HostFS

--[[

    host
    By Dave-ee Jones

    Local DNS hosting
    Uses file system instead of RAM

--]]

local DIR = ".hosts"
if not fs.exists(DIR) then
  fs.makeDir(DIR)
end

-- Create a new entry
function new(_NAME,_ID)
    if type(_NAME) == "string" then
        if type(_ID) == "number" then
            local _f = fs.open(DIR.."/".._NAME,"w")
            _f.write(_ID)
            _f.close()
            return true
        else
            error("host: ID needs to be a number",0)
        end
    else
        error("host: NAME needs to be a string",0)
    end
end

-- Change the ID of the name given
function setID(_NAME,_ID)
    if type(_NAME) == "string" then
        if type(_ID) == "number" then
            if fs.exists(DIR.."/".._NAME) then
                local _f = fs.open(DIR.."/".._NAME,"w")
                _f.write(_ID)
                _f.close()
                return true
            else
                error("host: Record for ".._NAME.." doesn't exist",0)
            end
        else
            error("host: ID needs to be a number",0)
        end
    end
    return false
end

-- Change the name of the ID given
function setName(_ID,_NAME)
    if type(_ID) == "number" then
        local b_FOUND = false
        for k,v in pairs(fs.list(DIR)) do
            local _f = fs.open(DIR.."/"..v,"w")
            local _contents = _f.readAll()
            _f.close()
            if tonumber(_contents) == _ID then
                b_FOUND = true
                delete(k)
                new(_NAME,_ID)
            end
        end
        if not b_FOUND then
            error("host: Record for "..tostring(_ID).." doesn't exist",0)
        end
    else
        error("host: NAME needs to be a string",0)
    end
end

-- Returns name of ID given or false if there isn't one
function getName(_ID)
    if type(_ID) == "number" then
        for k,v in pairs(fs.list(DIR)) do
            local _f = fs.open(DIR.."/"..v,"r")
            local _contents = _f.readAll()
            _f.close()
            if tonumber(_contents) == _ID then
                return v
            end
        end
    else
        error("host: ID needs to be a number",0)
    end
    return false
end

-- Returns ID of name given or false if there isn't one
function getID(_NAME)
    if type(_NAME) == "string" then
        if fs.exists(DIR.."/".._NAME) then
            local _f = fs.open(DIR.."/".._NAME,"r")
            local _contents = _f.readAll()
            _f.close()
            return tonumber(_contents)
        else
            return false
        end
    else
        error("host: NAME needs to be a string",0)
    end
end

-- Deletes a DNS entry
function delete(_NAME)
    if fs.exists(DIR.."/".._NAME) then
        fs.delete(DIR.."/".._NAME)
        return true
    end
    return false
end