#include "string.h"
#include "cutil.h"

size_t cu_strlen(const char* str)
{
    u32 len = 0;
    while(*str++) len++;
    return len;
}

void cu_strcpy(char* dst,const char* src)
{
    while((*dst++ = *src++)){}
}

void cu_strncpy(char* dst,const char* src,size_t maxLen)
{
    maxLen=-1;
    while((*dst++ = *src++) && --maxLen){}
    if(!maxLen) dst[maxLen] = '\0';
}

const char* cu_strchr(const char* src,char chr)
{
    while(*src)
    {
        if(*src == chr) return src;
        src++;
    }
    return NULL;
}

const char* cu_strrchr(const char* src,char chr)
{
    const char* ptr;
    
    ptr = src+cu_strlen(src)-1;
    while(ptr != src)
    {
        if(*ptr == chr) return ptr;
        ptr--;
    }
    return NULL;
}

int cu_strcmp(const char* src,const char* dst)
{
    if(cu_strlen(src) != cu_strlen(dst)) return 1;
    while(*src)
        if(*src++ != *dst++) return 1;
    return 0;
}

int cu_strncmp(const char* haystack,char* needle)
{
    return !!cu_memcmp(haystack,needle,cu_strlen(needle));
}

int cu_strcasecmp(const char* src,const char* dst)
{
    if(cu_strlen(src) != cu_strlen(dst)) return 1;
    while(*src)
    {
        if(cu_tolower(*src++) != cu_tolower(*dst++))
            return 1;
    }
    return 0;
}

char cu_toupper(char c)
{
    if(c >= 0x61 && c <= 0x7A) return c&0xDF;
    return c;
}

char cu_tolower(char c)
{
    if(c >= 0x41 && c <= 0x5A) return c|(1<<5);
    return c;
}

size_t cu_chrlen(char cchr)
{
    u8 chr = (u8)cchr;
    
    if(chr & 0b10000000)
    {
        if((chr>>5) == 0b110) return 2;
        else if((chr>>4) == 0b1110) return 3;
        else if((chr>>5) == 0b11110) return 4;
    }
    return 1;
}

dbcs_t cu_chr2dbcs(const char* ptr)
{
    const u8* chr = (u8*)ptr;
    
    switch(cu_chrlen(chr[0]))
    {
        case 1: return chr[0]&0x7F;
        case 2: return ((chr[0]&0x1F)<<6)|(chr[1]&0x3F);
        case 3: return ((chr[0]&0x0F)<<12)|((chr[1]&0x3F)<<6)|(chr[2]&0x3F);
        default: return 0x003F;
    }
}

size_t cu_dbcslen(dbcs_t chr)
{
    if(chr > 0x7FF) return 3;
    else if(chr > 0x7F) return 2;
    return 1;
}

void cu_dbcs2str(dbcs_t* dbcs,char* str,size_t maxStr)
{
    char* end = str + maxStr - 1;
    dbcs_t wc;
    
    while((wc = *dbcs++) && str != end)
    {
        size_t len = cu_dbcslen(wc);
        if((str+len) >= end) break;
        switch(len)
        {
            case 1:
                *str++ = wc&0x7F;
                break;
            case 2:
                *str++ = 0b11000000|((wc>>6)&0x1F);
                *str++ = 0b10000000|((wc)&0x3F);
                break;
            case 3:
                *str++ = 0b11100000|((wc>>12)&0x0F);
                *str++ = 0b10000000|((wc>>6)&0x3F);
                *str++ = 0b10000000|((wc)&0x3F);
                break;
            default: *str++ = '?';
        }
    }
    *str++ = '\0';
}