package com.taskttl.data.viewmodel

import androidx.lifecycle.viewModelScope
import com.taskttl.core.viewmodel.BaseViewModel
import com.taskttl.data.local.model.Category
import com.taskttl.data.local.model.CategoryType
import com.taskttl.data.local.model.Countdown
import com.taskttl.data.repository.CategoryRepository
import com.taskttl.data.repository.CountdownRepository
import com.taskttl.data.state.CountdownEffect
import com.taskttl.data.state.CountdownIntent
import com.taskttl.data.state.CountdownState
import kotlinx.coroutines.launch
import org.jetbrains.compose.resources.getString
import taskttl.composeapp.generated.resources.Res
import taskttl.composeapp.generated.resources.countdown_add_failed
import taskttl.composeapp.generated.resources.countdown_add_success
import taskttl.composeapp.generated.resources.countdown_delete_failed
import taskttl.composeapp.generated.resources.countdown_delete_success
import taskttl.composeapp.generated.resources.countdown_load_failed
import taskttl.composeapp.generated.resources.countdown_query_failed
import taskttl.composeapp.generated.resources.countdown_update_failed
import taskttl.composeapp.generated.resources.countdown_update_success

/**
 * 倒计时视图模型
 * @author admin
 * @date 2025/10/04
 * @constructor 创建[CountdownViewModel]
 * @param [countdownRepository] 倒计时存储库
 */
class CountdownViewModel(
    private val countdownRepository: CountdownRepository,
    private val categoryRepository: CategoryRepository,
) : BaseViewModel<CountdownState, CountdownIntent, CountdownEffect>(CountdownState()) {


    init {
        processIntent(CountdownIntent.LoadCountdowns)
    }

    public override fun handleIntent(intent: CountdownIntent) {
        when (intent) {
            is CountdownIntent.LoadCountdowns -> loadCountdowns()
            is CountdownIntent.GetCountdownById -> getCountdownById(intent.countdownId)
            is CountdownIntent.AddCountdown -> addCountdown(intent.countdown)
            is CountdownIntent.UpdateCountdown -> updateCountdown(intent.countdown)
            is CountdownIntent.DeleteCountdown -> deleteCountdown(intent.countdownId)
            is CountdownIntent.FilterByCategory -> filterByCategory(intent.category)
            is CountdownIntent.ClearError -> clearError()
        }
    }

    private fun loadCountdowns() {
        viewModelScope.launch {
            updateState { copy(isLoading = true) }
            try {
                launch {
                    categoryRepository.getCategoriesByType(CategoryType.COUNTDOWN)
                        .collect { categories -> updateState { copy(categories = categories) } }
                }
                launch {
                    countdownRepository.getAllCountdowns().collect { countdowns ->
                        updateState {
                            copy(
                                countdowns = countdowns,
                                filteredCountdowns = filterCountdowns(countdowns)
                            )
                        }
                    }
                }
            } catch (e: Exception) {
                val errStr = getString(Res.string.countdown_load_failed)
                updateState { copy(isLoading = false, error = e.message ?: errStr) }
            } finally {
                updateState { copy(isLoading = false) }
            }
        }
    }


    private fun getCountdownById(countdownId: String) {
        viewModelScope.launch {
            try {
                val countdown = countdownRepository.getCountdownById(countdownId)
                updateState { copy(editingCountdown = countdown) }
            } catch (e: Exception) {
                val errStr = getString(Res.string.countdown_query_failed)
                updateState { copy(isLoading = false, error = e.message ?: errStr) }
            }
        }
    }

    private fun addCountdown(countdown: Countdown) {
        viewModelScope.launch {
            try {
                if (state.value.isProcessing) return@launch
                updateState { copy(isLoading = false, isProcessing = true) }
                countdownRepository.insertCountdown(countdown)
                sendEvent(CountdownEffect.ShowMessage(getString(Res.string.countdown_add_success)))
                sendEvent(CountdownEffect.NavigateBack)
            } catch (e: Exception) {
                val errStr = getString(Res.string.countdown_add_failed)
                updateState { copy(error = e.message ?: errStr) }
            } finally {
                updateState { copy(isLoading = false, isProcessing = false) }
            }
        }
    }

    private fun updateCountdown(countdown: Countdown) {
        viewModelScope.launch {
            try {
                if (state.value.isProcessing) return@launch
                updateState { copy(isLoading = false, isProcessing = true) }
                countdownRepository.updateCountdown(countdown)
                sendEvent(CountdownEffect.ShowMessage(getString(Res.string.countdown_update_success)))
                sendEvent(CountdownEffect.NavigateBack)
            } catch (e: Exception) {
                val errStr = getString(Res.string.countdown_update_failed)
                updateState { copy(error = e.message ?: errStr) }
            } finally {
                updateState { copy(isLoading = false, isProcessing = false) }
            }
        }
    }

    private fun deleteCountdown(countdownId: String) {
        viewModelScope.launch {
            try {
                if (state.value.isProcessing) return@launch
                updateState { copy(isLoading = false, isProcessing = true) }
                countdownRepository.deleteCountdown(countdownId)
                sendEvent(CountdownEffect.ShowMessage(getString(Res.string.countdown_delete_success)))
            } catch (e: Exception) {
                val errStr = getString(Res.string.countdown_delete_failed)
                updateState { copy(error = e.message ?: errStr) }
            } finally {
                updateState { copy(isLoading = false, isProcessing = false) }
            }
        }
    }

    private fun filterByCategory(category: Category?) {
        updateState {
            copy(
                selectedCategory = category,
                filteredCountdowns = filterCountdowns(state.value.countdowns)
            )
        }
    }

    private fun clearError() {
        updateState { copy(error = null) }
    }

    private fun filterCountdowns(countdowns: List<Countdown>): List<Countdown> {
        val currentState = state.value
        return countdowns.filter { countdown ->
            currentState.selectedCategory?.let { countdown.category == it } ?: true
        }
    }
}