import React, { useEffect, useRef, useState } from 'react';
import { Button, Grid, InputLabel, TextField } from '@mui/material';
import { GeneralConfirmWindow, notifySaveSuccess } from "../../../utils/CommonFunction";
import axios from 'axios';
import {apiPath, adobeAPIKey} from "../../../auth/utils";
import {
    GET_PDF_TEMPLATE_PATH,
    GET_PDF_PATH,
    POST_PDF_PATH
} from "../../../utils/ApiPathConst";
import {LIONER_BUTTON_THEME} from "../../../themes/colorConst";
import {ThemeProvider} from "@emotion/react";
import {useNavigate} from "react-router-dom";
import {useForm} from "react-hook-form";
import {useLocation, useParams} from "react-router-dom";
import { base64ToBinary } from "../../../utils/CommonFunction";

import { CollectionsBookmarkRounded } from '../../../../node_modules/@mui/icons-material/index';
import LoadingComponent from "../../extra-pages/LoadingComponent";
import { fill } from 'lodash';

function PDF() {
    const viewerRef = useRef(null); // Ref for the DOM element where PDF will render
    const [pdfLoaded, setPdfLoaded] = useState(false);
    const [viewerLoaded, setViewerLoaded] = useState(false);
    const [isSaving, setIsSaving] = useState(false);
    const [viewInstance,setViewInstance] = useState();
    const [adobeDCView,setAdobeDCView] = useState();
    const [pdfUrl, setPdfUrl] = useState();
    const [record, setRecord] = useState();
    const [formName, setFormName] = useState();
    
    const navigate = useNavigate()
    const params = useParams();
    const location = useLocation();
    const queryParams = new URLSearchParams(location.search);
    const refId = queryParams.get("refId");

    const loadPdfForm = async (id, templateId = 0, clientId = 0) => {
        if (!pdfLoaded) {
            if (id > 0) {
                // axios.get(`${apiPath}${GET_PDF_TEMPLATE_PATH}`, {
                axios.get(`${apiPath}${GET_PDF_PATH}/${id}`, {
                    // responseType: 'arraybuffer', // Essential for binary data
                })
                .then((response) => {
                    if (response.status === 200) {
                        const res = response.data;
                        setRecord({ // WIP - allow to update all record
                            id : res.id,
                            clientId: res.clientId,
                            templateId: res.templateId,
                        })
                        setFormName(res.filename);

                        //Convert Base64 to binary data
                        handlePdfUrl(base64ToBinary(res.blobValue));
                        setPdfLoaded(true);
                    }
                })
                .catch(error => {
                    console.log(error);
                    return false;
                });

            } else {
                axios.get(`${apiPath}${GET_PDF_TEMPLATE_PATH}`, {
                    // responseType: 'arraybuffer', // Essential for binary data
                    params: {
                        templateId: templateId,
                        clientId: clientId,
                    },
                })
                .then((response) => {
                    if (response.status === 200) {
                        const res = response.data;
                        setFormName(res.filename);
                        //Convert Base64 to binary data
                        handlePdfUrl(base64ToBinary(res.blobValue));
                        setPdfLoaded(true);
                    }
                })
                .catch(error => {
                    console.log(error);
                    return false;
                });
            }
        }
    };

    const handlePdfUrl = (pdfBytes) => {
        const pdfBlob = new Blob([pdfBytes], { type: 'application/pdf' });
        // const pdfFile = new File([pdfBlob], 'document.pdf', { type: 'application/pdf' });
        console.log(pdfBlob);
        const pdfUrl = URL.createObjectURL(pdfBlob);
        setPdfUrl(pdfUrl);
    }

    const loadPdfViewer = async () => {
        if (pdfLoaded && viewerRef.current && !viewerLoaded && !adobeDCView) {
            try {
                loadAdobeSDK();
            } catch (error) {
                console.error('Error loading PDF:', error);
            }
        }
    };

    const loadAdobeSDK = async() => {
        // const token = localStorage.getItem('accessToken');
        if (window.AdobeDC) {
            const DCViewer = (new window.AdobeDC.View({
                clientId:  `${adobeAPIKey}`, 
                divId: 'adobe-dc-view',
            }));

            setAdobeDCView(DCViewer);
            
            await DCViewer.previewFile(
                {
                content: {
                    location: {
                    url: pdfUrl,
                    //   headers: [{ key: 'Authorization', value: `Bearer ${token}` }],
                    },
                },
                metaData: { fileName: formName },
                },
                {
                embedMode: 'FULL_WINDOW',
                showAnnotationTools: true,
                enableFormFilling: true,
                }
    
            ).catch(error => {
                console.error('Preview error:', error);
                setError('Failed to load PDF: ' + error.message);
            
            }).then(instance => {
                URL.revokeObjectURL(pdfUrl);
                setViewInstance(instance);
                console.log('Instance: ', instance);
                setViewerLoaded(true);
            });

          DCViewer.registerCallback(
            window.AdobeDC.View.Enum.CallbackType.SAVE_API,
            handleSavePdf,
            { autoSaveFrequency: 0, enableFormFilling: true }
          );
        console.log("viewer: ", DCViewer);
        } else {
          console.error('AdobeDC not available');
          setError('Adobe SDK not loaded');
        }
    };

    useEffect(() => {
        if (params.id !== null) {
            const pdfData = (params.id).split("T");
    
            if (pdfData[0] > 0) {   // Existing Record
                loadPdfForm(pdfData[0]);
            } else {    // New Record
                const clientId = pdfData[0] * -1;
                const templateId = pdfData[1] * 1;
                setRecord({
                    id: -1,
                    clientId: clientId, //If PDF ID is negative, convert it to client ID
                    templateId: templateId});
                loadPdfForm(-1, templateId, clientId);    // Load new Template
            }
        }
    }, [params.id]);

    useEffect(() => {   // Update Save function callback after record is updated
        console.log("Record Updated: ",record);
        if (record && adobeDCView) {
            adobeDCView.registerCallback(
                window.AdobeDC.View.Enum.CallbackType.SAVE_API,
                handleSavePdf,
                { autoSaveFrequency: 0, enableFormFilling: true }
            );
        }
    }, [record]);
    
    useEffect(() => {
        loadPdfViewer();
    }, [viewerRef.current, pdfLoaded]);

    const handleSavePdf = async (metaData, content, options) => {
        try {
            const filledPdfBlob = new Blob([content], { type: 'application/pdf' });
            // Create FormData to send the file to Spring Boot
            const formData = new FormData();
            formData.append('file', filledPdfBlob, 'filled_form.pdf');
            formData.append('record', JSON.stringify(record));
            setIsSaving(true);
            // Send the filled PDF to your Spring Boot backend's save endpoint
            await axios.post(`${apiPath}${POST_PDF_PATH}`, formData, {
                headers: {
                    'Content-Type': 'multipart/form-data' // Important for file uploads
                },
            })
            .then(response => {
                setIsSaving(false);
                console.log('PDF saved on server:', response.data);
                setRecord({
                    id: response.data.data.id,
                    clientId: record.clientId,
                    templateId: record.templateId
                });
                notifySaveSuccess()});
            return {
                code: window.AdobeDC.View.Enum.ApiResponseCode.SUCCESS,
                data: { metaData } // Return metaData to prevent t.data undefined
            };
        } catch (error) {
            console.error('Error saving PDF:', error);
            alert('Failed to save PDF.');
            return { code: window.AdobeDC.View.Enum.ApiResponseCode.FAIL };
        }
    };

    const handlePrintPdf = () => {
        if (viewInstance.current) {
            // Trigger the SDK's built-in print functionality
            viewInstance.current.print();
        }
    };

    // Confirmation Window //
    const [isWindowOpen, setIsWindowOpen] = useState(false);

    const handleClose = () => {
        setIsWindowOpen(false);
    };

    const handleBackClick = () => {
        setIsWindowOpen(true);
    };

    const handleBack = async () => {
        navigate(`/pdf/${record.clientId}`);
    };

    return (
        <ThemeProvider theme={LIONER_BUTTON_THEME}>
        <div className="pdf-form-page"> {/* This is your 'pdfForm' page */}
            <header className="page-header">
                <Grid item>
                    <Grid container>
                        <Grid item sx={{ml:3, mr:1.5, mb:2}}>
                            {/* <Button
                                variant="contained"
                                type="submit"
                                color="save"
                                // disabled={!viewerLoaded}
                                onClick={handleTest}
                                // onClick={handleSavePdf}
                            >
                                Save
                            </Button> */}
                        </Grid>
                        <Grid item sx={{ml:{xs:1.5, md:1.5, lg:1.5}, mr:1.5, mb:2}}>
                            <Button
                                variant="contained"
                                color="cancel"
                                onClick={viewerLoaded ? handleBackClick : handleBack}
                                disabled={isSaving}
                                >
                                Back
                            </Button>
                            <GeneralConfirmWindow
                                isWindowOpen={isWindowOpen}
                                title={"Back to previous page"}
                                //content={`Confirm to delete Event "${clientDetail.name}" ?`}
                                content={`Are you sure to leave this page?\nAny unsaved progress will be lost.`}
                                onNormalClose={handleClose}
                                onConfirmClose={handleBack}
                            />
                        </Grid>

                        {/* <Grid item xs={9} s={6} md={5} lg={3} sx={{ml:3, mr:3, mb:0.5}}>
                            <InputLabel htmlFor="remarks">Remarks</InputLabel>
                        </Grid>
                        <Grid item xs={9} s={6} md={5} lg={3} sx={{ml:3, mr:3, mb:0.5}}>
                            <TextField
                                fullWidth
                                inputProps={{maxLength: 500}}
                                id="remarks"
                                autoComplete="off"
                            />
                        </Grid> */}
                    </Grid>
                </Grid>
                {/* {pdfLoaded ? (
                    <div className="action-buttons">
                        <button onClick={handleSavePdf} className="action-button save-button">
                            Save Filled PDF
                        </button>
                        <button onClick={handlePrintPdf} className="action-button print-button">
                            Print PDF
                        </button>
                    </div>
                ) : (
                    <p>Loading PDF viewer...</p>
                )} */}
            </header>
            {!pdfLoaded && (<LoadingComponent/>)}
            <div id="adobe-dc-view" ref={viewerRef} style={{
                    width: '100%',
                    height: 'calc(100vh - 180px)', // Adjust height based on header/footer
                    border: '1px solid #ccc',
                }}
                hidden={!pdfLoaded}
            />
            {/* <div
                // id={viewerRef}
                ref={viewerRef}
                // className="pdf-viewer-container"
                style={{
                    width: '100%',
                    height: 'calc(100vh - 180px)', // Adjust height based on header/footer
                    border: '1px solid #ccc',
                }}
            >
            </div> */}
        </div>
        </ThemeProvider>
    );
}

export default PDF;