function _M.access()

in apisix/plugins/ai-prompt-guard.lua [96:151]

• 49 lines of code
• 15 McCabe index (conditional complexity)

function _M.access(conf, ctx)
    local body = core.request.get_body()
    if not body then
        core.log.error("Empty request body")
        return 400, {message = "Empty request body"}
    end

    local json_body, err = core.json.decode(body)
    if err then
        return 400, {message = err}
    end

    local messages = json_body.messages or {}
    messages = get_content_to_check(conf, messages)
    if not conf.match_all_roles then
        
        local new_messages = {}
        for _, msg in ipairs(messages) do
            if msg.role == "user" then
                core.table.insert(new_messages, msg)
            end
        end
        messages = new_messages
    end
    if #messages == 0 then 
        return 200
    end
    
    local content = {}
    for _, msg in ipairs(messages) do
        if msg.content then
            core.table.insert(content, msg.content)
        end
    end
    local content_to_check = table.concat(content, " ")
     
     if #conf.allow_patterns > 0 then
        local any_allowed = false
        for _, pattern in ipairs(conf.allow_patterns) do
            if re_find(content_to_check, pattern, "jou") then
                any_allowed = true
                break
            end
        end
        if not any_allowed then
            return 400, {message = "Request doesn't match allow patterns"}
        end
    end

    
    for _, pattern in ipairs(conf.deny_patterns) do
        if re_find(content_to_check, pattern, "jou") then
            return 400, {message = "Request contains prohibited content"}
        end
    end
end