/* This file is part of the 'stringi' project.
 * Copyright (c) 2013-2025, Marek Gagolewski <https://www.gagolewski.com/>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


#include "stri_stringi.h"
#include "stri_container_utf8_indexable.h"
#include "stri_container_bytesearch.h"
#include <deque>
#include <utility>
using namespace std;


/**
 * Locate first or last occurrences of a pattern in a string
 *
 * @param str character vector
 * @param pattern character vector
 * @param first looking for first or last match?
 * @return integer matrix (2 columns)
 *
 * @version 0.1-?? (Bartlomiej Tartanus)
 *
 * @version 0.1-?? (Marek Gagolewski, 2013-06-23)
 *          StriException friendly, use StriContainerByteSearch
 *
 * @version 0.2-1 (Marek Gagolewski, 2014-03-20)
 *          Use StriContainerUTF8_indexable
 *
 * @version 0.2-3 (Marek Gagolewski, 2014-05-08)
 *          stri_locate_fixed now uses byte search only
 *
 * @version 0.3-1 (Marek Gagolewski, 2014-11-05)
 *    Issue #112: str_prepare_arg* retvals were not PROTECTed from gc
 *
 * @version 0.4-1 (Marek Gagolewski, 2014-12-07)
 *    FR #110, #23: opts_fixed arg added
 *
 * @version 0.5-1 (Marek Gagolewski, 2015-02-14)
 *    use StriByteSearchMatcher
 *
 * @version 1.7.1 (Marek Gagolewski, 2021-06-29)
 *     get_length
 */
SEXP stri__locate_firstlast_fixed(SEXP str, SEXP pattern, SEXP opts_fixed, bool first, bool get_length1)
{
    uint32_t pattern_flags = StriContainerByteSearch::getByteSearchFlags(opts_fixed);
    PROTECT(str = stri__prepare_arg_string(str, "str"));
    PROTECT(pattern = stri__prepare_arg_string(pattern, "pattern"));

    STRI__ERROR_HANDLER_BEGIN(2)
    int vectorize_length = stri__recycling_rule(true, 2, LENGTH(str), LENGTH(pattern));
    StriContainerUTF8_indexable str_cont(str, vectorize_length);
    StriContainerByteSearch pattern_cont(pattern, vectorize_length, pattern_flags);

    SEXP ret;
    STRI__PROTECT(ret = Rf_allocMatrix(INTSXP, vectorize_length, 2));
    stri__locate_set_dimnames_matrix(ret, get_length1);
    int* ret_tab = INTEGER(ret);

    for (R_len_t i = pattern_cont.vectorize_init();
            i != pattern_cont.vectorize_end();
            i = pattern_cont.vectorize_next(i))
    {
        ret_tab[i]                  = NA_INTEGER;
        ret_tab[i+vectorize_length] = NA_INTEGER;
        STRI__CONTINUE_ON_EMPTY_OR_NA_STR_PATTERN(
            str_cont, pattern_cont,
            ;/*nothing on NA - keep NA_INTEGER*/,
            { if (get_length1) ret_tab[i] = ret_tab[i+vectorize_length] = -1; }
        )

        StriByteSearchMatcher* matcher = pattern_cont.getMatcher(i);
        matcher->reset(str_cont.get(i).c_str(), str_cont.get(i).length());
        int start;
        if (first) {
            start = matcher->findFirst();
        } else {
            start = matcher->findLast();
        }

        if (start != USEARCH_DONE) {  // there is a match
            ret_tab[i]                  = start;
            ret_tab[i+vectorize_length] = start+matcher->getMatchedLength();

            // Adjust UTF8 byte index -> UChar32 index
            str_cont.UTF8_to_UChar32_index(i,
                                           ret_tab+i, ret_tab+i+vectorize_length, 1,
                                           1, // 0-based index -> 1-based
                                           0  // end returns position of next character after match
                                          );

            if (get_length1) ret_tab[i+vectorize_length] -= ret_tab[i] - 1;  // to->length
        }
        else if (get_length1) {
            // not found
            ret_tab[i+vectorize_length] = ret_tab[i] = -1;
        }
        // else NA_INTEGER already
    }

    STRI__UNPROTECT_ALL
    return ret;
    STRI__ERROR_HANDLER_END( ;/* do nothing special on error */ )
}


/**
 * Locate first occurrences of pattern in a string [fixed pattern]
 *
 * @param str character vector
 * @param pattern character vector
 * @return integer matrix (2 columns)
 *
 * @version 0.1-?? (Bartlomiej Tartanus)
 *
 * @version 0.1-?? (Bartlomiej Tartanus, 2013-06-09)
 *          StriContainerUTF16 & collator
 *
 * @version 0.1-?? (Marek Gagolewski, 2013-06-23)
 *          use stri_locate_firstlast_fixed
 *
 * @version 0.2-3 (Marek Gagolewski, 2014-05-08)
 *          stri_locate_fixed now uses byte search only
 *
 * @version 0.4-1 (Marek Gagolewski, 2014-12-07)
 *    FR #110, #23: opts_fixed arg added
 *
 * @version 1.7.1 (Marek Gagolewski, 2021-06-29)
 *     get_length
 */
SEXP stri_locate_first_fixed(SEXP str, SEXP pattern, SEXP opts_fixed, SEXP get_length)
{
    bool get_length1 = stri__prepare_arg_logical_1_notNA(get_length, "get_length");
    return stri__locate_firstlast_fixed(str, pattern, opts_fixed, true, get_length1);
}


/**
 * Locate last occurrences of pattern in a string [fixed pattern]
 *
 * @param str character vector
 * @param pattern character vector
 * @return integer matrix (2 columns)
 *
 * @version 0.1-?? (Bartlomiej Tartanus)
 *
 * @version 0.1-?? (Bartlomiej Tartanus, 2013-06-09)
 *          StriContainerUTF16 & collator
 *
 * @version 0.1-?? (Marek Gagolewski, 2013-06-23)
 *          use stri_locate_firstlast_fixed
 *
 * @version 0.2-3 (Marek Gagolewski, 2014-05-08)
 *          stri_locate_fixed now uses byte search only
 *
 * @version 0.4-1 (Marek Gagolewski, 2014-12-07)
 *    FR #110, #23: opts_fixed arg added
 *
 * @version 1.7.1 (Marek Gagolewski, 2021-06-29)
 *     get_length
 */
SEXP stri_locate_last_fixed(SEXP str, SEXP pattern, SEXP opts_fixed, SEXP get_length)
{
    bool get_length1 = stri__prepare_arg_logical_1_notNA(get_length, "get_length");
    return stri__locate_firstlast_fixed(str, pattern, opts_fixed, false, get_length1);
}


/** Locate all occurrences of fixed-byte pattern
 *
 * @param str character vector
 * @param pattern character vector
 * @return list of integer matrices (2 columns)
 *
 * @version 0.1-?? (Bartek Tartanus)
 *
 * @version 0.1-?? (Marek Gagolewski, 2013-06-23)
 *          StriException friendly, use StriContainerByteSearch
 *
 * @version 0.2-1 (Marek Gagolewski, 2014-03-20)
 *          Use StriContainerUTF8_indexable
 *
 * @version 0.2-3 (Marek Gagolewski, 2014-05-08)
 *          stri_locate_fixed now uses byte search only
 *
 * @version 0.3-1 (Marek Gagolewski, 2014-11-05)
 *    #112: str_prepare_arg* retvals were not PROTECTed from gc
 *
 * @version 0.4-1 (Marek Gagolewski, 2014-11-27)
 *    #117: omit_no_match arg added
 *
 * @version 0.4-1 (Marek Gagolewski, 2014-12-07)
 *    #110, #23: opts_fixed arg added
 *
 * @version 0.5-1 (Marek Gagolewski, 2015-02-14)
 *    use StriByteSearchMatcher
 *
 * @version 1.7.1 (Marek Gagolewski, 2021-06-29)
 *     get_length
 */
SEXP stri_locate_all_fixed(SEXP str, SEXP pattern, SEXP omit_no_match, SEXP opts_fixed, SEXP get_length)
{
    uint32_t pattern_flags = StriContainerByteSearch::getByteSearchFlags(opts_fixed, /*allow_overlap*/true);
    bool omit_no_match1 = stri__prepare_arg_logical_1_notNA(omit_no_match, "omit_no_match");
    bool get_length1 = stri__prepare_arg_logical_1_notNA(get_length, "get_length");
    PROTECT(str = stri__prepare_arg_string(str, "str"));
    PROTECT(pattern = stri__prepare_arg_string(pattern, "pattern"));

    STRI__ERROR_HANDLER_BEGIN(2)
    int vectorize_length = stri__recycling_rule(true, 2, LENGTH(str), LENGTH(pattern));
    StriContainerUTF8_indexable str_cont(str, vectorize_length);
    StriContainerByteSearch pattern_cont(pattern, vectorize_length, pattern_flags);

    SEXP ret;
    STRI__PROTECT(ret = Rf_allocVector(VECSXP, vectorize_length));

    for (R_len_t i = pattern_cont.vectorize_init();
            i != pattern_cont.vectorize_end();
            i = pattern_cont.vectorize_next(i))
    {
        STRI__CONTINUE_ON_EMPTY_OR_NA_STR_PATTERN(str_cont, pattern_cont,
                SET_VECTOR_ELT(ret, i, stri__matrix_NA_INTEGER(1, 2));,
                SET_VECTOR_ELT(ret, i, stri__matrix_NA_INTEGER(omit_no_match1?0:1, 2, get_length1?-1:NA_INTEGER));)

        StriByteSearchMatcher* matcher = pattern_cont.getMatcher(i);
        matcher->reset(str_cont.get(i).c_str(), str_cont.get(i).length());

        int start = matcher->findFirst();
        if (start == USEARCH_DONE) { // no matches at all
            SET_VECTOR_ELT(ret, i, stri__matrix_NA_INTEGER(omit_no_match1?0:1, 2, get_length1?-1:NA_INTEGER));
            continue;
        }

        deque< pair<R_len_t, R_len_t> > occurrences;
        while (start != USEARCH_DONE) {
            occurrences.push_back(pair<R_len_t, R_len_t>(start, start+matcher->getMatchedLength()));
            start = matcher->findNext();
        }

        R_len_t noccurrences = (R_len_t)occurrences.size();
        SEXP ans;
        STRI__PROTECT(ans = Rf_allocMatrix(INTSXP, noccurrences, 2));
        int* ans_tab = INTEGER(ans);
        deque< pair<R_len_t, R_len_t> >::iterator iter = occurrences.begin();
        for (R_len_t j = 0; iter != occurrences.end(); ++iter, ++j) {
            pair<R_len_t, R_len_t> match = *iter;
            ans_tab[j]              = match.first;
            ans_tab[j+noccurrences] = match.second;
        }

        // Adjust UChar index -> UChar32 index (1-2 byte UTF16 to 1 byte UTF32-code points)
        str_cont.UTF8_to_UChar32_index(i, ans_tab,
                                       ans_tab+noccurrences, noccurrences,
                                       1, // 0-based index -> 1-based
                                       0  // end returns position of next character after match
                                      );

        if (get_length1) {
            for (R_len_t j=0; j < noccurrences; ++j)
                ans_tab[j+noccurrences] -= ans_tab[j] - 1;  // to->length
        }

        SET_VECTOR_ELT(ret, i, ans);
        STRI__UNPROTECT(1);
    }

    stri__locate_set_dimnames_list(ret, get_length1);
    STRI__UNPROTECT_ALL
    return ret;
    STRI__ERROR_HANDLER_END( ;/* do nothing special on error */ )
}