#ifndef _AL_LIST_H
#define _AL_LIST_H

#include "lib.h"

#define AL_LIST_DEFINE(type, name) \
    typedef struct list_##name list_##name; \
    struct list_##name { \
        type value; \
        list_##name *next; \
        list_##name *prev; \
    }; \
    static inline list_##name *list_new_node_##name(type value) \
    { \
        list_##name *node = (list_##name *)al_malloc(sizeof(list_##name)); \
        node->value = value; \
        return node; \
    } \
    static inline void list_free_node_##name(list_##name *l) \
    { \
        free(l); \
    } \
    static inline list_##name *list_last_##name(list_##name *l) \
    { \
        if (l) while (l->next) l = l->next; \
        return l; \
    } \
    static inline list_##name *list_nth_##name(list_##name *l, u32 n) \
    { \
        while (n-- > 0 && l) l = l->next; \
        return l; \
    } \
    static inline list_##name *list_append_##name(list_##name *l, type value) \
    { \
        list_##name *node = list_new_node_##name(value); \
        node->next = NULL; \
        if (l) { \
            list_##name *last = list_last_##name(l); \
            node->prev = last; \
            last->next = node; \
            return l; \
        } else { \
            node->prev = NULL; \
            return node; \
        } \
    } \
    static inline list_##name *list_prepend_##name(list_##name *l, type value) \
    { \
        list_##name *node = list_new_node_##name(value); \
        node->next = l; \
        node->prev = NULL; \
        if (l) l->prev = node; \
        return node; \
    } \
    static inline list_##name *list_insert_after_##name(list_##name *l, list_##name *s, type value) \
    { \
        if (!l) { \
            list_##name *node = list_new_node_##name(value); \
            node->next = NULL; \
            node->prev = NULL; \
            return node; \
        } else if (!s || !s->next) { \
            return list_append_##name(l, value); \
        } else { \
            list_##name *node = list_new_node_##name(value); \
            s->next->prev = node; \
            node->next = s->next; \
            node->prev = s; \
            s->next = node; \
            return l; \
        } \
    } \
    static inline list_##name *list_insert_before_##name(list_##name *l, list_##name *s, type value) \
    { \
        if (!l) { \
            list_##name *node = list_new_node_##name(value); \
            node->next = NULL; \
            node->prev = NULL; \
            return node; \
        } else if (!s) { \
            return list_append_##name(l, value); \
        } else if (s == l) { \
            return list_prepend_##name(l, value); \
        } else { \
            list_##name *node = list_new_node_##name(value); \
            s->prev->next = node; \
            node->prev = s->prev; \
            node->next = s; \
            s->prev = node; \
            return l; \
        } \
    } \
    static inline list_##name *list_remove_##name(list_##name *l, list_##name *n) \
    { \
        if (!l) { \
            return l; \
        } else if (l == n) { \
            if (n->next) { \
                n->next->prev = NULL; \
            } \
            l = n->next; \
            list_free_node_##name(n); \
        } else { \
            n->prev->next = n->next; \
            if (n->next) { \
                n->next->prev = n->prev; \
            } \
            list_free_node_##name(n); \
        } \
        return l; \
    }

#define list(name) list_##name

#define al_list_nth(name, list, n) list_nth_##name(list, n)
#define al_list_last(name, list) list_last_##name(list)

// If list is NULL, a new list is created.
#define al_list_append(name, list, value) list_append_##name(list, value)
#define al_list_prepend(name, list, value) list_prepend_##name(list, value)

// If sibiling->next is NULL (or just sibiling for before) append the value to the end of the list.
#define al_list_insert_after(name, list, sibling, value) list_insert_after_##name(list, sibling, value)
#define al_list_insert_before(name, list, sibling, value) list_insert_before_##name(list, sibling, value)

#define al_list_remove(name, list, node) list_remove_##name(list, node)

#define al_list_foreach(name, list, node) \
    for (list_##name *node = list; node; node = node->next)

#endif // _AL_LIST_H