amethyst/app/src/main/java/com/vitorpamplona/amethyst/model/Note.kt

package com.vitorpamplona.amethyst.model

import androidx.lifecycle.LiveData
import com.vitorpamplona.amethyst.service.NostrSingleEventDataSource
import com.vitorpamplona.amethyst.ui.note.toDisplayHex
import fr.acinq.secp256k1.Hex
import java.util.Collections
import nostr.postr.events.Event

class Note(val idHex: String) {
    val id = Hex.decode(idHex)
    val idDisplayHex = id.toDisplayHex()

    var event: Event? = null
    var author: User? = null
    var mentions: List<User>? = null
    var replyTo: MutableList<Note>? = null

    val replies = Collections.synchronizedSet(mutableSetOf<Note>())
    val reactions = Collections.synchronizedSet(mutableSetOf<Note>())
    val boosts = Collections.synchronizedSet(mutableSetOf<Note>())

    fun loadEvent(event: Event, author: User, mentions: List<User>, replyTo: MutableList<Note>) {
        this.event = event
        this.author = author
        this.mentions = mentions
        this.replyTo = replyTo

        refreshObservers()
    }

    fun addReply(note: Note) {
        if (replies.add(note))
            refreshObservers()
    }

    fun addBoost(note: Note) {
        if (boosts.add(note))
            refreshObservers()
    }

    fun addReaction(note: Note) {
        if (reactions.add(note))
            refreshObservers()
    }

    fun isReactedBy(user: User): Boolean {
        return reactions.any { it.author == user }
    }

    fun isBoostedBy(user: User): Boolean {
        return boosts.any { it.author == user }
    }

    // Observers line up here.
    val live: NoteLiveData = NoteLiveData(this)

    private fun refreshObservers() {
        live.refresh()
    }
}

class NoteLiveData(val note: Note): LiveData<NoteState>(NoteState(note)) {
    fun refresh() {
        postValue(NoteState(note))
    }

    override fun onActive() {
        super.onActive()
        NostrSingleEventDataSource.add(note.idHex)
    }

    override fun onInactive() {
        super.onInactive()
        NostrSingleEventDataSource.remove(note.idHex)
    }
}

class NoteState(val note: Note)