// Type info and methods for Text datatype, which uses the Boehm "cord" library
// and libunistr
#include <assert.h>
#include <ctype.h>
#include <err.h>
#include <gc.h>
#include <gc/cord.h>
#include <gmp.h>
#include <limits.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/param.h>
#include <unicase.h>
#include <unigbrk.h>
#include <uniname.h>
#include <uninorm.h>
#include <unistr.h>

#include "array.h"
#include "functions.h"
#include "halfsiphash.h"
#include "integers.h"
#include "text.h"
#include "types.h"

#define CLAMP(x, lo, hi) MIN(hi, MAX(x,lo))

static inline uint8_t *_normalize(CORD str, uint8_t *buf, size_t *len)
{
    const uint8_t *str_u8 = (const uint8_t*)CORD_to_const_char_star(str);
    uint8_t *normalized = u8_normalize(UNINORM_NFD, str_u8, strlen((char*)str_u8)+1, buf, len);
    if (!normalized) errx(1, "Unicode normalization error!");
    return normalized;
}

public CORD Text$as_text(const void *text, bool colorize, const TypeInfo *info)
{
    if (!text) return info->TextInfo.lang;
    CORD ret = Text$quoted(*(CORD*)text, colorize);
    if (!streq(info->TextInfo.lang, "Text"))
        ret = colorize ? CORD_all("\x1b[1m$", info->TextInfo.lang, "\x1b[m", ret) : CORD_all("$", info->TextInfo.lang, ret);
    return ret;
}

public CORD Text$quoted(CORD str, bool colorize)
{
    // Note: it's important to have unicode strings not get broken up with
    // escapes, otherwise they won't print right.
    if (colorize) {
        CORD quoted = "\x1b[35m\"";
        CORD_pos i;
        CORD_FOR(i, str) {
            char c = CORD_pos_fetch(i);
            switch (c) {
#define BACKSLASHED(esc) "\x1b[34m\\\x1b[1m" esc "\x1b[0;35m"
            case '\a': quoted = CORD_cat(quoted, BACKSLASHED("a")); break;
            case '\b': quoted = CORD_cat(quoted, BACKSLASHED("b")); break;
            case '\x1b': quoted = CORD_cat(quoted, BACKSLASHED("e")); break;
            case '\f': quoted = CORD_cat(quoted, BACKSLASHED("f")); break;
            case '\n': quoted = CORD_cat(quoted, BACKSLASHED("n")); break;
            case '\r': quoted = CORD_cat(quoted, BACKSLASHED("r")); break;
            case '\t': quoted = CORD_cat(quoted, BACKSLASHED("t")); break;
            case '\v': quoted = CORD_cat(quoted, BACKSLASHED("v")); break;
            case '"': quoted = CORD_cat(quoted, BACKSLASHED("\"")); break;
            case '\\': quoted = CORD_cat(quoted, BACKSLASHED("\\")); break;
            case '\x00' ... '\x06': case '\x0E' ... '\x1A':
            case '\x1C' ... '\x1F': case '\x7F' ... '\x7F':
                CORD_sprintf(&quoted, "%r" BACKSLASHED("x%02X"), quoted, c);
                break;
            default: quoted = CORD_cat_char(quoted, c); break;
#undef BACKSLASHED
            }
        }
        quoted = CORD_cat(quoted, "\"\x1b[m");
        return quoted;
    } else {
        CORD quoted = "\"";
        CORD_pos i;
        CORD_FOR(i, str) {
            char c = CORD_pos_fetch(i);
            switch (c) {
            case '\a': quoted = CORD_cat(quoted, "\\a"); break;
            case '\b': quoted = CORD_cat(quoted, "\\b"); break;
            case '\x1b': quoted = CORD_cat(quoted, "\\e"); break;
            case '\f': quoted = CORD_cat(quoted, "\\f"); break;
            case '\n': quoted = CORD_cat(quoted, "\\n"); break;
            case '\r': quoted = CORD_cat(quoted, "\\r"); break;
            case '\t': quoted = CORD_cat(quoted, "\\t"); break;
            case '\v': quoted = CORD_cat(quoted, "\\v"); break;
            case '"': quoted = CORD_cat(quoted, "\\\""); break;
            case '\\': quoted = CORD_cat(quoted, "\\\\"); break;
            case '\x00' ... '\x06': case '\x0E' ... '\x1A':
            case '\x1C' ... '\x1F': case '\x7F' ... '\x7F':
                CORD_sprintf(&quoted, "%r\\x%02X", quoted, c);
                break;
            default: quoted = CORD_cat_char(quoted, c); break;
            }
        }
        quoted = CORD_cat_char(quoted, '"');
        return quoted;
    }
}

public int Text$compare(const CORD *x, const CORD *y)
{
    uint8_t *xx = (uint8_t*)CORD_to_const_char_star(*x);
    uint8_t *yy = (uint8_t*)CORD_to_const_char_star(*y);
    int result = 0;
    if (u8_normcmp(xx, strlen((char*)xx), yy, strlen((char*)yy), UNINORM_NFD, &result))
        fail("Something went wrong while comparing text");
    return result;
}

public bool Text$equal(const CORD *x, const CORD *y)
{
    return Text$compare(x, y) == 0;
}

public uint32_t Text$hash(const CORD *cord)
{
    if (!*cord) return 0;

    uint8_t buf[128] = {0}; size_t norm_len = sizeof(buf);
    uint8_t *normalized = _normalize(*cord, buf, &norm_len);

    uint32_t hash;
    halfsiphash(normalized, norm_len, TOMO_HASH_KEY, (uint8_t*)&hash, sizeof(hash));
    if (normalized != buf) free(normalized);
    return hash;
}

public CORD Text$upper(CORD str)
{
    if (!str) return str;
    size_t len = strlen(str) + 1;
    uint8_t *dest = GC_MALLOC_ATOMIC(len);
    dest[len-1] = 0;
    return (CORD)u8_toupper((const uint8_t*)str, len-1, uc_locale_language(), NULL, dest, &len);
}

public CORD Text$lower(CORD str)
{
    if (!str) return str;
    size_t len = strlen(str) + 1;
    uint8_t *dest = GC_MALLOC_ATOMIC(len);
    dest[len-1] = 0;
    return (CORD)u8_tolower((const uint8_t*)str, len-1, uc_locale_language(), NULL, dest, &len);
}

public CORD Text$title(CORD str)
{
    if (!str) return str;
    size_t len = strlen(str) + 1;
    uint8_t *dest = GC_MALLOC_ATOMIC(len);
    dest[len-1] = 0;
    return (CORD)u8_totitle((const uint8_t*)str, len-1, uc_locale_language(), NULL, dest, &len);
}

public bool Text$has(CORD str, CORD target, Where_t where)
{
    if (!target) return true;
    if (!str) return false;

    uint8_t str_buf[128] = {0}; size_t str_norm_len = sizeof(str_buf);
    uint8_t *str_normalized = _normalize(str, str_buf, &str_norm_len);

    uint8_t target_buf[128] = {0}; size_t target_norm_len = sizeof(target_buf);
    uint8_t *target_normalized = _normalize(target, target_buf, &target_norm_len);

    if (target_norm_len > str_norm_len) return false;

    bool ret;
    if (where.$tag == $tag$Where$Start) {
        ret = (u8_strncmp(str_normalized, target_normalized, target_norm_len-1) == 0);
    } else if (where.$tag == $tag$Where$End) {
        ret = (u8_strcmp(str_normalized + str_norm_len - target_norm_len, target_normalized) == 0);
    } else {
        assert(where.$tag == $tag$Where$Anywhere);
        ret = (u8_strstr(str_normalized, target_normalized) != NULL);
    }

    if (str_normalized != str_buf) free(str_normalized);
    if (target_normalized != target_buf) free(target_normalized);
    return ret;
}

public CORD Text$without(CORD str, CORD target, Where_t where)
{
    if (!str || !target) return str;

    size_t target_len = CORD_len(target);
    size_t str_len = CORD_len(str);
    if (where.$tag == $tag$Where$Start) {
        if (CORD_ncmp(str, 0, target, 0, target_len) == 0)
            return CORD_substr(str, target_len, str_len - target_len);
        return str;
    } else if (where.$tag == $tag$Where$End) {
        if (CORD_ncmp(str, str_len-target_len, target, 0, target_len) == 0)
            return CORD_substr(str, 0, str_len - target_len);
        return str;
    } else {
        CORD ret = CORD_EMPTY;
        size_t i = 0;
        for (;;) {
            size_t match = CORD_str(str, i, target);
            if (match == CORD_NOT_FOUND) {
                if (i == 0) return str; // No matches!
                ret = CORD_cat(ret, CORD_substr(str, i, str_len));
                break;
            }
            ret = CORD_cat(ret, CORD_substr(str, i, (match-i)));
            i = match + target_len;
        }
        return ret;
    }
}

public CORD Text$trimmed(CORD str, CORD skip, Where_t where)
{
    if (!str || !skip) return str;
    const uint8_t *ustr = (const uint8_t*)CORD_to_const_char_star(str);
    const uint8_t *uskip = (const uint8_t*)CORD_to_const_char_star(skip);
    // TODO: implement proper reverse iteration with u8_prev()
    if (where.$tag == $tag$Where$Start) {
        size_t span = u8_strspn(ustr, uskip);
        return (CORD)ustr + span;
    } else if (where.$tag == $tag$Where$End) {
        size_t len = u8_strlen(ustr);
        const uint8_t *back = ustr + len;
        size_t back_span = 0;
        while (back - back_span > ustr && u8_strspn(back-back_span-1, uskip) > back_span)
            ++back_span;
        return CORD_substr((CORD)ustr, 0, len - back_span);
    } else {
        size_t span = u8_strspn(ustr, uskip);
        size_t len = u8_strlen(ustr);
        const uint8_t *back = ustr + len;
        size_t back_span = 0;
        while (back - back_span > ustr + span && u8_strspn(back-back_span-1, uskip) > back_span)
            ++back_span;
        return CORD_substr((CORD)(ustr + span), 0, len - span - back_span);
    }
}

public find_result_t Text$find(CORD str, CORD pat)
{
    if (!pat) return (find_result_t){.status=FIND_SUCCESS, .index=1};
    size_t pos = CORD_str(str, 0, pat);
    return (pos == CORD_NOT_FOUND) ? (find_result_t){.status=FIND_FAILURE} : (find_result_t){.status=FIND_SUCCESS, .index=(int32_t)pos};
}

public CORD Text$replace(CORD text, CORD pat, CORD replacement, Int_t int_limit)
{
    if (!text || !pat) return text;
    CORD ret = CORD_EMPTY;
    size_t pos = 0, pat_len = CORD_len(pat);
    int64_t limit = Int$as_i64(int_limit);
    for (size_t found; limit != 0 && (found=CORD_str(text, pos, pat)) != CORD_NOT_FOUND; --limit) {
        ret = CORD_all(ret, CORD_substr(text, pos, found - pos), replacement);
        pos = found + pat_len;
    }
    size_t str_len = CORD_len(text);
    return CORD_cat(ret, CORD_substr(text, pos, str_len - pos));
}

public array_t Text$split(CORD str, CORD split)
{
    if (!str) return (array_t){.data=GC_MALLOC(sizeof(CORD)), .atomic=1, .length=1, .stride=sizeof(CORD)};
    array_t strings = {.stride=sizeof(CORD), .atomic=1};

    const uint8_t *ustr = (uint8_t*)CORD_to_const_char_star(str);
    const uint8_t *usplit = (uint8_t*)CORD_to_const_char_star(split);
    for (int64_t i = 0; ; ) {
        size_t non_split = u8_strcspn(ustr + i, usplit);
        CORD chunk = CORD_substr((CORD)ustr, i, non_split);
        Array$insert(&strings, &chunk, I(0), sizeof(CORD));

        i += non_split;

        size_t split_span = u8_strspn(ustr + i, usplit);
        if (split_span == 0) break;
        i += split_span;
    }
    return strings;
}

public CORD Text$join(CORD glue, array_t pieces)
{
    if (pieces.length == 0) return CORD_EMPTY;

    CORD ret = CORD_EMPTY;
    for (int64_t i = 0; i < pieces.length; i++) {
        if (i > 0) ret = CORD_cat(ret, glue);
        ret = CORD_cat(ret, *(CORD*)((void*)pieces.data + i*pieces.stride));
    }
    return ret;
}

public array_t Text$clusters(CORD text)
{
    array_t clusters = {.atomic=1};
    uint8_t buf[128] = {0}; size_t norm_len = sizeof(buf);
    uint8_t *normalized = _normalize(text, buf, &norm_len);
    const uint8_t *end = normalized + strlen((char*)normalized);
    for (const uint8_t *pos = normalized; pos != end; ) {
        const uint8_t *next = u8_grapheme_next(pos, end);
        size_t len = (size_t)(next - pos);
        char cluster_buf[len+1];
        strlcpy(cluster_buf, (char*)pos, len+1);
        CORD cluster = CORD_from_char_star(cluster_buf);
        Array$insert(&clusters, &cluster, I(0), sizeof(CORD));
        pos = next;
    }

    if (normalized != buf) free(normalized);
    return clusters;
}

public array_t Text$codepoints(CORD text)
{
    uint8_t norm_buf[128] = {0}; size_t norm_len = sizeof(norm_buf);
    uint8_t *normalized = _normalize(text, norm_buf, &norm_len);

    uint32_t codepoint_buf[128] = {0};
    size_t codepoint_len = sizeof(codepoint_buf);
    uint32_t *codepoints = u8_to_u32(normalized, norm_len-1, codepoint_buf, &codepoint_len);
    array_t ret = {
        .length=codepoint_len,
        .data=memcpy(GC_MALLOC_ATOMIC(sizeof(int32_t[codepoint_len])), codepoints, sizeof(int32_t[codepoint_len])),
        .stride=sizeof(int32_t),
        .atomic=1,
    };

    if (normalized != norm_buf) free(normalized);
    if (codepoints != codepoint_buf) free(codepoints);
    return ret;
}

public array_t Text$bytes(CORD text)
{
    uint8_t norm_buf[128] = {0}; size_t norm_len = sizeof(norm_buf);
    uint8_t *normalized = _normalize(text, norm_buf, &norm_len);

    --norm_len; // NUL byte
    array_t ret = {
        .length=norm_len,
        .data=memcpy(GC_MALLOC_ATOMIC(sizeof(uint8_t[norm_len])), normalized, sizeof(uint8_t[norm_len])),
        .stride=sizeof(uint8_t),
        .atomic=1,
    };

    if (normalized != norm_buf) free(normalized);
    return ret;
}

public Int_t Text$num_clusters(CORD text)
{
    const uint8_t *ustr = (const uint8_t*)CORD_to_const_char_star(text);
    int64_t num_clusters = 0;
    const uint8_t *end = ustr + u8_strlen(ustr);
    for (const uint8_t *pos = ustr; pos != end; ) {
        const uint8_t *next = u8_grapheme_next(pos, end);
        ++num_clusters;
        pos = next;
    }
    return I(num_clusters);
}

public Int_t Text$num_codepoints(CORD text)
{
    uint8_t buf[128] = {0}; size_t norm_len = sizeof(buf);
    uint8_t *normalized = _normalize(text, buf, &norm_len);
    int64_t num_codepoints = u8_mbsnlen(normalized, norm_len-1);
    if (normalized != buf) free(normalized);
    return I(num_codepoints);
}

public Int_t Text$num_bytes(CORD text)
{
    uint8_t norm_buf[128] = {0}; size_t norm_len = sizeof(norm_buf);
    uint8_t *normalized = _normalize(text, norm_buf, &norm_len);
    --norm_len; // NUL byte
    if (!normalized) errx(1, "Unicode normalization error!");
    if (normalized != norm_buf) free(normalized);
    return I(norm_len);
}

public array_t Text$character_names(CORD text)
{
    array_t codepoints = Text$codepoints(text);
    array_t ret = {.length=codepoints.length, .stride=sizeof(CORD), .data=GC_MALLOC(sizeof(CORD[codepoints.length]))};
    for (int64_t i = 0; i < codepoints.length; i++) {
        char buf[UNINAME_MAX];
        unicode_character_name(*(ucs4_t*)(codepoints.data + codepoints.stride*i), buf);
        *(CORD*)(ret.data + ret.stride*i) = CORD_from_char_star(buf);
    }
    return ret;
}

public const TypeInfo $Text = {
    .size=sizeof(CORD),
    .align=__alignof__(CORD),
    .tag=TextInfo,
    .TextInfo={.lang="Text"},
};

// vim: ts=4 sw=0 et cino=L2,l1,(0,W4,m1,\:0