#!/bin/python

preamble = """
Rune*
rbsearch(Rune c, Rune *t, int n, int nelem)
{
    Rune *p;
    int   m;

    while (n > 1) {
        m = n >> 1;
        p = t + m*nelem;
        if (c >= p[0]) {
            t  = p;
            n -= m;
        } else n = m;
    }

    if (n && c >= t[0]) return t;
    else return 0;
}
"""

def findrange(s):
    rs = []
    ss = []
    b, c  = None, None
    for elt in sorted(s):
        if b is None:
            b, c = elt, elt
            continue
        if elt == c + 1:
            c = elt
            continue
        else:
            if b == c:
                ss.append(b)
            else:
                rs.append( (b, c) )
            b, c = elt, elt
    return rs, ss

def puttab(s, fd, name):
    lname  = name.lower()
    rs, ss = findrange(s)

    rtabn = "%s_rtab"%lname
    stabn = "%s_stab"%lname

    fd.write("static Rune %s[] = {" % rtabn)
    for i, elts in enumerate(sorted(rs)):
        fd.write("0x%04x, 0x%04x,\n" % (elts[0], elts[1]))
    fd.write("};\n\n")

    if len(ss) > 0:
        fd.write("static Rune %s[] = {" % stabn)
        for i, elt in enumerate(sorted(ss)):
            if i % 2 == 0:
                fd.write("\n")
            fd.write("0x%04x, "%(elt))
        fd.write("\n};\n\n")

    fd.write("int\n")
    fd.write("utf8·%s(Rune c)\n"%name)
    fd.write("{\n")
    fd.write("\tRune *p;\n\n")
    fd.write("\tp = rbsearch(c, %s, arrlen(%s)/2, 2);\n"%(rtabn,rtabn))
    fd.write("\tif (p && c >= p[0] && c <= p[1])\n")
    fd.write("\t\t\treturn 1;\n")
    if len(ss) > 0:
        fd.write("\tp = rbsearch(c, %s, arrlen(%s), 1);\n"%(stabn,stabn))
        fd.write("\tif (p && c == p[0])\n")
        fd.write("\t\treturn 1;\n")
    fd.write("\n\treturn 0;\n")
    fd.write("}\n\n")

RUNEMAX = 0x10FFFF

if __name__ == "__main__":
    alphas  = set()
    lowers  = set()
    uppers  = set()
    titles  = set()
    digits  = set()
    spaces  = set()

    tolower = {}
    toupper = {}
    totitle = {}

    with open("data/UnicodeData.txt") as utf8:
        for runedata in utf8:
            fields = runedata[:-1].split(";")
            rune   = int(fields[0], 16)
            kind   = fields[2]

            assert rune < RUNEMAX

            if kind[0] == 'Z':
                spaces.add(rune)
            elif kind[0] == 'L':
                alphas.add(rune)

                if   kind[1] == "l":
                    lowers.add(rune)
                elif kind[1] == "u":
                    uppers.add(rune)
                elif kind[1] == "t":
                    titles.add(rune)

                if (fields[12] != ""):
                    toupper[rune] = int(fields[12], 16)

                if (fields[13] != ""):
                    tolower[rune] = int(fields[13], 16)

                if (fields[14] != ""):
                    totitle[rune] = int(fields[14], 16)

            elif kind == 'Nd':
                digits.add(rune)

        # Some annoying exceptions...
        # These are counted as control characters
        spaces.add(ord('\t'))
        spaces.add(ord('\n'))
        spaces.add(ord('\f'))
        spaces.add(ord('\v'))
        spaces.add(0x85)
        spaces.add(0xfeff)

    # TODO: Add toLower/toUpper/toTitle...
    with open("utf8_gen.c", "w") as utf8:
        utf8.write(preamble)
        puttab(spaces, utf8, "IsSpace")
        puttab(lowers, utf8, "IsLower")
        puttab(uppers, utf8, "IsUpper")
        puttab(titles, utf8, "IsTitle")
        puttab(alphas, utf8, "IsLetter")
        puttab(digits, utf8, "IsDigit")