--[[
Handle Proxmark USB Commands
--]]

local _commands = require('usb_cmd')

local _reverse_lookup,k,v = {}
    for k, v in pairs(_commands) do
        _reverse_lookup[v] =  k
    end
    _commands.tostring = function(command)
    if(type(command) == 'number') then
        return ("%s (%d)"):format(_reverse_lookup[command]or "ERROR UNDEFINED!", command)
    end
    return ("Error, numeric argument expected, got : %s"):format(tostring(command))
end

Command = {

    new = function(self, o)

        local o = o or {}   -- create object if user does not provide one
        setmetatable(o, self) -- DIY inheritance a'la javascript
        self.__index = self

        o.cmd = o.cmd or _commands.CMD_UNKNOWN
        o.arg1 = o.arg1 or 0
        o.arg2 = o.arg2 or 0
        o.arg3 = o.arg3 or 0
        local data = o.data or "0"

        if(type(data) == 'string') then
            -- We need to check if it is correct length, otherwise pad it
            local len = string.len(data)
            if(len < 1024) then
                --Should be 1024 hex characters to represent 512 bytes of data
                data = data .. string.rep("0",1024 - len )
            end
            if(len > 1024) then
                -- OOps, a bit too much data here
                print( ( "WARNING: data size too large, was %s chars, will be truncated "):format(len) )
                --
                data = data:sub(1,1024)
            end
        else
            print(("WARNING; data was NOT a (hex-) string, but was %s"):format(type(data)))
        end
        o.data = data
        return o
    end,
    parse = function (packet)
        local count, cmd, arg1, arg2, arg3, data = bin.unpack('LLLLH511', packet)
        return Command:new{cmd = cmd, arg1 = arg1, arg2 = arg2, arg3 = arg3, data = data}
    end

}
function Command:__tostring()
    local output = ("%s\r\nargs : (%s, %s, %s)\r\ndata:\r\n%s\r\n"):format(
        _commands.tostring(self.cmd),
        tostring(self.arg1),
        tostring(self.arg2),
        tostring(self.arg3),
        tostring(self.data))
    return output
end
function Command:getBytes()
    --If a hex-string has been used
    local data  = self.data
    local cmd = self.cmd
    local arg1, arg2, arg3 = self.arg1, self.arg2, self.arg3
    return bin.pack("LLLLH",cmd, arg1, arg2, arg3, data);
end
return _commands