Upload documents

<script>
import { LightningElement, api, wire, track } from 'lwc';
import { ShowToastEvent } from 'lightning/platformShowToastEvent';
import { getRelatedFiles } from 'lightning/uiRelatedListApi';
import { createRecord } from 'lightning/uiRecordApi';
import CONTENT_DOCUMENT_LINK_OBJECT from '@salesforce/schema/ContentDocumentLink';
import LINKED_ENTITY_ID_FIELD from '@salesforce/schema/ContentDocumentLink.LinkedEntityId';
import CONTENT_DOCUMENT_ID_FIELD from '@salesforce/schema/ContentDocumentLink.ContentDocumentId';

export default class UploadOrSelectFile extends LightningElement {
    @api recordId;
    @track files = [];

    @wire(getRelatedFiles, { recordId: '$recordId' })
    wiredFiles({ error, data }) {
        if (data) {
            this.files = data.map(file => ({
                label: file.Title,
                value: file.ContentDocumentId
            }));
        } else if (error) {
            console.error('Error fetching files:', error);
        }
    }

    handleUploadFinished(event) {
        const uploadedFiles = event.detail.files;
        this.showToast('Success', `${uploadedFiles.length} file(s) uploaded successfully.`, 'success');
    }

    handleFileSelection(event) {
        const selectedFileId = event.target.value;
        this.linkFileToRecord(selectedFileId);
    }

    linkFileToRecord(fileId) {
        const fields = {};
        fields[LINKED_ENTITY_ID_FIELD.fieldApiName] = this.recordId;
        fields[CONTENT_DOCUMENT_ID_FIELD.fieldApiName] = fileId;

        const recordInput = { apiName: CONTENT_DOCUMENT_LINK_OBJECT.objectApiName, fields };

        createRecord(recordInput)
            .then(() => {
                this.showToast('Success', 'File linked successfully.', 'success');
            })
            .catch(error => {
                this.showToast('Error', 'Failed to link file.', 'error');
                console.error('Error linking file:', error);
            });
    }

    showToast(title, message, variant) {
        this.dispatchEvent(
            new ShowToastEvent({
                title,
                message,
                variant
            })
        );
    }
}
</script>


<template>
    <lightning-card title="Upload or Select File">
        <div class="slds-m-around_medium">
            <!-- File Upload -->
            <lightning-file-upload
                label="Upload File"
                record-id={recordId}
                onuploadfinished={handleUploadFinished}
                multiple>
            </lightning-file-upload>

            <!-- Select Existing File -->
            <template if:true={files.length}>
                <lightning-combobox
                    name="fileSelect"
                    label="Select Existing File"
                    options={files}
                    onchange={handleFileSelection}>
                </lightning-combobox>
            </template>
        </div>
    </lightning-card>
</template>