all: add function to load ClientOptions from file

The LoadClientOptions load the ClientOptions from configuration file.
The file configuration is using INI, for example

  [duitku]
  server_url = https://sandbox.duitku.com
  disburse_user_id = 3551
  disburse_email = test@chakratechnology.com
  disburse_api_key = de5...

4 files changed, 48 insertions, 19 deletions

diff --git a/.gitignore b/.gitignore
index 9d97b82..21b0a79 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 ## SPDX-FileCopyrightText: 2022 M. Shulhan <ms@kilabit.info>
 ## SPDX-License-Identifier: GPL-3.0-or-later
 *.json
-cover.html
-cover.out
+/client.conf
+/cover.html
+/cover.out
diff --git a/client.conf.example b/client.conf.example
new file mode 100644
index 0000000..8f6141f
--- /dev/null
+++ b/client.conf.example
@@ -0,0 +1,5 @@
+[duitku]
+server_url = https://sandbox.duitku.com
+disburse_user_id = 3551
+disburse_email = test@chakratechnology.com
+disburse_api_key = de56f832487bc1ce1de5ff2cfacf8d9486c61da69df6fd61d5537b6b7d6d354d
diff --git a/client_options.go b/client_options.go
index 293b7c3..d4d6500 100644
--- a/client_options.go
+++ b/client_options.go
@@ -6,11 +6,14 @@ package duitku
 import (
 	"fmt"
 	"net/url"
+	"os"
+
+	"github.com/shuLhan/share/lib/ini"
 )
 
 // ClientOptions configuration for HTTP client.
 type ClientOptions struct {
-	ServerUrl string
+	ServerUrl string `ini:"duitku::server_url"`
 
 	// The hostname extracted from ServerUrl.
 	host string
@@ -23,23 +26,44 @@ type ClientOptions struct {
 	// [merchant portal].
 	//
 	// [merchant portal]: https://passport.duitku.com/merchant/Project
-	MerchantCode string
+	MerchantCode string `ini:"duitku::merchant_code"`
 
 	// MerchantApiKey The API key for signing merchant related request.
-	MerchantApiKey string
+	MerchantApiKey string `ini:"duitku::merchant_api_key"`
 
 	// Merchant code and API key for payment through Indomaret.
-	IndomaretMerchantCode string
-	IndomaretApiKey       string
+	IndomaretMerchantCode string `ini:"duitku::indomaret_merchant_code"`
+	IndomaretApiKey       string `ini:"duitku::indomaret_api_key"`
 
 	// DisburseApiKey API key for signing disbursement request.
-	DisburseApiKey string
+	DisburseApiKey string `ini:"duitku::disburse_api_key"`
 
 	// DisburseEmail The email registered for disbursement in Duitku.
-	DisburseEmail string
+	DisburseEmail string `ini:"duitku::disburse_email"`
 
 	// DisburseUserID user ID for disbursement request.
-	DisburseUserID int64
+	DisburseUserID int64 `ini:"duitku::disburse_user_id"`
+}
+
+// LoadClientOptions load ClientOptions from file.
+// See the client.conf.example for an example for client configuration.
+func LoadClientOptions(file string) (opts *ClientOptions, err error) {
+	var (
+		logp    = `LoadClientOptions`
+		content []byte
+	)
+	content, err = os.ReadFile(file)
+	if err != nil {
+		return nil, fmt.Errorf(`%s: %w`, logp, err)
+	}
+
+	opts = &ClientOptions{}
+	err = ini.Unmarshal(content, opts)
+	if err != nil {
+		return nil, fmt.Errorf(`%s: %w`, logp, err)
+	}
+
+	return opts, nil
 }
 
 // validate each field values.
diff --git a/duitku_test.go b/duitku_test.go
index 37d1ba6..9f158c5 100644
--- a/duitku_test.go
+++ b/duitku_test.go
@@ -15,17 +15,16 @@ var (
 
 func TestMain(m *testing.M) {
 	var (
-		clOpts = ClientOptions{
-			ServerUrl:      ServerUrlSandbox,
-			DisburseUserID: 3551,
-			DisburseEmail:  `test@chakratechnology.com`,
-			DisburseApiKey: `de56f832487bc1ce1de5ff2cfacf8d9486c61da69df6fd61d5537b6b7d6d354d`,
-		}
-
-		err error
+		opts *ClientOptions
+		err  error
 	)
 
-	testClient, err = NewClient(clOpts)
+	opts, err = LoadClientOptions(`client.conf.example`)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	testClient, err = NewClient(*opts)
 	if err != nil {
 		log.Fatal(err)
 	}