//
// Simple Bitcoin Payment Protocol messages
//
// Use fields 1000+ for extensions;
// to avoid conflicts, register extensions via pull-req at
// https://github.com/bitcoin/bips/bip-0070/extensions.mediawiki
//

package payments;
option java_package = "org.bitcoin.protocols.payments";
option java_outer_classname = "Protos";

// Generalized form of "send payment to this/these bitcoin addresses"
message Output {
        optional uint64 amount = 1 [default = 0]; // amount is integer-number-of-satoshis
        required bytes script = 2; // usually one of the standard Script forms
}
message PaymentDetails {
        optional string network = 1 [default = "main"]; // "main" or "test"
        repeated Output outputs = 2;                // Where payment should be sent
        required uint64 time = 3;                   // Timestamp; when payment request created
        optional uint64 expires = 4;                // Timestamp; when this request should be considered invalid
        optional string memo = 5;                   // Human-readable description of request for the customer
        optional string payment_url = 6;            // URL to send Payment and get PaymentACK
        optional bytes  merchant_data = 7;          // Arbitrary data to include in the Payment message
}
message PaymentRequest {
        optional uint32 payment_details_version = 1 [default = 1];
        optional string pki_type = 2 [default = "none"];  // none / x509+sha256 / x509+sha1
        optional bytes pki_data = 3;                      // depends on pki_type
        required bytes serialized_payment_details = 4;    // PaymentDetails
        optional bytes signature = 5;                     // pki-dependent signature
}
message X509Certificates {
        repeated bytes certificate = 1;    // DER-encoded X.509 certificate chain
}
message Payment {
        optional bytes merchant_data = 1;       // From PaymentDetails.merchant_data
        repeated bytes transactions = 2;        // Signed transactions that satisfy PaymentDetails.outputs
        repeated Output refund_to = 3;          // Where to send refunds, if a refund is necessary
        optional string memo = 4;               // Human-readable message for the merchant
}
message PaymentACK {
        required Payment payment = 1;           // Payment message that triggered this ACK
        optional string memo = 2;               // Human-readable message for customer
}

// BIP-IR Extensions
message InvoiceRequest {
        required bytes  sender_public_key = 1;              // Sender's DER-Encoded EC Public Key
        optional uint64 amount = 2 [default = 0];           // amount is integer-number-of-satoshis
        optional string pki_type = 3 [default = "none"];    // none / x509+sha256
        optional bytes  pki_data = 4;                       // Depends on pki_type
        optional string memo = 5;                           // Human-readable description of invoice request for the receiver
        optional string notification_url = 6;               // URL to notify on EncryptedPaymentRequest ready
        optional bytes  signature = 7;                      // PKI-dependent signature
}

enum ProtocolMessageType {
    UNKNOWN_MESSAGE_TYPE = 0;
    INVOICE_REQUEST = 1;
    PAYMENT_REQUEST = 2;
    PAYMENT = 3;
    PAYMENT_ACK =  4;
}

message ProtocolMessage {
    required uint64 version = 1 [default = 1];      // Protocol version number
    required uint64 status_code = 2 [default = 1];  // Payment Protocol Status Code (Default: 1 "OK")
    required ProtocolMessageType message_type = 3;  // Message Type of serialized_message
    required bytes serialized_message = 4;          // Serialized Payment Protocol Message
    optional string status_message = 5;             // Human-readable Payment Protocol status message
    required bytes identifier = 6;                  // Unique key to identify this entire exchange on the server. Default value SHOULD be SHA256(Serialized Initial InvoiceRequest + Current Epoch Time in Seconds as a String)
}

message EncryptedProtocolMessage {
    required uint64 version = 1 [default = 1];      // Protocol version number
    required uint64 status_code = 2 [default = 1];  // Payment Protocol Status Code (Default: 1 "OK")
    required ProtocolMessageType message_type = 3;  // Message Type of Decrypted encrypted_message
    required bytes encrypted_message = 4;           // AES-256-GCM Encrypted (as defined in BIP75) Payment Protocol Message
    required bytes receiver_public_key = 5;         // Receiver's DER-encoded EC Public Key
    required bytes sender_public_key = 6;           // Sender's DER-encoded EC Public Key
    required uint64 nonce = 7;                      // Microseconds since epoch
    required bytes identifier = 8;                  // Unique key to identify this entire exchange on the server. Default value SHOULD be SHA256(Serialized Initial InvoiceRequest + Current Epoch Time in Seconds as a String)
    optional string status_message = 9;             // Human-readable Payment Protocol status message
    optional bytes signature = 10;                   // Signature over the full EncryptedProtocolMessage with EC Key Belonging to Sender / Receiver, respectively
}