package com.freeletics.feature.notifications

import com.freeletics.flowredux.dsl.ChangeState
import com.freeletics.flowredux.dsl.reduce
import io.kotest.matchers.shouldBe

class FlowReduxInStateTestBuilder<InputState : S, S : Any>(private val state: InputState) {
    fun onEnter(handler: suspend (InputState) -> ChangeState<S>): FlowReduxInStateOnEnterTestBuilder<InputState, S> =
        FlowReduxInStateOnEnterTestBuilder(state = state, onEnter = handler)

    fun <A : Any> onAction(
        action: A,
        handler: suspend (A, InputState) -> ChangeState<S>
    ): FlowReduxInStateOnActionTestBuilder<InputState, S, A> =
        FlowReduxInStateOnActionTestBuilder(state, action, handler)
}

class FlowReduxInStateOnEnterTestBuilder<InputState : S, S : Any>(
    private val state: InputState, private val onEnter: suspend (InputState) -> ChangeState<S>
) {
    suspend fun then(expectedState: S) {
        val newState = onEnter(state).reduce(state)
        newState shouldBe expectedState
    }
}

class FlowReduxInStateOnActionTestBuilder<InputState : S, S, A : Any>(
    private val state: InputState,
    private val action: A,
    private val onAction: suspend (A, InputState) -> ChangeState<S>
) {
    suspend fun then(expectedState: S) {
        val newState = onAction(action, state).reduce(state)
        newState shouldBe expectedState
    }

    suspend fun then(assertionBlock: (S) -> Unit) {
        val newState = onAction(action, state).reduce(state)
        assertionBlock(newState)
    }
}

fun <InputState : S, S : Any> givenState(state: InputState): FlowReduxInStateTestBuilder<InputState, S> =
    FlowReduxInStateTestBuilder(state)