package io.oxygenhub.android.ui.issues

import androidx.lifecycle.ViewModel

import io.oxygenhub.android.api.HubApi

import io.oxygenhub.android.api.Issue

import io.oxygenhub.android.api.IssueState

import io.oxygenhub.android.ui.common.Load

import io.oxygenhub.android.ui.common.load

import kotlinx.coroutines.Job

import kotlinx.coroutines.flow.MutableStateFlow

import kotlinx.coroutines.flow.StateFlow

import kotlinx.coroutines.flow.asStateFlow

/** A repository's issues, open, closed or all; pinned ones first. */

class IssuesViewModel(

    private val api: HubApi,

    val owner: String,

    val name: String,

) : ViewModel() {

    private val _state = MutableStateFlow<Load<List<Issue>>>(Load.Loading)

    val state: StateFlow<Load<List<Issue>>> = _state.asStateFlow()

    private val _filter = MutableStateFlow(IssueState.Open)

    val filter: StateFlow<IssueState> = _filter.asStateFlow()

    private var job: Job? = null

    init {

        refresh()

    }

    fun setFilter(state: IssueState) {

        if (state == _filter.value) return

        _filter.value = state

        // Another list: show the spinner rather than the last filter's issues.

        _state.value = Load.Loading

        refresh()

    }

    fun refresh() {

        val state = _filter.value

        job = load(_state, job) { order(api.issues(owner, name, state)) }

    }

    companion object {

        /** Pinned first, then newest first, as the hub's issue page lists them. */

        fun order(issues: List<Issue>): List<Issue> =

            issues.sortedWith(compareByDescending<Issue> { it.pinned }.thenByDescending { it.number })

    }

}