import { createContext, useContext, useCallback, ReactNode } from 'react';
import { overlayHeldBundle } from '../utils/writeThroughHold';
import { ActivityDefinition, Bundle } from 'fhir/r4';
import { environment } from '../environments/environment';
import { useHttpService } from './HttpService.tsx';
import { fetchAllPagesAsBundle } from '../utils/fetchAllPagesAsBundle';
import { searchPageSize } from '../utils/pageSizeOverride';

const API_URL = environment.fhirClinicalApi;

export const useActivityDefinitionService = () => {
    const { get, post, put, delete: del } = useHttpService();

    const fetchActivityDefinitions = useCallback(async (): Promise<Bundle<ActivityDefinition>> => {
        // Server scopes the result to the caller's organization via the X-Organization-ID header.
        // The list is the whole practice, and the hold is emptied when the practice changes.
        return overlayHeldBundle('ActivityDefinition', await fetchAllPagesAsBundle<ActivityDefinition>((pageParam) => {
            const params = new URLSearchParams();

            params.append('_count', searchPageSize('100'));
            if (pageParam) params.set('page', pageParam);

            return get<Bundle<ActivityDefinition>>(`${API_URL}/ActivityDefinition?${params.toString()}`);
        }), () => true) as Bundle<ActivityDefinition>;
    }, [get]);

    const createActivityDefinition = useCallback(async (resource: ActivityDefinition): Promise<ActivityDefinition> => {
        return post<ActivityDefinition>(`${API_URL}/ActivityDefinition`, resource);
    }, [post]);

    const updateActivityDefinition = useCallback(async (resource: ActivityDefinition): Promise<ActivityDefinition> => {
        return put<ActivityDefinition>(`${API_URL}/ActivityDefinition/${resource.id}`, resource);
    }, [put]);

    const deleteActivityDefinition = useCallback(async (resource: ActivityDefinition): Promise<void> => {
        await del<ActivityDefinition>(`${API_URL}/ActivityDefinition/${resource.id}`);
    }, [del]);

    return { fetchActivityDefinitions, createActivityDefinition, updateActivityDefinition, deleteActivityDefinition };
};

const ActivityDefinitionServiceContext = createContext<ReturnType<typeof useActivityDefinitionService> | undefined>(undefined);

export const ActivityDefinitionServiceProvider: React.FC<{ children: ReactNode }> = ({ children }) => {
    const service = useActivityDefinitionService();
    return (
        <ActivityDefinitionServiceContext.Provider value={service}>
            {children}
        </ActivityDefinitionServiceContext.Provider>
    );
};

export const useActivityDefinitionServiceContext = () => {
    const context = useContext(ActivityDefinitionServiceContext);
    if (context === undefined) {
        throw new Error('useActivityDefinitionServiceContext must be used within an ActivityDefinitionServiceProvider');
    }
    return context;
};