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#include "map/ge0_parser.hpp"
#include "map/mwm_url.hpp"
#include "api/internal/c/api-client-internals.h"
#include "indexer/mercator.hpp"
#include "coding/url_encode.hpp"
#include "base/math.hpp"
#include "base/string_utils.hpp"
namespace url_scheme
{
Ge0Parser::Ge0Parser()
{
for (size_t i = 0; i < 256; ++i)
m_base64ReverseCharTable[i] = 255;
for (uint8_t i = 0; i < 64; ++i)
{
char c = MapsWithMe_Base64Char(i);
m_base64ReverseCharTable[static_cast<uint8_t>(c)] = i;
}
}
bool Ge0Parser::Parse(string const & url, url_scheme::ApiPoint & outPoint, double & outZoomLevel)
{
// URL format:
//
// +------------------ 1 byte: zoom level
// |+-------+--------- 9 bytes: lat,lon
// || | +--+---- Variable number of bytes: point name
// || | | |
// ge0://ZCoordba64/Name
const int ZOOM_POSITION = 6;
const int LATLON_POSITION = ZOOM_POSITION + 1;
const int NAME_POSITON_IN_URL = 17;
const int LATLON_LENGTH = NAME_POSITON_IN_URL - LATLON_POSITION - 1;
const size_t MAX_NAME_LENGTH = 256;
if (url.size() < 16 || !strings::StartsWith(url, "ge0://"))
return false;
uint8_t const zoomI = DecodeBase64Char(url[ZOOM_POSITION]);
if (zoomI > 63)
return false;
outZoomLevel = DecodeZoom(zoomI);
DecodeLatLon(url.substr(LATLON_POSITION, LATLON_LENGTH), outPoint.m_lat, outPoint.m_lon);
ASSERT(MercatorBounds::ValidLon(outPoint.m_lon), (outPoint.m_lon));
ASSERT(MercatorBounds::ValidLat(outPoint.m_lat), (outPoint.m_lat));
if (url.size() >= NAME_POSITON_IN_URL)
outPoint.m_name = DecodeName(url.substr(NAME_POSITON_IN_URL, min(url.size() - NAME_POSITON_IN_URL, MAX_NAME_LENGTH)));
return true;
}
uint8_t Ge0Parser::DecodeBase64Char(char const c)
{
return m_base64ReverseCharTable[static_cast<uint8_t>(c)];
}
double Ge0Parser::DecodeZoom(uint8_t const zoomByte)
{
//Coding zoom - int newZoom = ((oldZoom - 4) * 4)
return static_cast<double>(zoomByte) / 4 + 4;
}
void Ge0Parser::DecodeLatLon(string const & url, double & lat, double & lon)
{
int latInt = 0, lonInt = 0;
DecodeLatLonToInt(url, latInt, lonInt, url.size());
lat = DecodeLatFromInt(latInt, (1 << MAPSWITHME_MAX_COORD_BITS) - 1);
lon = DecodeLonFromInt(lonInt, (1 << MAPSWITHME_MAX_COORD_BITS) - 1);
}
void Ge0Parser::DecodeLatLonToInt(string const & url, int & lat, int & lon, int const bytes)
{
for(int i = 0, shift = MAPSWITHME_MAX_COORD_BITS - 3; i < bytes; ++i, shift -= 3)
{
const uint8_t a = DecodeBase64Char(url[i]);
const int lat1 = (((a >> 5) & 1) << 2 |
((a >> 3) & 1) << 1 |
((a >> 1) & 1));
const int lon1 = (((a >> 4) & 1) << 2 |
((a >> 2) & 1) << 1 |
(a & 1));
lat |= lat1 << shift;
lon |= lon1 << shift;
}
const double middleOfSquare = 1 << (3 * (MAPSWITHME_MAX_POINT_BYTES - bytes) - 1);
lat += middleOfSquare;
lon += middleOfSquare;
}
double Ge0Parser::DecodeLatFromInt(int const lat, int const maxValue)
{
return static_cast<double>(lat) / maxValue * 180 - 90;
}
double Ge0Parser::DecodeLonFromInt(int const lon, int const maxValue)
{
return static_cast<double>(lon) / (maxValue + 1.0) * 360.0 - 180;
}
string Ge0Parser::DecodeName(string name)
{
ValidateName(name);
name = UrlDecode(name);
SpacesToUnderscore(name);
return name;
}
void Ge0Parser::SpacesToUnderscore(string & name)
{
for (size_t i = 0; i < name.size(); ++i)
if (name[i] == ' ')
name[i] = '_';
else if (name[i] == '_')
name[i] = ' ';
}
void Ge0Parser::ValidateName(string & name)
{
if (name.empty())
return;
for (size_t i = 0; i + 2 < name.size(); ++i)
{
if (name[i] == '%' && (!IsHexChar(name[i + 1]) || !IsHexChar(name[i + 2])))
{
name.resize(i);
return;
}
}
if (name[name.size() - 1] == '%')
name.resize(name.size() - 1);
else if (name.size() > 1 && name[name.size() - 2] == '%')
name.resize(name.size() - 2);
}
bool Ge0Parser::IsHexChar(char const a)
{
return ((a >= '0' && a <= '9') || (a >= 'A' && a <= 'F') || (a >= 'a' && a <= 'f'));
}
} // namespace url_scheme
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