/*
 * Author: VKing
 * Gets the current map's MGRS grid zone designator and 100km square.
 * Also gets longitude, latitude and altitude offset for the map.
 * Writes return values to GVAR(MGRS_data) if run on the current map.
 *
 * Argument:
 * 0: Map name (default: worldName) <STRING>
 *
 * Return Value:
 * 0: Grid zone designator <STRING>
 * 1: 100km square <STRING>
 * 2: GZD + 100km sq. as a single string <STRING>
 *
 * Public: No
 */
#include "script_component.hpp"

params [["_map", worldName]];

private _long = getNumber (configFile >> "CfgWorlds" >> _map >> "longitude");
private _lat =  getNumber (configFile >> "CfgWorlds" >> _map >> "latitude");
private _altitude =  getNumber (configFile >> "CfgWorlds" >> _map >> "elevationOffset");

private _mapData = _map call FUNC(getMapData);
if (!(_mapData isEqualTo [])) then {
    _lat = _mapData select 0;
    _alt = _mapData select 1;
};
TRACE_2("Latitude and Altitude",_lat,_alt);

private _UTM = [_long, _lat] call BIS_fnc_posDegToUTM;
private _easting = _UTM select 0;
private _northing = _UTM select 1;
//private _zone = _UTM select 2;
TRACE_4("",_UTM,_easting,_northing,_zone);

/*
private _band = switch (true) do {
    case (_lat<-72): {"C"};
    case (_lat<-64): {"D"};
    case (_lat<-56): {"E"};
    case (_lat<-48): {"F"};
    case (_lat<-40): {"G"};
    case (_lat<-32): {"H"};
    case (_lat<-24): {"J"};
    case (_lat<-16): {"K"};
    case (_lat<-8): {"L"};
    case (_lat<0): {"M"};
    case (_lat>72): {"X"};
    case (_lat>64): {"W"};
    case (_lat>56): {"V"};
    case (_lat>48): {"U"};
    case (_lat>40): {"T"};
    case (_lat>32): {"S"};
    case (_lat>24): {"R"};
    case (_lat>16): {"Q"};
    case (_lat>8): {"P"};
    case (_lat>=0): {"N"};
};
*/

private _zone = 1 + (floor ((_long + 180) / 6));
private _band = "Z";

if (_lat <= -80) then {
    _band = "A";
} else {
    if (_lat < 84) then {
        _band = "CDEFGHJKLMNPQRSTUVWXX" select [(floor ((_lat / 8) + 10)), 1];
    };
};

if (_map == "VR") then {_zone = 0; _band = "RV";};

private _GZD = format ["%1%2",_zone,_band];
TRACE_3("",_zone,_band,_GZD);

private ["_metaE", "_metaN", "_letterE", "_letterN"];

private _set1 = [1,7,13,19,25,31,37,43,49,55];
private _set2 = [2,8,14,20,26,32,38,44,50,56];
private _set3 = [3,9,15,21,27,33,39,45,51,57];
private _set4 = [4,10,16,22,28,34,40,46,52,58];
private _set5 = [5,11,17,23,29,35,41,47,53,59];
private _set6 = [6,12,18,24,30,36,42,48,54,60];

switch (true) do {
    case (_zone in _set1): {_metaE = 1; _metaN = 1;};
    case (_zone in _set2): {_metaE = 2; _metaN = 2;};
    case (_zone in _set3): {_metaE = 3; _metaN = 1;};
    case (_zone in _set4): {_metaE = 1; _metaN = 2;};
    case (_zone in _set5): {_metaE = 2; _metaN = 1;};
    case (_zone in _set6): {_metaE = 3; _metaN = 2;};
};
TRACE_2("",_metaE,_metaN);

switch (true) do {
    case (_zone == 0): {_letterE = "E"};
    case (_easting > 800000): {LOG("E8"); switch (_metaE) do {case 1: {_letterE="H"}; case 2: {_letterE="R"}; case 3: {_letterE="Z"}; }; };
    case (_easting > 700000): {LOG("E7"); switch (_metaE) do {case 1: {_letterE="G"}; case 2: {_letterE="Q"}; case 3: {_letterE="Y"}; }; };
    case (_easting > 600000): {LOG("E6"); switch (_metaE) do {case 1: {_letterE="F"}; case 2: {_letterE="P"}; case 3: {_letterE="X"}; }; };
    case (_easting > 500000): {LOG("E5"); switch (_metaE) do {case 1: {_letterE="E"}; case 2: {_letterE="N"}; case 3: {_letterE="W"}; }; };
    case (_easting > 400000): {LOG("E4"); switch (_metaE) do {case 1: {_letterE="D"}; case 2: {_letterE="M"}; case 3: {_letterE="V"}; }; };
    case (_easting > 300000): {LOG("E3"); switch (_metaE) do {case 1: {_letterE="C"}; case 2: {_letterE="L"}; case 3: {_letterE="U"}; }; };
    case (_easting > 200000): {LOG("E2"); switch (_metaE) do {case 1: {_letterE="B"}; case 2: {_letterE="K"}; case 3: {_letterE="T"}; }; };
    case (_easting > 100000): {LOG("E1"); switch (_metaE) do {case 1: {_letterE="A"}; case 2: {_letterE="J"}; case 3: {_letterE="S"}; }; };
    default {_letterE="@"};
};
TRACE_1("",_letterE);

_northing = _northing mod 2000000;
TRACE_1("",_northing);

switch (true) do {
    case (_zone == 0): {_letterN = "N"};
    case (_northing > 1900000): {LOG("N19"); switch (_metaN) do {case 1: {_letterN = "V"}; case 2: {_letterN = "E"}; }; };
    case (_northing > 1800000): {LOG("N18"); switch (_metaN) do {case 1: {_letterN = "U"}; case 2: {_letterN = "D"}; }; };
    case (_northing > 1700000): {LOG("N17"); switch (_metaN) do {case 1: {_letterN = "T"}; case 2: {_letterN = "C"}; }; };
    case (_northing > 1600000): {LOG("N16"); switch (_metaN) do {case 1: {_letterN = "S"}; case 2: {_letterN = "B"}; }; };
    case (_northing > 1500000): {LOG("N15"); switch (_metaN) do {case 1: {_letterN = "R"}; case 2: {_letterN = "A"}; }; };
    case (_northing > 1400000): {LOG("N14"); switch (_metaN) do {case 1: {_letterN = "Q"}; case 2: {_letterN = "V"}; }; };
    case (_northing > 1300000): {LOG("N13"); switch (_metaN) do {case 1: {_letterN = "P"}; case 2: {_letterN = "U"}; }; };
    case (_northing > 1200000): {LOG("N12"); switch (_metaN) do {case 1: {_letterN = "N"}; case 2: {_letterN = "T"}; }; };
    case (_northing > 1100000): {LOG("N11"); switch (_metaN) do {case 1: {_letterN = "M"}; case 2: {_letterN = "S"}; }; };
    case (_northing > 1000000): {LOG("N10"); switch (_metaN) do {case 1: {_letterN = "L"}; case 2: {_letterN = "R"}; }; };
    case (_northing >  900000): {LOG("N09"); switch (_metaN) do {case 1: {_letterN = "K"}; case 2: {_letterN = "Q"}; }; };
    case (_northing >  800000): {LOG("N08"); switch (_metaN) do {case 1: {_letterN = "J"}; case 2: {_letterN = "P"}; }; };
    case (_northing >  700000): {LOG("N07"); switch (_metaN) do {case 1: {_letterN = "H"}; case 2: {_letterN = "N"}; }; };
    case (_northing >  600000): {LOG("N06"); switch (_metaN) do {case 1: {_letterN = "G"}; case 2: {_letterN = "M"}; }; };
    case (_northing >  500000): {LOG("N05"); switch (_metaN) do {case 1: {_letterN = "F"}; case 2: {_letterN = "L"}; }; };
    case (_northing >  400000): {LOG("N04"); switch (_metaN) do {case 1: {_letterN = "E"}; case 2: {_letterN = "K"}; }; };
    case (_northing >  300000): {LOG("N03"); switch (_metaN) do {case 1: {_letterN = "D"}; case 2: {_letterN = "J"}; }; };
    case (_northing >  200000): {LOG("N02"); switch (_metaN) do {case 1: {_letterN = "C"}; case 2: {_letterN = "H"}; }; };
    case (_northing >  100000): {LOG("N01"); switch (_metaN) do {case 1: {_letterN = "B"}; case 2: {_letterN = "G"}; }; };
    case (_northing >       0): {LOG("N00"); switch (_metaN) do {case 1: {_letterN = "A"}; case 2: {_letterN = "F"}; }; };
};
TRACE_1("",_letterN);

private _grid100km = _letterE + _letterN;
TRACE_1("",_grid100km);

if (_map == worldName) then {
    GVAR(MGRS_data) = [_GZD, _grid100km, _GZD + _grid100km];
    GVAR(mapAltitude) = _altitude;
    GVAR(mapLatitude) = _lat;
    GVAR(mapLongitude) = _long;
};

[_GZD, _grid100km, _GZD + _grid100km]