-module(test).
-export([test_string_contact/1,
         test_list_contact/1,
         test_list_contact2/1,
         string_contact/0,
         list_contact/0,
         list_contact2/0]).

test_string_contact(N) ->
    statistics(runtime),
    statistics(wall_clock),
    %%loop(fun string_contact/0, N),
    string_contact(N),
    {_, Time1} = statistics(runtime),
    {_, Time2} = statistics(wall_clock),
    U1 = Time1 * 1000 /N,
    U2 = Time2 * 1000/N,
    io:format("string++ time: ~p/~p micro-seconds (runtime/wallclock)~n", [U1, U2]).

loop(_Fun, 0) ->
    ok;
loop(Fun, N) ->
    Fun(),
    loop(Fun, N-1).

string_contact(0) ->
    ok;
string_contact(N) ->
    string_contact(),
    string_contact(N-1).

string_contact() ->
    L1 = "INVITE sip:1000@192.168.1.3 SIP/2.0\r\n",
    L2 = "From: sip:1000@192.168.1.3\r\n",
    L3 = "To: sip:bob@192.168.1.3\r\n",
    L4 = "Via: SIP/2.0/UDP server.biloxi.com;branch=z9hgbK4bawer\r\n",
    L5 = "Max-Forwards: 70\r\n",
    L6 = "Call-ID: a84b4c76e66710\r\n",
    L7 = "CSeq: 314519 INVITE\r\n",
    L8 = "Contact: <sip:alice@192.168.1.3>\r\n",
    L9 = "Content-TYpe: application/sdp\r\n",
    L10 = "Content-Length: 0\r\n",
    L1 ++ L2 ++ L3 ++ L4 ++ L5 ++ L6 ++ L7 ++ L8 ++ L9 ++ L10.

test_list_contact(N) ->
    statistics(runtime),
    statistics(wall_clock),
    %%loop(fun list_contact/0, N),
    list_contact(N),
    {_, Time1} = statistics(runtime),
    {_, Time2} = statistics(wall_clock),
    U1 = Time1 * 1000 /N,
    U2 = Time2 * 1000/N,
    io:format("list contact time: ~p/~p micro-seconds (runtime/wallclock)~n", [U1, U2]).

list_contact(0) ->
    ok;
list_contact(N) ->
    list_contact(),
    list_contact(N-1).

list_contact() ->
    L1 = "INVITE sip:1000@192.168.1.3 SIP/2.0\r\n",
    L2 = "From: sip:1000@192.168.1.3\r\n",
    L3 = "To: sip:bob@192.168.1.3\r\n",
    L4 = "Via: SIP/2.0/UDP server.biloxi.com;branch=z9hgbK4bawer\r\n",
    L5 = "Max-Forwards: 70\r\n",
    L6 = "Call-ID: a84b4c76e66710\r\n",
    L7 = "CSeq: 314519 INVITE\r\n",
    L8 = "Contact: <sip:alice@192.168.1.3>\r\n",
    L9 = "Content-TYpe: application/sdp\r\n",
    L10 = "Content-Length: 0\r\n",
    R1 = [L1],
    R2 = [L2 | R1],
    R3 = [L3 | R2],
    R4 = [L4 | R3],
    R5 = [L5 | R4],
    R6 = [L6 | R5],
    R7 = [L7 | R6],
    R8 = [L8 | R7],
    R9 = [L9 | R8],
    R10 = [L10 | R9],
    lists:reverse(R10).

test_list_contact2(N) ->
    statistics(runtime),
    statistics(wall_clock),
    %%loop(fun list_contact2/0, N),
    list_contact2(N),
    {_, Time1} = statistics(runtime),
    {_, Time2} = statistics(wall_clock),
    U1 = Time1 * 1000 /N,
    U2 = Time2 * 1000/N,
    io:format("list contact time: ~p/~p micro-seconds (runtime/wallclock)~n", [U1, U2]).

list_contact2(0) ->
    ok;
list_contact2(N) ->
    list_contact2(),
    list_contact2(N-1).

list_contact2() ->  
    lists:flatten(list_contact()).


%%%% NOTE:
%%%% 1. For short message like above, string_contact with ++ is even faster than%%%%    list_contact with list operation.

%%%% 2. lists:flatten() is very heavy. test_list_contact is way faster than tes
%%%%    t_list_contact2.