/*
* Author: Rocko and esteldunedain
* Calculates the current map illumination for a given unit
*
* Arguments:
* 0: Unit <OBJECT>
*
* Return Value:
* 0: Does the map needs shading? <BOOL>
* 1: Color of the overlay <ARRAY>
*
* Public: No
*/
#include "script_component.hpp"
params ["_unit"];

private ["_fnc_blendColor", "_lightTint", "_fnc_calcColor", "_l", "_lightLevel", "_vehicle", "_isEnclosed", "_nearObjects", "_light", "_ll", "_flashlight", "_flareTint"];

// Blend two colors
_fnc_blendColor = {
    params ["_c1", "_c2", "_alpha"];
    [(_c1 select 0) * (1 - _alpha) + (_c2 select 0) * _alpha,
     (_c1 select 1) * (1 - _alpha) + (_c2 select 1) * _alpha,
     (_c1 select 2) * (1 - _alpha) + (_c2 select 2) * _alpha,
     (_c1 select 3) * (1 - _alpha) + (_c2 select 3) * _alpha]
};

// Ambient light tint depending on time of day
_lightTint = call {
    if (sunOrMoon == 1.0) exitWith { [0.5,0.5,0.5,1] };
    if (sunOrMoon > 0.80) exitWith { [[1.0 - overcast,0.2,0,1], [1,1,1,1],   (sunOrMoon - 0.8)/0.2] call _fnc_blendColor };
    if (sunOrMoon > 0.50) exitWith { [[0,0,0.1,1], [1.0 - overcast,0.2,0,1], (sunOrMoon - 0.5)/0.3] call _fnc_blendColor };
    if (sunOrMoon <= 0.5) exitWith { [0,0,0.1,1] };
    [0,0,0,0]
};

// Calculates overlay color from tint and light level
_fnc_calcColor = {
    params ["_c1", "_lightLevel"];

    if (_lightLevel < 0.5) then {
        _l = _lightLevel / 0.5;
        [(_c1 select 0) * _l,
         (_c1 select 1) * _l,
         (_c1 select 2) * _l,
         (_c1 select 3) * (1 - _lightLevel)]
    } else {
        _l = (_lightLevel - 0.5) / 0.5;
        [(_c1 select 0) * (1 - _l) + _l,
         (_c1 select 1) * (1 - _l) + _l,
         (_c1 select 2) * (1 - _l) + _l,
         (_c1 select 3) * (1 - _lightLevel)]
    };
};

_lightLevel = 0.04 + (0.96 * call EFUNC(common,ambientBrightness));

/*
// check if player has NVG enabled
if (currentVisionMode _unit == 1) exitWith {
    // stick to nvg color
    [true, [154/255,253/255,177/255,0.5]]
};
*/

// Do not obscure the map if the ambient light level is above 0.95
if (_lightLevel > 0.95) exitWith {
    [false, [0.5,0.5,0.5,0]]
};

_vehicle = vehicle _unit;

// Do not obscure the map if the player is on a enclosed vehicle (assume internal illumination)
if (_vehicle != _unit) then {
    // Player is in a vehicle
    if (!isTurnedOut _unit && { _vehicle isKindOf "Tank" || { ( _vehicle isKindOf "Helicopter" || _vehicle isKindOf "Plane" ) && { (driver _vehicle) == _unit || { (gunner _vehicle) == _unit } } } || {_vehicle isKindOf "Wheeled_APC"}}) then {
        _isEnclosed = true;
    };
};
if (_isEnclosed) exitWith {
    TRACE_1("Player in a enclosed vehicle","");
    [false, [1,1,1,0]]
};

// Player is not in a vehicle
TRACE_1("Player is on foot or in an open vehicle","");

// Check if player is near a campfires, streetlamps, units with flashlights, vehicles with lights on, etc. - 40m
{
    _lightLevel = _lightLevel max ([_unit, _x] call EFUNC(common,lightIntensityFromObject));
} forEach nearestObjects [_unit, ["All"], 40];

// @todo: Illumination flares (timed)

// Using chemlights
_nearObjects = (_unit nearObjects ["SmokeShell", 4]) select {alive _x && {toLower typeOf _x in ["chemlight_red", "chemlight_green", "chemlight_blue", "chemlight_yellow"]}};

if (count (_nearObjects) > 0) then {
    _light = _nearObjects select 0;

    _ll = (1 - ((((_unit distance _light) - 2)/2) max 0)) * 0.4;
    if (_ll > _lightLevel) then {
        _flareTint = switch (toLower typeOf _light) do {
            case "chemlight_red" : {[1,0,0,1]};
            case "chemlight_green" : {[0,1,0,1]};
            case "chemlight_blue" : {[0,0,1,1]};
            case "chemlight_yellow" : {[1,1,0,1]};
        };
        _lightTint = [_lightTint, _flareTint, (_ll - _lightLevel)/(1 - _lightLevel)] call _fnc_blendColor;
        _lightLevel = _ll;
        TRACE_1("player near chemlight","");
    };
};

// Do not obscure the map if the ambient light level is above 0.95
if (_lightLevel > 0.95) exitWith {
    [false, [0.5,0.5,0.5,0]]
};

// Calculate resulting map color
[true, [_lightTint, _lightLevel] call _fnc_calcColor]