#include "memory.h"
#include <string.h>
#include <ctype.h>

struct memory_pool {
    void **free_list;
    size_t block_size;
    size_t capacity;
    size_t free_count;
    mutex_t mutex;
};

memory_pool_t *mempool_create(size_t block_size, size_t initial_count) {
    memory_pool_t *pool = calloc(1, sizeof(memory_pool_t));
    if (!pool) return NULL;

    pool->block_size = block_size;
    pool->capacity = initial_count;
    pool->free_count = initial_count;

    pool->free_list = calloc(initial_count, sizeof(void *));
    if (!pool->free_list) {
        free(pool);
        return NULL;
    }

    for (size_t i = 0; i < initial_count; i++) {
        pool->free_list[i] = malloc(block_size);
        if (!pool->free_list[i]) {
            for (size_t j = 0; j < i; j++) {
                free(pool->free_list[j]);
            }
            free(pool->free_list);
            free(pool);
            return NULL;
        }
    }

    pal_mutex_init(&pool->mutex);
    return pool;
}

void mempool_destroy(memory_pool_t *pool) {
    if (!pool) return;

    pal_mutex_lock(&pool->mutex);
    for (size_t i = 0; i < pool->free_count; i++) {
        free(pool->free_list[i]);
    }
    free(pool->free_list);
    pal_mutex_unlock(&pool->mutex);
    pal_mutex_destroy(&pool->mutex);
    free(pool);
}

void *mempool_alloc(memory_pool_t *pool) {
    if (!pool) return malloc(64);

    pal_mutex_lock(&pool->mutex);

    void *ptr;
    if (pool->free_count > 0) {
        ptr = pool->free_list[--pool->free_count];
    } else {
        ptr = malloc(pool->block_size);
    }

    pal_mutex_unlock(&pool->mutex);
    return ptr;
}

void mempool_free(memory_pool_t *pool, void *ptr) {
    if (!ptr) return;
    if (!pool) {
        free(ptr);
        return;
    }

    pal_mutex_lock(&pool->mutex);

    if (pool->free_count < pool->capacity) {
        pool->free_list[pool->free_count++] = ptr;
    } else {
        void **new_list = realloc(pool->free_list, (pool->capacity * 2) * sizeof(void *));
        if (new_list) {
            pool->free_list = new_list;
            pool->capacity *= 2;
            pool->free_list[pool->free_count++] = ptr;
        } else {
            free(ptr);
        }
    }

    pal_mutex_unlock(&pool->mutex);
}

size_t mempool_available(memory_pool_t *pool) {
    if (!pool) return 0;
    pal_mutex_lock(&pool->mutex);
    size_t count = pool->free_count;
    pal_mutex_unlock(&pool->mutex);
    return count;
}

buffer_t *buffer_create(size_t initial_capacity) {
    buffer_t *buf = calloc(1, sizeof(buffer_t));
    if (!buf) return NULL;

    if (initial_capacity > 0) {
        buf->data = malloc(initial_capacity);
        if (!buf->data) {
            free(buf);
            return NULL;
        }
        buf->capacity = initial_capacity;
        buf->data[0] = '\0';
    }

    return buf;
}

void buffer_destroy(buffer_t *buf) {
    if (!buf) return;
    free(buf->data);
    free(buf);
}

int buffer_reserve(buffer_t *buf, size_t capacity) {
    if (!buf) return NWEDAV_ERROR;
    if (buf->capacity >= capacity) return NWEDAV_OK;

    size_t new_cap = buf->capacity ? buf->capacity : 64;
    while (new_cap < capacity) {
        new_cap *= 2;
    }

    char *new_data = realloc(buf->data, new_cap);
    if (!new_data) return NWEDAV_ERROR_MEMORY;

    buf->data = new_data;
    buf->capacity = new_cap;
    return NWEDAV_OK;
}

int buffer_append(buffer_t *buf, const void *data, size_t len) {
    if (!buf || !data || len == 0) return NWEDAV_OK;

    if (buffer_reserve(buf, buf->size + len + 1) != NWEDAV_OK) {
        return NWEDAV_ERROR_MEMORY;
    }

    memcpy(buf->data + buf->size, data, len);
    buf->size += len;
    buf->data[buf->size] = '\0';
    return NWEDAV_OK;
}

int buffer_append_str(buffer_t *buf, const char *str) {
    if (!str) return NWEDAV_OK;
    return buffer_append(buf, str, strlen(str));
}

int buffer_append_fmt(buffer_t *buf, const char *fmt, ...) {
    if (!buf || !fmt) return NWEDAV_ERROR;

    va_list ap;
    va_start(ap, fmt);
    int needed = vsnprintf(NULL, 0, fmt, ap);
    va_end(ap);

    if (needed < 0) return NWEDAV_ERROR;

    if (buffer_reserve(buf, buf->size + needed + 1) != NWEDAV_OK) {
        return NWEDAV_ERROR_MEMORY;
    }

    va_start(ap, fmt);
    vsnprintf(buf->data + buf->size, needed + 1, fmt, ap);
    va_end(ap);

    buf->size += needed;
    return NWEDAV_OK;
}

void buffer_consume(buffer_t *buf, size_t len) {
    if (!buf || len == 0) return;

    if (len >= buf->size) {
        buf->size = 0;
        if (buf->data) buf->data[0] = '\0';
        return;
    }

    memmove(buf->data, buf->data + len, buf->size - len);
    buf->size -= len;
    buf->data[buf->size] = '\0';
}

void buffer_reset(buffer_t *buf) {
    if (!buf) return;
    buf->size = 0;
    if (buf->data) buf->data[0] = '\0';
}

char *buffer_detach(buffer_t *buf) {
    if (!buf) return NULL;
    char *data = buf->data;
    buf->data = NULL;
    buf->size = 0;
    buf->capacity = 0;
    return data;
}

char *str_dup(const char *str) {
    if (!str) return NULL;
    size_t len = strlen(str);
    char *dup = malloc(len + 1);
    if (dup) {
        memcpy(dup, str, len + 1);
    }
    return dup;
}

char *str_ndup(const char *str, size_t n) {
    if (!str) return NULL;
    size_t len = strlen(str);
    if (n < len) len = n;
    char *dup = malloc(len + 1);
    if (dup) {
        memcpy(dup, str, len);
        dup[len] = '\0';
    }
    return dup;
}

char *str_lower(char *str) {
    if (!str) return NULL;
    for (char *p = str; *p; p++) {
        *p = tolower((unsigned char)*p);
    }
    return str;
}

char *str_upper(char *str) {
    if (!str) return NULL;
    for (char *p = str; *p; p++) {
        *p = toupper((unsigned char)*p);
    }
    return str;
}

char *str_trim(char *str) {
    if (!str) return NULL;

    while (isspace((unsigned char)*str)) str++;

    if (*str == '\0') return str;

    char *end = str + strlen(str) - 1;
    while (end > str && isspace((unsigned char)*end)) end--;
    end[1] = '\0';

    return str;
}

int str_starts_with(const char *str, const char *prefix) {
    if (!str || !prefix) return 0;
    size_t prefix_len = strlen(prefix);
    return strncmp(str, prefix, prefix_len) == 0;
}

int str_ends_with(const char *str, const char *suffix) {
    if (!str || !suffix) return 0;
    size_t str_len = strlen(str);
    size_t suffix_len = strlen(suffix);
    if (suffix_len > str_len) return 0;
    return strcmp(str + str_len - suffix_len, suffix) == 0;
}

int str_casecmp(const char *a, const char *b) {
    if (!a && !b) return 0;
    if (!a) return -1;
    if (!b) return 1;

#ifdef _WIN32
    return _stricmp(a, b);
#else
    return strcasecmp(a, b);
#endif
}

int str_ncasecmp(const char *a, const char *b, size_t n) {
    if (!a && !b) return 0;
    if (!a) return -1;
    if (!b) return 1;

#ifdef _WIN32
    return _strnicmp(a, b, n);
#else
    return strncasecmp(a, b, n);
#endif
}