#include "str.h"
#include "crash.h"
#include <stdlib.h>
#include <string.h>

#define CRASH_IF_OOB(str, len) {\
    if (len > str.length)\
        crash("String access out of bounds: %ld > %ld\n", len, str.length);\
}

static inline char* alloc_data_ptr(size_t length) {
    char* data_ptr = malloc(length);
    if (data_ptr == NULL)
        crash("Out of memory allocating new string of length %ld\n", length);
    return data_ptr;
}

static inline char* alloc_c_str(size_t length) {
    char* c_str = malloc(length + 1);
    if (c_str == NULL)
        crash("Out of memory allocating C string buffer of size %ld", length + 1);

    c_str[length] = 0;
    return c_str;
}

char* str_at(const str_t str, size_t idx) {
    CRASH_IF_OOB(str, idx + 1);
    return str.__data + idx;
}

str_t str_slice(const str_t str, size_t start, size_t length) {
    CRASH_IF_OOB(str, start + length);
    str_t slice = {.length = length, .__data = str.__data + start};
    return slice;
}

int str_cmp(const str_t s1, const str_t s2) {
    if (s1.length == s2.length)
        return memcmp(s1.__data, s2.__data, s1.length);
    else if (s1.length > s2.length) {
        int cmp = memcmp(s1.__data, s2.__data, s2.length);
        if (cmp != 0) return cmp;
        return 1;
    } else {
        int cmp = memcmp(s1.__data, s2.__data, s1.length);
        if (cmp != 0) return cmp;
        return -1;
    }
}

ssize_t str_indexof(const str_t str, char c) {
    for (ssize_t i = 0; i < str.length; i++) {
        if (str.__data[i] == c) return i;
    }
    return -1;
}

ssize_t str_rindexof(const str_t str, char c) {
    for (ssize_t i = (ssize_t)str.length - 1; i >= 0; i--) {
        if (str.__data[i] == c) return i;
    }
    return -1;
}

str_t str_heap_dup(const str_t str) {
    char* data_ptr = alloc_data_ptr(str.length);
    str_t dup_str = {.length = str.length, .__data = data_ptr};
    return dup_str;
}

str_t str_heap_cat(const str_t s1, const str_t s2) {
    size_t new_len = s1.length + s2.length;
    char* data_ptr = alloc_data_ptr(new_len);
    str_t cat_str = {.length = new_len, .__data = data_ptr};
    return cat_str;
}

void str_to_c_str(char* dst, size_t dst_size, const str_t* src) {
    if (src->length >= dst_size)
        crash(
            "String is too long to hold in C string buffer: %ld >= %ld\n",
            src->length,
            dst_size);

    memmove(dst, src->__data, src->length);
    dst[src->length] = 0;
}

char* str_to_heap_c_str(const str_t src) {
    char* dst = alloc_c_str(src.length);
    memcpy(dst, src.__data, src.length);
    return dst;
}

str_t str_init(char* data, size_t length) {
    str_t str = {.length = length, .__data = data};
    return str;
}

str_t str_heap_alloc(size_t length) {
    char* data_ptr = alloc_data_ptr(length);
    str_t str = {.length = length, .__data = data_ptr};
    return str;
}

str_t str_heap_alloc_iv(const char* c_str) {
    size_t length = strlen(c_str);
    char* data_ptr = alloc_data_ptr(length);
    memcpy(data_ptr, c_str, length);
    str_t str = {.length = length, .__data = data_ptr};
    return str;
}

str_t str_heap_alloc_iv_slice(const char* c_str, size_t start, size_t length) {
    char* data_ptr = alloc_data_ptr(length);
    memcpy(data_ptr, c_str + start, length);
    str_t str = {.length = length, .__data = data_ptr};
    return str;
}

void str_heap_destroy(str_t str) {
    free(str.__data);
}