classdef OptLaserN7714A < handle
    % Minimal controller for Keysight N7714A tunable laser over VISA-LAN
    % Methods: getLaserInfo, setPower, setWavelength
    %
    % Examples:
    %   L = OptLaserN7714A('TCPIP::192.168.0.50::INSTR');
    %   L.setWavelength(1550);       % nm
    %   L.setPower(-3.0, true);      % dBm, also turns output ON
    %   info = L.getLaserInfo();

    properties (Access=private)
        v               % visadev handle
        resource char   % VISA resource string, e.g. 'TCPIP::...::INSTR'
    end

    methods
        function obj = OptLaserN7714A(resource)
            arguments
                resource (1,:) char
            end
            obj.resource = resource;

            % Robust connect with small retry loop
            maxRetries = 3; pauseTime = 1.0; lastErr = [];
            for k = 1:maxRetries
                try
                    obj.v = visadev(obj.resource);
                    % Identify instrument (SCPI *IDN?)
                    writeline(obj.v, '*IDN?');     % SCPI common, identification
                    idn = strtrim(readline(obj.v)); %#ok<NASGU>
                    break
                catch ME
                    lastErr = ME;
                    pause(pauseTime);
                end
            end
            if isempty(obj.v) || ~isvalid(obj.v)
                error('OptLaserN7714A:ConnectFailed', ...
                    'Could not connect to %s. Last error: %s', obj.resource, lastErr.message);
            end

            % Set power unit to dBm for SOURce tree to be explicit (optional)
            % [:SOUR]:POWer:UNIT dBm  (laser power unit)
            % Ref: SOURce:POWer:UNIT. :contentReference[oaicite:0]{index=0}
            try
                writeline(obj.v, 'SOUR:POW:UNIT DBM');
            catch
                % non-fatal
            end
        end

        function delete(obj)
            if ~isempty(obj.v) && isvalid(obj.v); delete(obj.v); end
        end

        function setPower(obj, power_dBm, outputOn, channel)
            arguments
                obj
                power_dBm (1,1) double
                outputOn (1,1) logical = true
                channel (1,1) double {mustBeMember(channel,0:4)} = 1
            end

            v = obj.v;
            cmd = sprintf('SOUR%d:POW:LEV:IMM:AMPL %g DBM', channel, power_dBm);
            writeline(v, cmd);

            if outputOn
                writeline(v, sprintf('SOUR%d:POW:STAT 1', channel)); %SOUR1:POW:STAT 0
            else
                writeline(v, sprintf('SOUR%d:POW:STAT 0', channel));
            end

            writeline(v, '*OPC?');
            a=readline(v);
        end

        function setWavelength(obj, wavelength_nm, channel)
            arguments
                obj
                wavelength_nm (1,1) double {mustBePositive}
                channel (1,1) double {mustBeMember(channel,0:4)} = 1
            end
            v = obj.v;
            cmd = sprintf('SOUR%d:WAV %gNM', channel, wavelength_nm);
            writeline(v, cmd);
            writeline(v, '*OPC?'); readline(v);
        end

        function setDither(obj, enable, port)
            % Enable or disable laser frequency dither (stabilization).
            % enable = false → no dither (FIX), true → stabilization (STAB).
            % port = 1..4 (default 1).
            if nargin < 3
                port = 1;
            end

            v = obj.v;
            if enable
                writeline(v, sprintf('SOUR%d:CONTrol:FCDither ON', port)); %[:SOURce[n]][:CHANnel[m]]:CONTrol:FCDither
            else
                writeline(v, sprintf('SOUR%d:CONTrol:FCDither OFF', port));
            end

            % optional confirmation
            writeline(v, sprintf('SOUR%d:CONTrol:FCDither?', port));
            modeStr = strtrim(readline(v));
            fprintf('Port %d dither mode set to %s\n', port, modeStr);
        end



        function info = getLaserInfo(obj, port)
            % Returns struct with IDN, output state, wavelength (nm), power (dBm)
            % port = 1..4 (for N7714A with 4 outputs). Default = 1.
            if nargin < 2
                port = 1;
            end

            v = obj.v;

            % *IDN?
            writeline(v, '*IDN?');
            idn = strtrim(readline(v));

            % Output state: :SOURn:POW:STAT?
            writeline(v, sprintf('SOUR%d:POW:STAT?', port));
            out_state = str2double(readline(v)) ~= 0;

            % Wavelength query (returns meters → convert to nm)
            writeline(v, sprintf('SOUR%d:WAV?', port));
            wav_m = str2double(readline(v));
            wav_nm = wav_m * 1e9;

            % Power (set level) query (dBm)
            writeline(v, sprintf('SOUR%d:POW:LEV:IMM:AMPL?', port));
            p_dBm = str2double(readline(v));

            info = struct('idn', idn, ...
                'output_on', out_state, ...
                'wavelength_nm', wav_nm, ...
                'power_dBm', p_dBm);
        end

    end
end