package main

import (
	"embed"
	"errors"
	"fmt"
	"os"
	"sync"

	"github.com/pelletier/go-toml/v2"
)

const CONFIG_DIR = "./data"

//go:embed sample_configs/*
var sampleConfig embed.FS

type Config struct {
	Web struct {
		Bind string `toml:"bind"`
		Port int    `toml:"port"`
	} `toml:"web"`
	Jack struct {
		Enabled    bool   `toml:"enabled"`
		ClientName string `toml:"client_name"`
	} `toml:"jack"`
}

var config Config

var shouldSaveConfigsMutex = new(sync.Mutex)
var shouldSaveConfigs = map[string]bool{
	"ports": false,
}

// Copy default config if `{name}.toml` file does not exist
func createDefaultConfig(name string) {
	dest_path := fmt.Sprintf("%s/%s.toml", CONFIG_DIR, name)
	source_path := fmt.Sprintf("sample_configs/%s.toml", name)

	if _, err := os.Stat(CONFIG_DIR); errors.Is(err, os.ErrNotExist) {
		os.MkdirAll(CONFIG_DIR, 0744)
	}
	if _, err := os.Stat(dest_path); errors.Is(err, os.ErrNotExist) {
		content, err := sampleConfig.ReadFile(source_path)
		if err != nil {
			fmt.Printf("Warning! Default config for `%s` does not exist!\n", name)
			return
		}
		os.WriteFile(dest_path, content, 0644)
	}
}

// Load config from `.toml` file into a struct
func loadConfig(name string, dest interface{}) {
	createDefaultConfig(name)

	file, err := os.ReadFile(fmt.Sprintf("%s/%s.toml", CONFIG_DIR, name))
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	err = toml.Unmarshal(file, dest)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
}

// Mark a config file as changed, so it gets saved to disk later
func markConfig(name string) {
	shouldSaveConfigsMutex.Lock()
	shouldSaveConfigs[name] = true
	shouldSaveConfigsMutex.Unlock()
}

// Save struct as a `.toml` file
func saveConfig(name string, dest interface{}) {
	bin, err := toml.Marshal(dest)
	if err != nil {
		fmt.Println(err)
	}
	err = os.WriteFile(fmt.Sprintf("%s/%s.toml", CONFIG_DIR, name), bin, 0644)
	if err != nil {
		fmt.Println(err)
	}
}

func saveConfigIfMarked(name string, dest interface{}) {
	shouldSaveConfigsMutex.Lock()
	if shouldSaveConfigs[name] {
		shouldSaveConfigs[name] = false
		saveConfig(name, dest)
	}
	shouldSaveConfigsMutex.Unlock()
}