module interface
    
export vecToDict, mqttClient, mqttRun, publish, request, respond

using JSON3, Redis, UUIDs, Dates

# Mosquitto.jl requires C++ Mosquitto lib (linux only). Ref: https://github.com/denglerchr/Mosquitto.jl
# push!(Base.DL_LOAD_PATH, "/usr", "/usr/local/lib", "/usr/include", "/usr/lib")
using Mosquitto
   

#------------------------------------------------------------------------------------------------100

""" Convert received MQTT payload of JSON data to julia dict.
    copy() convert JSON3 obj to julia dict
"""
vecToDict(vec::Vector{UInt8}) = copy(JSON3.read(String(vec)))


# ---------------------------------------------------------------------------- #
#          publish image with julia PythonCall (python 3.9) and opencv         #
# ---------------------------------------------------------------------------- #
"""
    using Revise
    using Images, UUIDs

    # https://pyshine.com/Video-and-bidirectional-text-streaming/
    using CondaPkg; CondaPkg.add_pip("pybase64"); CondaPkg.add_pip("opencv-python"); CondaPkg.add("jsons"); CondaPkg.add("numpy");
    using PythonCall
    cv = pyimport("cv2")
    base64 = pyimport("pybase64")
    np = pyimport("numpy")

    using imageUtils

    # ---------------------------------------------------------------------------- #
    #                            client - publish image                            #
    # ---------------------------------------------------------------------------- #
    webcam = cv2.VideoCapture(0)

    _, frame_1 = webcam.read()      # julia's PythonCall python-obj numpy array
    # frame_1 = cv.imread("20.jpg")     

    # compress image data formats in order to make network transfer easier.
    _, buffer = cv.imencode(".jpg", frame_1)    

    jpg_as_pyStr = base64.b64encode(buffer).decode("utf-8")
    jpg_as_juliaStr = pyconvert(String, jpg_as_pyStr)   # for base64, python string or julia string is the same
    juliaDict = Dict("img"=> jpg_as_juliaStr)
    publish(mqttClient, "sometopic", JSON3.write(juliaDict))    # mqtt publish
    

    # ---------------------------------------------------------------------------- #
    #                            server - receive image                            #
    # ---------------------------------------------------------------------------- #
    img_str = payload["img"]    # payload received thru mqtt
    buf = base64.b64decode(img_str)
    buffer = np.frombuffer(buf, dtype=np.uint8)
    frame_1 = cv.imdecode(buffer, 1)
    frame_1_julia = pyconvert(Array, frame_1);
    img_julia_RGB = imageUtils.np2juliaImage(frame_1_julia)


    # ----------------------------- modify image here ---------------------------- #


    img_bgr = imageUtils.juliaImg2npImg(img_julia_RGB);
    frame_2 = np.array(img_bgr)  # julia's PythonCall python-obj numpy array
"""

# ---------------------------------------------------------------------------- #
#                                     mqtt                                     #
# ---------------------------------------------------------------------------- #
""" 
    ```
    Store mqtt client info with client instance
    ```
    # Example
    mqttClientSpec = (
        clientName= "someclient",   # name of this client
        clientID= mqttclienid,
        broker= "192.168.88.10", 
        pub= (faceAI="face_problem_detection/request",),
    )
    client = CommUtils.mqttClient(mqttClientSpec)

    # msg format
    msg = Dict{Symbol, Any}(
        :msgMeta=> Dict(
            :msgPurpose=> "updateStatus",
            :from=> "tempCtrl",       
            :to=> "masterCtrl",
            :requestrespond=> "request",    # this is a request or respond msg
            :sendto=> "",      # responder's topic
            :replyTo=> nothing,    # requester ask responder to send reply to this topic
            :repondToMsgId=> ",   # responder is responding to this msg id
            :taskstatus=> "",       # "complete", "fail", "waiting" or other status
            :timestamp=> Dates.now(),
            :msgId=> uuid4()
        ),
        :userdata1=> somedata,
        :userdata2=> somedata,
    )
"""
Base.@kwdef mutable struct mqttClient
    # client info
    clientName::String= ""  # name of this client
    clientID::String= ""
    userName::String= ""
    password::String= ""    # e.g. raw"GP$gxe_2W8vJ-9-5)YU8#-x".    use raw"" if $ is present

    # server info
    serverName::String= "localmqttserver"
    # 172.17.0.1 is docker internal gateway that bind to "0.0.0.0"(linux) or "127.0.0.1"(windows)
    broker::String="172.17.0.1"     
    port::Integer=1883

    pubtopic::NamedTuple= (
        respondtopic= "",
    )   
    telemetrytopic::NamedTuple= NamedTuple()    # e.g. (temp="temp/telemetry", humid="humid/telemetry)
    debugtopic::NamedTuple= NamedTuple()
    subtopic::NamedTuple= (
        requesttopic= "",
        selfmailboxtopic= "",    # use it to receive result from other microservices
    )   

    # client operation
    clientInstance::Any= nothing    # client instance after connected to mqtt server resides here
    connectStatus::Bool= false
    subStatus::Bool= false
    boottime::DateTime= Dates.now()
    retainedMsgCleared= false

end
function mqttClient(kwargs::NamedTuple)

    # instantiate client data struct
    s = mqttClient() 

    for (k, v) in pairs(kwargs)
        s.:($k) = v
    end

    # instantiate mqtt client
    if s.clientID != ""
        s.clientInstance = Mosquitto.Client(id=s.clientID)
    else
        s.clientInstance = Mosquitto.Client()
    end

    # connect
    mqttConnect!(s)

    return s
end

function mqttConnect!(client::mqttClient)
    if client.userName != ""
        result = Mosquitto.connect(client.client, client.broker, client.port,
                                    username=client.userName, 
                                    password=client.password)
        client.connectStatus = result == 0 ? true : false
    else
        result = Mosquitto.connect(client.clientInstance, client.broker, client.port)
        client.connectStatus = result == 0 ? true : false
    end
end

# loop client instance manually
mqttLoop!(client::mqttClient; timeout=100) = loop(client.clientInstance, timeout=timeout)


""" 
    Checking all client for potential connection lost and mark the lost connection
"""
function mqttCheckConnection!(client::mqttClient)
    # check channel, if there is something todo
    nmessages = Base.n_avail(get_connect_channel())

    if nmessages == 0
        return 0
    else
        for i = 1:nmessages
            # each conncb in a channel is a connection struct resulted from Mosquitto.connect()
            conncb = take!(get_connect_channel()) 
            if conncb.clientptr == client.clientInstance.cptr.mosc # use conncb.clientptr (pointer) as identifier
                if conncb.val == 1
                    println("$(conncb.clientptr): connection successfull")
                    client.connectStatus = true
                elseif conncb.val == 0
                    println("$(conncb.clientptr): $(client.clientName) disconnected")
                    client.connectStatus = false
                    client.subStatus = false
                else
                    error("undefined condition line $(@__LINE__)")
                end
            end
        end
    end
end


""" 
    Reconnect all client that is marked "lost connection"
"""
function mqttReconnect!(client::mqttClient)
    if client.connectStatus == false
        Mosquitto.disconnect(client.clientInstance) # disconnect to release port before attemping new connection

        if client.userName === nothing    # check if the member needs username/password
            result = Mosquitto.connect(client.clientInstance, client.broker, client.port)
            client.connectStatus = result == 0 ? true : false
        else
            result = Mosquitto.connect(client.clientInstance, client.broker, client.port,
                            username=client.userName, 
                            password=client.password)
            client.connectStatus = result == 0 ? true : false
        end

    end
end


""" 
    Subscribe all topic for all client
"""
function mqttSubOnConnect!(client::mqttClient)
    if client.connectStatus == true && client.subStatus == false
        for (k, v) in pairs(client.subtopic)
            if v != ""
                println("sub to $k")
                Mosquitto.subscribe(client.clientInstance, v)
                client.subStatus = true
            end
        end
    end
end


"""
    mqtt communication loop, call this function manually 
"""
function mqttRun(client::mqttClient, userMsgHandler::Function)
    mqttLoop!(client)
    mqttCheckConnection!(client)
    mqttReconnect!(client)
    mqttSubOnConnect!(client)
    mqttOnmessage!(client, userMsgHandler)
end


"""
    userMsgHandler. A user defined function in user space.

    # Example

    function mqttMsgHander(topic::String, payload)
        # this function access workSpace by global variable and do something with msg
    end

"""
function mqttOnmessage!(client::mqttClient, userMsgHandler::Function)
    nmessages = Base.n_avail(get_messages_channel())
    nmessages == 0 && return 0

    timepass = (Dates.now() - client.boottime).value / 1000.0
    
    if timepass <= 1 && client.retainedMsgCleared == false
        # discard all retained message
        for i = 1:nmessages
            _ = take!(get_messages_channel()) # discard new arrival package
        end
    elseif timepass > 1 && client.retainedMsgCleared == false
        client.retainedMsgCleared = true
        println("retained mqtt messages cleared")
    else
        for i = 1:nmessages
            pkg = take!(get_messages_channel()) # take new arrival package
            topic = pkg.topic
            # sptoptic = split(topic, "/")
            payload = vecToDict(pkg.payload)    # payload in Dict format

            # Do something with the message
            userMsgHandler(topic, payload)      # user defined function in user space. How to handle msg
        end
    end
end 



function publish(client::mqttClient, msg::Dict, pubtopic::String="")
    Mosquitto.publish(client.clientInstance, pubtopic, JSON3.write(msg))
end


"""
    request function check msg for additional communication info in addition to publish()
"""
function request(client::mqttClient, msg::Dict; pubtopic::String="")
    pubto = Vector{String}()
    if pubtopic != ""
        push!(pubto, pubtopic)
    elseif  msg[:msgMeta][:sendto] != ""
        push!(pubto, msg[:msgMeta][:sendto])
    else
        if length(client.pubtopic) != 0
            for (k, topic) in pairs(client.pubtopic)
                push!(pubto, topic)
            end
        else
            error("publish topic not defined")
        end
    end


    for i in pubto
        Mosquitto.publish(client.clientInstance, i, JSON3.write(msg))
    end
end

"""
    respond function check msg for additional communication info in addition to publish()
"""
function respond(client::mqttClient, respond_msg::Dict, request_msg::Dict; pubtopic::String="")
    replyTo = request_msg[:msgMeta][:replyTo]
    respond_msg[:msgMeta][:repondToMsgId] = request_msg[:msgMeta][:msgId]
    respond_msg[:msgMeta][:requestrespond] = "respond"

    pubto = Vector{String}()
    if pubtopic != ""
        push!(pubto, pubtopic)
    elseif  replyTo != ""
        push!(pubto, replyTo)
    else
        if length(client.pubtopic) != 0
            for (k, topic) in pairs(client.pubtopic)
                push!(pubto, topic)
            end
        else
            error("publish topic not defined")
        end
    end

    for i in pubto
        Mosquitto.publish(client.clientInstance, i, JSON3.write(respond_msg))
    end
end















"""
    Store details about mqtt and connected-Clients1
"""
mqtt_member_dict = Dict(
    :firstClient=> Dict(    # masterController itself for internal communication
            :clientName=> "masterController",   # name of this client
            :clientID=> "09f165cf-df9e-4607-bb34-a3c9f0a6bb98",
            :username=> nothing,
            :password=> nothing,

            # mqtt container is located outside of greenhouse-network1, 
            # 172.17.0.1 is local docker IP
            :serverName=> "local_mqtt_server",  # name of the server this client is connecting
            :broker=> "172.17.0.1", 
            :port=> 1883,
            :requesttopic=> "09f165cf-df9e-4607-bb34-a3c9f0a6bb98/request",         # channel of THIS client
            :respondtopic=> "09f165cf-df9e-4607-bb34-a3c9f0a6bb98/respond",         # channel of THIS client
            :telemetrytopic=> "09f165cf-df9e-4607-bb34-a3c9f0a6bb98/telemetry",     # channel of THIS client
            :debugtopic=> "09f165cf-df9e-4607-bb34-a3c9f0a6bb98/debug",             # channel of THIS client
            :pubtoptic=> Vector{String}(),     # other channel this client publish to
            :subtoptic=> Vector{String}(),     # other channel this client subscribe to
            :mqttClient=> nothing,      # client instance after connected to mqtt server resides here
            :connectStatus=> false,
            :subStatus=> false
    ),
    :secondClient=> Dict(    # masterController itself for internal communication
            :clientName=> "masterController",   # name of this client
            :clientID=> "42f53073-b2ed-4b4a-8b11-155c58135dfc",
            :username=> nothing,
            :password=> nothing,

            # mqtt container is located outside of greenhouse-network1, 
            # 172.17.0.1 is local docker IP
            :serverName=> "yiemMaintenance",  # name of the server this client is connecting
            :broker=> "mqtt.yiem.ai", 
            :port=> 1883,
            :requesttopic=> "42f53073-b2ed-4b4a-8b11-155c58135dfc/request",         # channel of THIS client
            :respondtopic=> "42f53073-b2ed-4b4a-8b11-155c58135dfc/respond",         # channel of THIS client
            :telemetrytopic=> "42f53073-b2ed-4b4a-8b11-155c58135dfc/telemetry",     # channel of THIS client
            :debugtopic=> "42f53073-b2ed-4b4a-8b11-155c58135dfc/debug",             # channel of THIS client
            :pubtoptic=> Vector{String}(),     # other channel this client publish to
            :subtoptic=> Vector{String}(),     # other channel this client subscribe to
            :mqttClient=> nothing,      # client instance after connected to mqtt server resides here
            :connectStatus=> false,
            :subStatus=> false
    ),
    :thirdClient=> Dict(    # masterController itself for internal communication
            :clientName=> "masterController",   # name of this client
            :clientID=> "f64e864b-e93f-4d1e-8662-0d6da68c9c03", #TODO change here netpie clientID
            :username=> "t5gBa",    #TODO change here netpie token
            :password=> raw"GP$gxe_2W8vJ-9-5)YU8#-x",   #TODO change here netpie secret

            # mqtt container is located outside of greenhouse-network1, 
            # 172.17.0.1 is local docker IP
            :serverName=> "netpie2020",  # name of the server this client is connecting
            :broker=> "broker.netpie.io", 
            :port=> 1883,
            :requesttopic=> "@msg/masterController",         # channel of THIS client
            :respondtopic=> "@shadow/data/update",         # channel of THIS client           # channel of THIS client
            :pubtoptic=> Vector{String}(),     # other channel this client publish to
            :subtoptic=> Vector{String}(),     # other channel this client subscribe to
            :mqttClient=> nothing,      # client instance after connected to mqtt server resides here
            :connectStatus=> false,
            :subStatus=> false
    ),
)




""" operate on mqtt_member_dict
    Connect all clients to relevent server
"""
function mqttConnect!(mqttMemberDict::Dict)
    for (k, v) in mqttMemberDict
        member = mqttMemberDict[k]
        member[:mqttClient] = member[:clientID] === nothing ? Mosquitto.Client() : 
                                    Mosquitto.Client(id=member[:clientID])
        println("connecting member $k")
        port = haskey(member, :port) ? member[:port] : 1883
        if member[:username] === nothing
            result = Mosquitto.connect(member[:mqttClient], member[:broker], port)
            member[:connectStatus] = result == 0 ? true : false
        else
            result = Mosquitto.connect(member[:mqttClient], member[:broker], port,
                            username=member[:username], 
                            password=member[:password])
            member[:connectStatus] = result == 0 ? true : false
        end
    end
end


""" operate on mqtt_member_dict
    Checking all client for potential connection lost and mark the lost connection
"""
function mqttCheckConnection!(mqttMemberDict::Dict)
    # check channel, if there is something todo
    nmessages = Base.n_avail(get_connect_channel())

    if nmessages == 0
        return 0
    else
        for i = 1:nmessages
            # each conncb in a channel is a connection struct resulted from Mosquitto.connect()
            conncb = take!(get_connect_channel()) 
            for (k, v) in mqttMemberDict
                member = mqttMemberDict[k]
                if conncb.clientptr == member[:mqttClient].cptr.mosc # use conncb.clientptr (pointer) as identifier
                    if conncb.val == 1
                        println("$(conncb.clientptr): connection successfull")
                        member[:connectStatus] = true
                    elseif conncb.val == 0
                        println("$(conncb.clientptr): member $i disconnected")
                        member[:connectStatus] = false
                        member[:subStatus] = false
                    else
                        error("something wrong with connection message")
                    end
                end
            end
        end
    end
end


""" operate on mqtt_member_dict
    Reconnect all client that is marked "lost connection"
"""
function mqttReconnect!(mqttMemberDict::Dict)
    for (k, v) in mqttMemberDict   # find the disconnected member 
        member = mqttMemberDict[k]
        if member[:connectStatus] == false
            Mosquitto.disconnect(member[:mqttClient]) # disconnect to release port before attemping new connection

            port = haskey(member, :port) ? member[:port] : 1883
            if member[:username] === nothing    # check if the member needs username/password
                result = Mosquitto.connect(member[:mqttClient], member[:broker], port)
                member[:connectStatus] = result == 0 ? true : false
            else
                result = Mosquitto.connect(member[:mqttClient], member[:broker], port,
                                username=member[:username], 
                                password=member[:password])
                member[:connectStatus] = result == 0 ? true : false
            end

        end
    end
end


""" operate on mqtt_member_dict
    Subscribe all topic for all client
"""
function mqttSubOnConnect!(mqttMemberDict::Dict, subChannel::Vector{String})
    for (k, v) in mqttMemberDict
        member = mqttMemberDict[k]
        #TODO once reconnect, publish current machine state to netpie
        if member[:connectStatus] == true && member[:subStatus] == false
            Mosquitto.subscribe(member[:mqttClient], member[:requesttopic])   # sub to its own channel

            # mastercontroller sub to other controller
            if k == :firstClient
                Mosquitto.subscribe(member[:mqttClient], "$(config[:farminfo][:farmId])/controller/+/telemetry")
                Mosquitto.subscribe(member[:mqttClient], "$(config[:farminfo][:farmId])/controller/+/respond")
            end
            member[:subStatus] = true
        end
    end
end


""" operate on mqtt_member_dict
"""
# What to do if there is a message
function mqttOnmessage!(mqttMemberDict, netpieCommDict::Dict, workDict::Dict)
    nmessages = Base.n_avail(get_messages_channel())
    nmessages == 0 && return 0

    if workDict[:residueMsgClearedStartTime] === nothing
        workDict[:residueMsgClearedStartTime] = Dates.now()
    end
    timepass = (Dates.now() - workDict[:residueMsgClearedStartTime]).value / 1000.0
    
    if timepass <= 10 && workDict[:residueMsgCleared] == 0
        # discard all residue message
        for i = 1:nmessages
            _ = take!(get_messages_channel()) # take new arrival package
        end
    elseif timepass > 10 && workDict[:residueMsgCleared] == 0
        workDict[:residueMsgCleared] = 1
        println("residue mqtt messages cleared")
    else
        for i = 1:nmessages
            pkg = take!(get_messages_channel()) # take new arrival package
            topic = pkg.topic
            sptoptic = split(topic, "/")
            payload = vecToDict(pkg.payload)
            # println("topic ", topic)
            # println("payload ", payload)
            # Do something with the message
            if topic == mqttMemberDict[:firstClient][:requesttopic]
                # publish(c2, "julia", "From member 2"; qos = 2)
                # result = yiemHandler()
                return 0
            #FIXME add yiem.ai in config.json file
            # elseif topic == mqttMemberDict[:yiemMaintenance][:requesttopic]
                # localHandler(payload, workDict)
            elseif topic == mqttMemberDict[:netpieGreenhouseActive][:requesttopic]    # command from NETPIE
                println("NETPIE msg")
                netpieMsgHandler(payload, netpieCommDict, workDict, mqttMemberDict[:netpieGreenhouseActive])

            elseif sptoptic[2] == "controller"
                controllerName = sptoptic[3]
                if controllerName == "fertilizerController_1"
                    fertilizerController_msgHandler(sptoptic[end], payload, workDict)
                elseif controllerName == "temperatureController_1"
                    temperatureController_msgHandler(sptoptic[end], payload, workDict)
                elseif controllerName == "humidityController_1"
                    humidityController_msgHandler(sptoptic[end], payload, workDict)
                elseif controllerName == "illuminanceController_1"
                    illuminanceController_msgHandler(sptoptic[end], payload, workDict)
                elseif controllerName == "co2Controller_1"
                    co2Controller_msgHandler(sptoptic[end], payload, workDict)
                elseif controllerName == "ventilationController_1"
                    ventilationController_msgHandler(sptoptic[end], payload, workDict)
                else
                    error("undefined condition")
                end
            else
                println("Not yet define what to do with message from this topic: $topic")
                return 1
            end

            return 0
        end
    end
end 


""" operate on mqtt_member_dict
    network run
"""
function mqttLoop!(mqttMemberDict; timeout=100)
    for (k, v) in mqttMemberDict
        member = mqttMemberDict[k]
        loop(member[:mqttClient], timeout=timeout)
    end
end

""" operate on mqtt_member_dict
"""
function mqttDisconnect!(memberList)
    for member in memberList
        disconnect(member[:mqttClient])
    end
end


"""
    publish msg with msgMeta information.

    sourceName = "fertilizerController_1" or could be any name
    destinationName = "masterController" or could be any name
    topic = :requesttopic, :respondtopic, :telemetrytopic will use its own topic
                or
            "masterController/request" will use specified topic
"""
function publishMsg(destinationName::String, msgPurpose::String, topic::Symbol,
             variableNameAndValue::Dict, workDict::Dict, config::Dict; 
             sourceName=workDict[:mainCtrlName])

    msg = Dict{Symbol, Any}(
        :msgMeta=> Dict(
            :msgPurpose=> msgPurpose, # "updateStatus", "fertilizerMixOrder"
            :from=> sourceName,
            :to=> destinationName,
            :repondToMsgId=> nothing,   # the msg this msg is responding to 
            :repondtopic=> nothing,     # ask server to reply to this topic
            :timestamp=> Dates.now(),
            :msgId=> uuid4()),
        :payload=> nothing,
        )
    for (k, v) in variableNameAndValue
        msg[k] = v
    end

    pubtopic = config[workDict[:mainCtrlName]][:mqttMembers][:firstClient][topic]
    publish(config[workDict[:mainCtrlName]][:mqttMembers][:firstClient][:mqttClient], 
    pubtopic, JSON3.write(msg))
end

function publishMsg(destinationName::String, msgPurpose::String, topic::String,
    variableNameAndValue::Dict, workDict::Dict, config::Dict; 
    sourceName=workDict[:mainCtrlName])

    msg = Dict{Symbol, Any}(
        :msgMeta=> Dict(
            :msgPurpose=> msgPurpose, # "updateStatus", "fertilizerMixOrder"
            :from=> sourceName,
            :to=> destinationName,
            :repondToMsgId=> nothing,   # the msg this msg is responding to 
            :repondtopic=> nothing,     # ask server to reply to this topic
            :timestamp=> Dates.now(),
            :msgId=> uuid4()),
        :payload=> nothing,
        )
    for (k, v) in variableNameAndValue
        msg[k] = v
    end

    pubtopic = topic
    publish(config[workDict[:mainCtrlName]][:mqttMembers][:firstClient][:mqttClient], 
    pubtopic, JSON3.write(msg))
end







































































end # module end