Simple multi type config data with autosave

config.go

// Copyright(C) 2025 soursop

// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at <https://mozilla.org/MPL/2.0/>.

// soursop is a WhatsApp bot based on whatsmeow (github.com/tulir/whatsmeow)

package config

import (
	"encoding/json"
	"iter"
	"os"
	"soursop/core/tool/pen"
	"unsafe"

	"github.com/alphadose/haxmap"
	"golang.org/x/exp/constraints"
)

type hashable interface {
	constraints.Integer | constraints.Float | constraints.Complex | ~string | uintptr | ~unsafe.Pointer
}

type ConfigType[K hashable, V any] struct {
	autosave bool
	filename string
	data     *haxmap.Map[K, V]
}

// Usage example :
//
//	key = string
//	value = int // it can be anything
//
// var db = NewConfigType[string, int]("config.json", true)
//
// db.Set("key", true) // for setting a key-value pair
//
// value, ok := db.Get("key") // for getting a value by key
func NewConfigType[K hashable, V any](filename string, autosave bool) *ConfigType[K, V] {
	ct := &ConfigType[K, V]{
		autosave: autosave,
		filename: filename,
		data:     haxmap.New[K, V](),
	}

	ct.Load()

	return ct
}

func (c *ConfigType[K, V]) Save() error {
	f, err := os.OpenFile(c.filename, os.O_RDWR|os.O_CREATE, 0666)
	if err != nil {
		pen.Error(err)
		return err
	}
	defer f.Close()
	je := json.NewEncoder(f)
	je.SetIndent("", "  ")
	return je.Encode(c.data)
}

func (c *ConfigType[K, V]) Load() error {
	f, err := os.Open(c.filename)
	if err != nil {
		return err
	}
	defer f.Close()
	jd := json.NewDecoder(f)
	var data map[K]V
	err = jd.Decode(&data)
	if err != nil {
		return err
	}
	c.data = haxmap.New[K, V]()
	for k, v := range data {
		c.data.Set(k, v)
	}
	return nil
}

func (c *ConfigType[K, V]) Set(key K, value V) {
	c.data.Set(key, value)
	if c.autosave {
		err := c.Save()
		if err != nil {
			panic(err)
		}
	}
}

func (c *ConfigType[K, V]) Get(key K) (V, bool) {
	return c.data.Get(key)
}

func (c *ConfigType[K, V]) Del(key K) {
	c.data.Del(key)
	if c.autosave {
		c.Save()
	}
}

func (c *ConfigType[K, V]) Keys() iter.Seq[K] {
	return c.data.Keys()
}

func (c *ConfigType[K, V]) Clear() {
	c.data.Clear()
}

func (c *ConfigType[K, V]) Len() int {
	return int(c.data.Len())
}