

i32  harvestEvent(ecs_entity_t entity, HarvestEvent event);
void depositEvent(ecs_entity_t entity, DepositEvent event);


/**********************************
 * Input systems
 **********************************/

/*
 * Task:
 * 0: Game (singleton)
 * 0: InputState (singleton)
 */
void updatePlayerInput();

/*
 * Task (rendering above ground):
 * 0: Game (singleton)
 * 0: InputState (singleton)
 */
void drawPlayerInputUIGround();

/*
 * Task (rendering on top):
 * 0: Game (singleton)
 * 0: InputState (singleton)
 */
void drawPlayerInputUI();

/**********************************
 * UI systems
 **********************************/

/**********************************
 * MISC
 **********************************/

static void setupSystems(ecs_world_t *ecs) {

    ECS_OBSERVER(ecs, entityPathRemove, EcsOnRemove, Path);

    ECS_SYSTEM(ecs, entityUpdateSpatialID, EcsOnUpdate, Position, Size, Velocity, SpatialGridID);
    ECS_SYSTEM(ecs, entityUpdateKinematic, EcsOnUpdate, Position, Rotation, Velocity, Steering);

    ECS_SYSTEM(ecs, entityMoveToTarget, EcsOnUpdate, Position, Rotation, Velocity, TargetPosition, Steering);
    ECS_SYSTEM(ecs, entityFollowPath, EcsOnUpdate, Path);

    ECS_SYSTEM(ecs, handleUnitActionsSystem, EcsOnUpdate, UnitAction);
    ECS_SYSTEM(ecs, updateUnitAISystem, EcsOnUpdate, UnitAI, UnitAction);
    // Needs to be called after AI update, since it removes finished actions
    ECS_SYSTEM(ecs, updateUnitActionsSystem, EcsOnUpdate, UnitAction);

    ECS_SYSTEM(ecs, updateAnimationState, EcsOnUpdate, Animation, TextureRegion);
    ECS_SYSTEM(ecs, updateAnimation, EcsOnUpdate, Animation, TextureRegion);
    ECS_SYSTEM(ecs, updateEasingSystem, EcsOnUpdate, Easing, Position, Size, Rotation);

    ECS_SYSTEM(ecs, renderDebugPath, EcsOnUpdate, Path);

    ECS_SYSTEM(ecs, renderColliders, EcsOnUpdate, Position, Size);
    ECS_SYSTEM(ecs, renderRotationDirection, EcsOnUpdate, Position, Rotation);
}

#endif //PIXELDEFENSE_SYSTEMS_H