(function () {
    "use strict";

    const searchInput = document.getElementById("customerSearch");
    const searchWrap = document.getElementById("searchWrap");
    const suggestionsBox = document.getElementById("suggestions");
    const advancedToggle = document.getElementById("advancedToggle");
    const advancedFields = document.getElementById("advancedFields");
    const fieldToggleButtons = Array.from(document.querySelectorAll(".field-toggle"));
    const applyExtraValuesToggle = document.getElementById("applyExtraValues");
    const customerChip = document.getElementById("customerChip");
    const chipNumber = document.getElementById("chipNumber");
    const chipName = document.getElementById("chipName");
    const chipReset = document.getElementById("chipReset");
    const stepIssue = document.getElementById("stepIssue");
    const subjectInput = document.getElementById("subject");
    const descriptionInput = document.getElementById("description");
    const submitButton = document.getElementById("submitButton");
    const feedback = document.getElementById("feedback");

    let selectedCustomer = null;
    let currentResults = [];
    let currentQuery = "";
    let activeIndex = -1;
    let debounceTimer = null;
    const selectedFields = new Set();

    function appendHighlighted(target, text, query) {
        const words = (query || "").toLowerCase().split(/\s+/).filter(Boolean);
        if (words.length === 0) { target.appendChild(document.createTextNode(text)); return; }

        const lowerText = text.toLowerCase();
        const mask = new Array(text.length).fill(false);
        for (const word of words) {
            let fromIndex = 0;
            let matchIndex;
            while ((matchIndex = lowerText.indexOf(word, fromIndex)) !== -1) {
                for (let i = matchIndex; i < matchIndex + word.length; i++) { mask[i] = true; }
                fromIndex = matchIndex + 1;
            }
        }

        let i = 0;
        while (i < text.length) {
            const highlighted = mask[i];
            let j = i;
            while (j < text.length && mask[j] === highlighted) { j++; }
            const chunk = text.slice(i, j);
            if (highlighted) {
                const strong = document.createElement("strong");
                strong.textContent = chunk;
                target.appendChild(strong);
            } else {
                target.appendChild(document.createTextNode(chunk));
            }
            i = j;
        }
    }

    function updateSubmitState() {
        const subjectOk = subjectInput.value.trim().length >= 5;
        submitButton.disabled = !(selectedCustomer && subjectOk);
    }

    function closeSuggestions() {
        suggestionsBox.classList.remove("open");
        searchInput.setAttribute("aria-expanded", "false");
        activeIndex = -1;
    }

    function renderSuggestions() {
        suggestionsBox.innerHTML = "";
        if (currentResults.length === 0) {
            const empty = document.createElement("div");
            empty.className = "suggestion-empty";
            empty.textContent = "Kein Kunde gefunden. Nummer und Schreibweise prüfen.";
            suggestionsBox.appendChild(empty);
        } else {
            currentResults.forEach((customer, index) => {
                const item = document.createElement("button");
                item.type = "button";
                item.className = index === activeIndex ? "suggestion active" : "suggestion";
                item.setAttribute("role", "option");
                item.innerHTML = "";
                const numberSpan = document.createElement("span");
                numberSpan.className = "cnum";
                appendHighlighted(numberSpan, customer.number, currentQuery);
                const nameSpan = document.createElement("span");
                appendHighlighted(nameSpan, customer.name, currentQuery);
                if (customer.extraMatches && customer.extraMatches.length > 0) {
                    nameSpan.appendChild(document.createTextNode(` (${customer.extraMatches.join(", ")})`));
                }
                item.appendChild(numberSpan);
                item.appendChild(nameSpan);
                item.addEventListener("click", () => selectCustomer(customer));
                suggestionsBox.appendChild(item);
            });
        }
        suggestionsBox.classList.add("open");
        searchInput.setAttribute("aria-expanded", "true");
    }

    async function runSearch(query) {
        currentQuery = query;
        try {
            const params = new URLSearchParams({ search: query });
            if (advancedToggle.checked && selectedFields.size > 0) {
                params.set("fields", Array.from(selectedFields).join(","));
            }
            const response = await fetch("/api/customers?" + params.toString());
            const payload = await response.json();
            currentResults = payload.results;
            activeIndex = currentResults.length > 0 ? 0 : -1;
            renderSuggestions();
        } catch (error) {
            currentResults = [];
            renderSuggestions();
        }
    }

    function selectCustomer(customer) {
        selectedCustomer = customer;
        chipNumber.textContent = customer.number;
        const useExtraValues = applyExtraValuesToggle.checked && customer.extraMatches && customer.extraMatches.length > 0;
        chipName.textContent = useExtraValues
            ? `${customer.name} (${customer.extraMatches.join(", ")})`
            : customer.name;
        customerChip.classList.add("visible");
        searchWrap.style.display = "none";
        closeSuggestions();
        stepIssue.dataset.disabled = "false";
        updateSubmitState();
        subjectInput.focus();
    }

    function resetCustomer() {
        selectedCustomer = null;
        customerChip.classList.remove("visible");
        searchWrap.style.display = "";
        searchInput.value = "";
        stepIssue.dataset.disabled = "true";
        updateSubmitState();
        searchInput.focus();
    }

    searchInput.addEventListener("input", () => {
        const query = searchInput.value.trim();
        clearTimeout(debounceTimer);
        if (query.length < 2) { closeSuggestions(); return; }
        debounceTimer = setTimeout(() => runSearch(query), 200);
    });

    searchInput.addEventListener("keydown", (event) => {
        const isOpen = suggestionsBox.classList.contains("open");
        if (event.key === "ArrowDown" && isOpen) {
            event.preventDefault();
            activeIndex = Math.min(activeIndex + 1, currentResults.length - 1);
            renderSuggestions();
        } else if (event.key === "ArrowUp" && isOpen) {
            event.preventDefault();
            activeIndex = Math.max(activeIndex - 1, 0);
            renderSuggestions();
        } else if (event.key === "Enter" && isOpen && activeIndex >= 0) {
            event.preventDefault();
            selectCustomer(currentResults[activeIndex]);
        } else if (event.key === "Escape") {
            closeSuggestions();
        }
    });

    document.addEventListener("click", (event) => {
        if (!searchWrap.contains(event.target)) { closeSuggestions(); }
    });

    advancedToggle.addEventListener("change", () => {
        advancedFields.hidden = !advancedToggle.checked;
        if (!advancedToggle.checked) {
            selectedFields.clear();
            fieldToggleButtons.forEach((button) => button.setAttribute("aria-pressed", "false"));
        }
        if (currentQuery.length >= 2) { runSearch(currentQuery); }
    });

    fieldToggleButtons.forEach((button) => {
        button.addEventListener("click", () => {
            const field = button.dataset.field;
            const isPressed = button.getAttribute("aria-pressed") === "true";
            button.setAttribute("aria-pressed", String(!isPressed));
            if (isPressed) { selectedFields.delete(field); } else { selectedFields.add(field); }
            if (currentQuery.length >= 2) { runSearch(currentQuery); }
        });
    });

    chipReset.addEventListener("click", resetCustomer);
    subjectInput.addEventListener("input", updateSubmitState);

    submitButton.addEventListener("click", async () => {
        feedback.className = "feedback";
        submitButton.disabled = true;
        submitButton.textContent = "Wird angelegt ...";

        try {
            const response = await fetch("/api/tickets", {
                method: "POST",
                headers: { "Content-Type": "application/json" },
                body: JSON.stringify({
                    customerNumber: selectedCustomer.number,
                    subject: subjectInput.value,
                    description: descriptionInput.value,
                }),
            });
            const payload = await response.json();

            if (response.status === 201) {
                const dryRunHint = payload.dryRun ? " (Trockenlauf, nicht wirklich in Redmine angelegt)" : "";
                feedback.className = "feedback success";
                feedback.innerHTML = "Ticket <a class=\"mono\" href=\"" + payload.issueUrl + "\" target=\"_blank\" rel=\"noopener\">#" + payload.issueId + "</a> fuer <span class=\"mono\">" + payload.customer.number + "</span> angelegt." + dryRunHint;
                subjectInput.value = "";
                descriptionInput.value = "";
            } else {
                feedback.className = "feedback error";
                feedback.textContent = payload.error || "Unbekannter Fehler beim Anlegen des Tickets.";
            }
        } catch (error) {
            feedback.className = "feedback error";
            feedback.textContent = "Server nicht erreichbar. Bitte später erneut versuchen.";
        } finally {
            submitButton.textContent = "Ticket anlegen";
            updateSubmitState();
        }
    });
})();