package com.keylesspalace.tusky.viewmodel

import android.util.Log
import androidx.lifecycle.MutableLiveData
import com.keylesspalace.tusky.appstore.*
import com.keylesspalace.tusky.db.AccountManager
import com.keylesspalace.tusky.entity.Account
import com.keylesspalace.tusky.entity.Field
import com.keylesspalace.tusky.entity.IdentityProof
import com.keylesspalace.tusky.entity.Relationship
import com.keylesspalace.tusky.network.MastodonApi
import com.keylesspalace.tusky.util.*
import io.reactivex.Single
import io.reactivex.disposables.Disposable
import retrofit2.Call
import retrofit2.Callback
import retrofit2.Response
import java.util.concurrent.TimeUnit
import javax.inject.Inject

class AccountViewModel @Inject constructor(
        private val mastodonApi: MastodonApi,
        private val eventHub: EventHub,
        private val accountManager: AccountManager
) : RxAwareViewModel() {

    val accountData = MutableLiveData<Resource<Account>>()
    val relationshipData = MutableLiveData<Resource<Relationship>>()

    val noteSaved = MutableLiveData<Boolean>()

    private val identityProofData = MutableLiveData<List<IdentityProof>>()

    val accountFieldData = combineOptionalLiveData(accountData, identityProofData) { accountRes, identityProofs ->
        identityProofs.orEmpty().map { Either.Left<IdentityProof, Field>(it) }
                .plus(accountRes?.data?.fields.orEmpty().map { Either.Right(it) })
    }

    val isRefreshing = MutableLiveData<Boolean>().apply { value = false }
    private var isDataLoading = false

    lateinit var accountId: String
    var isSelf = false

    private var noteDisposable: Disposable? = null

    init {
        eventHub.events
                .subscribe { event ->
                    if (event is ProfileEditedEvent && event.newProfileData.id == accountData.value?.data?.id) {
                        accountData.postValue(Success(event.newProfileData))
                    }
                }.autoDispose()
    }

    private fun obtainAccount(reload: Boolean = false) {
        if (accountData.value == null || reload) {
            isDataLoading = true
            accountData.postValue(Loading())

            mastodonApi.account(accountId)
                    .subscribe({ account ->
                        accountData.postValue(Success(account))
                        isDataLoading = false
                        isRefreshing.postValue(false)
                    }, {t ->
                        Log.w(TAG, "failed obtaining account", t)
                        accountData.postValue(Error())
                        isDataLoading = false
                        isRefreshing.postValue(false)
                    })
                    .autoDispose()
        }
    }

    private fun obtainRelationship(reload: Boolean = false) {
        if (relationshipData.value == null || reload) {

            relationshipData.postValue(Loading())

            mastodonApi.relationships(listOf(accountId))
                    .subscribe({ relationships ->
                        relationshipData.postValue(Success(relationships[0]))
                    }, { t ->
                        Log.w(TAG, "failed obtaining relationships", t)
                        relationshipData.postValue(Error())
                    })
                    .autoDispose()
        }
    }

    private fun obtainIdentityProof(reload: Boolean = false) {
        if (identityProofData.value == null || reload) {

            mastodonApi.identityProofs(accountId)
                    .subscribe({ proofs ->
                        identityProofData.postValue(proofs)
                    }, { t ->
                        Log.w(TAG, "failed obtaining identity proofs", t)
                    })
                    .autoDispose()
        }
    }

    fun changeFollowState() {
        val relationship = relationshipData.value?.data
        if (relationship?.following == true || relationship?.requested == true) {
            changeRelationship(RelationShipAction.UNFOLLOW)
        } else {
            changeRelationship(RelationShipAction.FOLLOW)
        }
    }

    fun changeBlockState() {
        if (relationshipData.value?.data?.blocking == true) {
            changeRelationship(RelationShipAction.UNBLOCK)
        } else {
            changeRelationship(RelationShipAction.BLOCK)
        }
    }

    fun muteAccount(notifications: Boolean) {
        changeRelationship(RelationShipAction.MUTE, notifications)
    }

    fun unmuteAccount() {
        changeRelationship(RelationShipAction.UNMUTE)
    }
    
    fun changeSubscribingState() {
        val relationship = relationshipData.value?.data
        if(relationship?.notifying == true /* Mastodon 3.3.0rc1 */
            || relationship?.subscribing == true /* Pleroma */ ) {
            changeRelationship(RelationShipAction.UNSUBSCRIBE)
        } else {
            changeRelationship(RelationShipAction.SUBSCRIBE)
        }
    }

    fun blockDomain(instance: String) {
        mastodonApi.blockDomain(instance).enqueue(object: Callback<Any> {
            override fun onResponse(call: Call<Any>, response: Response<Any>) {
                if (response.isSuccessful) {
                    eventHub.dispatch(DomainMuteEvent(instance))
                    val relation = relationshipData.value?.data
                    if(relation != null) {
                        relationshipData.postValue(Success(relation.copy(blockingDomain = true)))
                    }
                } else {
                    Log.e(TAG, "Error muting %s".format(instance))
                }
            }

            override fun onFailure(call: Call<Any>, t: Throwable) {
                Log.e(TAG, "Error muting %s".format(instance), t)
            }
        })
    }

    fun unblockDomain(instance: String) {
        mastodonApi.unblockDomain(instance).enqueue(object: Callback<Any> {
            override fun onResponse(call: Call<Any>, response: Response<Any>) {
                if (response.isSuccessful) {
                    val relation = relationshipData.value?.data
                    if(relation != null) {
                        relationshipData.postValue(Success(relation.copy(blockingDomain = false)))
                    }
                } else {
                    Log.e(TAG, "Error unmuting %s".format(instance))
                }
            }

            override fun onFailure(call: Call<Any>, t: Throwable) {
                Log.e(TAG, "Error unmuting %s".format(instance), t)
            }
        })
    }

    fun changeShowReblogsState() {
        if (relationshipData.value?.data?.showingReblogs == true) {
            changeRelationship(RelationShipAction.FOLLOW, false)
        } else {
            changeRelationship(RelationShipAction.FOLLOW, true)
        }
    }

    /**
     * @param parameter showReblogs if RelationShipAction.FOLLOW, notifications if MUTE
     */
    private fun changeRelationship(relationshipAction: RelationShipAction, parameter: Boolean? = null) {
        val relation = relationshipData.value?.data
        val account = accountData.value?.data
        val isMastodon = relationshipData.value?.data?.notifying != null

        if (relation != null && account != null) {
            // optimistically post new state for faster response

            val newRelation = when (relationshipAction) {
                RelationShipAction.FOLLOW -> {
                    if (account.locked) {
                        relation.copy(requested = true)
                    } else {
                        relation.copy(following = true)
                    }
                }
                RelationShipAction.UNFOLLOW -> relation.copy(following = false)
                RelationShipAction.BLOCK -> relation.copy(blocking = true)
                RelationShipAction.UNBLOCK -> relation.copy(blocking = false)
                RelationShipAction.MUTE -> relation.copy(muting = true)
                RelationShipAction.UNMUTE -> relation.copy(muting = false)
                RelationShipAction.SUBSCRIBE -> {
                    if(isMastodon)
                        relation.copy(notifying = true)
                    else relation.copy(subscribing = true)
                }
                RelationShipAction.UNSUBSCRIBE -> {
                    if(isMastodon)
                        relation.copy(notifying = false)
                    else relation.copy(subscribing = false)
                }
            }
            relationshipData.postValue(Loading(newRelation))
        }

        when (relationshipAction) {
            RelationShipAction.FOLLOW -> mastodonApi.followAccount(accountId, showReblogs = parameter ?: true)
            RelationShipAction.UNFOLLOW -> mastodonApi.unfollowAccount(accountId)
            RelationShipAction.BLOCK -> mastodonApi.blockAccount(accountId)
            RelationShipAction.UNBLOCK -> mastodonApi.unblockAccount(accountId)
            RelationShipAction.MUTE -> mastodonApi.muteAccount(accountId, parameter ?: true)
            RelationShipAction.UNMUTE -> mastodonApi.unmuteAccount(accountId)
            RelationShipAction.SUBSCRIBE -> {
                if(isMastodon)
                    mastodonApi.followAccount(accountId, notify = true)
                else mastodonApi.subscribeAccount(accountId)
            }
            RelationShipAction.UNSUBSCRIBE -> {
                if(isMastodon)
                    mastodonApi.followAccount(accountId, notify = false)
                else mastodonApi.unsubscribeAccount(accountId)
            }
        }.subscribe(
                { relationship ->
                    relationshipData.postValue(Success(relationship))

                    when (relationshipAction) {
                        RelationShipAction.UNFOLLOW -> eventHub.dispatch(UnfollowEvent(accountId))
                        RelationShipAction.BLOCK -> eventHub.dispatch(BlockEvent(accountId))
                        RelationShipAction.MUTE -> eventHub.dispatch(MuteEvent(accountId))
                        else -> {
                        }
                    }
                },
                {
                    relationshipData.postValue(Error(relation))
                }
        )
                .autoDispose()
    }

    fun noteChanged(newNote: String) {
        noteSaved.postValue(false)
        noteDisposable?.dispose()
        noteDisposable = Single.timer(1500, TimeUnit.MILLISECONDS)
                .flatMap {
                    mastodonApi.updateAccountNote(accountId, newNote)
                }
                .doOnSuccess {
                    noteSaved.postValue(true)
                }
                .delay(4, TimeUnit.SECONDS)
                .subscribe({
                    noteSaved.postValue(false)
                }, {
                    Log.e(TAG, "Error updating note", it)
                })
    }

    override fun onCleared() {
        super.onCleared()
        noteDisposable?.dispose()
    }

    fun refresh() {
        reload(true)
    }

    private fun reload(isReload: Boolean = false) {
        if (isDataLoading)
            return
        accountId.let {
            obtainAccount(isReload)
            obtainIdentityProof()
            if (!isSelf)
                obtainRelationship(isReload)
        }
    }

    fun setAccountInfo(accountId: String) {
        this.accountId = accountId
        this.isSelf = accountManager.activeAccount?.accountId == accountId
        reload(false)
    }

    enum class RelationShipAction {
        FOLLOW, UNFOLLOW, BLOCK, UNBLOCK, MUTE, UNMUTE, SUBSCRIBE, UNSUBSCRIBE
    }

    companion object {
        const val TAG = "AccountViewModel"
    }
}