#include "input.h"
#include "debug.h"
#include "list.h"
#include <stdint.h>

typedef struct InputAction {
    const uint8_t* positive;
    const uint8_t* negative;
    int last;
    void* object_arg;
    InputActionDelegate delegate;
} InputAction;

static List _actions;

static const uint8_t* _keys;

void input_init() {
    _actions = list_from_type(InputAction);
    _keys = SDL_GetKeyboardState(NULL);
}

void input_clean() {
    list_empty(&_actions);
}

static
void _key_changed_event(SDL_Event evt) {
    const uint8_t* keyptr = _keys + evt.key.keysym.scancode;
    list_foreach(InputAction, action, &_actions) {
        if(keyptr == action->positive || keyptr == action->negative) {
            int val = *action->positive - *action->negative;
            if(val != action->last) {
                action->last = val;
                action->delegate(action->object_arg, val);
            }
        }
    }
}

void input_handle_event(SDL_Event event) {
    switch(event.type) {
        default:return;
        case SDL_KEYDOWN:
        case SDL_KEYUP:
            _key_changed_event(event);
        break;
    }
}

void input_add_axis_action(void* object, InputActionDelegate delegate, SDL_Scancode negative, SDL_Scancode positive) {
    list_add(&_actions, &(InputAction){
        .negative = _keys + negative,
        .positive = _keys + positive,
        .delegate = delegate,
        .object_arg = object,
    });
}

void input_add_key_action(void* object, InputActionDelegate delegate, SDL_Scancode key) {
    list_add(&_actions, &(InputAction) {
        .negative = _keys + SDL_SCANCODE_UNKNOWN,
        .positive = _keys + key,
        .delegate = delegate,
        .object_arg = object,
    });
}

void input_remove_actions(void* object) {
    for(size_t i = 0; i < _actions.len; ++i) {
        if(list_at_as(InputAction, &_actions, i)->object_arg == object) {
            list_erase(&_actions, i);
        }
    }
}