#include <errno.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include "scufcont/scufcont.h"
#include "scufcont/DString.h"

ScufContResult SCDString_alloc(SCDString *const dstr, const char *str, const size_t len) {
    dstr->data = (char *) malloc(sizeof(char) * (len + 1));
    dstr->len = len;
    dstr->capacity = len + 1;
    if (dstr->data == NULL) {
        return SCUFCONT_OUT_OF_MEMORY;
    }
    dstr->data = memcpy(dstr->data, str, len);
    dstr->data[len] = '\0';

    return SCUFCONT_SUCCESS;
}

ScufContResult SCDString_alloc_copy(SCDString *const dstr, const SCDString *const o) {
    return SCDString_alloc(dstr, SCDString_c_str(o), o->len);
}

ScufContResult SCDString_reserve(SCDString *const dstr, const size_t new_capacity) {
    if (dstr->capacity < new_capacity) {
        errno = 0;
        dstr->data = (char *) realloc(dstr->data, sizeof(char) * new_capacity);
        if (errno != 0) {
            return SCUFCONT_OUT_OF_MEMORY;
        }
        dstr->capacity = new_capacity;
    }

    return SCUFCONT_SUCCESS;
}

void SCDString_free(SCDString *const dstr) {
    if (dstr->data != NULL) {
        free(dstr->data);
        dstr->data = NULL;
    }
    dstr->len = 0;
    dstr->capacity = 0;
}

void SCDString_shrink_to_fit(SCDString *const dstr) {
    if (dstr->capacity > dstr->len + 1) {
        dstr->capacity = dstr->len + 1;
        dstr->data = (char *) realloc(dstr->data, dstr->capacity);
    }
}

ScufContResult SCDString_copy(const SCDString *const src, SCDString *const dst) {
    ScufContResult res = SCDString_reserve(dst, src->len + 1);
    if (res != SCUFCONT_SUCCESS) {
        return res;
    }

    dst->len = src->len;

    memcpy(dst->data, src->data, dst->len);
    dst->data[dst->len] = '\0';

    return SCUFCONT_SUCCESS;
}

ScufContResult SCDString_at(const SCDString *const dstr, const size_t i) {
    if (i > dstr->len - 1) {
        return SCUFCONT_OUT_OF_BOUNDS;
    }

    return dstr->data[i];
}

bool SCDString_equal(const SCDString *const s1, const SCDString *const s2) {
    if (s1->data == NULL || s2->data == NULL) {
        return false;
    }

    if (s1->len != s2->len) {
        return false;
    }

    for (size_t i = 0; i < s1->len; i++) {
        if (s1->data[i] != s2->data[i]) {
            return false;
        }
    }

    return true;
}

bool SCDString_equal_c_str(const SCDString *const s1, const char *s2) {
    if (s1->data == NULL || s2 == NULL) {
        return false;
    }

    if (s1->len != strlen(s2)) {
        return false;
    }

    for (size_t i = 0; i < s1->len; i++) {
        if (s1->data[i] != s2[i]) {
            return false;
        }
    }

    return true;
}

bool SCDString_equal_next_chars_c_str(
    const SCDString *const dstr,
    const char *str,
    const size_t str_len,
    size_t s
) {
    if (dstr->len < s || dstr->len < s + str_len) {
        return false;
    }

    const size_t e = s + str_len;
    for (size_t i = 0; s < e; s++, i++) {
        if (dstr->data[s] != str[i]) {
            return false;
        }
    }

    return true;
}

ScufContResult SCDString_concat_char(SCDString *const dstr, const char ch) {
    const size_t new_len = dstr->len + 1;
    if (new_len > dstr->capacity) {
        ScufContResult res = SCDString_reserve(dstr, new_len + 1);
        if (res != SCUFCONT_SUCCESS) {
            return res;
        }
    }

    dstr->data[new_len - 1] = ch;
    dstr->data[new_len] = '\0';
    dstr->len = new_len;

    return SCUFCONT_SUCCESS;
}

ScufContResult SCDString_concat_c_str(
    SCDString *const dstr,
    const char *str,
    const size_t str_len
) {
    const size_t new_len = dstr->len + str_len;
    if (new_len > dstr->capacity) {
        ScufContResult res = SCDString_reserve(dstr, new_len + 1);
        if (res != SCUFCONT_SUCCESS) {
            return res;
        }
    }

    strncpy(dstr->data + dstr->len, str, str_len);
    dstr->data[new_len] = '\0';
    dstr->len = new_len;

    return SCUFCONT_SUCCESS;
}

ScufContResult SCDString_alloc_concat_c_strs(
    SCDString *const dstr,
    const char *s1,
    const size_t s1_len,
    const char *s2,
    const size_t s2_len
) {
    ScufContResult res = SCDString_alloc(dstr, s1, s1_len);
    if (res != SCUFCONT_SUCCESS) {
        return res;
    }
    res = SCDString_concat_c_str(dstr, s2, s2_len);
    if (res != SCUFCONT_SUCCESS) {
        return res;
    }
    return SCUFCONT_SUCCESS;
}

ScufContResult SCDString_split(
    const SCDString *const dstr,
    const char *delim,
    SCDString **const split_arr,
    size_t *arr_len
) {
    ScufContResult ret = SCUFCONT_SUCCESS;
    *arr_len = 0;
    SCDString elem;
    ScufContResult res = SCDString_alloc(&elem, "", 0);
    if (res != SCUFCONT_SUCCESS) {
        return res;
    }
    const size_t delim_len = strlen(delim);
    for (size_t i = 0; i < dstr->len; i++) {
        if (SCDString_equal_next_chars_c_str(dstr, delim, delim_len, i)) {
            *arr_len += 1;
            *split_arr = realloc(*split_arr, sizeof(SCDString) * (*arr_len));
            if (split_arr == NULL) {
                ret = SCUFCONT_OUT_OF_MEMORY;
                break;
            }
            (*split_arr)[(*arr_len) - 1] = elem;
            res = SCDString_alloc(&elem, "", 0);
            if (res != SCUFCONT_SUCCESS) {
                ret = res;
                break;
            }
            i += delim_len - 1;
        } else {
            SCDString_concat_c_str(&elem, dstr->data + i, 1);
        }
    }

    if (ret == SCUFCONT_SUCCESS) {
        *split_arr = realloc(*split_arr, sizeof(SCDString) * (*arr_len + 1));
        if (split_arr != NULL) {
            (*split_arr)[*arr_len] = elem;
            *arr_len += 1;
            return ret;
        }
        ret = SCUFCONT_OUT_OF_MEMORY;
    }

    for (size_t i = 0; i < *arr_len; i++) {
        SCDString_free((*split_arr) + i);
    }
    free(*split_arr);
    *split_arr = NULL;
    SCDString_free(&elem);

    return ret;
}

void SCDString_split_arr_free(SCDString **const arr, const size_t arr_len) {
    for (size_t i = 0; i < arr_len; i++) {
        SCDString_free((*arr) + i);
    }
    free(*arr);
    *arr = NULL;
}

ScufContResult SCDString_char_mod(SCDString *const dstr, const size_t at, const char ch) {
    if (at > dstr->len - 1) {
        return SCUFCONT_OUT_OF_BOUNDS;
    }

    dstr->data[at] = ch;

    return SCUFCONT_SUCCESS;
}

ScufContResult SCDString_char_remove_no_shrink(SCDString *const dstr, const size_t at) {
    if (at > dstr->len - 1) {
        return SCUFCONT_OUT_OF_BOUNDS;
    }
    memmove(&dstr->data[at], &dstr->data[at] + 1, dstr->len - at);
    dstr->len--;

    return SCUFCONT_SUCCESS;
}

ScufContResult SCDString_char_remove(SCDString *const dstr, const size_t at) {
    const ScufContResult res = SCDString_char_remove_no_shrink(dstr, at);
    if (res != SCUFCONT_SUCCESS) {
        return res;
    }

    SCDString_shrink_to_fit(dstr);

    return SCUFCONT_SUCCESS;
}

ScufContResult SCDString_char_insert(SCDString *const dstr, const size_t at, const char ch) {
    if (at > dstr->len) {
        return SCUFCONT_OUT_OF_BOUNDS;
    }

    ScufContResult res = SCDString_reserve(dstr, dstr->len + 2);
    if (res != SCUFCONT_SUCCESS) {
        return res;
    }

    const size_t move_block_size = at == dstr->len ? 1 : dstr->len - at;
    memmove(&dstr->data[at] + 1, &dstr->data[at], move_block_size);

    dstr->data[at] = ch;
    dstr->len++;

    return SCUFCONT_SUCCESS;
}

ScufContResult SCDString_replace_c_str_no_shrink(SCDString *const dstr, const char *str, const size_t str_len) {
    if (dstr->capacity < str_len + 1) {
        const ScufContResult res = SCDString_reserve(dstr, str_len + 1);
        if (res != SCUFCONT_SUCCESS) {
            return res;
        }
    }

    memcpy(dstr->data, str, str_len);
    dstr->len = str_len;

    return SCUFCONT_SUCCESS;
}

ScufContResult SCDString_replace_c_str(SCDString *const dstr, const char *str, const size_t str_len) {
    const ScufContResult res = SCDString_replace_c_str_no_shrink(dstr, str, str_len);
    if (res != SCUFCONT_SUCCESS) {
        return res;
    }

    SCDString_shrink_to_fit(dstr);

    return SCUFCONT_SUCCESS;
}

void SCDString_trim_whitespace_leading(SCDString *const dstr) {
    while (isspace(dstr->data[0])) {
        SCDString_char_remove_no_shrink(dstr, 0);
    }

    SCDString_shrink_to_fit(dstr);
}

void SCDString_trim_whitespace_trailing(SCDString *const dstr) {
    while (isspace(dstr->data[dstr->len - 1])) {
        SCDString_char_remove_no_shrink(dstr, dstr->len - 1);
    }

    SCDString_shrink_to_fit(dstr);
}

void SCDString_trim_whitespace(SCDString *const dstr) {
    SCDString_trim_whitespace_leading(dstr);
    SCDString_trim_whitespace_trailing(dstr);
}