import { computed, ref } from 'vue';
import { defineStore } from 'pinia';
import { unwrapAndClone } from 'src/utils/unwrap-and-clone';
import { timesheetApprovalService } from 'src/modules/timesheet-approval/services/timesheet-approval-service';
import { timesheetService } from 'src/modules/timesheets/services/timesheet-service';
import type { PayPeriodOverviewResponse, TimesheetApprovalOverview } from "src/modules/timesheet-approval/models/timesheet-overview.models";
import type { PayPeriod } from 'src/modules/shared/models/pay-period.models';
import type { Timesheet } from 'src/modules/timesheets/models/timesheet.models';
import type { PayPeriodEvent } from 'src/modules/timesheet-approval/models/pay-period-event.models';
import type { TimesheetApprovalCSVReportFilters } from 'src/modules/timesheet-approval/models/timesheet-approval-csv-report.models';
import { type FederalHoliday, TARGO_HOLIDAY_NAMES_FR } from 'src/modules/timesheets/models/federal-holidays.models';
import { Notify } from 'quasar';
import { useI18n } from 'vue-i18n';


export const useTimesheetStore = defineStore('timesheet', () => {
    const { t } = useI18n();
    const is_loading = ref<boolean>(false);
    const pay_period = ref<PayPeriod>();
    const timesheets = ref<Timesheet[]>([]);
    const all_current_shifts = computed(() => timesheets.value.flatMap(week => week.days.flatMap(day => day.shifts)) ?? []);
    const initial_timesheets = ref<Timesheet[]>([]);

    const pay_period_overviews = ref<TimesheetApprovalOverview[]>([]);
    const pay_period_infos = ref<PayPeriodOverviewResponse>();
    const is_report_dialog_open = ref(false);

    const is_details_dialog_open = ref(false);
    const selected_employee_name = ref<string>();
    const has_timesheet_preset = ref(false);
    const current_pay_period_overview = ref<TimesheetApprovalOverview>();
    const pay_period_report = ref();
    const pay_period_observer = ref<EventSource | undefined>();

    const federal_holidays = ref<FederalHoliday[]>([]);

    const getCurrentFederalHolidays = async (): Promise<boolean> => {
        const all_federal_holidays = await timesheetService.getAllFederalHolidays();
        const all_federal_holidays_2025 = await timesheetService.getAllFederalHolidays(2025);
        if (!all_federal_holidays || !all_federal_holidays_2025) return false;

        federal_holidays.value = all_federal_holidays.filter(holiday => TARGO_HOLIDAY_NAMES_FR.includes(holiday.nameFr));
        const targo_fed_holidays_2025 = all_federal_holidays_2025.filter(holiday => TARGO_HOLIDAY_NAMES_FR.includes(holiday.nameFr));
        targo_fed_holidays_2025.forEach(holiday => federal_holidays.value.push(holiday));

        return true;
    };

    const getNextOrPreviousPayPeriod = (direction: number) => {
        if (!pay_period.value) return;

        pay_period.value.pay_period_no += direction;

        if (pay_period.value.pay_period_no > 26) {
            pay_period.value.pay_period_no = 1;
            pay_period.value.pay_year += direction;
        }

        if (pay_period.value.pay_period_no < 1) {
            pay_period.value.pay_period_no = 26;
            pay_period.value.pay_year += direction;
        }
    };

    const getPayPeriodByDateOrYearAndNumber = async (date?: string): Promise<boolean> => {
        try {
            if (date !== undefined) {
                pay_period.value = await timesheetService.getPayPeriodByDate(date);
            } else if (pay_period.value !== undefined) {
                pay_period.value = await timesheetService.getPayPeriodByYearAndPeriodNumber(pay_period.value.pay_year, pay_period.value.pay_period_no);
            } else return false;

            return true;
        } catch (error) {
            console.error('Could not get current pay period: ', error);
            pay_period.value = undefined;
            pay_period_overviews.value = [];
            //TODO: More in-depth error-handling here

            return false;
        }
    };

    const getTimesheetOverviews = async (): Promise<boolean> => {
        is_loading.value = true;

        try {
            if (pay_period.value === undefined) {
                is_loading.value = false;
                return false;
            }

            const response = await timesheetApprovalService.getPayPeriodOverviews(pay_period.value.pay_year, pay_period.value.pay_period_no);
            pay_period_overviews.value = response.employees_overview;
            is_loading.value = false;

            return true;
        } catch (error) {
            console.error('There was an error retrieving Employee Pay Period overviews: ', error);
            pay_period_overviews.value = [];
            // TODO: More in-depth error-handling here
            is_loading.value = false;

            return false;
        }
    };

    const getTimesheetsByOptionalEmployeeEmail = async (employee_email?: string): Promise<boolean> => {
        if (pay_period.value === undefined) return false;
        is_loading.value = true;
        let response;

        try {
            if (employee_email) {
                response = await timesheetService.getTimesheetsByPayPeriodAndOptionalEmail(pay_period.value.pay_year, pay_period.value.pay_period_no, employee_email);
            } else {
                response = await timesheetService.getTimesheetsByPayPeriodAndOptionalEmail(pay_period.value.pay_year, pay_period.value.pay_period_no);
            }

            if (response.success && response.data) {
                has_timesheet_preset.value = response.data.has_preset_schedule;
                selected_employee_name.value = response.data.employee_fullname;
                timesheets.value = response.data.timesheets;
                initial_timesheets.value = unwrapAndClone(timesheets.value);
            } else {
                selected_employee_name.value = '';
                timesheets.value = [];
                initial_timesheets.value = [];
            }

            is_loading.value = false;
            return response.success;
        } catch (error) {
            console.error('There was an error retrieving timesheet details for this employee: ', error);
            // TODO: More in-depth error-handling here
            timesheets.value = [];
            is_loading.value = false;
            return false;
        }
    };

    const toggleTimesheetsApprovalByEmployeeEmail = async (email: string, approval_status: boolean): Promise<boolean> => {
        try {
            const timesheet_ids = timesheets.value.map(timesheet => timesheet.timesheet_id);

            // Backend returns the amount of shifts and expenses successfully updated, could be useful for error handling???
            // const shift_expense_count = timesheets.value.reduce((timesheets_sum, timesheet) => {
            //     return timesheets_sum + timesheet.days.reduce((day_sum, day) => {
            //         return day_sum + day.shifts.length + day.expenses.length
            //     }, 0);
            // }, 0);

            const response = await timesheetApprovalService.updateTimesheetsApprovalStatus(email, timesheet_ids, approval_status);
            return response.success;
        } catch (error) {
            console.error("couldn't approve timesheets for employee: ", error);
        }

        return false;
    };

    const getPayPeriodReport = async (report_filters: TimesheetApprovalCSVReportFilters) => {
        try {
            if (!pay_period.value) return false;
            const response = await timesheetApprovalService.getPayPeriodReportByYearAndPeriodNumber(pay_period.value.pay_year, pay_period.value.pay_period_no, report_filters);
            pay_period_report.value = response;
            return response.data;
        } catch (error) {
            console.error('There was an error retrieving the report CSV: ', error);
            // TODO: More in-depth error-handling here
        }

        return false;
    };

    const openReportDialog = () => {
        is_report_dialog_open.value = true;
        is_loading.value = true;


        is_loading.value = false;
    };

    const closeReportDialog = () => {
        is_report_dialog_open.value = false;
    };

    const subscribeToPayPeriodObservable = () => {
        if (pay_period_observer.value === undefined) {
            pay_period_observer.value = timesheetApprovalService.subscribeToPayPeriodObservable();
            pay_period_observer.value.onmessage = async (event: MessageEvent<string>) => {
                // find employee that modified their timesheets
                const pay_period_event: PayPeriodEvent = JSON.parse(event.data);
                const overview = pay_period_overviews.value.find(overview => overview.email === pay_period_event.employee_email);
                const employee_name = overview?.employee_first_name + ' ' + overview?.employee_last_name;

                // update overviews
                await getTimesheetOverviews();

                // if user is looking at details of employee that generated event, update
                if (selected_employee_name.value === employee_name)
                    await getTimesheetsByOptionalEmployeeEmail(pay_period_event.employee_email);

                // create visual feedback of notification and update
                Notify.create({
                    message: `${employee_name} ${t('timesheet_approvals.event.' + pay_period_event.action)} ${t('timesheet_approvals.event.' + pay_period_event.event_type)}`,
                    color: 'warning',
                    textColor: 'primary',
                    classes: 'text-weight-bolder',
                    caption: t('timesheet_approvals.event.update_notification'),
                })
            }
        }
    }

    const unsubscribeToPayPeriodObservable = () => {
        if (pay_period_observer.value) {
            pay_period_observer.value.close();
            pay_period_observer.value = undefined;
        }
    }

    return {
        is_loading,
        is_report_dialog_open,
        is_details_dialog_open,
        pay_period,
        pay_period_overviews,
        current_pay_period_overview,
        pay_period_infos,
        selected_employee_name,
        has_timesheet_preset,
        timesheets,
        all_current_shifts,
        initial_timesheets,
        federal_holidays,
        getCurrentFederalHolidays,
        getNextOrPreviousPayPeriod,
        getPayPeriodByDateOrYearAndNumber,
        getTimesheetOverviews,
        getTimesheetsByOptionalEmployeeEmail,
        toggleTimesheetsApprovalByEmployeeEmail,
        getPayPeriodReport,
        openReportDialog,
        closeReportDialog,
        subscribeToPayPeriodObservable,
        unsubscribeToPayPeriodObservable,
    };
});