import { useState } from 'react';
import { Item, ItemGroup } from "../../../../components/ui/item-group";
import { useNavigate } from 'react-router-dom';
import { Icon } from "../../../../components/ui/icon";
import { Flex, FlexItem, FlexBlock } from '../../../../components/ui/flex';
import { Text } from '../../../../components/ui/text';
import { Spacer } from '../../../../components/ui/spacer';
// `calendar` and `check` still feed WordPress icon components on each row - a separate sweep.
import { Pencil, Plus, Calendar as calendar, Check as check } from 'lucide-react';
import { ImmunizationRecommendation, ImmunizationRecommendationRecommendation } from 'fhir/r4';
import { AppSpinner, FhirImmunizationRecommendationDisplay, ScrollableTab } from '../../../../components';
import { ResourceListStatus } from '../../../../components/ui/resource-list-status';
import { formatFhirCodeableConcept } from '../../../../utils/fhirCodeableConcept.tsx';
import { formatDate } from '../../../../utils/dateUtils.ts';
import {
    useFhirImmunizationRecommendationBroadcast,
    useFhirImmunizationRecommendations,
    useFhirImmunizationRecommendationTargetedBroadcast
} from '../../../../hooks';
import { useAuthServiceContext, useImmunizationRecommendationServiceContext } from '../../../../services';
import { mayEditRecord } from '../../../../utils/recordEditability';
import { useSeatStanding } from '../../../../utils/seatStanding';
import '../medicationRecords.css';
import { SourcePractice } from '../../../../components/ui/source-practice';
import { RecordPracticeNote, recordPracticeId, useRecordPracticeView, useRetireOnPracticeChange } from '../../../../contexts/RecordPracticeContext';

const ImmunizationRecommendations = () => {
    const navigate = useNavigate();
    const { userRole, USER_ROLES, practitionerRoles } = useAuthServiceContext();
    const seatStanding = useSeatStanding();
    const { getImmunizationRecommendationDisplay } = useImmunizationRecommendationServiceContext();
    const { loading, error, clearError, immunizationRecommendationsList, attempted } = useFhirImmunizationRecommendations();
    const [selectedImmunizationRecommendation, setSelectedImmunizationRecommendation] = useState<ImmunizationRecommendation | null>(null);
    const [showDisplayModal, setShowDisplayModal] = useState<boolean>(false);
    // The record's practice context: its own recommendations under a named practice; the empty state speaks for the whole record.
    const practiceView = useRecordPracticeView(immunizationRecommendationsList, recordPracticeId);
    useRetireOnPracticeChange(() => { setShowDisplayModal(false); setSelectedImmunizationRecommendation(null); });

    useFhirImmunizationRecommendationBroadcast();
    useFhirImmunizationRecommendationTargetedBroadcast({
        immunizationRecommendation: selectedImmunizationRecommendation || undefined,
        isOpen: showDisplayModal,
        onUpdate: (updatedImmunizationRecommendation) => {
            setSelectedImmunizationRecommendation(updatedImmunizationRecommendation);
        },
        onDelete: () => {
            setShowDisplayModal(false);
            setSelectedImmunizationRecommendation(null);
        }
    });

    const viewImmunizationRecommendation = (immunizationRecommendation: ImmunizationRecommendation) => {
        setSelectedImmunizationRecommendation(immunizationRecommendation);
        setShowDisplayModal(true);
    };

    const editImmunizationRecommendation = (event: React.MouseEvent, immunizationRecommendation: ImmunizationRecommendation) => {
        event.stopPropagation();
        navigate(immunizationRecommendation.id as string, { relative: 'path' });
    };

    const addImmunizationRecommendation = () => {
        navigate('new', { relative: 'path' });
    };

    const roleAllowsEdit = () => {
        return userRole && [USER_ROLES.PRACTITIONER].includes(userRole as string);
    };

    /*
     * AND THE ROLE IS NOT THE RULE THE SERVER APPLIES.
     *
     * Writing a ImmunizationRecommendation needs a paid clinician seat, resolved per request by `callerMayWrite`. The role
     * check above passes for an unseated practitioner - a medical assistant, a nurse rooming patients,
     * somebody whose seat was turned off this morning - so the page offered Add and Edit, and the save
     * came back refused. A refusal that arrives after the typing has already spent the work.
     */
    const seat = mayEditRecord({ seatStanding,
        resourceType: 'ImmunizationRecommendation',
        viewerIsStaff: Boolean(userRole)
            && ![USER_ROLES.PATIENT, USER_ROLES.RELATED_PERSON].includes(userRole as string),
        practitionerRoles,
    });

    const isAuthorizedToEdit = () => roleAllowsEdit() && seat.mayEdit;

    const getForecastStatusDisplay = (recommendation: ImmunizationRecommendationRecommendation): { text: string, color?: string } => {
        if (!recommendation || !recommendation.forecastStatus) return { text: '' };

        const status = formatFhirCodeableConcept(recommendation.forecastStatus);

        if (status.toLowerCase().includes('due')) {
            return { text: status, color: '#e39700' };
        } else if (status.toLowerCase().includes('overdue')) {
            return { text: status, color: '#cc1818' };
        } else if (status.toLowerCase().includes('complete')) {
            return { text: status, color: '#00a32a' };
        } else {
            return { text: status };
        }
    };

    const getNextDoseDate = (recommendation: ImmunizationRecommendationRecommendation): string => {
        if (!recommendation || !recommendation.dateCriterion || recommendation.dateCriterion.length === 0) {
            return '';
        }

        const dueDateCriterion = recommendation.dateCriterion.find(criterion =>
            criterion.code && formatFhirCodeableConcept(criterion.code).toLowerCase().includes('due'));

        if (dueDateCriterion && dueDateCriterion.value) {
            return formatDate(dueDateCriterion.value);
        }

        return recommendation.dateCriterion[0].value ? formatDate(recommendation.dateCriterion[0].value) : '';
    };

    return (
        <div>

            <Flex align="center" justify="space-between">
                <FlexBlock>
                </FlexBlock>
                
                {/* SAID, NOT WITHHELD. A control that simply disappears reads as a broken screen or as a
                    permission the reader has lost, and both send them to an administrator to check permissions
                    that are already correct. A seat is nameable, and a practice can enable one in a minute. */}
                {roleAllowsEdit() && !seat.mayEdit && (
                    <p className="text-sm text-secondary max-w-[22rem] text-right">{seat.reason}</p>
                )}
                {isAuthorizedToEdit() && (
                    <FlexItem>
                        <button
                            type="button"
                            className="btn btn-blue"
                            onClick={addImmunizationRecommendation}
                        >
                            <Plus />
                            Add
                        </button>
                    </FlexItem>
                )}
            </Flex>
            <Spacer margin="8"/>

            <ResourceListStatus
                loading={loading}
                error={error}
                isEmpty={immunizationRecommendationsList.length === 0}

                /* - without this the empty message is a claim about the patient's
 record made before the server was ever asked. */
                attempted={attempted}
                resourceLabel="immunization recommendations"
                emptyMessage="No immunization recommendations found."
                onDismissError={clearError}
            />

            <>
                {loading ? (
                    <AppSpinner/>
                ) : (
                    <ScrollableTab>
                        <RecordPracticeNote view={practiceView} />
                        {practiceView.shown.length !== 0 && (
                            <ItemGroup isBordered isSeparated isRounded size='large'>
                                {practiceView.shown.map((immunizationRecommendation: ImmunizationRecommendation) => {
                                    const displayTitle = getImmunizationRecommendationDisplay(immunizationRecommendation);
                                    const firstRecommendation = immunizationRecommendation.recommendation &&
                                    immunizationRecommendation.recommendation.length > 0 ?
                                        immunizationRecommendation.recommendation[0] : null;

                                    const { text: forecastStatusText, color: forecastStatusColor } =
                                        firstRecommendation ? getForecastStatusDisplay(firstRecommendation) : { text: '' };

                                    const nextDoseDate = firstRecommendation ? getNextDoseDate(firstRecommendation) : '';
                                    const recommendationDate = immunizationRecommendation.date ?
                                        formatDate(immunizationRecommendation.date) : '';

                                    const recommendationCount = immunizationRecommendation.recommendation ?
                                        immunizationRecommendation.recommendation.length : 0;

                                    return (
                                        <Item key={immunizationRecommendation.id}
                                              onClick={() => viewImmunizationRecommendation(immunizationRecommendation)}>
                                            <Flex>
                                                <FlexItem>
                                                    <Icon icon={check}
                                                          size={24}
                                                          className="ahr-record-row__icon"
                                                          style={{ color: forecastStatusColor }}/>
                                                </FlexItem>
                                                <FlexBlock>
                                                    {/* Wraps: on a narrow row Edit moves below the whole title rather than being squeezed past the card's edge. */}
                                                    <Flex align="center" justify="space-between" wrap>
                                                        <FlexItem className="ahr-record-row__main">
                                                            <Text className="ahr-record-row__title">
                                                                {displayTitle}
                                                            </Text>
                                                            {recommendationCount > 1 && (
                                                                <Text variant="muted" className="ahr-record-row__line">
                                                                    {recommendationCount} recommendations
                                                                </Text>
                                                            )}
                                                            {(nextDoseDate || recommendationDate) && (
                                                                <Text variant="muted" className="ahr-record-row__line">
                                                                    <Icon icon={calendar}
                                                                          size={16}
                                                                          className="ahr-record-row__line-icon"/>
                                                                    {nextDoseDate ? `Next dose: ${nextDoseDate}` :
                                                                        recommendationDate ? `Recommended: ${recommendationDate}` : ''}
                                                                </Text>
                                                            )}
                                                            <Text variant="muted" className="ahr-record-row__line"><SourcePractice resource={immunizationRecommendation} /></Text>
                                                        </FlexItem>
                                                        {isAuthorizedToEdit() && (
                                                            <FlexItem className="ahr-record-row__action">
                                                                <button
                                                                    type="button"
                                                                    className="btn btn-blue-ghost-sm"
                                                                    onClick={(event: React.MouseEvent) => editImmunizationRecommendation(event, immunizationRecommendation)}
                                                                >
                                                                    <Pencil />
                                                                    Edit
                                                                </button>
                                                            </FlexItem>
                                                        )}
                                                    </Flex>
                                                </FlexBlock>
                                            </Flex>
                                        </Item>
                                    );
                                })}
                            </ItemGroup>
                        )}
                    </ScrollableTab>
                )}
            </>

            {selectedImmunizationRecommendation && (
                <FhirImmunizationRecommendationDisplay
                    immunizationRecommendation={selectedImmunizationRecommendation}
                    isOpen={showDisplayModal}
                    onClose={() => {
                        setShowDisplayModal(false);
                        setSelectedImmunizationRecommendation(null);
                    }}
                />
            )}
        </div>
    );
};

export default ImmunizationRecommendations;