package db

import (
	"encoding/json"
	"fmt"
	"io"
	"os"
)

func ExecDB(db_name string) map[string]interface{} {
	var result map[string]interface{}

	if db_name == "users" {
		users_db, err := os.Open("./test_data/users.json")
		if err != nil {
			fmt.Println(err)
			return nil
		}
		fmt.Println("Successfully opened Users DB")
		defer users_db.Close()

		byteValue, _ := io.ReadAll(users_db)
		var users []interface{}
		json.Unmarshal(byteValue, &users)
		result = map[string]interface{}{"users": users}

	} else if db_name == "messages" {
		messages_db, err := os.Open("./test_data/messages.json")
		if err != nil {
			fmt.Println(err)
			return nil
		}
		fmt.Println("Successfully opened Messages DB")
		defer messages_db.Close()

		byteValue, _ := io.ReadAll(messages_db)
		var messages []interface{}
		json.Unmarshal(byteValue, &messages)
		result = map[string]interface{}{"messages": messages}

	} else {
		fmt.Println("Invalid DB name")
		return nil
	}

	return result
}

func WriteDB(db_name string, data interface{}) error {
	var filePath string

	switch db_name {
	case "users":
		filePath = "./test_data/users.json"
	case "messages":
		filePath = "./test_data/messages.json"
	default:
		return fmt.Errorf("invalid database name: %s", db_name)
	}

	jsonData, err := json.MarshalIndent(data, "", "  ")
	if err != nil {
		return fmt.Errorf("error marshaling data to JSON: %v", err)
	}

	err = os.WriteFile(filePath, jsonData, 0644)
	if err != nil {
		return fmt.Errorf("error writing to file: %v", err)
	}

	fmt.Printf("Successfully wrote to %s DB\n", db_name)
	return nil
}

func AddUser(user map[string]interface{}) error {
	currentData := ExecDB("users")
	if currentData == nil {
		return fmt.Errorf("error reading users database")
	}

	users := currentData["users"].([]interface{})
	users = append(users, user)
	return WriteDB("users", users)
}

func AddMessage(message map[string]interface{}) error {
	currentData := ExecDB("messages")
	if currentData == nil {
		return fmt.Errorf("error reading messages database")
	}

	messages := currentData["messages"].([]interface{})
	messages = append(messages, message)
	return WriteDB("messages", messages)
}