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';
// `warning` still feeds the WordPress icon component on the severity marker below -
// a separate sweep. The three Button icons moved to lucide.
import { Pencil, Plus, TriangleAlert as warning } from 'lucide-react';
import { DetectedIssue } from 'fhir/r4';
import { AppSpinner, FhirDetectedIssueDisplay, ScrollableTab } from '../../../../components';
import { ResourceListStatus } from '../../../../components/ui/resource-list-status';
import {
    useFhirDetectedIssueBroadcast,
    useFhirDetectedIssues,
    useFhirDetectedIssueTargetedBroadcast
} from '../../../../hooks';
import { useAuthServiceContext, useDetectedIssueServiceContext } from '../../../../services';
import { mayEditRecord } from '../../../../utils/recordEditability';
import { useSeatStanding } from '../../../../utils/seatStanding';
import { SourcePractice } from '../../../../components/ui/source-practice';
import { RecordPracticeNote, recordPracticeId, useRecordPracticeView, useRetireOnPracticeChange } from '../../../../contexts/RecordPracticeContext';

const DetectedIssues = () => {
    const navigate = useNavigate();
    const { userRole, USER_ROLES, practitionerRoles } = useAuthServiceContext();
    const seatStanding = useSeatStanding();
    const { getDetectedIssueDisplay } = useDetectedIssueServiceContext();
    const { loading, error, clearError, detectedIssuesList, attempted } = useFhirDetectedIssues();
    const [selectedDetectedIssue, setSelectedDetectedIssue] = useState<DetectedIssue | null>(null);
    const [showDisplayModal, setShowDisplayModal] = useState<boolean>(false);
    // The record's practice context: its own detected issues under a named practice; the empty state speaks for the whole record.
    const practiceView = useRecordPracticeView(detectedIssuesList, recordPracticeId);
    useRetireOnPracticeChange(() => { setShowDisplayModal(false); setSelectedDetectedIssue(null); });

    useFhirDetectedIssueBroadcast();
    useFhirDetectedIssueTargetedBroadcast({
        detectedIssue: selectedDetectedIssue || undefined,
        isOpen: showDisplayModal,
        onUpdate: (updatedDetectedIssue) => {
            setSelectedDetectedIssue(updatedDetectedIssue);
        },
        onDelete: () => {
            setShowDisplayModal(false);
            setSelectedDetectedIssue(null);
        }
    });

    const viewDetectedIssue = (detectedIssue: DetectedIssue) => {
        setSelectedDetectedIssue(detectedIssue);
        setShowDisplayModal(true);
    };

    const editDetectedIssue = (event: React.MouseEvent, detectedIssue: DetectedIssue) => {
        event.stopPropagation();
        navigate(detectedIssue.id as string, { relative: 'path' });
    };

    const addDetectedIssue = () => {
        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 DetectedIssue 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: 'DetectedIssue',
        viewerIsStaff: Boolean(userRole)
            && ![USER_ROLES.PATIENT, USER_ROLES.RELATED_PERSON].includes(userRole as string),
        practitionerRoles,
    });

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

    const getSeverityDisplay = (detectedIssue: DetectedIssue): { text: string, color?: string } => {
        if (!detectedIssue || !detectedIssue.severity) return { text: '' };

        switch (detectedIssue.severity) {
            case 'high':
                return { text: 'High', color: '#cc1818' };
            case 'moderate':
                return { text: 'Moderate', color: '#e39700' };
            case 'low':
                return { text: 'Low', color: '#00a32a' };
            default:
                return { text: detectedIssue.severity.charAt(0).toUpperCase() + detectedIssue.severity.slice(1) };
        }
    };

    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={addDetectedIssue}
                        >
                            <Plus />
                            Add
                        </button>
                    </FlexItem>
                )}
            </Flex>
            <Spacer margin="8"/>

            <ResourceListStatus
                loading={loading}
                error={error}
                isEmpty={detectedIssuesList.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="detected issues"
                emptyMessage="No detected issues found."
                onDismissError={clearError}
            />

            <>
                {loading ? (
                    <AppSpinner/>
                ) : (
                    <ScrollableTab>
                        <RecordPracticeNote view={practiceView} />
                        {practiceView.shown.length !== 0 && (
                            <ItemGroup isBordered isSeparated isRounded size='large'>
                                {practiceView.shown.map((detectedIssue: DetectedIssue) => {
                                    const displayTitle = getDetectedIssueDisplay(detectedIssue);
                                    const { text: severityText, color: severityColor } = getSeverityDisplay(detectedIssue);
                                    const mitigationCount = detectedIssue.mitigation?.length || 0;
                                    const implicatedCount = detectedIssue.implicated?.length || 0;

                                    return (
                                        <Item key={detectedIssue.id}
                                              onClick={() => viewDetectedIssue(detectedIssue)}>
                                            <Flex>
                                                <FlexItem>
                                                    <Icon icon={warning}
                                                          size={24}
                                                          style={{
                                                              marginRight: 12,
                                                              color: severityColor || '#e39700'
                                                          }}/>
                                                </FlexItem>
                                                <FlexBlock>
                                                    <Flex align="center" justify="space-between">
                                                        <FlexItem>
                                                            <Text style={{ fontWeight: 500 }}>
                                                                {displayTitle}
                                                            </Text>
                                                            {detectedIssue.detail && (
                                                                <Text variant="muted" style={{ display: 'block' }}>
                                                                    {detectedIssue.detail.length > 60
                                                                        ? detectedIssue.detail.substring(0, 60) + '...'
                                                                        : detectedIssue.detail}
                                                                </Text>
                                                            )}
                                                            {(mitigationCount > 0 || implicatedCount > 0) && (
                                                                <Text variant="muted" style={{ display: 'block' }}>
                                                                    {implicatedCount > 0 && `${implicatedCount} implicated`}
                                                                    {implicatedCount > 0 && mitigationCount > 0 && ', '}
                                                                    {mitigationCount > 0 && `${mitigationCount} mitigation${mitigationCount !== 1 ? 's' : ''}`}
                                                                </Text>
                                                            )}
                                                            <Text variant="muted" style={{ display: 'block' }}><SourcePractice resource={detectedIssue} /></Text>
                                                        </FlexItem>
                                                        {isAuthorizedToEdit() && (
                                                            <FlexItem>
                                                                <button
                                                                    type="button"
                                                                    className="btn btn-blue-ghost-sm"
                                                                    onClick={(event: React.MouseEvent) => editDetectedIssue(event, detectedIssue)}
                                                                >
                                                                    <Pencil />
                                                                    Edit
                                                                </button>
                                                            </FlexItem>
                                                        )}
                                                    </Flex>
                                                </FlexBlock>
                                            </Flex>
                                        </Item>
                                    );
                                })}
                            </ItemGroup>
                        )}
                    </ScrollableTab>
                )}
            </>

            {selectedDetectedIssue && (
                <FhirDetectedIssueDisplay detectedIssue={selectedDetectedIssue}
                                          isOpen={showDisplayModal}
                                          onClose={() => {
                                              setShowDisplayModal(false);
                                              setSelectedDetectedIssue(null);
                                          }}/>
            )}
        </div>
    );
};

export default DetectedIssues;