LIMIT / Filtering on LEFT JOIN

I have two tables, one table is a list of purchases with revenue, purchase_time and a user id, the other table has a list of a list of campaign clicks with campaign_id, user_id, click_time. campaign_clicks essentially logs all clicks from a campaign, there can any number of clicks or none and these could happen anytime, before or after a purchase but what I need to do is determine which campaign_id was the last campaign to be clicked on before the purchase was made by any given user and what was the total revenue attributed to that campaign_id. I want to only attribute revenue to clicks that occurred within 3 days prior to the purchase.

purchases

campaign_clicks

desired result

purchase from user id 20 shouldn't be included because it occurred before the click_time. User 10 revenue should be attributed to campaign 2 because the click occurred just before the purchase.

My problem is the join I have is returning all the clicks which is inflating the revenue. The select in the inner join isn’t aware of the purchase time, I need to somehow filter and narrow down the clicks to a single click, the last click. I've tried using ROW_NUMBER() to apply an index but that doesn't allow me to filter out clicks that occur after the purchase.

This is where I’m at

SELECT  
  date
  ,ROUND(sum(revenue)) as revenue
  ,campaign_clicks.campaign_id
FROM 
    purchases                    
       
        LEFT JOIN ( 

                   SELECT                                   
                        campaign_id 
                        ,user_id
                        ,click_time                       
                   FROM 
                      campaign_clicks            
                   ORDER BY         
                      click_time DESC                             
                  ) AS clicks ON clicks.user_id = purchases.user_id 
WHERE 
  -- only select campaign clicks that occurred before the purchase                
  purchases.purchase_time > clicks.click_time

  -- only include clicks that occurred within 3 days of the purchase               
  AND DATEDIFF(minutes, clicks.click_time,purchases.purchase_time) <= (60*24*3)

  -- PROBLEM HERE - there can be still a number of other clicks that occurred before the purchase I need to filter to only the last one 
GROUP BY 
   date
 ,clicks.campaign_id

Snowflake supports joining laterally. That is, on to a function or correlated sub-query. This allows you to join on to a query that returns just one row (per input row).

SELECT  
  purchases.date
 ,purchases.revenue
 ,clicks.campaign_id
FROM 
  purchases    
LEFT JOIN LATERAL
(
  SELECT
    campaign_id 
   ,user_id
   ,click_time                       
  FROM 
    campaign_clicks
  WHERE
            user_id = purchases.user_id
    -- only select campaign clicks that occurred before the purchase                
    AND click_time <  purchases.purchase_time
    -- only include clicks that occurred within 3 days of the purchase               
    AND click_time >= DATEADD(days, -3, purchases.purchase_time)
  ORDER BY
    click_time DESC
  LIMIT
    1                        
)
  AS clicks