Récupérer un flux json dans un fchier csv

Bonjour.

Je souhaite écrire un script tout simple pour parser le contenu d'un flux json (sortie url) et le copier dans un fichier csv.

Exemple data json :

{"headers":{},"body":{"offers":[{"origin":{"name":"Paris","code":"FRPMO"},"destination":{"name":"Saint-Brieuc","code":"FRSBK"},"date":"201503080908","price":1900,"supercal":true,"transporter":"idtgv","originStation":"FRPMO","destinationStation":"FRSBK"},{"origin":{"name":"Lyon","code":"FRLPD"},"destination":{"name":"Rennes","code":"FRRNS"},"date":"201503291033","price":2500,"supercal":true,"transporter":"tgv","originStation":"FRLPD","destinationStation":"FRRNS"},{"origin":{"name":"Toulon","code":"FRTLN"},"destination":{"name":"Paris","code":"FRPLY"},"date":"201504041854","price":2400,"supercal":true,"transporter":"idtgv","originStation":"FRTLN","destinationStation":"FRPLY"},{"origin":{"name":"Montpellier","code":"FRMPL"},"destination":{"name":"Lille","code":"FRLLE"},"date":"201502251758","price":4900,"supercal":true,"transporter":"tgv","originStation":"FRMPL","destinationStation":"FRLLE"},{"origin":{"name":"Luxembourg","code":"LULUX"},"destination":{"name":"Paris","code":"FRPST"},"date":"201503170611","price":3500,"supercal":true,"transporter":"tgv","originStation":"LULUX","destinationStation":"FRPST"},{"origin":{"name":"Avignon","code":"FRAVG"},"destination":{"name":"Lyon","code":"FRLPD"},"date":"201502141252","price":1500,"supercal":true,"transporter":"tgv","originStation":"FRAVG","destinationStation":"FRLPD"},{"origin":{"name":"Saint-Raphaël - Valescure","code":"FRXSK"},"destination":{"name":"Paris","code":"FRPLY"},"date":"201504041601","price":3600,"supercal":true,"transporter":null,"originStation":"FRXSK","destinationStation":"FRPLY"}],"lang":"fr","error":null},"statusCode":"OK"}

sortie en csv :

origin/name origin/code destination/name destination/code date price supercal transporter originStation destinationStation
Paris FRPMO Saint-Brieuc FRSBK 201503080908 1900 true idtgv FRPMO FRSBK
Lyon FRLPD Rennes FRRNS 201503291033 2500 true tgv FRLPD FRRNS
Toulon FRTLN Paris FRPLY 201504041854 2400 true idtgv FRTLN FRPLY
Montpellier FRMPL Lille FRLLE 201502251758 4900 true tgv FRMPL FRLLE
Luxembourg LULUX Paris FRPST 201503170611 3500 true tgv LULUX FRPST
Avignon FRAVG Lyon FRLPD 201502141252 1500 true tgv FRAVG FRLPD
Saint-Raphaël - Valescure FRXSK Paris FRPLY 201504041601 3600 true FRXSK FRPLY