Add default config parsing

This is a first step towards configurability.

4 files changed, 64 insertions, 0 deletions

diff --git a/config.go b/config.go
new file mode 100644
index 0000000..38f0af9
--- /dev/null
+++ b/config.go
@@ -0,0 +1,38 @@
+package main
+
+import (
+	_ "embed"
+	"encoding/json"
+	"log"
+)
+
+//go:embed configs/default.json
+var defaultConfig []byte
+
+type StartupConfig struct {
+	MQTT struct {
+		Broker      string `json:"broker"`
+		ClientID    string `json:"client-id"`
+		TopicPrefix string `json:"topic-prefix"`
+	} `json:"mqtt"`
+
+	Homematic struct {
+		CCU                       string `json:"ccu"`
+		PollingPeriodMilliseconds int `json:"polling-period-milliseconds"`
+	} `json:"homematic"`
+}
+
+func (sc *StartupConfig) FromJSON(data []byte) error {
+	return json.Unmarshal(data, sc)
+}
+
+func GetStartupConfig() StartupConfig {
+	config := StartupConfig{}
+
+	err := config.FromJSON(defaultConfig)
+	if err != nil {
+		log.Fatalf("Could not parse default config: %v", err)
+	}
+
+	return config
+}
diff --git a/config_test.go b/config_test.go
new file mode 100644
index 0000000..c568a34
--- /dev/null
+++ b/config_test.go
@@ -0,0 +1,14 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestDefaultConfig(t *testing.T) {
+	config := StartupConfig{}
+
+	err := config.FromJSON(defaultConfig)
+	if err != nil {
+		t.Fatalf("Failed parsing default config from JSON: %v", err)
+	}
+}
diff --git a/configs/default.json b/configs/default.json
new file mode 100644
index 0000000..9d3fb07
--- /dev/null
+++ b/configs/default.json
@@ -0,0 +1,11 @@
+{
+	"mqtt": {
+		"broker": "tcp://127.0.0.1:1883",
+		"client-id": "siaserver",
+		"topic-prefix": "sia"
+	},
+	"homematic": {
+		"ccu": "http://127.0.0.1:8080",
+		"polling-period-milliseconds": 50
+	}
+}
diff --git a/meson.build b/meson.build
index 9861cdf..0917410 100644
--- a/meson.build
+++ b/meson.build
@@ -8,6 +8,7 @@ sia_server = custom_target(
     meson.current_source_dir() / 'cache.go',
     meson.current_source_dir() / 'mqtt.go',
     meson.current_source_dir() / 'homematic.go',
+    meson.current_source_dir() / 'config.go',
   ],
   output : 'sia-server',
   command : [