let notes = [];
let goals = [];
let editingNoteId = null;
let filterTimer = null;
let currentUser = null;
let savedGoalId = null;

async function loadNotes() {
    const goalId = document.getElementById("filter-goal").value;
    const search = document.getElementById("filter-search").value.trim();

    let params = new URLSearchParams();
    if (goalId) params.set("goal_id", goalId);
    if (search) params.set("search", search);

    try {
        notes = await get(`/api/notes?${params.toString()}`);
        renderNotes();
    } catch (error) {
        console.error("Failed to load notes:", error);
    }
}

async function loadGoals() {
    try {
        goals = await get("/api/goals");
        currentUser = await get("/api/auth/me");
        savedGoalId = currentUser.selected_goal_id;
        populateGoalSelectors();
    } catch (error) {
        console.error("Failed to load goals:", error);
    }
}

function populateGoalSelectors() {
    const filterSelect = document.getElementById("filter-goal");
    const modalSelect = document.getElementById("note-goal");

    const activated = goals.filter(g => g.activated);
    const options = activated.map(g =>
        `<option value="${g.id}">${escapeHtml(g.title)}</option>`
    ).join("");

    const savedGoalExists = savedGoalId && activated.some(g => g.id === savedGoalId);

    filterSelect.innerHTML = `<option value="">All Goals</option>` + options;
    if (savedGoalExists) {
        filterSelect.value = savedGoalId;
    }

    modalSelect.innerHTML = `<option value="">None</option>` + options;
}

function renderNotes() {
    const container = document.getElementById("notes-list");

    if (notes.length === 0) {
        container.innerHTML = `
            <div class="empty-state">
                <h3>No notes yet</h3>
                <p>Create your first note to get started!</p>
            </div>
        `;
        return;
    }

    container.innerHTML = notes.map(note => {
        const snippet = (note.content || "").replace(/[#*`\[\]()>|~_-]/g, "").substring(0, 120);
        const time = formatTime(note.updated_at);
        let link = "";
        if (note.task_title) {
            link = `<span class="note-card-link">${escapeHtml(note.goal_title)} / ${escapeHtml(note.task_title)}</span>`;
        } else if (note.goal_title) {
            link = `<span class="note-card-link">${escapeHtml(note.goal_title)}</span>`;
        }

        return `
            <div class="note-card" onclick="openNote(${note.id})">
                <div class="note-card-title">${escapeHtml(note.title)}</div>
                <div class="note-card-meta">
                    <span>${time}</span>
                    ${link}
                </div>
                <div class="note-card-snippet">${escapeHtml(snippet)}</div>
            </div>
        `;
    }).join("");
}

async function openNote(noteId) {
    editingNoteId = noteId;
    const note = notes.find(n => n.id === noteId);
    if (!note) return;

    document.getElementById("note-modal-title").textContent = "Edit Note";
    document.getElementById("note-id").value = note.id;
    document.getElementById("note-title").value = note.title;
    document.getElementById("note-content").value = note.content || "";
    document.getElementById("note-goal").value = note.goal_id || "";
    document.getElementById("note-error").textContent = "";

    await populateTasks(note.goal_id);
    document.getElementById("note-task").value = note.task_id || "";

    document.getElementById("delete-note-btn").style.display = "inline-block";
    updatePreview();
    document.getElementById("note-modal").classList.add("active");
}

async function openNewNote() {
    editingNoteId = null;
    document.getElementById("note-modal-title").textContent = "New Note";
    document.getElementById("note-id").value = "";
    document.getElementById("note-title").value = "";
    document.getElementById("note-content").value = "";
    document.getElementById("note-goal").value = savedGoalId || "";
    document.getElementById("note-error").textContent = "";
    document.getElementById("delete-note-btn").style.display = "none";
    updatePreview();
    document.getElementById("note-modal").classList.add("active");

    if (savedGoalId) {
        await populateTasks(savedGoalId);
        const goal = goals.find(g => g.id === savedGoalId);
        if (goal && goal.selected_task_id) {
            document.getElementById("note-task").value = goal.selected_task_id;
        }
    } else {
        document.getElementById("note-task").innerHTML = '<option value="">None</option>';
    }
}

function closeNoteModal() {
    document.getElementById("note-modal").classList.remove("active");
    editingNoteId = null;
}

async function populateTasks(goalId) {
    const select = document.getElementById("note-task");
    select.innerHTML = '<option value="">None</option>';
    if (!goalId) return;

    try {
        const tasks = await get(`/api/tasks?goal_id=${goalId}`);
        select.innerHTML += tasks.map(t =>
            `<option value="${t.id}">${escapeHtml(t.title)}</option>`
        ).join("");
    } catch (error) {
        console.error("Failed to load tasks:", error);
    }
}

function updatePreview() {
    const content = document.getElementById("note-content").value;
    const preview = document.getElementById("note-preview");
    try {
        preview.innerHTML = marked.parse(content || "");
    } catch (e) {
        preview.innerHTML = escapeHtml(content || "");
    }
}

async function handleNoteSubmit(event) {
    event.preventDefault();
    const error = document.getElementById("note-error");
    error.textContent = "";

    const title = document.getElementById("note-title").value.trim();
    if (!title) {
        error.textContent = "Title is required";
        return;
    }

    const goalId = parseInt(document.getElementById("note-goal").value) || null;
    const taskId = parseInt(document.getElementById("note-task").value) || null;
    const content = document.getElementById("note-content").value;

    try {
        if (editingNoteId) {
            await put(`/api/notes/${editingNoteId}`, { title, content });
        } else {
            await post("/api/notes", { goal_id: goalId, task_id: taskId, title, content });
        }
        closeNoteModal();
        await loadNotes();
    } catch (err) {
        error.textContent = err.message;
    }
}

async function deleteNote() {
    if (!editingNoteId) return;
    if (!confirm("Delete this note?")) return;

    try {
        await del(`/api/notes/${editingNoteId}`);
        closeNoteModal();
        await loadNotes();
    } catch (error) {
        console.error("Failed to delete note:", error);
    }
}

function formatTime(isoString) {
    if (!isoString) return "";
    const date = new Date(isoString);
    return date.toLocaleString();
}

function escapeHtml(text) {
    const div = document.createElement('div');
    div.textContent = text;
    return div.innerHTML;
}

document.addEventListener("DOMContentLoaded", () => {
    document.getElementById("create-note-btn").addEventListener("click", openNewNote);
    document.getElementById("note-modal-close").addEventListener("click", closeNoteModal);
    document.getElementById("note-modal-cancel").addEventListener("click", closeNoteModal);
    document.getElementById("note-form").addEventListener("submit", handleNoteSubmit);
    document.getElementById("delete-note-btn").addEventListener("click", deleteNote);

    document.getElementById("note-content").addEventListener("input", updatePreview);

    document.getElementById("note-goal").addEventListener("change", async (e) => {
        const goalId = parseInt(e.target.value) || null;
        savedGoalId = goalId;
        await patch("/api/user/selected-goal", { goal_id: goalId });
        populateTasks(goalId);
    });

    document.getElementById("filter-goal").addEventListener("change", () => {
        loadNotes();
    });

    document.getElementById("filter-search").addEventListener("input", () => {
        clearTimeout(filterTimer);
        filterTimer = setTimeout(loadNotes, 300);
    });

    loadGoals();
    loadNotes();
});