Pixelcat-App-Android/app/src/main/kotlin/at/connyduck/pixelcat/components/profile/ProfileViewModel.kt

package at.connyduck.pixelcat.components.profile

import androidx.lifecycle.MutableLiveData
import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import androidx.paging.PagedList
import at.connyduck.pixelcat.components.util.Error
import at.connyduck.pixelcat.components.util.Success
import at.connyduck.pixelcat.components.util.UiState
import at.connyduck.pixelcat.db.AccountManager
import at.connyduck.pixelcat.model.Account
import at.connyduck.pixelcat.model.Relationship
import at.connyduck.pixelcat.model.Status
import at.connyduck.pixelcat.network.FediverseApi
import com.bumptech.glide.util.Executors
import kotlinx.coroutines.launch
import javax.inject.Inject

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

    val profile = MutableLiveData<UiState<Account>>()
    val relationship = MutableLiveData<UiState<Relationship>>()
    val profileImages = MutableLiveData<PagedList<Status>>()

    val isSelf: Boolean
        get() = accountId == null

    private var accountId: String? = null

    fun load(reload: Boolean = false) {
        loadAccount(reload)
        if (!isSelf) {
            loadRelationship(reload)
        }
        loadImages(reload)
    }

    fun setAccountInfo(accountId: String?) {
        this@ProfileViewModel.accountId = accountId
        load(false)
    }

    private fun loadAccount(reload: Boolean = false) {
        if (profile.value == null || reload) {
            viewModelScope.launch {
                fediverseApi.account(getAccountId()).fold(
                    {
                        profile.value = Success(it)
                    },
                    {
                        profile.value = Error(cause = it)
                    }
                )
            }
        }
    }

    private fun loadRelationship(reload: Boolean = false) {
        if (relationship.value == null || reload) {
            viewModelScope.launch {
                fediverseApi.relationships(listOf(getAccountId())).fold(
                    {
                        relationship.value = Success(it.first())
                    },
                    {
                        relationship.value = Error(cause = it)
                    }
                )
            }
        }
    }

    private fun loadImages(reload: Boolean = false) {
        if (profileImages.value == null || reload) {
            profileImages.value = PagedList.Builder(
                ProfileImageDataSource(
                    fediverseApi,
                    accountId,
                    accountManager,
                    viewModelScope
                ),
                20
            ).setNotifyExecutor(Executors.mainThreadExecutor())
                .setFetchExecutor(java.util.concurrent.Executors.newSingleThreadExecutor())
                .build()
        }
    }

    private suspend fun getAccountId(): String {
        return accountId ?: accountManager.activeAccount()?.accountId!!
    }
}