DCS: World / Dynamic Extraction Team

local assetUnit     = Unit.getByName('Downed Pilot')
local assetGroup    = Group.getByName('Downed Pilot')
local rescueUnit    = false
local rescueGroup   = false
local verifyGroup   = false

trigger.action.setUserFlag('15', false)
trigger.action.setUserFlag('5000', false)
trigger.action.setUserFlag('5001', false)
trigger.action.setUserFlag('5002', false)
trigger.action.setUserFlag('5003', false)

mist.flagFunc.units_in_zones {
    units       = {'Pontiac 1-1', 'Pontiac 1-2', 'Chevy 1-1', 'Chevy 2-1', 'Chevy 3-1', 'Chevy 4-1'},
    zones       = {'RescueBegins'},
    flag        = 5000,
    stopflag    = 15
}

mist.flagFunc.units_in_moving_zones {
    units       = {'Delta', 'Echo'},
    zone_units  = {'Downed Pilot'},
    radius      = 10,
    flag        = 5001,
    stopflag    = 15
}

mist.flagFunc.units_in_moving_zones {
    units       = {'Downed Pilot', 'Delta', 'Echo'},
    zone_units  = {'Pontiac 1-1', 'Pontiac 1-2', 'Chevy 1-1', 'Chevy 2-1', 'Chevy 3-1', 'Chevy 4-1'},
    zone_type   = 'sphere',
    radius      = 20,
    flag        = 5002,
    req_num     = 2,
    stopflag    = 15
}

function generateVerifyGroupData(assetUnit, rescueUnit)
    local assetUnitPosition     = assetUnit:getPosition().p
    local rescueUnitPosition    = rescueUnit:getPosition().p

    local rescueUnitHeading     = mist.getHeading(rescueUnit)
    local verifySpawnDistance   = 20

    local verifyGroupX          = rescueUnitPosition.x + verifySpawnDistance * math.cos(rescueUnitHeading + math.pi / 2)
    local verifyGroupY          = rescueUnitPosition.z + verifySpawnDistance * math.sin(rescueUnitHeading + math.pi / 2)
    local verifyGroupLeftX      = rescueUnitPosition.x + verifySpawnDistance * math.cos(rescueUnitHeading + (math.pi * 3) / 2)
    local verifyGroupLeftY      = rescueUnitPosition.z + verifySpawnDistance * math.sin(rescueUnitHeading + (math.pi * 3) / 2)
    local leftDistance          = math.sqrt((verifyGroupLeftX - assetUnitPosition.x) ^ 2 + (verifyGroupLeftY - assetUnitPosition.z) ^ 2)
    local rightDistance         = math.sqrt((verifyGroupX - assetUnitPosition.x) ^ 2 + (verifyGroupY - assetUnitPosition.z) ^ 2)

    if rightDistance >= leftDistance then
        verifyGroupX = verifyGroupLeftX
        verifyGroupY = verifyGroupLeftY
    end

    local verifyGroupData = {
        ["name"] = "VerificationGroup",
        ["taskSelected"] = true,
        ["hidden"] = false,
        ["groupId"] = math.random(1111111,9999999),
        ["visible"] = false,
        ["units"] =
        {
            [1] =
            {
                ["y"] = verifyGroupY,
                ["type"] = "Soldier M4",
                ["name"] = "Delta",
                ["unitId"] = math.random(1111111,9999999),
                ["heading"] = rescueUnitHeading,
                ["playerCanDrive"] = true,
                ["skill"] = "Average",
                ["x"] = verifyGroupX,
            }, -- end of [1]
            [2] =
            {
                ["y"] = verifyGroupY - 1,
                ["type"] = "Soldier M4",
                ["name"] = "Echo",
                ["unitId"] = math.random(1111111,9999999),
                ["heading"] = rescueUnitHeading,
                ["playerCanDrive"] = true,
                ["skill"] = "Average",
                ["x"] = verifyGroupX - 1,
            }, -- end of [2]
        },
        ["y"] = verifyGroupY,
        ["x"] = verifyGroupX,
        ["start_time"] = 0,
        ["task"] = "Ground Nothing",
    }

    return verifyGroupData
end

function generateWaypoints(assetUnit, rescueUnit, waypointType)
    local waypoints = {}
    local assetPos  = assetUnit:getPosition().p
    local rescuePos = rescueUnit:getPosition().p
    local verifyPos = Unit.getByName("Delta"):getPosition().p

    local assetPoint = {
        ["type"] = "Flyover Point",
        ["ETA"] = 0,
        ["y"] = assetPos.z - 6,
        ["x"] = assetPos.x,
        ["ETA_locked"] = true,
        ["speed"] = 15,
        ["speed_locked"] = true,
    }

    local rescuePoint = {
        ["type"] = "Flyover Point",
        ["ETA"] = 0,
        ["y"] = rescuePos.z,
        ["x"] = rescuePos.x,
        ["ETA_locked"] = true,
        ["speed"] = 15,
        ["speed_locked"] = true,
    }

    local verifyPoint = {
        ["type"] = "Flyover Point",
        ["ETA"] = 0,
        ["y"] = verifyPos.z,
        ["x"] = verifyPos.x,
        ["ETA_locked"] = true,
        ["speed"] = 15,
        ["speed_locked"] = true,
    }

    if waypointType == 'ingress' then
        waypoints[#waypoints+1] = mist.ground.buildWP(verifyPoint, 'Off Road', 20)
        waypoints[#waypoints+1] = mist.ground.buildWP(assetPoint, 'Diamond', 20)
    elseif waypointType == 'egress' then
        waypoints[#waypoints+1] = mist.ground.buildWP(assetPoint, 'Off Road', 20)
        waypoints[#waypoints+1] = mist.ground.buildWP(rescuePoint, 'Diamond', 20)
    elseif waypointType == 'stopPush' then
        waypoints[#waypoints+1] = mist.ground.buildWP(verifyPoint, 'Off Road', 20)
        waypoints[#waypoints+1] = mist.ground.buildWP(assetPoint, 'Diamond', 20)
    end

    return waypoints
end

function getRescueUnit(rescueUnit)
    if (trigger.misc.getUserFlag('5000') == 1 and not rescueUnit) or (rescueUnit and rescueUnit:inAir()) then
        if Unit.getByName('Pontiac 1-1') and not Unit.getByName('Pontiac 1-1'):inAir() and next(mist.getUnitsInZones({'Pontiac 1-1'}, {'RescueBegins'})) then
            rescueUnit = Unit.getByName('Pontiac 1-1')
        elseif Unit.getByName('Pontiac 1-2') and not Unit.getByName('Pontiac 1-2'):inAir() and next(mist.getUnitsInZones({'Pontiac 1-2'}, {'RescueBegins'})) then
            rescueUnit = Unit.getByName('Pontiac 1-2')
        elseif Unit.getByName('Chevy 1-1') and not Unit.getByName('Chevy 1-1'):inAir() and next(mist.getUnitsInZones({'Chevy 1-1'}, {'RescueBegins'})) then
            rescueUnit = Unit.getByName('Chevy 1-1')
        elseif Unit.getByName('Chevy 2-1') and not Unit.getByName('Chevy 2-1'):inAir() and next(mist.getUnitsInZones({'Chevy 2-1'}, {'RescueBegins'})) then
            rescueUnit = Unit.getByName('Chevy 2-1')
        elseif Unit.getByName('Chevy 3-1') and not Unit.getByName('Chevy 3-1'):inAir() and next(mist.getUnitsInZones({'Chevy 3-1'}, {'RescueBegins'})) then
            rescueUnit = Unit.getByName('Chevy 3-1')
        elseif Unit.getByName('Chevy 4-1') and not Unit.getByName('Chevy 4-1'):inAir() and next(mist.getUnitsInZones({'Chevy 4-1'}, {'RescueBegins'})) then
            rescueUnit = Unit.getByName('Chevy 4-1')
        else
            rescueUnit = false
        end
    end

    return rescueUnit
end

function spawnVerifyGroup(assetUnit, rescueUnit)
    local verifyGroupData   = generateVerifyGroupData(assetUnit, rescueUnit)
    local verifyGroup       = coalition.addGroup(country.id.USA, Group.Category.GROUND, verifyGroupData)

    return verifyGroup
end

function main(assetUnit, assetGroup, rescueUnit, verifyGroup, verifyStarted, verifyDone, pushingToEgress)
    local egress            = nil
    local ingress           = nil
    local stopPush          = nil
    local verifyTime        = 600   -- time in seconds (ten minutes)

    if next(mist.getUnitsInZones({'Pontiac 1-1', 'Pontiac 1-2', 'Chevy 1-1', 'Chevy 2-1', 'Chevy 3-1', 'Chevy 4-1'}, {'RescueBegins'})) ==  nil then
        trigger.action.setUserFlag('5000', 0)
    end

    if trigger.misc.getUserFlag('5001') == 1 and verifyStarted == false then
        mist.scheduleFunction(trigger.action.setUserFlag, {'5003', true}, timer.getTime() + verifyTime) -- Verify Complete Flag
        trigger.action.outText("This is Delta squad. We have made contact with the asset. Give us close air support for ten minutes while we verify his identity.", 40)
        trigger.action.outSound('DeltaSupportRequest.ogg')

        verifyStarted = true
    end

    rescueUnit = getRescueUnit(rescueUnit)

    if rescueUnit then
        rescueUnitVelocity = rescueUnit:getVelocity()

        if verifyGroup then
            egress  = generateWaypoints(assetUnit, rescueUnit, 'egress')

            if trigger.misc.getUserFlag('5001') == 1 and trigger.misc.getUserFlag('5002') == 1 and trigger.misc.getUserFlag('5003') == 1 then
                trigger.action.outText("This is Delta squad. We're on board with the asset and ready for dust off.", 40)
                trigger.action.outSound('ExtractComplete.ogg')
                trigger.action.setUserFlag('500', false)
                trigger.action.setUserFlag('15', true)
                verifyGroup:destroy()
                assetGroup:destroy()
            elseif trigger.misc.getUserFlag('5001') == 1 and trigger.misc.getUserFlag('5003') == 1 and not pushingToEgress then
                if rescueUnitVelocity.x < 1 and rescueUnitVelocity.y < 1 and rescueUnitVelocity.z < 1 then
                    pushingToEgress = true
                    mist.goRoute(verifyGroup, egress)
                    mist.scheduleFunction(mist.goRoute, {assetGroup, egress}, timer.getTime() + 5)
                    if not verifyDone then
                        verifyDone = true
                        trigger.action.outText("This is Delta squad. We have verified the identity of the asset. We are pushing to extraction.", 40)
                        trigger.action.outSound('StartPushToExtraction.ogg')
                    else
                        trigger.action.outText("This is Delta squad. We are pushing to extraction.", 40)
                        trigger.action.outSound('ResumePushToExtraction.ogg')
                    end
                end
            end
        else
            if rescueUnitVelocity.x < 1 and rescueUnitVelocity.y < 1 and rescueUnitVelocity.z < 1 then
                verifyGroup = spawnVerifyGroup(assetUnit, rescueUnit)

                ingress     = generateWaypoints(assetUnit, rescueUnit, 'ingress')
                trigger.action.outText("This is Delta squad. We have boots on the ground and we're pushing towards the asset.", 40)
                trigger.action.outSound('StartPushToAsset.ogg')

                mist.goRoute(verifyGroup, ingress)
            end
        end
    elseif verifyGroup then
        trigger.action.setUserFlag('5002', false)

        if pushingToEgress then
            stopPush    = generateWaypoints(assetUnit, assetUnit, 'stopPush')

            trigger.action.outText("This is Delta squad. Um - we're not on board yet. Return to the extraction zone for dust off.", 40)
            trigger.action.outSound('StopPushToExtraction.ogg')
            mist.goRoute(verifyGroup, stopPush)
            mist.goRoute(assetGroup, stopPush)
            pushingToEgress = false
        end

        if trigger.misc.getUserFlag('5001') == 1 and trigger.misc.getUserFlag('5003') == 1 and not verifyDone then
            trigger.action.outText("This is Delta squad. We have verified the identity of the asset. Return to the extraction zone for dust off.", 40)
            trigger.action.outSound('AssetVerificationComplete.ogg')
            verifyDone = true
        end
    end

    if trigger.misc.getUserFlag('15') == 0 and trigger.misc.getUserFlag('999') == 0 then
        mist.scheduleFunction(main, {assetUnit, assetGroup, rescueUnit, verifyGroup, verifyStarted, verifyDone, pushingToEgress}, timer.getTime() + 1)
    end
end

main(assetUnit, assetGroup, rescueUnit, verifyGroup, false, false, false)