package config

import (
	"fmt"
	"os"

	"go.yaml.in/yaml/v3"
)

type Config struct {
	BotToken                   *string `yaml:"bot_token"`
	AdminChatId                *int64  `yaml:"admin_chat_id"`
	AdminChatTopicId           *int    `yaml:"admin_chat_topic_id"`
	TargetChatId               *int64  `yaml:"target_chat_id"`
	EntryMessage               string  `yaml:"entry_message"`
	ApprovalMessage            string  `yaml:"approval_message"`
	SendApprovalMessage        bool    `yaml:"send_approval_message"`
	DeleteRequestAfterDecision bool    `yaml:"delete_request_after_decision"`
}

func (c *Config) LoadConfig() error {
	f, err := os.Open("config.yaml")
	if err != nil {
		c.CreateConfig()
		return fmt.Errorf("config.yaml not found, a new one has been created. Please fill it out and restart the bot")
	}
	defer f.Close()

	decoder := yaml.NewDecoder(f)
	err = decoder.Decode(c)
	return err
}

func (c *Config) CreateConfig() error {
	f, err := os.Create("config.yaml")
	if err != nil {
		return err
	}
	defer f.Close()

	defaultConfig := Config{
		BotToken:                   StringPtr("YOUR_BOT_TOKEN_HERE"),
		AdminChatId:                Int64Ptr(0),
		AdminChatTopicId:           IntPtr(0),
		TargetChatId:               Int64Ptr(0),
		EntryMessage:               "You have requested to join the group, please write a brief message explaining why you want to join.",
		ApprovalMessage:            "",
		SendApprovalMessage:        false,
		DeleteRequestAfterDecision: false,
	}

	encoder := yaml.NewEncoder(f)
	err = encoder.Encode(defaultConfig)
	return err
}

// SaveConfig writes the current Config back to config.yaml, overwriting the file.
func (c *Config) SaveConfig() error {
	f, err := os.OpenFile("config.yaml", os.O_WRONLY|os.O_TRUNC, 0644)
	if err != nil {
		return err
	}
	defer f.Close()

	encoder := yaml.NewEncoder(f)
	err = encoder.Encode(c)
	return err
}

// StringPtr returns a pointer to the given string.
func StringPtr(s string) *string { return &s }

// Int64Ptr returns a pointer to the given int64.
func Int64Ptr(i int64) *int64 { return &i }

// IntPtr returns a pointer to the given int.
func IntPtr(i int) *int { return &i }