// Copyright (c) Epic Games Tools
// Licensed under the MIT license (https://opensource.org/license/mit/)

#pragma once

typedef struct KeyValuePair
{
  union {
    String8 key_string;
    void   *key_raw;
    U32     key_u32;
    U64     key_u64;
  };
  union {
    String8  value_string;
    void    *value_raw;
    U32      value_u32;
    U64      value_u64;
  };
} KeyValuePair;

typedef struct BucketNode
{
  struct BucketNode *next;
  KeyValuePair       v;
} BucketNode;

typedef struct BucketList
{
  BucketNode *first;
  BucketNode *last;
} BucketList;

typedef struct HashTable
{
  U64         count;
  U64         cap;
  BucketList *buckets;
  BucketList  free_buckets;
} HashTable;

// --- Bucket List -------------------------------------------------------------

internal void         bucket_list_concat_in_place(BucketList *list, BucketList *to_concat);
internal BucketNode * bucket_list_pop            (BucketList *list);

// --- Hash Table --------------------------------------------------------------

internal U64 hash_table_hasher(String8 string);

internal HashTable * hash_table_init (Arena *arena, U64 cap);
internal void        hash_table_purge(HashTable *ht);

internal BucketNode * hash_table_push(Arena *arena, HashTable *ht, U64 hash,     KeyValuePair  kv);

internal BucketNode * hash_table_push_u32_string   (Arena *arena, HashTable *ht, U32     key,  String8       value);
internal BucketNode * hash_table_push_u64_string   (Arena *arena, HashTable *ht, U64     key,  String8       value);
internal BucketNode * hash_table_push_string_string(Arena *arena, HashTable *ht, String8 key,  String8       value);
internal BucketNode * hash_table_push_path_string  (Arena *arena, HashTable *ht, String8 key,  String8       value);
internal BucketNode * hash_table_push_u32_raw      (Arena *arena, HashTable *ht, U32     key,  void         *value);
internal BucketNode * hash_table_push_u64_raw      (Arena *arena, HashTable *ht, U64     key,  void         *value);
internal BucketNode * hash_table_push_path_raw     (Arena *arena, HashTable *ht, String8 path, void         *value);
internal BucketNode * hash_table_push_path_u64     (Arena *arena, HashTable *ht, String8 path, U64           value);
internal BucketNode * hash_table_push_u64_u64      (Arena *arena, HashTable *ht, U64     key,  U64           value);
internal BucketNode * hash_table_push_u32_u32      (Arena *arena, HashTable *ht, U32     key,  U32           value);

internal KeyValuePair * hash_table_search_string  (HashTable *ht, String8 key);
internal KeyValuePair * hash_table_search_u32     (HashTable *ht, U32     key);
internal KeyValuePair * hash_table_search_u64     (HashTable *ht, U64     key);
internal KeyValuePair * hash_table_search_path    (HashTable *ht, String8 key);
internal KeyValuePair * hash_table_search_raw     (HashTable *ht, void   *key);

internal B32 hash_table_search_path_u64     (HashTable *ht, String8 key, U64     *value_out);
internal B32 hash_table_search_string_u64   (HashTable *ht, String8 key, U64     *value_out);
internal B32 hash_table_search_string_string(HashTable *ht, String8 key, String8 *value_out);
internal B32 hash_table_search_u32_u32      (HashTable *ht, U32 key,     U32     *value_out);

internal void * hash_table_search_string_raw(HashTable *ht, String8 key);
internal void * hash_table_search_u64_raw   (HashTable *ht, U64     key);
internal void * hash_table_search_path_raw  (HashTable *ht, String8 key);
internal void * hash_table_search_raw_raw   (HashTable *ht, void   *key);

// --- Key Value Helpers -------------------------------------------------------

internal U32 *          keys_from_hash_table_u32       (Arena *arena, HashTable *ht);
internal U64 *          keys_from_hash_table_u64       (Arena *arena, HashTable *ht);
internal String8        keys_from_hash_table_str8      (Arena *arena, HashTable *ht);
internal KeyValuePair * key_value_pairs_from_hash_table(Arena *arena, HashTable *ht);

internal void * keys_from_hash_table_raw  (Arena *arena, HashTable *ht);
internal void * values_from_hash_table_raw(Arena *arena, HashTable *ht);

internal void sort_key_value_pairs_as_u32             (KeyValuePair *pairs, U64 count);
internal void sort_key_value_pairs_as_u64             (KeyValuePair *pairs, U64 count);
internal void sort_key_value_pairs_as_string_sensitive(KeyValuePair *pairs, U64 count);

// --- Misc --------------------------------------------------------------------

internal U64Array    remove_duplicates_u64_array(Arena *arena, U64Array arr);
internal String8List remove_duplicates_str8_list(Arena *arena, String8List list);