Kotlin DI Scratch

DIExample.kt

package com.luiztm.ui.dependency

import kotlin.reflect.KClass

//interface Analytics
interface Analytics {
    fun doSomething(): String
}

fun Map<String, () -> Any>.injectAnalytics(): Lazy<Analytics> = lazy {
    this[Analytics::class.java.name]?.invoke() as Analytics
}

fun ((KClass<*>) -> Any).injectAnalytics(): Lazy<Analytics> = lazy {
    this.invoke(Analytics::class) as Analytics
}
//

//interface Cache
interface Cache {
    fun doSomething(): String
}

fun Map<String, () -> Any>.injectCache(): Lazy<Cache> = lazy {
    this[Cache::class.java.name]?.invoke() as Cache
}

fun ((KClass<*>) -> Any).injectCache(): Lazy<Cache> = lazy {
    this.invoke(Cache::class) as Cache
}
//

//Main Application
typealias FactoryType = () -> Any
typealias FactoryType2 = (KClass<*>) -> Any

interface Factory : Map<String, FactoryType>
interface Factory2 : FactoryType2


class FactoryImpl(
    items: Map<String, FactoryType> =
        mapOf(
            Analytics::class.java.name to {
                object : Analytics {
                    override fun doSomething() = "Hello Analytics"
                }
            },
            Cache::class.java.name to {
                object : Cache {
                    override fun doSomething() = "Hello Cache"
                }
            },
        )
) : Factory, Map<String, FactoryType> by items


class FactoryImpl2 : Factory2 {
    override fun invoke(kClass: KClass<*>): Any {
        return when (kClass) {
            Analytics::class -> object : Analytics {
                override fun doSomething() = "Hello Analytics 2"
            }

            Cache::class -> object : Cache {
                override fun doSomething() = "Hello Cache 2"
            }

            else -> throw IllegalArgumentException("some message error here!")
        }
    }
}


object Application :
    Factory by FactoryImpl(),
    Factory2 by FactoryImpl2()

// Main Application


// inside feature module
class Feature {
    private val context = Application as Map<String, FactoryType>
    private val context2 = Application as as ((KClass<*>) -> Any)

    val cache: Cache by context.injectCache()

    val analytics: Analytics by context.injectAnalytics()


    val analytics2: Analytics by context2.injectAnalytics()

    val cache2: Cache by context2.injectCache()
}

fun main() {
    val feat = Feature()
    println(feat.cache.doSomething())
    println(feat.analytics.doSomething())

    println(feat.cache2.doSomething())
    println(feat.analytics2.doSomething())
}

// inside feature module