package world.respect.shared.viewmodel.report.list

import androidx.lifecycle.SavedStateHandle
import androidx.lifecycle.viewModelScope
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.asStateFlow
import kotlinx.coroutines.flow.flow
import kotlinx.coroutines.flow.map
import kotlinx.coroutines.flow.update
import kotlinx.coroutines.launch
import kotlinx.datetime.TimeZone
import org.koin.core.component.KoinScopeComponent
import org.koin.core.component.inject
import org.koin.core.scope.Scope
import world.respect.datalayer.DataLoadState
import world.respect.datalayer.DataLoadingState
import world.respect.datalayer.SchoolDataSource
import world.respect.datalayer.school.model.report.ReportOptions
import world.respect.datalayer.school.model.Report
import world.respect.shared.domain.account.RespectAccountManager
import world.respect.shared.domain.report.formatter.CreateGraphFormatterUseCase
import world.respect.shared.domain.report.model.RunReportResultAndFormatters
import world.respect.shared.domain.report.query.RunReportUseCase
import world.respect.shared.generated.resources.Res
import world.respect.shared.generated.resources.select_template
import world.respect.shared.navigation.NavCommand
import world.respect.shared.navigation.ReportEdit
import world.respect.shared.util.ext.asUiText
import world.respect.shared.viewmodel.RespectViewModel
import kotlin.time.Clock
import kotlin.time.ExperimentalTime

data class ReportTemplateListUiState(
    val templates: DataLoadState<List<Report>> = DataLoadingState(),
    val isLoading: Boolean = false,
    val error: String? = null,
    val activeUserPersonUid: Long = 0L,
)

class ReportTemplateListViewModel(
    savedStateHandle: SavedStateHandle,
    private val runReportUseCase: RunReportUseCase,
    private val createGraphFormatterUseCase: CreateGraphFormatterUseCase,
    accountManager: RespectAccountManager
) : RespectViewModel(savedStateHandle), KoinScopeComponent {

    override val scope: Scope = accountManager.requireActiveAccountScope()
    private val _uiState = MutableStateFlow(ReportTemplateListUiState())
    val uiState = _uiState.asStateFlow()
    private val activeUserPersonUid: Long = 0
    private val schoolDataSource: SchoolDataSource by inject()


    init {
        _appUiState.update { prev ->
            prev.copy(
                navigationVisible = true,
                title = Res.string.select_template.asUiText(),
            )
        }

        viewModelScope.launch {
            schoolDataSource.reportDataSource.allReportsAsFlow(template = true).collect {
                _uiState.update { state ->
                    state.copy(templates = it)
                }
            }
        }
    }

    @OptIn(ExperimentalTime::class)
    fun runReport(report: Report): Flow<RunReportResultAndFormatters> {
        if (report.guid == "0") {
            return flow {
                emit(
                    RunReportResultAndFormatters(
                        reportResult = RunReportUseCase.RunReportResult(
                            timestamp = Clock.System.now().toEpochMilliseconds(),
                            request = RunReportUseCase.RunReportRequest(
                                reportUid = 0L,
                                reportOptions = ReportOptions(),
                                accountPersonUid = activeUserPersonUid,
                                timeZone = TimeZone.currentSystemDefault()
                            ),
                            results = emptyList()
                        ),
                        xAxisFormatter = null,
                        yAxisFormatter = null
                    )
                )
            }
        } else {
            val request = RunReportUseCase.RunReportRequest(
                reportUid = report.guid.toLong(),
                reportOptions = report.reportOptions,
                accountPersonUid = activeUserPersonUid,
                timeZone = TimeZone.currentSystemDefault()
            )

            return runReportUseCase(request).map { reportResult ->
                val xAxisFormatter = createGraphFormatterUseCase(
                    reportResult = reportResult,
                    options = CreateGraphFormatterUseCase.FormatterOptions(
                        paramType = String::class,
                        axis = CreateGraphFormatterUseCase.FormatterOptions.Axis.X_AXIS_VALUES
                    )
                )

                val yAxisFormatter = createGraphFormatterUseCase(
                    reportResult = reportResult,
                    options = CreateGraphFormatterUseCase.FormatterOptions(
                        paramType = Double::class,
                        axis = CreateGraphFormatterUseCase.FormatterOptions.Axis.Y_AXIS_VALUES
                    )
                )

                RunReportResultAndFormatters(
                    reportResult = reportResult,
                    xAxisFormatter = xAxisFormatter,
                    yAxisFormatter = yAxisFormatter
                )
            }
        }
    }

    fun onTemplateSelected(template: Report) {
        if (template.guid == "0") { // blank template
            _navCommandFlow.tryEmit(
                NavCommand.Navigate(
                    ReportEdit(null)
                )
            )
        } else {
            _navCommandFlow.tryEmit(
                NavCommand.Navigate(
                    ReportEdit(template.guid)
                )
            )
        }
    }
}