package com.kanawish.sample.mvi.model

sealed class TaskEditorState {

    object Closed : TaskEditorState() {
        fun addTask(task: Task) = Editing(task, true)
        fun editTask(task: Task) = Editing(task)
    }

    data class Editing(val task: Task, val adding: Boolean = false) : TaskEditorState() {
        fun edit(block: Task.() -> Task) = copy(task = task.block())
        fun save() = Saving(task)
        fun delete() = Deleting(task.id)
        fun cancel() = Closed
    }

    data class Saving(val task: Task) : TaskEditorState() {
        fun saved() = Closed
    }

    data class Deleting(val taskId: String) : TaskEditorState() {
        fun deleted() = Closed
    }
}

/*
    What would be a full State Machine with error handling?

    @startuml
    [*] --> CLOSED
    CLOSED --> EDITING : addTask()
    CLOSED --> EDITING : editTask()

    EDITING : task
    EDITING : error?
    EDITING --> EDITING : edit()

    EDITING -down-> SAVING : save()
    EDITING -down-> DELETING : delete()
    EDITING -left-> CLOSED : cancel()

    DELETING -up-> CLOSED : deleted()
    DELETING --> EDITING : error(msg)
    DELETING : taskId

    SAVING -up-> CLOSED : saved()
    SAVING --> EDITING : error(msg)
    SAVING : task

    @enduml
 */