/* This software is licensed by the MIT License, see LICENSE file */
/*                                Copyright © 2022 Gregory Lirent */

#include "include.h"

/*#####################################################################################################################*/

typedef struct trim_handler {
    union {
        struct {
            size_t pad;

            struct {
                const char* ptr;
                size_t      len;
            } *values;

            size_t size;
        };
  #ifndef STRING_TRIM_MEMOPT
        u8_t x[128];
  #else
        size_t x[(16/sizeof(size_t))];
  #endif
    };
} th_t;

/*#####################################################################################################################*/

static void th_init(th_t* x, const char* s) {
    size_t n = (!is_null(s)) ? strlen(s) : 0;

    memset(x, 0, sizeof(*x));

    if (n && n == strasciilen(s)) {
        for (int i = 0; i < n; ++i) {
  #ifndef STRING_TRIM_MEMOPT
            x->x[((unsigned char*)s)[i]] = 1;
  #else
            x->x[((unsigned char*)s)[i]/(8*sizeof(size_t))] |= (size_t)1<<(((unsigned char*)s)[i]%(8*sizeof(size_t)));
  #endif
        }
    } else if (n) {
        x->pad = (size_t)-1;
        do {
            if ((n = charsize(s))) {

                x->values = realloc(x->values, sizeof(*x->values)*x->size + 1);
                x->values[x->size].len = n;
                x->values[x->size].ptr = s;

                ++x->size;
                s += n;
                s += n;
            } else ++s;
        } while (*s);
    } else {
  #ifndef STRING_TRIM_MEMOPT
        x->x[ ' '] = 1;
        x->x['\r'] = 1;
        x->x['\n'] = 1;
        x->x['\t'] = 1;
        x->x['\v'] = 1;
  #else
        x->x[ ' '/(8*sizeof(size_t))] |= (size_t)1<<( ' '%(8*sizeof(size_t)));
        x->x['\r'/(8*sizeof(size_t))] |= (size_t)1<<('\r'%(8*sizeof(size_t)));
        x->x['\n'/(8*sizeof(size_t))] |= (size_t)1<<('\n'%(8*sizeof(size_t)));
        x->x['\t'/(8*sizeof(size_t))] |= (size_t)1<<('\t'%(8*sizeof(size_t)));
        x->x['\v'/(8*sizeof(size_t))] |= (size_t)1<<('\v'%(8*sizeof(size_t)));
  #endif
    }
}



static void th_free(th_t* x) {
    if (x->pad == (size_t)-1) {
        free(x->values);
    }
}



static char* th_next(const th_t* x, char* s) {

    if (!(x->pad != (size_t)-1) && *(u8_t*)s <= 0x7f) {
  #ifndef STRING_TRIM_MEMOPT
        if (x->x[*(u8_t*)s]) {
  #else
        if (x->x[(*(u8_t*)s)/(8*sizeof(size_t))] & ((size_t)1<<((*(u8_t*)s)%(8*sizeof(size_t))))) {
  #endif
            return ++s;
        }
    } else for (int i = 0; i < x->size; ++i) {
        if (memcmp(x->values[i].ptr, s, x->values[i].len) == 0) {
            return s + x->values[i].len;
        }
    }

    return nullptr;
}



static char* th_prev(const th_t* x, char* s) {

    if (!(x->pad != (size_t)-1) && *(u8_t*)(--s) <= 0x7f) {
  #ifndef STRING_TRIM_MEMOPT
        if (x->x[*(u8_t*)s]) {
  #else
        if (x->x[(*(u8_t*)s)/(8*sizeof(size_t))] & ((size_t)1<<((*(u8_t*)s)%(8*sizeof(size_t))))) {
  #endif
            return s;
        }
    } else for (int i = 0; i < x->size; ++i) {
        char* p = s - x->values[i].len;
        if (memcmp(x->values[i].ptr, p, x->values[i].len) == 0) {
            return p;
        }
    }

    return nullptr;
}


/*#####################################################################################################################*/


void string_trim_cstring(str_t* x, const char* s) {
    size_t n;

    if (!is_null(x->buffer) && (n = strlen(x->buffer))) {
        th_t t;
        char *p0, *p1;

        th_init(&t, s);

        p0 = x->buffer;

        while ((p1 = th_next(&t, p0))) { p0 = p1; }

        n -= p0 - x->buffer;
        p0 = memmove(x->buffer, p0, n + 1) + n;

        while ((p1 = th_prev(&t, p0))) { p0 = p1; }
        *p0 = 0;

        th_free(&t);
    }
}


void string_trim_char(str_t* x, int sc) {
    size_t n;
    char s[5] = {0};

    if (!is_null(x->buffer) && tochar_unicode(s, sc) && (n = strlen(x->buffer))) {
        th_t t;
        char *p0, *p1;

        th_init(&t, s);

        p0 = x->buffer;

        while ((p1 = th_next(&t, p0))) { p0 = p1; }

        n -= p0 - x->buffer;
        p0 = memmove(x->buffer, p0, n + 1) + n;

        while ((p1 = th_prev(&t, p0))) { p0 = p1; }
        *p0 = 0;

        th_free(&t);
    }
}


void string_ltrim_cstring(str_t* x, const char* s) {
    size_t n;

    if (!is_null(x->buffer) && (n = strlen(x->buffer))) {
        th_t t;
        char *p0, *p1;

        th_init(&t, s);

        p0 = x->buffer;

        while ((p1 = th_next(&t, p0))) { p0 = p1; }

        n -= p0 - x->buffer;

        memmove(x->buffer, p0, ++n);

        th_free(&t);
    }
}


void string_ltrim_char(str_t* x, int sc) {
    size_t n;
    char s[5] = {0};

    if (!is_null(x->buffer) && tochar_unicode(s, sc) && (n = strlen(x->buffer))) {
        th_t t;
        char *p0, *p1;

        th_init(&t, s);

        p0 = x->buffer;

        while ((p1 = th_next(&t, p0))) { p0 = p1; }

        n -= p0 - x->buffer;

        memmove(x->buffer, p0, ++n);

        th_free(&t);
    }
}


void string_rtrim_cstring(str_t* x, const char* s) {
    size_t n;

    if (!is_null(x->buffer) && (n = strlen(x->buffer))) {
        th_t t;
        char *p0, *p1;

        th_init(&t, s);

        p0 = x->buffer + n;

        while ((p1 = th_prev(&t, p0))) { p0 = p1; }
        *p0 = 0;

        th_free(&t);
    }
}


void string_rtrim_char(str_t* x, int sc) {
    size_t n;
    char s[5] = {0};

    if (!is_null(x->buffer) && tochar_unicode(s, sc) && (n = strlen(x->buffer))) {
        th_t t;
        char *p0, *p1;

        th_init(&t, s);

        p0 = x->buffer + n;

        while ((p1 = th_prev(&t, p0))) { p0 = p1; }
        *p0 = 0;

        th_free(&t);
    }
}