function initPdfToWord() {
    const fileInput = document.getElementById("pdfToWordFile");
    const fileNameEl = document.getElementById("pdfToWordFileName");
    const titleEl = document.getElementById("pdfToWordTitle");
    const subtitleEl = document.getElementById("pdfToWordSubtitle");
    const chooseTextEl = document.getElementById("pdfToWordChooseText");
    const statusEl = document.getElementById("pdfToWordStatus");
    const convertBtn = document.getElementById("pdfToWordConvertBtn");
    const downloadBtn = document.getElementById("pdfToWordDownloadBtn");
    const clearBtn = document.getElementById("pdfToWordClearBtn");
    const csrfTokenEl = document.getElementById("csrfToken");
    const progressWrap = document.getElementById("pdfToWordProgress");
    const progressBar = document.getElementById("pdfToWordProgressBar");
    const progressText = document.getElementById("pdfToWordProgressText");
    const chooseLabelEl = document.getElementById("pdfToWordChooseLabel");

    if (!fileInput || !convertBtn) return;

    let selectedFile = null;
    let docxBlob = null;
    let docxObjectUrl = null;
    let isConverted = false;

    function setStatus(text, isError) {
        if (!statusEl) return;
        statusEl.textContent = text;
        statusEl.classList.toggle("status-error", !!isError);
        statusEl.classList.toggle("status-success", !isError);
    }

    function setUploadBoxCopy(mode) {
        if (!titleEl || !subtitleEl || !chooseTextEl) return;
        const showChoose = () => {
            if (!chooseLabelEl) return;
            chooseLabelEl.hidden = false;
            chooseLabelEl.style.display = "inline-block";
        };
        const hideChoose = () => {
            if (!chooseLabelEl) return;
            chooseLabelEl.hidden = true;
            chooseLabelEl.style.display = "none";
        };

        if (mode === "uploading") {
            titleEl.textContent = "Uploading your document...";
            subtitleEl.textContent = "Please wait while the file upload completes.";
            chooseTextEl.textContent = "Choose Another PDF";
            hideChoose();
            return;
        }
        if (mode === "converting") {
            titleEl.textContent = "Processing your document...";
            subtitleEl.textContent = "Upload complete. Conversion is running.";
            chooseTextEl.textContent = "Choose Another PDF";
            hideChoose();
            return;
        }
        if (mode === "completed") {
            titleEl.textContent = "Conversion complete";
            subtitleEl.textContent = "Your DOCX is ready. Click Download DOCX.";
            chooseTextEl.textContent = "Choose Another PDF";
            showChoose();
            return;
        }
        if (mode === "selected") {
            titleEl.textContent = "File selected";
            subtitleEl.textContent = "Click Convert to DOCX to start conversion.";
            chooseTextEl.textContent = "Choose Another PDF";
            showChoose();
            return;
        }
        titleEl.textContent = "Upload your PDF document";
        subtitleEl.textContent = "Supported format: .pdf (max 25MB)";
        chooseTextEl.textContent = "Choose PDF File";
        showChoose();
    }

    function resetProgress() {
        if (progressWrap) progressWrap.style.display = "none";
        if (progressText) progressText.style.display = "none";
        if (progressBar) progressBar.style.width = "0%";
        if (progressText) progressText.textContent = "0%";
        if (progressWrap) progressWrap.classList.remove("processing");
    }

    function startProgress() {
        if (progressWrap) progressWrap.style.display = "block";
        if (progressText) progressText.style.display = "block";
        if (progressBar) progressBar.style.width = "0%";
        if (progressText) progressText.textContent = "0%";
        if (progressWrap) progressWrap.classList.remove("processing");
    }

    function updateUi() {
        const hasFile = !!selectedFile;
        const hasDocx = !!docxBlob;
        convertBtn.disabled = !hasFile || isConverted;
        if (downloadBtn) {
            downloadBtn.disabled = !hasDocx;
            downloadBtn.hidden = !hasDocx;
        }
        if (clearBtn) clearBtn.disabled = !hasFile;
        if (fileNameEl) fileNameEl.textContent = hasFile ? selectedFile.name : "No file selected";
    }

    function clearDocxOutput() {
        docxBlob = null;
        isConverted = false;
        if (docxObjectUrl) {
            URL.revokeObjectURL(docxObjectUrl);
            docxObjectUrl = null;
        }
    }

    function startConversionIndicator() {
        if (progressWrap) progressWrap.classList.add("processing");
        if (progressBar) progressBar.style.width = "100%";
        if (progressText) progressText.textContent = "Converting...";
    }

    function convertFile() {
        if (!selectedFile || isConverted) return;

        const formData = new FormData();
        formData.append("file", selectedFile);
        clearDocxOutput();
        startProgress();
        setStatus("Converting PDF to DOCX...", false);
        setUploadBoxCopy("uploading");
        convertBtn.disabled = true;
        if (downloadBtn) downloadBtn.disabled = true;

        const xhr = new XMLHttpRequest();
        xhr.open("POST", "/api/pdf-to-word/", true);
        xhr.responseType = "blob";
        if (csrfTokenEl?.value) {
            xhr.setRequestHeader("X-CSRFToken", csrfTokenEl.value);
        }

        xhr.upload.onprogress = (event) => {
            if (!event.lengthComputable || !progressBar || !progressText) return;
            const percent = Math.min(100, Math.round((event.loaded / event.total) * 100));
            progressBar.style.width = `${percent}%`;
            progressText.textContent = `${percent}% uploaded`;
        };

        xhr.upload.onload = () => {
            startConversionIndicator();
            setStatus("Upload complete. Converting...", false);
            setUploadBoxCopy("converting");
        };

        xhr.onload = async () => {
            if (xhr.status >= 400) {
                let errorMessage = "Conversion failed.";
                try {
                    const text = await xhr.response.text();
                    const data = JSON.parse(text || "{}");
                    if (data.error) errorMessage = data.error;
                    if (data.detail) errorMessage = `${errorMessage} (${data.detail})`;
                } catch {
                    // keep default
                }
                setStatus(errorMessage, true);
                setUploadBoxCopy("selected");
                clearDocxOutput();
                resetProgress();
                updateUi();
                return;
            }

            docxBlob = xhr.response;
            docxObjectUrl = URL.createObjectURL(docxBlob);
            isConverted = true;
            setStatus("DOCX generated. Click Download DOCX.", false);
            setUploadBoxCopy("completed");
            resetProgress();
            updateUi();
        };

        xhr.onerror = () => {
            setStatus("Conversion failed.", true);
            setUploadBoxCopy("selected");
            clearDocxOutput();
            resetProgress();
            updateUi();
        };

        xhr.send(formData);
    }

    function downloadDocx() {
        if (!docxBlob || !docxObjectUrl || !selectedFile) return;
        const link = document.createElement("a");
        link.href = docxObjectUrl;
        const baseName = selectedFile.name.replace(/\.pdf$/i, "") || "document";
        link.download = `${baseName}.docx`;
        link.click();
    }

    fileInput.addEventListener("change", () => {
        const file = fileInput.files && fileInput.files[0];
        if (!file) {
            selectedFile = null;
            clearDocxOutput();
            setStatus("Upload a .pdf file and convert it to DOCX.", false);
            setUploadBoxCopy("idle");
            resetProgress();
            updateUi();
            return;
        }

        if (!file.name.toLowerCase().endsWith(".pdf")) {
            selectedFile = null;
            clearDocxOutput();
            fileInput.value = "";
            setStatus("Only .pdf files are supported.", true);
            setUploadBoxCopy("idle");
            resetProgress();
            updateUi();
            return;
        }

        if (file.size > 25 * 1024 * 1024) {
            selectedFile = null;
            clearDocxOutput();
            fileInput.value = "";
            setStatus("File must be under 25MB.", true);
            setUploadBoxCopy("idle");
            resetProgress();
            updateUi();
            return;
        }

        selectedFile = file;
        clearDocxOutput();
        setStatus("Ready to convert.", false);
        setUploadBoxCopy("selected");
        resetProgress();
        updateUi();
    });

    convertBtn.addEventListener("click", () => {
        convertFile();
    });
    if (downloadBtn) {
        downloadBtn.addEventListener("click", downloadDocx);
    }

    if (clearBtn) {
        clearBtn.addEventListener("click", () => {
            selectedFile = null;
            clearDocxOutput();
            fileInput.value = "";
            setStatus("Upload a .pdf file and convert it to DOCX.", false);
            setUploadBoxCopy("idle");
            resetProgress();
            updateUi();
        });
    }

    setUploadBoxCopy("idle");
    resetProgress();
    updateUi();
}

if (document.readyState === "loading") {
    document.addEventListener("DOMContentLoaded", initPdfToWord);
} else {
    initPdfToWord();
}