function ok = check_hdl_support(target, varargin)
%CHECK_HDL_SUPPORT  HDL Coder compatibility check for an RTL-bound subsystem.
%
%   ok = CHECK_HDL_SUPPORT('model/HdlSubsystem')
%   ok = CHECK_HDL_SUPPORT(..., 'Out', 'hdl_support.txt')
%
%   Wraps checkhdl: catches blocks that cannot become RTL at all -- the other
%   half of Task12-1 rule 1 ("must be built from blocks that generate RTL
%   directly").  The m-code policy audit is audit_hdl_blocks.m; run both.

p = inputParser;
p.addParameter('Out', '');
p.parse(varargin{:});

model = strtok(target, '/');
if ~bdIsLoaded(model)
    load_system(model);
end

txt = '';
threw = false;
try
    txt = evalc('checkhdl(target)');
catch e
    threw = true;
    txt = sprintf('checkhdl threw: %s\n%s', e.identifier, e.message);
end

% The summary line is localised ("0 个错误、2 个警告" / "0 errors, 2 warnings"),
% so count both spellings rather than grepping for the word "error".
nErr  = local_count(txt, {'(\d+)\s*个错误', '(\d+)\s+errors?'});
nWarn = local_count(txt, {'(\d+)\s*个警告', '(\d+)\s+warnings?'});
ok = ~threw && nErr == 0;

rep = regexp(txt, '(?<=file:///)[^''"<>]*_report\.html', 'match', 'once');
fprintf('=== checkhdl %s : %s (%d error(s), %d warning(s)) ===\n', ...
        target, string(ok), nErr, nWarn);
if ~isempty(rep)
    fprintf('report: %s\n', strrep(rep, '/', filesep));
end
disp(txt);
if nWarn > 0
    fprintf(['NOTE: warnings are not a pass/fail gate here, but read them -- they are usually\n' ...
             '      "this block will cost you area/latency in RTL" hints.\n']);
end

if ~isempty(p.Results.Out)
    fid = fopen(p.Results.Out, 'w');
    fwrite(fid, txt);
    fclose(fid);
    fprintf('checkhdl log -> %s\n', p.Results.Out);
end
end

function n = local_count(txt, pats)
n = 0;
for i = 1:numel(pats)
    t = regexp(txt, pats{i}, 'tokens', 'once');
    if ~isempty(t)
        n = str2double(t{1});
        return
    end
end
end