#define WIN32_NO_STATUS
#include <wine/unicode.h>

#define NDEBUG
#include <debug.h>

/* Taken from Wine kernel32/locale.c */

enum {
    BASE = 36,
    TMIN = 1,
    TMAX = 26,
    SKEW = 38,
    DAMP = 700,
    INIT_BIAS = 72,
    INIT_N = 128
};

static inline INT adapt(INT delta, INT numpoints, BOOL firsttime)
{
    INT k;

    delta /= (firsttime ? DAMP : 2);
    delta += delta/numpoints;

    for(k=0; delta>((BASE-TMIN)*TMAX)/2; k+=BASE)
        delta /= BASE-TMIN;
    return k+((BASE-TMIN+1)*delta)/(delta+SKEW);
}

static inline unsigned short get_table_entry( const unsigned short *table, WCHAR ch )
{
    return table[table[table[ch >> 8] + ((ch >> 4) & 0x0f)] + (ch & 0xf)];
}

INT WINAPI IdnToNameprepUnicode(DWORD dwFlags, LPCWSTR lpUnicodeCharStr, INT cchUnicodeChar,
                                LPWSTR lpNameprepCharStr, INT cchNameprepChar)
{
    enum {
        UNASSIGNED = 0x1,
        PROHIBITED = 0x2,
        BIDI_RAL   = 0x4,
        BIDI_L     = 0x8
    };

    extern const unsigned short nameprep_char_type[];
    extern const WCHAR nameprep_mapping[];
    const WCHAR *ptr;
    WORD flags;
    WCHAR buf[64], *map_str, norm_str[64], ch;
    DWORD i, map_len, norm_len, mask, label_start, label_end, out = 0;
    BOOL have_bidi_ral, prohibit_bidi_ral, ascii_only;

    DPRINT("%x %p %d %p %d\n", dwFlags, lpUnicodeCharStr, cchUnicodeChar,
           lpNameprepCharStr, cchNameprepChar);

    if(dwFlags & ~(IDN_ALLOW_UNASSIGNED|IDN_USE_STD3_ASCII_RULES)) {
        SetLastError(ERROR_INVALID_FLAGS);
        return 0;
    }

    if(!lpUnicodeCharStr || cchUnicodeChar<-1) {
        SetLastError(ERROR_INVALID_PARAMETER);
        return 0;
    }

    if(cchUnicodeChar == -1)
        cchUnicodeChar = (UINT)strlenW(lpUnicodeCharStr)+1;
    if(!cchUnicodeChar || (cchUnicodeChar==1 && lpUnicodeCharStr[0]==0)) {
        SetLastError(ERROR_INVALID_NAME);
        return 0;
    }

    for(label_start=0; label_start<(UINT)cchUnicodeChar;) {
        ascii_only = TRUE;
        for(i=label_start; i<(UINT)cchUnicodeChar; i++) {
            ch = lpUnicodeCharStr[i];

            if(i!=cchUnicodeChar-1 && !ch) {
                SetLastError(ERROR_INVALID_NAME);
                return 0;
            }
            /* check if ch is one of label separators defined in RFC3490 */
            if(!ch || ch=='.' || ch==0x3002 || ch==0xff0e || ch==0xff61)
                break;

            if(ch > 0x7f) {
                ascii_only = FALSE;
                continue;
            }

            if((dwFlags&IDN_USE_STD3_ASCII_RULES) == 0)
                continue;
            if((ch>='a' && ch<='z') || (ch>='A' && ch<='Z')
                    || (ch>='0' && ch<='9') || ch=='-')
                continue;

            SetLastError(ERROR_INVALID_NAME);
            return 0;
        }
        label_end = i;
        /* last label may be empty */
        if(label_start==label_end && ch) {
            SetLastError(ERROR_INVALID_NAME);
            return 0;
        }

        if((dwFlags&IDN_USE_STD3_ASCII_RULES) && (lpUnicodeCharStr[label_start]=='-' ||
                    lpUnicodeCharStr[label_end-1]=='-')) {
            SetLastError(ERROR_INVALID_NAME);
            return 0;
        }

        if(ascii_only) {
            /* maximal label length is 63 characters */
            if(label_end-label_start > 63) {
                SetLastError(ERROR_INVALID_NAME);
                return 0;
            }
            if(label_end < (UINT)cchUnicodeChar)
                label_end++;

            if(!lpNameprepCharStr) {
                out += label_end-label_start;
            }else if(out+label_end-label_start <= (UINT)cchNameprepChar) {
                memcpy(lpNameprepCharStr+out, lpUnicodeCharStr+label_start,
                        (label_end-label_start)*sizeof(WCHAR));
                if(lpUnicodeCharStr[label_end-1] > 0x7f)
                    lpNameprepCharStr[out+label_end-label_start-1] = '.';
                out += label_end-label_start;
            }else {
                SetLastError(ERROR_INSUFFICIENT_BUFFER);
                return 0;
            }

            label_start = label_end;
            continue;
        }

        map_len = 0;
        for(i=label_start; i<label_end; i++) {
            ch = lpUnicodeCharStr[i];
            ptr = nameprep_mapping + nameprep_mapping[ch>>8];
            ptr = nameprep_mapping + ptr[(ch>>4)&0x0f] + 3*(ch&0x0f);

            if(!ptr[0]) map_len++;
            else if(!ptr[1]) map_len++;
            else if(!ptr[2]) map_len += 2;
            else if(ptr[0]!=0xffff || ptr[1]!=0xffff || ptr[2]!=0xffff) map_len += 3;
        }
        if(map_len*sizeof(WCHAR) > sizeof(buf)) {
            map_str = HeapAlloc(GetProcessHeap(), 0, map_len*sizeof(WCHAR));
            if(!map_str) {
                SetLastError(ERROR_NOT_ENOUGH_MEMORY);
                return 0;
            }
        }else {
            map_str = buf;
        }
        map_len = 0;
        for(i=label_start; i<label_end; i++) {
            ch = lpUnicodeCharStr[i];
            ptr = nameprep_mapping + nameprep_mapping[ch>>8];
            ptr = nameprep_mapping + ptr[(ch>>4)&0x0f] + 3*(ch&0x0f);

            if(!ptr[0]) {
                map_str[map_len++] = ch;
            }else if(!ptr[1]) {
                map_str[map_len++] = ptr[0];
            }else if(!ptr[2]) {
                map_str[map_len++] = ptr[0];
                map_str[map_len++] = ptr[1];
            }else if(ptr[0]!=0xffff || ptr[1]!=0xffff || ptr[2]!=0xffff) {
                map_str[map_len++] = ptr[0];
                map_str[map_len++] = ptr[1];
                map_str[map_len++] = ptr[2];
            }
        }

        norm_len = FoldStringW(MAP_FOLDCZONE, map_str, map_len,
                norm_str, sizeof(norm_str)/sizeof(WCHAR)-1);
        if(map_str != buf)
            HeapFree(GetProcessHeap(), 0, map_str);
        if(!norm_len) {
            if(GetLastError() == ERROR_INSUFFICIENT_BUFFER)
                SetLastError(ERROR_INVALID_NAME);
            return 0;
        }

        if(label_end < (UINT)cchUnicodeChar) {
            norm_str[norm_len++] = lpUnicodeCharStr[label_end] ? '.' : 0;
            label_end++;
        }

        if(!lpNameprepCharStr) {
            out += norm_len;
        }else if(out+norm_len <= (UINT)cchNameprepChar) {
            memcpy(lpNameprepCharStr+out, norm_str, norm_len*sizeof(WCHAR));
            out += norm_len;
        }else {
            SetLastError(ERROR_INSUFFICIENT_BUFFER);
            return 0;
        }

        have_bidi_ral = prohibit_bidi_ral = FALSE;
        mask = PROHIBITED;
        if((dwFlags&IDN_ALLOW_UNASSIGNED) == 0)
            mask |= UNASSIGNED;
        for(i=0; i<norm_len; i++) {
            ch = norm_str[i];
            flags = get_table_entry( nameprep_char_type, ch );

            if(flags & mask) {
                SetLastError((flags & PROHIBITED) ? ERROR_INVALID_NAME
                        : ERROR_NO_UNICODE_TRANSLATION);
                return 0;
            }

            if(flags & BIDI_RAL)
                have_bidi_ral = TRUE;
            if(flags & BIDI_L)
                prohibit_bidi_ral = TRUE;
        }

        if(have_bidi_ral) {
            ch = norm_str[0];
            flags = get_table_entry( nameprep_char_type, ch );
            if((flags & BIDI_RAL) == 0)
                prohibit_bidi_ral = TRUE;

            ch = norm_str[norm_len-1];
            flags = get_table_entry( nameprep_char_type, ch );
            if((flags & BIDI_RAL) == 0)
                prohibit_bidi_ral = TRUE;
        }

        if(have_bidi_ral && prohibit_bidi_ral) {
            SetLastError(ERROR_INVALID_NAME);
            return 0;
        }

        label_start = label_end;
    }

    return out;
}

INT WINAPI IdnToAscii(DWORD dwFlags, LPCWSTR lpUnicodeCharStr, INT cchUnicodeChar,
                      LPWSTR lpASCIICharStr, INT cchASCIIChar)
{
    static const WCHAR prefixW[] = {'x','n','-','-'};

    WCHAR *norm_str;
    INT i, label_start, label_end, norm_len, out_label, out = 0;

    DPRINT("%x %p %d %p %d\n", dwFlags, lpUnicodeCharStr, cchUnicodeChar,
           lpASCIICharStr, cchASCIIChar);

    norm_len = IdnToNameprepUnicode(dwFlags, lpUnicodeCharStr, cchUnicodeChar, NULL, 0);
    if(!norm_len)
        return 0;
    norm_str = HeapAlloc(GetProcessHeap(), 0, norm_len*sizeof(WCHAR));
    if(!norm_str) {
        SetLastError(ERROR_NOT_ENOUGH_MEMORY);
        return 0;
    }
    norm_len = IdnToNameprepUnicode(dwFlags, lpUnicodeCharStr,
            cchUnicodeChar, norm_str, norm_len);
    if(!norm_len) {
        HeapFree(GetProcessHeap(), 0, norm_str);
        return 0;
    }

    for(label_start=0; label_start<norm_len;) {
        INT n = INIT_N, bias = INIT_BIAS;
        INT delta = 0, b = 0, h;

        out_label = out;
        for(i=label_start; i<norm_len && norm_str[i]!='.' &&
                norm_str[i]!=0x3002 && norm_str[i]!='\0'; i++)
            if(norm_str[i] < 0x80)
                b++;
        label_end = i;

        if(b == label_end-label_start) {
            if(label_end < norm_len)
                b++;
            if(!lpASCIICharStr) {
                out += b;
            }else if(out+b <= cchASCIIChar) {
                memcpy(lpASCIICharStr+out, norm_str+label_start, b*sizeof(WCHAR));
                out += b;
            }else {
                HeapFree(GetProcessHeap(), 0, norm_str);
                SetLastError(ERROR_INSUFFICIENT_BUFFER);
                return 0;
            }
            label_start = label_end+1;
            continue;
        }

        if(!lpASCIICharStr) {
            out += 5+b; /* strlen(xn--...-) */
        }else if(out+5+b <= cchASCIIChar) {
            memcpy(lpASCIICharStr+out, prefixW, sizeof(prefixW));
            out += 4;
            for(i=label_start; i<label_end; i++)
                if(norm_str[i] < 0x80)
                    lpASCIICharStr[out++] = norm_str[i];
            lpASCIICharStr[out++] = '-';
        }else {
            HeapFree(GetProcessHeap(), 0, norm_str);
            SetLastError(ERROR_INSUFFICIENT_BUFFER);
            return 0;
        }
        if(!b)
            out--;

        for(h=b; h<label_end-label_start;) {
            INT m = 0xffff, q, k;

            for(i=label_start; i<label_end; i++) {
                if(norm_str[i]>=n && m>norm_str[i])
                    m = norm_str[i];
            }
            delta += (m-n)*(h+1);
            n = m;

            for(i=label_start; i<label_end; i++) {
                if(norm_str[i] < n) {
                    delta++;
                }else if(norm_str[i] == n) {
                    for(q=delta, k=BASE; ; k+=BASE) {
                        INT t = k<=bias ? TMIN : k>=bias+TMAX ? TMAX : k-bias;
                        INT disp = q<t ? q : t+(q-t)%(BASE-t);
                        if(!lpASCIICharStr) {
                            out++;
                        }else if(out+1 <= cchASCIIChar) {
                            lpASCIICharStr[out++] = disp<='z'-'a' ?
                                'a'+disp : '0'+disp-'z'+'a'-1;
                        }else {
                            HeapFree(GetProcessHeap(), 0, norm_str);
                            SetLastError(ERROR_INSUFFICIENT_BUFFER);
                            return 0;
                        }
                        if(q < t)
                            break;
                        q = (q-t)/(BASE-t);
                    }
                    bias = adapt(delta, h+1, h==b);
                    delta = 0;
                    h++;
                }
            }
            delta++;
            n++;
        }

        if(out-out_label > 63) {
            HeapFree(GetProcessHeap(), 0, norm_str);
            SetLastError(ERROR_INVALID_NAME);
            return 0;
        }

        if(label_end < norm_len) {
            if(!lpASCIICharStr) {
                out++;
            }else if(out+1 <= cchASCIIChar) {
                lpASCIICharStr[out++] = norm_str[label_end] ? '.' : 0;
            }else {
                HeapFree(GetProcessHeap(), 0, norm_str);
                SetLastError(ERROR_INSUFFICIENT_BUFFER);
                return 0;
            }
        }
        label_start = label_end+1;
    }

    HeapFree(GetProcessHeap(), 0, norm_str);
    return out;
}