syntax = "proto3";

package gpmodel;

option csharp_namespace = "Echo.Model.Grpc";

// ========================= Enums =========================

enum Currency {
  CURRENCY_IQD = 0;
  CURRENCY_CNH = 1;
  CURRENCY_USD = 2;
  CURRENCY_EUR = 3;
  CURRENCY_JPY = 4;
  CURRENCY_GBP = 5;
}

enum DocType {
  DOC_TYPE_QUOTE       = 0;
  DOC_TYPE_ORDER       = 1;
  DOC_TYPE_INVOICE     = 2;
  DOC_TYPE_CREDIT_NOTE = 3;
}

enum PaymentMethod {
  PAYMENT_METHOD_CASH   = 0;
  PAYMENT_METHOD_CARD   = 1;
  PAYMENT_METHOD_WIRE   = 2;
  PAYMENT_METHOD_CRYPTO = 3;
  PAYMENT_METHOD_OTHER  = 4;
}

enum LineType {
  LINE_TYPE_PRODUCT  = 0;
  LINE_TYPE_SERVICE  = 1;
  LINE_TYPE_DISCOUNT = 2;
  LINE_TYPE_SHIPPING = 3;
}

// Variant.Kind
enum Kind {
  KIND_NULL     = 0;
  KIND_BOOL     = 1;
  KIND_INT64    = 2;
  KIND_UINT64   = 3;
  KIND_DOUBLE   = 4;
  KIND_DECIMAL  = 5;
  KIND_STRING   = 6;
  KIND_BYTES    = 7;
  KIND_DATETIME = 8;
  KIND_GUID     = 9;
}

// ========================= Variant =========================
//
// C# Variant:
//   Tag:   Kind
//   Bool:  bool?
//   I64:   long?
//   U64:   ulong?
//   F64:   double?
//   Str:   string?
//   Bytes: byte[]?
//   Dt:    DateTime?  -> int64 (ticks or epoch millis)
//   Guid:  byte[]?

message Variant {
  Kind   tag       = 1;
  bool   bool_val  = 2;  // optional in C#
  int64  i64_val   = 3;  // optional in C#
  uint64 u64_val   = 4;  // optional in C#
  double f64_val   = 5;  // optional in C#
  string str_val   = 6;  // optional in C#
  bytes  bytes_val = 7;  // optional in C#
  int64  dt_val    = 8;  // optional in C# (DateTime)
  bytes  guid_val  = 9;  // optional in C# (Guid as 16-byte array)
}

// Optional helpers mirroring MetaEntry / ExtEntry (not required for RPC)
message MetaEntry {
  string  key   = 1;
  Variant value = 2;
}

message ExtEntry {
  string  key   = 1;
  Variant value = 2;
}

// ========================= Address & Party =========================

message Address {
  string line1       = 1;
  optional string line2       = 2;  // optional in C#
  string city        = 3;
  string region      = 4;
  string country     = 5;
  optional string postal_code = 6;  // optional in C#
}

message Party {
  uint64 id                 = 1;
  string name               = 2;
  string tax_id             = 3; // optional in C#
  string email              = 4; // optional in C#
  string phone              = 5; // optional in C#
  Address address           = 6; // optional in C#
  string preferred_language = 7; // optional in C#
}

// ========================= DocumentHeader =========================
//
// DateTime/DateTime? -> int64 (ticks or epoch millis, your choice)

message DocumentHeader {
  bytes     doc_id      = 1;
  DocType   type        = 2;
  int32     version     = 3;
  int64     created_at  = 4; // DateTime
  optional int64     updated_at  = 5; // optional in C#
  Currency  currency    = 6;
  string    notes       = 7; // optional in C#
  map<string, Variant> meta = 8;
}

// ========================= LineItem, Payment, Attachment =========================

message LineItem {
  int32      line_no      = 1;
  LineType   type         = 2;
  string     sku          = 3;
  string     description  = 4;
  double     qty          = 5;
  string     qty_unit     = 6;
  double     unit_price   = 7;
  optional double     vat_rate     = 8;  // optional in C#
  optional double     discount     = 9;  // optional in C#
  map<string, Variant> ext = 10;
}

message Payment {
  PaymentMethod method    = 1;
  double        amount    = 2;
  string        reference = 3;  // optional in C#
  int64         timestamp = 4;  // DateTime
  double        fee       = 5;  // optional in C#
  Currency      currency  = 6;
}

message Attachment {
  string name      = 1;
  string mime_type = 2;
  bytes  data      = 3;
}

// ========================= Top-level BusinessDocument =========================

message BusinessDocument {
  DocumentHeader      header       = 1;
  Party               seller       = 2;
  Party               buyer        = 3;
  repeated LineItem   items        = 4;
  repeated Payment    payments     = 5;
  repeated Attachment attachments  = 6;
  repeated int32      risk_scores  = 7;
}

// ========================= Echo Service Messages =========================
//
// C# signatures:
//
//   byte[] EchoBytes(byte[])
//   BusinessDocument[] EchoDocuments(BusinessDocument[] docs)
//   int[] EchoIntArray(int[] array)
//   string[] EchoStringArray(string[] array)
//   Map<string, BusinessDocument> EchoMap(Map<string, BusinessDocument> map)
//   DocType EchoEnumArray(DocType[] docTypes);

// --- Bytes ---
message BytesRequest {
  bytes data = 1;
}

// --- Bytes ---
message BytesResponse {
  bytes data = 1;
}


// --- Documents ---
message DocumentsRequest {
  repeated BusinessDocument docs = 1;
}

message DocumentsResponse {
  repeated BusinessDocument docs = 1;
}

// --- Int array ---
message IntArrayRequest {
  repeated int32 array = 1;
}

message IntArrayResponse {
  repeated int32 array = 1;
}

// --- String array ---
message StringArrayRequest {
  repeated string array = 1;
}

message StringArrayResponse {
  repeated string array = 1;
}

// --- Map<string, BusinessDocument> ---
message DocMapRequest {
  map<string, BusinessDocument> map = 1;
}

message DocMapResponse {
  map<string, BusinessDocument> map = 1;
}

// --- Enum array (returns a single DocType, e.g. last element) ---
message EnumArrayRequest {
  repeated DocType doc_types = 1;
}

message EnumResponse {
  repeated DocType doc_types = 1;
}

// ========================= Echo Service =========================

service EchoService {
  rpc EchoBytes       (BytesRequest)       returns (BytesResponse);
  rpc EchoDocuments   (DocumentsRequest)   returns (DocumentsResponse);
  rpc EchoIntArray    (IntArrayRequest)    returns (IntArrayResponse);
  rpc EchoStringArray (StringArrayRequest) returns (StringArrayResponse);
  rpc EchoMap         (DocMapRequest)      returns (DocMapResponse);
  rpc EchoEnumArray   (EnumArrayRequest)   returns (EnumResponse);
}