DAX concatenate list of a column value (ex. contract) grouped by date

I'm trying to create a list of contracts that expire by dates. I looked on the many sites for a solution.

I have a measure that calculates the date and i need calculated table with a summurazed version.

I have been able to create the middle step, that is the list of contracts by date. And I can't get to the last steps that is one line per date with a concatenate list of the contracts.

step one : 1 line per contract to renew

this is the dax code for the mid step table

Table contracts by date = 

VAR T1 = 
CALCULATETABLE(
    SUMMARIZE(contracts,
       contracts[Contrat], 
       contracts[Mandat], 
       contracts[CléContratDemande], 
       "date",[_mesure_date_expire], 
       "fullKey", contracts[CléContratDemande]
    ),
    contracts[Statut] = "Active",
    ALLEXCEPT(contracts, contracts[Contrat],contracts[Mandat])
)

RETURN 
t1

[_mesure_date_expire] is a measure outside of the table that calculate the expiration date.

This is the result of the mid step table:

Wanted result

The result i'm trying to achieve is this :

the column contracts is the concatenation of the column fullkey of the mid table step.

you see that april 11th has 2 contracts on the same line

I tried to create a var for the second table with different combinations of VALUES, SUMMARIZE, GROUPBY, CONCATENATE, CONCATENATEX without success.

Help and input will be appreciated.

Thanks

Pat

You can achieve this using SUMMARIZE to group by date, and CONCATENATEX to concatenate the fullKey values.

Final Table = 
VAR MidStep = 
    CALCULATETABLE(
        SUMMARIZE(
            contracts,
            contracts[Contrat], 
            contracts[Mandat], 
            contracts[CléContratDemande], 
            "date", [_mesure_date_expire], 
            "fullKey", contracts[CléContratDemande]
        ),
        contracts[Statut] = "Active",
        ALLEXCEPT(contracts, contracts[Contrat], contracts[Mandat])
    )

RETURN
    ADDCOLUMNS(
        SUMMARIZE(MidStep, [date]),
        "Contracts", 
        CALCULATE(
            CONCATENATEX(
                VALUES(FILTER(MidStep, [date] = EARLIER([date]))[fullKey]), 
                [fullKey],
                ", "
            ) //Unique Values
        )
    )