%% Generator for the golden ETF vectors used in tests/test_etf.py.
%% Re-run when adding new test cases:
%%
%%   erlc -o /tmp docs/etf_vectors.erl
%%   erl -noshell -pa /tmp -eval 'etf_vectors:main([]), init:stop().'
%%   cat /tmp/etf_vectors.txt
%%
-module(etf_vectors).
-export([main/1]).

main(_) ->
    Terms = [
        {small_int_0, 0},
        {small_int_42, 42},
        {small_int_255, 255},
        {int_256, 256},
        {int_neg_1, -1},
        {int_max32, 2147483647},
        {int_min32, -2147483648},
        {big_pos, 9999999999999999},
        {big_neg, -9999999999999999},
        {atom_hello, hello},
        {atom_true, true},
        {atom_false, false},
        {atom_nil, nil},
        {atom_unicode, 'привет'},
        {binary_empty, <<>>},
        {binary_hi, <<"hi">>},
        {binary_utf8, <<"héllo"/utf8>>},
        {tuple_empty, {}},
        {tuple_pair, {ok, <<"value">>}},
        {tuple_triple, {1, 2, 3}},
        {list_empty, []},
        {list_ints, [1, 2, 3]},
        {list_mixed, [hello, <<"world">>, 42]},
        {nested, {gen_call, [{node, 'wallet@cammy'}], {get_balance, xmr}}}
    ],
    Out = [
        io_lib:format("~s|~s~n", [atom_to_list(N), bin_to_hex(term_to_binary(T))])
        || {N, T} <- Terms
    ],
    ok = file:write_file("/tmp/etf_vectors.txt", iolist_to_binary(Out)).

bin_to_hex(B) ->
    << <<(hex(N div 16)), (hex(N rem 16))>> || <<N>> <= B >>.
hex(N) when N < 10 -> $0 + N;
hex(N) -> $a + N - 10.