package at.connyduck.pixelcat.components.timeline

import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import androidx.paging.ExperimentalPagingApi
import androidx.paging.Pager
import androidx.paging.PagingConfig
import androidx.paging.cachedIn
import at.connyduck.pixelcat.db.AccountManager
import at.connyduck.pixelcat.db.AppDatabase
import at.connyduck.pixelcat.db.entitity.StatusEntity
import at.connyduck.pixelcat.db.entitity.toEntity
import at.connyduck.pixelcat.model.Status
import at.connyduck.pixelcat.network.FediverseApi
import at.connyduck.pixelcat.network.calladapter.NetworkResponse
import kotlinx.coroutines.FlowPreview
import kotlinx.coroutines.flow.asFlow
import kotlinx.coroutines.flow.flatMapConcat
import kotlinx.coroutines.launch
import javax.inject.Inject

class TimelineViewModel @Inject constructor(
    private val accountManager: AccountManager,
    private val db: AppDatabase,
    private val fediverseApi: FediverseApi
) : ViewModel() {

    @OptIn(FlowPreview::class)
    @ExperimentalPagingApi
    val statusFlow = accountManager::activeAccount.asFlow()
        .flatMapConcat { activeAccount ->
            Pager(
                config = PagingConfig(pageSize = 10, enablePlaceholders = false),
                remoteMediator = TimelineRemoteMediator(activeAccount?.id!!, fediverseApi, db),
                pagingSourceFactory = { db.statusDao().statuses(activeAccount.id) }
            ).flow
        }
        .cachedIn(viewModelScope)

    fun onFavorite(status: StatusEntity) {
        viewModelScope.launch {
            val alreadyFavourited = status.favourited
            if (alreadyFavourited) {
                fediverseApi.unfavouriteStatus(status.actionableId)
            } else {
                fediverseApi.favouriteStatus(status.actionableId)
            }.updateStatusInDb()
        }
    }

    fun onBoost(status: StatusEntity) {
        viewModelScope.launch {
            val alreadyBoosted = status.reblogged
            if (alreadyBoosted) {
                fediverseApi.unreblogStatus(status.actionableId)
            } else {
                fediverseApi.reblogStatus(status.actionableId)
            }.updateStatusInDb()
        }
    }

    fun onMediaVisibilityChanged(status: StatusEntity) {
        viewModelScope.launch {
            db.statusDao().changeMediaVisibility(
                !status.mediaVisible,
                status.id,
                accountManager.activeAccount()?.id!!
            )
        }
    }

    private suspend fun NetworkResponse<Status>.updateStatusInDb() {
        fold<Any?>(
            { updatedStatus ->
                val accountId = accountManager.activeAccount()?.id!!
                val updatedStatusEntity = updatedStatus.toEntity(accountId)
                db.statusDao().insertOrReplace(updatedStatusEntity)
            },
            {
                // Todo
            }
        )
    }
}