function _M.rewrite()

in apisix/plugins/ai-aws-content-moderation.lua [90:159]
60 lines of code
12 McCabe index (conditional complexity)

function _M.rewrite(conf, ctx)
    conf = fetch_secrets(conf, true, conf, "")
    if not conf then
        return HTTP_INTERNAL_SERVER_ERROR, "failed to retrieve secrets from conf"
    end

    local body, err = core.request.get_body()
    if not body then
        return HTTP_BAD_REQUEST, err
    end

    local comprehend = conf.comprehend

    if not aws_instance then
        aws_instance = aws()
    end
    local credentials = aws_instance:Credentials({
        accessKeyId = comprehend.access_key_id,
        secretAccessKey = comprehend.secret_access_key,
        sessionToken = comprehend.session_token,
    })

    local default_endpoint = "https://comprehend." .. comprehend.region .. ".amazonaws.com"
    local scheme, host, port = unpack(http:parse_uri(comprehend.endpoint or default_endpoint))
    local endpoint = scheme .. "://" .. host
    aws_instance.config.endpoint = endpoint
    aws_instance.config.ssl_verify = comprehend.ssl_verify

    local comprehend = aws_instance:Comprehend({
        credentials = credentials,
        endpoint = endpoint,
        region = comprehend.region,
        port = port,
    })

    local res, err = comprehend:detectToxicContent({
        LanguageCode = "en",
        TextSegments = {{
            Text = body
        }},
    })

    if not res then
        core.log.error("failed to send request to ", endpoint, ": ", err)
        return HTTP_INTERNAL_SERVER_ERROR, err
    end

    local results = res.body and res.body.ResultList
    if type(results) ~= "table" or core.table.isempty(results) then
        return HTTP_INTERNAL_SERVER_ERROR, "failed to get moderation results from response"
    end

    for _, result in ipairs(results) do
        if conf.moderation_categories then
            for _, item in pairs(result.Labels) do
                if not conf.moderation_categories[item.Name] then
                    goto continue
                end
                if item.Score > conf.moderation_categories[item.Name] then
                    return HTTP_BAD_REQUEST, "request body exceeds " .. item.Name .. " threshold"
                end
                ::continue::
            end
        end

        if result.Toxicity > conf.moderation_threshold then
            return HTTP_BAD_REQUEST, "request body exceeds toxicity threshold"
        end
    end
end