# This file is a part of Julia. License is MIT: https://julialang.org/license

pids = addprocs_with_testenv(4; topology="master_slave")
p1 = pids[1]
p2 = pids[2]

@test_throws RemoteException remotecall_fetch(()->remotecall_fetch(myid, p2), p1)

function test_worker_counts()
    # check if the nprocs/nworkers/workers are the same on the remaining workers
    np=nprocs()
    nw=nworkers()
    ws=sort(workers())

    for p in workers()
        @test (true, true, true) == remotecall_fetch(p, np, nw, ws) do x,y,z
            (x==nprocs(), y==nworkers(), z==sort(workers()))
        end
    end
end

function remove_workers_and_test()
    while nworkers() > 0
        rmprocs(workers()[1]; waitfor=2.0)
        test_worker_counts()
        if nworkers() == nprocs()
            break
        end
    end
end

remove_workers_and_test()

# connect even pids to other even pids, odd to odd.
mutable struct TopoTestManager <: ClusterManager
    np::Integer
end

function Base.launch(manager::TopoTestManager, params::Dict, launched::Array, c::Condition)
    dir = params[:dir]
    exename = params[:exename]
    exeflags = params[:exeflags]

    cmd = `$exename $exeflags --bind-to $(Base.Distributed.LPROC.bind_addr) --worker $(Base.cluster_cookie())`
    cmd = pipeline(detach(setenv(cmd, dir=dir)))
    for i in 1:manager.np
        io = open(cmd)
        wconfig = WorkerConfig()
        wconfig.process = io
        wconfig.io = io.out
        wconfig.ident = i
        wconfig.connect_idents = collect(i+2:2:manager.np)
        push!(launched, wconfig)
    end

    notify(c)
end

const map_pid_ident=Dict()
function Base.manage(manager::TopoTestManager, id::Integer, config::WorkerConfig, op::Symbol)
    if op == :register
        map_pid_ident[id] = get(config.ident)
    elseif op == :interrupt
        kill(get(config.process), 2)
    end
end

addprocs_with_testenv(TopoTestManager(8); topology="custom")

while true
    if any(x->get(map_pid_ident, x, 0)==0, workers())
        yield()
    else
        break
    end
end

for p1 in workers()
    for p2 in workers()
        i1 = map_pid_ident[p1]
        i2 = map_pid_ident[p2]
        if (iseven(i1) && iseven(i2)) || (isodd(i1) && isodd(i2))
            @test p2 == remotecall_fetch(p->remotecall_fetch(myid, p), p1, p2)
        else
            @test_throws RemoteException remotecall_fetch(p->remotecall_fetch(myid, p), p1, p2)
        end
    end
end

remove_workers_and_test()