ariane/app/src/main/java/oppen/ariane/ui/GemViewModel.kt

package oppen.ariane.ui

import android.net.Uri
import androidx.lifecycle.ViewModel
import oppen.ariane.Ariane
import oppen.ariane.io.gemini.Datasource
import oppen.ariane.io.GemState
import oppen.ariane.io.bookmarks.BookmarksDatasource
import java.net.URI

class GemViewModel: ViewModel() {

    private lateinit var gemini: Datasource
    private lateinit var bookmarks: BookmarksDatasource
    private var onState: (state: GemState) -> Unit = {}

    private val history = mutableListOf<URI>()

    fun initialise(home: String, gemini: Datasource, bookmarks: BookmarksDatasource, onState: (state: GemState) -> Unit){
        this.gemini = gemini
        this.bookmarks = bookmarks
        this.onState = onState

        request(home)
    }

    fun request(address: String) {
        request(URI.create(address))
    }

    fun request(uri: URI){
        gemini.request(uri){ state ->
            if(state is GemState.ResponseGemtext) {
                when {
                    history.isEmpty() -> history.add(uri)
                    !history.takeLast(5).contains(uri) -> {
                        println("Adding $uri to runtime history")
                        history.add(uri)
                    }
                }
            }
            onState(state)
        }
    }

    fun requestInlineImage(uri: URI, onImageReady: (cacheUri: Uri?) -> Unit){
        gemini.request(uri){ state ->
            when (state) {
                is GemState.ResponseImage -> onImageReady(state.cacheUri)
                else -> onState(state)
            }
        }
    }

    fun canGoBack(): Boolean = history.size > 1

    @ExperimentalStdlibApi
    fun goBack(){
        when {
            history.size >= 2 -> {
                logHistory()
                val previous = history[history.size - 2]
                history.removeLast()

                println("Requesting history item: $previous")
                request(previous)
                logHistory()
            }
        }
    }

    private fun logHistory(){
        history.forEach { uri ->
            println("History: $uri")
        }
    }
}