# Copyright (C) 2003-2007, 2009-2011 Nominum, Inc.
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose with or without fee is hereby granted,
# provided that the above copyright notice and this permission notice
# appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

import cStringIO
import struct

import dns.exception
import dns.rdata

_pows = (1L, 10L, 100L, 1000L, 10000L, 100000L, 1000000L, 10000000L,
         100000000L, 1000000000L, 10000000000L)

# default values are in centimeters
_default_size = 100.0
_default_hprec = 1000000.0
_default_vprec = 1000.0

def _exponent_of(what, desc):
    if what == 0:
        return 0
    exp = None
    for i in xrange(len(_pows)):
        if what // _pows[i] == 0L:
            exp = i - 1
            break
    if exp is None or exp < 0:
        raise dns.exception.SyntaxError("%s value out of bounds" % desc)
    return exp

def _float_to_tuple(what):
    if what < 0:
        sign = -1
        what *= -1
    else:
        sign = 1
    what = long(round(what * 3600000))
    degrees = int(what // 3600000)
    what -= degrees * 3600000
    minutes = int(what // 60000)
    what -= minutes * 60000
    seconds = int(what // 1000)
    what -= int(seconds * 1000)
    what = int(what)
    return (degrees * sign, minutes, seconds, what)

def _tuple_to_float(what):
    if what[0] < 0:
        sign = -1
        value = float(what[0]) * -1
    else:
        sign = 1
        value = float(what[0])
    value += float(what[1]) / 60.0
    value += float(what[2]) / 3600.0
    value += float(what[3]) / 3600000.0
    return sign * value

def _encode_size(what, desc):
    what = long(what);
    exponent = _exponent_of(what, desc) & 0xF
    base = what // pow(10, exponent) & 0xF
    return base * 16 + exponent

def _decode_size(what, desc):
    exponent = what & 0x0F
    if exponent > 9:
        raise dns.exception.SyntaxError("bad %s exponent" % desc)
    base = (what & 0xF0) >> 4
    if base > 9:
        raise dns.exception.SyntaxError("bad %s base" % desc)
    return long(base) * pow(10, exponent)

class LOC(dns.rdata.Rdata):
    """LOC record

    @ivar latitude: latitude
    @type latitude: (int, int, int, int) tuple specifying the degrees, minutes,
    seconds, and milliseconds of the coordinate.
    @ivar longitude: longitude
    @type longitude: (int, int, int, int) tuple specifying the degrees,
    minutes, seconds, and milliseconds of the coordinate.
    @ivar altitude: altitude
    @type altitude: float
    @ivar size: size of the sphere
    @type size: float
    @ivar horizontal_precision: horizontal precision
    @type horizontal_precision: float
    @ivar vertical_precision: vertical precision
    @type vertical_precision: float
    @see: RFC 1876"""

    __slots__ = ['latitude', 'longitude', 'altitude', 'size',
                 'horizontal_precision', 'vertical_precision']

    def __init__(self, rdclass, rdtype, latitude, longitude, altitude,
                 size=_default_size, hprec=_default_hprec, vprec=_default_vprec):
        """Initialize a LOC record instance.

        The parameters I{latitude} and I{longitude} may be either a 4-tuple
        of integers specifying (degrees, minutes, seconds, milliseconds),
        or they may be floating point values specifying the number of
        degrees. The other parameters are floats. Size, horizontal precision,
        and vertical precision are specified in centimeters."""

        super(LOC, self).__init__(rdclass, rdtype)
        if isinstance(latitude, int) or isinstance(latitude, long):
            latitude = float(latitude)
        if isinstance(latitude, float):
            latitude = _float_to_tuple(latitude)
        self.latitude = latitude
        if isinstance(longitude, int) or isinstance(longitude, long):
            longitude = float(longitude)
        if isinstance(longitude, float):
            longitude = _float_to_tuple(longitude)
        self.longitude = longitude
        self.altitude = float(altitude)
        self.size = float(size)
        self.horizontal_precision = float(hprec)
        self.vertical_precision = float(vprec)

    def to_text(self, origin=None, relativize=True, **kw):
        if self.latitude[0] > 0:
            lat_hemisphere = 'N'
            lat_degrees = self.latitude[0]
        else:
            lat_hemisphere = 'S'
            lat_degrees = -1 * self.latitude[0]
        if self.longitude[0] > 0:
            long_hemisphere = 'E'
            long_degrees = self.longitude[0]
        else:
            long_hemisphere = 'W'
            long_degrees = -1 * self.longitude[0]
        text = "%d %d %d.%03d %s %d %d %d.%03d %s %0.2fm" % (
            lat_degrees, self.latitude[1], self.latitude[2], self.latitude[3],
            lat_hemisphere, long_degrees, self.longitude[1], self.longitude[2],
            self.longitude[3], long_hemisphere, self.altitude / 100.0
            )

        # do not print default values
        if self.size != _default_size or \
            self.horizontal_precision != _default_hprec or \
            self.vertical_precision != _default_vprec:
            text += " %0.2fm %0.2fm %0.2fm" % (
                self.size / 100.0, self.horizontal_precision / 100.0,
                self.vertical_precision / 100.0
            )
        return text

    def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
        latitude = [0, 0, 0, 0]
        longitude = [0, 0, 0, 0]
        size = _default_size
        hprec = _default_hprec
        vprec = _default_vprec

        latitude[0] = tok.get_int()
        t = tok.get_string()
        if t.isdigit():
            latitude[1] = int(t)
            t = tok.get_string()
            if '.' in t:
                (seconds, milliseconds) = t.split('.')
                if not seconds.isdigit():
                    raise dns.exception.SyntaxError('bad latitude seconds value')
                latitude[2] = int(seconds)
                if latitude[2] >= 60:
                    raise dns.exception.SyntaxError('latitude seconds >= 60')
                l = len(milliseconds)
                if l == 0 or l > 3 or not milliseconds.isdigit():
                    raise dns.exception.SyntaxError('bad latitude milliseconds value')
                if l == 1:
                    m = 100
                elif l == 2:
                    m = 10
                else:
                    m = 1
                latitude[3] = m * int(milliseconds)
                t = tok.get_string()
            elif t.isdigit():
                latitude[2] = int(t)
                t = tok.get_string()
        if t == 'S':
            latitude[0] *= -1
        elif t != 'N':
            raise dns.exception.SyntaxError('bad latitude hemisphere value')

        longitude[0] = tok.get_int()
        t = tok.get_string()
        if t.isdigit():
            longitude[1] = int(t)
            t = tok.get_string()
            if '.' in t:
                (seconds, milliseconds) = t.split('.')
                if not seconds.isdigit():
                    raise dns.exception.SyntaxError('bad longitude seconds value')
                longitude[2] = int(seconds)
                if longitude[2] >= 60:
                    raise dns.exception.SyntaxError('longitude seconds >= 60')
                l = len(milliseconds)
                if l == 0 or l > 3 or not milliseconds.isdigit():
                    raise dns.exception.SyntaxError('bad longitude milliseconds value')
                if l == 1:
                    m = 100
                elif l == 2:
                    m = 10
                else:
                    m = 1
                longitude[3] = m * int(milliseconds)
                t = tok.get_string()
            elif t.isdigit():
                longitude[2] = int(t)
                t = tok.get_string()
        if t == 'W':
            longitude[0] *= -1
        elif t != 'E':
            raise dns.exception.SyntaxError('bad longitude hemisphere value')

        t = tok.get_string()
        if t[-1] == 'm':
            t = t[0 : -1]
        altitude = float(t) * 100.0        # m -> cm

        token = tok.get().unescape()
        if not token.is_eol_or_eof():
            value = token.value
            if value[-1] == 'm':
                value = value[0 : -1]
            size = float(value) * 100.0        # m -> cm
            token = tok.get().unescape()
            if not token.is_eol_or_eof():
                value = token.value
                if value[-1] == 'm':
                    value = value[0 : -1]
                hprec = float(value) * 100.0        # m -> cm
                token = tok.get().unescape()
                if not token.is_eol_or_eof():
                    value = token.value
                    if value[-1] == 'm':
                        value = value[0 : -1]
                    vprec = float(value) * 100.0        # m -> cm
                    tok.get_eol()

        return cls(rdclass, rdtype, latitude, longitude, altitude,
                   size, hprec, vprec)

    from_text = classmethod(from_text)

    def to_wire(self, file, compress = None, origin = None):
        if self.latitude[0] < 0:
            sign = -1
            degrees = long(-1 * self.latitude[0])
        else:
            sign = 1
            degrees = long(self.latitude[0])
        milliseconds = (degrees * 3600000 +
                        self.latitude[1] * 60000 +
                        self.latitude[2] * 1000 +
                        self.latitude[3]) * sign
        latitude = 0x80000000L + milliseconds
        if self.longitude[0] < 0:
            sign = -1
            degrees = long(-1 * self.longitude[0])
        else:
            sign = 1
            degrees = long(self.longitude[0])
        milliseconds = (degrees * 3600000 +
                        self.longitude[1] * 60000 +
                        self.longitude[2] * 1000 +
                        self.longitude[3]) * sign
        longitude = 0x80000000L + milliseconds
        altitude = long(self.altitude) + 10000000L
        size = _encode_size(self.size, "size")
        hprec = _encode_size(self.horizontal_precision, "horizontal precision")
        vprec = _encode_size(self.vertical_precision, "vertical precision")
        wire = struct.pack("!BBBBIII", 0, size, hprec, vprec, latitude,
                           longitude, altitude)
        file.write(wire)

    def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
        (version, size, hprec, vprec, latitude, longitude, altitude) = \
                  struct.unpack("!BBBBIII", wire[current : current + rdlen])
        if latitude > 0x80000000L:
            latitude = float(latitude - 0x80000000L) / 3600000
        else:
            latitude = -1 * float(0x80000000L - latitude) / 3600000
        if latitude < -90.0 or latitude > 90.0:
            raise dns.exception.FormError("bad latitude")
        if longitude > 0x80000000L:
            longitude = float(longitude - 0x80000000L) / 3600000
        else:
            longitude = -1 * float(0x80000000L - longitude) / 3600000
        if longitude < -180.0 or longitude > 180.0:
            raise dns.exception.FormError("bad longitude")
        altitude = float(altitude) - 10000000.0
        size = _decode_size(size, "size")
        hprec = _decode_size(hprec, "horizontal precision")
        vprec = _decode_size(vprec, "vertical precision")
        return cls(rdclass, rdtype, latitude, longitude, altitude,
                   size, hprec, vprec)

    from_wire = classmethod(from_wire)

    def _get_float_latitude(self):
        return _tuple_to_float(self.latitude)

    def _set_float_latitude(self, value):
        self.latitude = _float_to_tuple(value)

    float_latitude = property(_get_float_latitude, _set_float_latitude,
                              doc="latitude as a floating point value")

    def _get_float_longitude(self):
        return _tuple_to_float(self.longitude)

    def _set_float_longitude(self, value):
        self.longitude = _float_to_tuple(value)

    float_longitude = property(_get_float_longitude, _set_float_longitude,
                               doc="longitude as a floating point value")
