Conditional debit from credits and running balance using SQL

I’ve data like below in a table cryptotransactionledger

id	transaction_typeid	transaction_type	amount	totalcoins
1	1	bitcoin-credit	30	30
2	2	ethereum-credit	20	50

If I spend bitcoin, I’m putting a new entry like below in the same table with transaction_typeid 3 and similarly for ethereum with transaction_typeid 4

id	transaction_typeid	transaction_type	amount	totalcoins
1	1	bitcoin-credit	30	30
2	2	etherium-credit	20	50
3	3	bitcoin-debit	-10	40
4	4	etherium-debit	-5	35

Suppose if my final data in the table is like below, I will have 35 bitcoin and 20 ethereum remaning.

id	transaction_typeid	transaction_type	amount	totalcoins
1	1	bitcoin-credit	30	30
2	2	etherium-credit	20	50
3	3	bitcoin-debit	-10	40
4	4	etherium-debit	-5	35
5	1	bitcoin-credit	15	50
6	2	etherium-credit	10	60
7	4	etherium-debit	-5	55

How can I arrive at below balance summary using SQL after reducing all debits from respective credits

id	transaction_type	amount	totalcoins
1	bitcoin-credit	35	35
2	etherium-credit	20	55

Answer

Thanks to all those gave suggestions and different solutions. I’ve finally used below query that provides me the results as expected.

WITH cte1
 AS (SELECT a.*,
            CASE
              WHEN ( transaction_typeid = 1
                      OR transaction_typeid = 3 ) THEN 0
              ELSE 1
            END AS category
     FROM   cryptotransactionledger a
     ORDER  BY id),
 cte2
 AS (SELECT CASE
              WHEN ( category = 0 ) THEN 'bitcoin-credit'
              ELSE 'etherium-credit'
            END         AS transaction_type,
            Sum(amount) AS amount
     FROM   cte1 o
     GROUP  BY category),
 cte3
 AS (SELECT Row_number()
              OVER (ORDER BY c.transaction_type) AS id,
            c.*
     FROM   cte2 c) SELECT f.*,
     Sum(amount) OVER(ORDER BY f.id) AS total_coins FROM cte3 f;

Link to DB Fiddle