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 `info` still feed WordPress icon components on each row - `info` also fed
// the Help button, so it survives its Button's conversion. A separate sweep.
import { Pencil, Plus, Calendar as calendar, Info as info } from 'lucide-react';
import { MedicationDispense } from 'fhir/r4';
import { AppSpinner, FhirMedicationDispenseDisplay, ScrollableTab } from '../../../../components';
import { ResourceListStatus } from '../../../../components/ui/resource-list-status';
import { formatFhirCodeableConcept } from '../../../../utils/fhirCodeableConcept.tsx';
import { formatDate } from '../../../../utils/dateUtils.ts';
import {
    useFhirMedicationDispenseBroadcast,
    useFhirMedicationDispenses,
    useFhirMedicationDispenseTargetedBroadcast
} from '../../../../hooks';
import { useAuthServiceContext, useMedicationDispenseServiceContext } from '../../../../services';
import '../medicationRecords.css';
import { SourcePractice } from '../../../../components/ui/source-practice';
import { RecordPracticeNote, recordPracticeId, useRecordPracticeView, useRetireOnPracticeChange } from '../../../../contexts/RecordPracticeContext';

const MedicationDispenses = () => {
    const navigate = useNavigate();
    const { userRole, USER_ROLES } = useAuthServiceContext();
    const { getMedicationDispenseDisplay } = useMedicationDispenseServiceContext();
    const { loading, error, clearError, medicationDispensesList, attempted } = useFhirMedicationDispenses();
    const [selectedMedicationDispense, setSelectedMedicationDispense] = useState<MedicationDispense | null>(null);
    const [showDisplayModal, setShowDisplayModal] = useState<boolean>(false);
    // The record's practice context: its own dispenses under a named practice; the empty state speaks for the whole record.
    const practiceView = useRecordPracticeView(medicationDispensesList, recordPracticeId);
    useRetireOnPracticeChange(() => { setShowDisplayModal(false); setSelectedMedicationDispense(null); });

    useFhirMedicationDispenseBroadcast();
    useFhirMedicationDispenseTargetedBroadcast({
        medicationDispense: selectedMedicationDispense || undefined,
        isOpen: showDisplayModal,
        onUpdate: (updatedMedicationDispense) => {
            setSelectedMedicationDispense(updatedMedicationDispense);
        },
        onDelete: () => {
            setShowDisplayModal(false);
            setSelectedMedicationDispense(null);
        }
    });

    const viewMedicationDispense = (medicationDispense: MedicationDispense) => {
        setSelectedMedicationDispense(medicationDispense);
        setShowDisplayModal(true);
    };

    const editMedicationDispense = (event: React.MouseEvent, medicationDispense: MedicationDispense) => {
        event.stopPropagation();
        navigate(medicationDispense.id as string, { relative: 'path' });
    };

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

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

    const getStatusDisplay = (medicationDispense: MedicationDispense): { text: string, color?: string } => {
        if (!medicationDispense) return { text: 'Unknown' };

        switch (medicationDispense.status) {
            case 'preparation':
                return { text: 'Preparation', color: '#e39700' };
            case 'in-progress':
                return { text: 'In Progress', color: '#e39700' };
            case 'cancelled':
                return { text: 'Cancelled', color: '#cc1818' };
            case 'on-hold':
                return { text: 'On Hold', color: '#e39700' };
            case 'completed':
                return { text: 'Completed', color: '#00a32a' };
            case 'entered-in-error':
                return { text: 'Error', color: '#cc1818' };
            case 'stopped':
                return { text: 'Stopped', color: '#cc1818' };
            case 'declined':
                return { text: 'Declined', color: '#cc1818' };
            case 'unknown':
            default:
                return { text: medicationDispense.status?.charAt(0).toUpperCase() + medicationDispense.status?.slice(1) || 'Unknown' };
        }
    };

    const getDateDisplay = (medicationDispense: MedicationDispense): string => {
        if (medicationDispense.whenHandedOver) {
            return `Handed over: ${formatDate(medicationDispense.whenHandedOver)}`;
        }

        if (medicationDispense.whenPrepared) {
            return `Prepared: ${formatDate(medicationDispense.whenPrepared)}`;
        }

        return '';
    };

    return (
        <div>

            <Flex align="center" justify="space-between">
                <FlexBlock>
                </FlexBlock>
                
                {isAuthorizedToEdit() && (
                    <FlexItem>
                        <button
                            type="button"
                            className="btn btn-blue"
                            onClick={addMedicationDispense}
                        >
                            <Plus />
                            Add
                        </button>
                    </FlexItem>
                )}
            </Flex>
            <Spacer margin="8"/>

            <ResourceListStatus
                loading={loading}
                error={error}
                isEmpty={medicationDispensesList.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="medication dispenses"
                emptyMessage="No medication dispenses found."
                onDismissError={clearError}
            />

            <>
                {loading ? (
                    <AppSpinner />
                ) : (
                    <ScrollableTab>
                        <RecordPracticeNote view={practiceView} />
                        {practiceView.shown.length !== 0 && (
                            <ItemGroup isBordered isSeparated isRounded size='large'>
                                {practiceView.shown.map((medicationDispense: MedicationDispense) => {
                                    const displayTitle = getMedicationDispenseDisplay(medicationDispense);
                                    const { text: statusText, color: statusColor } = getStatusDisplay(medicationDispense);
                                    const category = medicationDispense.category ? formatFhirCodeableConcept(medicationDispense.category) : '';
                                    const type = medicationDispense.type ? formatFhirCodeableConcept(medicationDispense.type) : '';
                                    const dateDisplay = getDateDisplay(medicationDispense);
                                    const dosageCount = medicationDispense.dosageInstruction?.length || 0;

                                    return (
                                        <Item key={medicationDispense.id}
                                              onClick={() => viewMedicationDispense(medicationDispense)}>
                                            <Flex>
                                                <FlexItem>
                                                    <Icon icon={info}
                                                          size={24}
                                                          className="ahr-record-row__icon"
                                                          style={{ color: statusColor }}/>
                                                </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>
                                                            {(category || type) && (
                                                                <Text variant="muted" className="ahr-record-row__line">
                                                                    {category && `Category: ${category}`}
                                                                    {category && type && ' • '}
                                                                    {type && `Type: ${type}`}
                                                                </Text>
                                                            )}
                                                            {dosageCount > 0 && (
                                                                <Text variant="muted" className="ahr-record-row__line">
                                                                    {dosageCount} dosage instruction{dosageCount !== 1 ? 's' : ''}
                                                                </Text>
                                                            )}
                                                            {dateDisplay && (
                                                                <Text variant="muted" className="ahr-record-row__line">
                                                                    <Icon icon={calendar}
                                                                          size={16}
                                                                          className="ahr-record-row__line-icon"/>
                                                                    {dateDisplay}
                                                                </Text>
                                                            )}
                                                            <Text variant="muted" className="ahr-record-row__line"><SourcePractice resource={medicationDispense} /></Text>
                                                        </FlexItem>
                                                        {isAuthorizedToEdit() && (
                                                            <FlexItem className="ahr-record-row__action">
                                                                <button
                                                                    type="button"
                                                                    className="btn btn-blue-ghost-sm"
                                                                    onClick={(event: React.MouseEvent) => editMedicationDispense(event, medicationDispense)}
                                                                >
                                                                    <Pencil />
                                                                    Edit
                                                                </button>
                                                            </FlexItem>
                                                        )}
                                                    </Flex>
                                                </FlexBlock>
                                            </Flex>
                                        </Item>
                                    );
                                })}
                            </ItemGroup>
                        )}
                    </ScrollableTab>
                )}
            </>

            {selectedMedicationDispense && (
                <FhirMedicationDispenseDisplay
                    medicationDispense={selectedMedicationDispense}
                    isOpen={showDisplayModal}
                    onClose={() => {
                        setShowDisplayModal(false);
                        setSelectedMedicationDispense(null);
                    }}
                />
            )}
        </div>
    );
};

export default MedicationDispenses;