package main

import (
	"fmt"
	"net/http"
	"os"
	"reflect"

	"github.com/gin-gonic/gin"
	"github.com/pelletier/go-toml/v2"
	log "github.com/sirupsen/logrus"
)

var AppConfig Config

func main() {
	if len(os.Args) != 2 {
		AppConfig.Mode = "env"
	} else {
		AppConfig.Mode = "argv"
	}

	err := InitConfig()
	if err != nil {
		log.Fatalf("Failed to init config: %v\n", err)
	}

	r := gin.Default()

	r.LoadHTMLGlob("templates/*")

	r.GET("/", func(c *gin.Context) {
		c.HTML(http.StatusOK, "index.html", gin.H{
			"title":   "Welcome Page",
			"message": "Hello, Gin with HTML templates!",
		})
	})

	r.Run(":8080")
}

func InitConfig() error {
	if AppConfig.Mode == "argv" {
		content, err := os.ReadFile(os.Args[1])
		if err != nil {
			return err
		}

		toml.Unmarshal(content, &AppConfig)

		fmt.Printf("%+v\n", AppConfig)

		return nil
	} else if AppConfig.Mode == "env" {
		f := reflect.ValueOf(AppConfig)

		for i := 0; i < f.NumField(); i++ {
			field := f.Type().Field(i)
			tag := field.Tag
			env_var := tag.Get("env")
			fmt.Printf("Field: %v.\nEnvironment variable: %v.\n", field.Name, env_var)
			if env_var != "" {
				env_value, exists := os.LookupEnv(env_var)
				if !exists {
					return fmt.Errorf("there is no env variable %s", env_var)
				}
				err := setField(&AppConfig, field.Name, env_value)
				if err != nil {
					return fmt.Errorf("failed to set config field %s: %v", field.Name, err)
				}
			}
		}

		return nil
	} else {
		return fmt.Errorf("incorrect config mode")
	}
}