Add database driver and config module

Signed-off-by: Asai Neko <sugar@sne.moe>

config/config.go

@@ -1,5 +1,40 @@
 package config
 
-func Init() {
+import (
+	"log"
 
+	"github.com/spf13/viper"
+)
+
+func Init() {
+	// Read global config
+	viper.SetConfigFile("config.yaml")
+	viper.SetDefault("Server", serverDef)
+	viper.SetDefault("Database", databaseDef)
+	conf := &config{}
+	if err := viper.ReadInConfig(); err != nil {
+		log.Println("Can't read config, trying to modify!")
+		if err := viper.WriteConfig(); err != nil {
+			log.Fatal("[Config] Error writing config: ", err)
+		}
+	}
+	if err := viper.Unmarshal(conf); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func Get(key string) any {
+	viper.SetConfigFile("config.yaml")
+	if err := viper.ReadInConfig(); err != nil {
+		log.Fatal("[Config] Error reading config: ", err)
+	}
+	return viper.Get(key)
+}
+
+func Set(key string, value any) {
+	viper.SetConfigFile("config.yaml")
+	if err := viper.ReadInConfig(); err != nil {
+		log.Fatal("[Config] Error reading config: ", err)
+	}
+	viper.Set(key, value)
 }

config/default.go

@@ -0,0 +1,15 @@
+package config
+
+var serverDef = server{
+	Address:    ":8000",
+	DebugMode:  false,
+	FileLogger: false,
+}
+
+var databaseDef = database{
+	Type:     "postgres",
+	Host:     "",
+	Name:     "",
+	Username: "",
+	Password: "",
+}

config/env.go

@@ -0,0 +1,72 @@
+package config
+
+import (
+	"log"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/joho/godotenv"
+)
+
+func GetEnv(Key string) string {
+	_ = godotenv.Load()
+	return os.Getenv(Key)
+}
+
+func SetEnvConf(ConfKey string, ConfSub string) {
+	var Config = []string{ConfKey, ConfSub}
+	var EnvKey = strings.Join(Config, "_")
+	env := GetEnv(EnvKey)
+	var orig = Get(ConfKey + "." + ConfSub)
+	if env != "" {
+		switch orig.(type) {
+		case string:
+			Set(ConfKey, env)
+		case int:
+			conv, err := strconv.Atoi(env)
+			if err != nil {
+				log.Panic("[Config] Error converting string to int: ", err)
+			}
+			Set(ConfKey, conv)
+		case bool:
+			switch env {
+			case "true":
+				Set(ConfKey, true)
+			case "false":
+				Set(ConfKey, false)
+			}
+		case []string:
+			trim := strings.TrimSpace(env)
+			trim = strings.TrimPrefix(trim, "[")
+			trim = strings.TrimSuffix(trim, "]")
+			var envArray []string
+			for _, v := range strings.Split(trim, ",") {
+				trimSub := strings.TrimPrefix(v, "\"")
+				trimSub = strings.TrimSuffix(trimSub, "\"")
+				envArray = append(envArray, trimSub)
+			}
+			Set(ConfKey, envArray)
+		}
+	}
+}
+
+func EnvInit() {
+	var dict = map[string][]string{
+		"server":   {"address", "debug_mode", "file_logger"},
+		"database": {"type", "host", "name", "username", "password"},
+	}
+	for key, value := range dict {
+		for _, sub := range value {
+			SetEnvConf(key, sub)
+		}
+	}
+}
+
+func TZ() string {
+	tz := GetEnv("TZ")
+	if tz == "" {
+		return "Asia/Shanghai"
+	}
+	return tz
+}

config/types.go

@@ -0,0 +1,20 @@
+package config
+
+type config struct {
+	Server   server   `yaml:"server"`
+	Database database `yaml:"database"`
+}
+
+type server struct {
+	Address    string `yaml:"address"`
+	DebugMode  bool   `yaml:"debug_mode"`
+	FileLogger bool   `yaml:"file_logger"`
+}
+
+type database struct {
+	Type     string `yaml:"type"`
+	Host     string `yaml:"host"`
+	Name     string `yaml:"name"`
+	Username string `yaml:"username"`
+	Password string `yaml:"password"`
+}