// Package config
// Path: /internal/platform/config
// File: config.go
//
// Purpose
//   Provide a safe one-time initialization and global access point for
//   the application's Config object, once it has been constructed during
//   bootstrap.
//
//   This allows other packages to retrieve configuration without needing
//   dependency injection at every call site, while still preventing
//   accidental mutation after init.
//
// Responsibilities (as implemented here)
//   1) Store a single *Config instance for the lifetime of the process.
//   2) Ensure Init() can only succeed once via sync.Once.
//   3) Expose Get() as a global accessor.
//
// Design notes
//   - Config is written once at startup via Init() inside bootstrap.
//   - Calls to Init() after the first are ignored silently.
//   - Get() may return nil if called before Init() — caller must ensure
//     bootstrap has completed.
//
// TODOs (from current architectural direction)
//   - Evaluate replacing global access with explicit dependency injection
//     in future modules for stronger compile-time guarantees.
//   - Consider panicking or logging if Get() is called before Init().
//   - Move non-static configuration into runtime struct(s) owned by App.
//   - Ensure immutability: avoid mutating Config fields after Init().
//
// Change log
//   [2025-10-28] Documentation aligned with real runtime responsibilities.

package config

import (
	"sync"
)

var (
	appConfig *Config
	once      sync.Once
)

func Init(config *Config) {
	once.Do(func() {
		appConfig = config
	})
}

func Get() *Config {
	return appConfig
}