/* ============================================
   IVY'S RSS HUB — Sidebar Module
   Search, Bookmarks, Trending, Favorites, Calendar
   ============================================ */

/**
 * SidebarManager - Handles all sidebar functionality
 */
class SidebarManager {
    constructor(app) {
        this.app = app;

        // State
        this.bookmarks = this.loadBookmarks();
        this.favoriteSources = this.loadFavorites();
        this.allArticles = [];
        this.searchDebounceTimer = null;
        this.trendingCache = null; // Cache for trending topics
        this.trendingCacheKey = null; // Cache key based on article count

        // DOM Elements
        this.elements = {
            sidebar: document.getElementById("sidebar"),
            sidebarToggle: document.getElementById("sidebar-toggle"),
            // Search
            searchInput: document.getElementById("search-input"),
            searchClear: document.getElementById("search-clear"),
            searchResults: document.getElementById("search-results"),
            // Bookmarks
            bookmarksList: document.getElementById("bookmarks-list"),
            btnClearBookmarks: document.getElementById("btn-clear-bookmarks"),
            // Trending
            trendingTags: document.getElementById("trending-tags"),
            // Favorites
            favoritesList: document.getElementById("favorites-list"),
            // Calendar
            calendarGrid: document.getElementById("calendar-grid")
        };

        this.init();
    }

    /**
     * Initialize sidebar
     */
    init() {
        this.setupEventListeners();
        this.setupCollapsibleSections();
        this.renderBookmarks();
        this.renderFavorites();
        this.renderCalendar();
    }

    /**
     * Cleanup method (call on app destroy if needed)
     */
    destroy() {
        if (this.searchDebounceTimer) {
            clearTimeout(this.searchDebounceTimer);
            this.searchDebounceTimer = null;
        }
    }

    /**
     * Setup event listeners
     */
    setupEventListeners() {
        // Sidebar toggle (mobile)
        this.elements.sidebarToggle?.addEventListener("click", () => {
            this.elements.sidebar.classList.toggle("open");
        });

        // Close sidebar when clicking outside (mobile)
        document.addEventListener("click", e => {
            if (window.innerWidth <= 1100) {
                if (
                    !this.elements.sidebar.contains(e.target) &&
                    !this.elements.sidebarToggle.contains(e.target) &&
                    this.elements.sidebar.classList.contains("open")
                ) {
                    this.elements.sidebar.classList.remove("open");
                }
            }
        });

        // Search with debounce for performance
        this.elements.searchInput?.addEventListener("input", e => {
            clearTimeout(this.searchDebounceTimer);
            this.searchDebounceTimer = setTimeout(() => {
                this.handleSearch(e.target.value);
            }, 150);
        });

        this.elements.searchClear?.addEventListener("click", () => {
            this.elements.searchInput.value = "";
            this.handleSearch("");
        });

        // Clear bookmarks with double-click protection
        this.elements.btnClearBookmarks?.addEventListener("click", e => {
            // Use data attribute for confirmation state
            if (e.target.dataset.confirmClear === "true") {
                this.bookmarks = [];
                this.saveBookmarks();
                this.renderBookmarks();
                e.target.textContent = "Clear All";
                e.target.dataset.confirmClear = "false";
                e.target.setAttribute("aria-label", "Clear all bookmarks");
                // Refresh main feed to update bookmark icons
                if (this.app) this.app.renderFeeds();
                this.app?.showToast("All bookmarks cleared", "info");
            } else {
                e.target.textContent = "Click again to confirm";
                e.target.dataset.confirmClear = "true";
                e.target.setAttribute("aria-label", "Click again to confirm clearing all bookmarks");
                // Reset after 3 seconds
                setTimeout(() => {
                    e.target.textContent = "Clear All";
                    e.target.dataset.confirmClear = "false";
                    e.target.setAttribute("aria-label", "Clear all bookmarks");
                }, 3000);
            }
        });
    }

    /**
     * Setup collapsible sections
     */
    setupCollapsibleSections() {
        document.querySelectorAll(".sidebar-title.collapsible").forEach(title => {
            title.addEventListener("click", () => {
                const targetId = title.dataset.target;
                const content = document.getElementById(targetId);
                if (content) {
                    title.classList.toggle("collapsed");
                    content.classList.toggle("collapsed");
                }
            });
        });
    }

    /**
     * Update sidebar with new article data
     */
    updateWithArticles(feedResults) {
        // Collect all articles
        this.allArticles = feedResults
            .filter(r => r.status === "success" && r.feed)
            .flatMap(result =>
                result.feed.items.map(item => ({
                    ...item,
                    sourceName: result.name,
                    sourceIcon: result.icon,
                    sourceId: result.id
                }))
            );

        // Update components
        this.renderTrendingTopics();
        this.renderCalendar();
        this.renderFavorites();
    }

    /* ============================================
       SEARCH
       ============================================ */

    handleSearch(query) {
        // Clear any pending debounce
        if (this.searchDebounceTimer) {
            clearTimeout(this.searchDebounceTimer);
            this.searchDebounceTimer = null;
        }

        if (!query || query.length < 2) {
            this.elements.searchResults.innerHTML =
                '<span class="search-hint">Type at least 2 characters to search...</span>';
            return;
        }

        // Show loading indicator immediately for better UX
        this.elements.searchResults.innerHTML =
            '<span class="search-hint"><span class="search-spinner"></span> Searching...</span>';

        // Guard against empty allArticles
        if (!this.allArticles || this.allArticles.length === 0) {
            this.elements.searchResults.innerHTML =
                '<span class="search-hint">No articles loaded yet. Please wait...</span>';
            return;
        }

        const queryLower = query.toLowerCase();
        const results = this.allArticles
            .filter(article => article.title && article.title.toLowerCase().includes(queryLower))
            .slice(0, 20);

        if (results.length === 0) {
            this.elements.searchResults.innerHTML =
                '<span class="search-hint">No results found for "' + this.escapeHtml(query) + '"</span>';
            return;
        }

        // Show count in results header
        const countText =
            results.length === 20 ? "20+ results" : `${results.length} result${results.length > 1 ? "s" : ""}`;

        this.elements.searchResults.innerHTML =
            `<div class="search-count">${countText} for "${this.escapeHtml(query)}"</div>` +
            results
                .map(
                    article => `
            <a class="search-result-item" href="${this.escapeHtml(article.link)}" target="_blank" rel="noopener">
                ${this.highlightMatch(article.title, query)}
                <div class="search-result-source">${article.sourceIcon} ${this.escapeHtml(article.sourceName)}</div>
            </a>
        `
                )
                .join("");
    }

    highlightMatch(text, query) {
        // First escape the text for HTML display
        const escaped = this.escapeHtml(text);
        // Escape the query for use in regex (not HTML escape, regex escape)
        const regexSafeQuery = this.escapeRegex(query);
        // Also need to escape HTML entities in the escaped text for matching
        const escapedQueryForMatch = this.escapeHtml(query);
        const regexSafeEscapedQuery = this.escapeRegex(escapedQueryForMatch);
        const regex = new RegExp(`(${regexSafeEscapedQuery})`, "gi");
        return escaped.replace(regex, "<mark>$1</mark>");
    }

    escapeRegex(str) {
        return str.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
    }

    /* ============================================
       BOOKMARKS
       ============================================ */

    loadBookmarks() {
        try {
            return JSON.parse(localStorage.getItem("ivy-rss-bookmarks") || "[]");
        } catch {
            return [];
        }
    }

    saveBookmarks() {
        localStorage.setItem("ivy-rss-bookmarks", JSON.stringify(this.bookmarks));
    }

    addBookmark(article) {
        // Check if already bookmarked
        if (this.bookmarks.find(b => b.link === article.link)) {
            return false;
        }

        this.bookmarks.unshift({
            title: article.title,
            link: article.link,
            source: article.sourceName || "Unknown",
            savedAt: new Date().toISOString()
        });

        // Limit to 50 bookmarks
        if (this.bookmarks.length > 50) {
            this.bookmarks = this.bookmarks.slice(0, 50);
        }

        this.saveBookmarks();
        this.renderBookmarks();
        return true;
    }

    removeBookmark(link) {
        this.bookmarks = this.bookmarks.filter(b => b.link !== link);
        this.saveBookmarks();
        this.renderBookmarks();
    }

    isBookmarked(link) {
        return this.bookmarks.some(b => b.link === link);
    }

    renderBookmarks() {
        // Update bookmark count badge
        const countBadge = document.getElementById("bookmark-count");
        if (countBadge) {
            countBadge.textContent = this.bookmarks.length > 0 ? `(${this.bookmarks.length})` : "";
        }

        if (this.bookmarks.length === 0) {
            this.elements.bookmarksList.innerHTML =
                '<span class="empty-hint">No bookmarks yet. Click ⭐ on articles to save them.</span>';
            return;
        }

        this.elements.bookmarksList.innerHTML = this.bookmarks
            .map(
                bookmark => `
            <div class="bookmark-item">
                <a class="bookmark-link" href="${this.escapeHtml(bookmark.link)}" target="_blank" rel="noopener">
                    ${this.escapeHtml(this.truncate(bookmark.title, 60))}
                </a>
                <button class="bookmark-remove" data-link="${this.escapeAttr(bookmark.link)}" onclick="sidebar.removeBookmarkFromElement(this)" title="Remove" aria-label="Remove bookmark">×</button>
            </div>
        `
            )
            .join("");
    }

    /**
     * Remove bookmark from button element (uses data-link)
     */
    removeBookmarkFromElement(element) {
        const link = element.dataset.link;
        if (link) {
            this.removeBookmark(link);
            // Refresh main feed view to update star icons
            if (this.app) this.app.renderFeeds();
        }
    }

    /* ============================================
       TRENDING TOPICS
       ============================================ */

    renderTrendingTopics() {
        // Check cache - only recalculate if article count changed
        const cacheKey = this.allArticles.length;
        if (this.trendingCache && this.trendingCacheKey === cacheKey) {
            this.elements.trendingTags.innerHTML = this.trendingCache;
            return;
        }

        // Extract keywords from titles
        const wordCounts = {};
        const stopWords = new Set([
            "the",
            "a",
            "an",
            "and",
            "or",
            "but",
            "in",
            "on",
            "at",
            "to",
            "for",
            "of",
            "with",
            "by",
            "from",
            "is",
            "are",
            "was",
            "were",
            "be",
            "been",
            "have",
            "has",
            "had",
            "do",
            "does",
            "did",
            "will",
            "would",
            "could",
            "should",
            "may",
            "might",
            "must",
            "can",
            "this",
            "that",
            "these",
            "those",
            "it",
            "its",
            "as",
            "if",
            "when",
            "where",
            "how",
            "what",
            "which",
            "who",
            "whom",
            "why",
            "not",
            "no",
            "yes",
            "all",
            "any",
            "both",
            "each",
            "few",
            "more",
            "most",
            "other",
            "some",
            "such",
            "than",
            "too",
            "very",
            "just",
            "also",
            "now",
            "new",
            "like",
            "your",
            "you",
            "we",
            "they",
            "he",
            "she",
            "his",
            "her",
            "their",
            "our",
            "le",
            "la",
            "les",
            "de",
            "du",
            "des",
            "un",
            "une",
            "et",
            "ou",
            "pour",
            "avec",
            "sur",
            "dans",
            "par",
            "plus",
            "que",
            "qui",
            "est",
            "son",
            "sa",
            "ses",
            "ce",
            "cette",
            "ces",
            "en",
            "au",
            "aux",
            "ne",
            "pas",
            "se",
            "si",
            "il",
            "elle",
            "ils",
            "nous",
            "vous",
            "être",
            "avoir",
            "fait",
            "faire",
            "après",
            "avant",
            "tout",
            "tous",
            "comment"
        ]);

        this.allArticles.forEach(article => {
            const words = article.title
                .toLowerCase()
                .replace(/[^\w\sàâäéèêëïîôùûüç-]/g, " ")
                .split(/\s+/)
                .filter(word => word.length > 3 && !stopWords.has(word) && !/^\d+$/.test(word));

            words.forEach(word => {
                wordCounts[word] = (wordCounts[word] || 0) + 1;
            });
        });

        // Sort by count and take top 15
        const trending = Object.entries(wordCounts)
            .sort((a, b) => b[1] - a[1])
            .slice(0, 15);

        if (trending.length === 0) {
            this.elements.trendingTags.innerHTML = '<span class="empty-hint">No trending topics yet.</span>';
            return;
        }

        const maxCount = trending[0][1];

        const html = trending
            .map(([word, count]) => {
                const isHot = count >= maxCount * 0.7;
                return `
                <button class="trending-tag ${isHot ? "hot" : ""}"
                        onclick="sidebar.filterByTag('${this.escapeHtml(word)}')"
                        onkeydown="if(event.key==='Enter'||event.key===' '){event.preventDefault();sidebar.filterByTag('${this.escapeHtml(word)}')}"
                        tabindex="0"
                        role="button"
                        aria-label="Filter by ${this.escapeHtml(word)}, ${count} articles">
                    ${word}
                    <span class="tag-count" aria-hidden="true">${count}</span>
                </button>
            `;
            })
            .join("");

        // Cache the result
        this.trendingCache = html;
        this.trendingCacheKey = cacheKey;
        this.elements.trendingTags.innerHTML = html;
    }

    filterByTag(tag) {
        this.elements.searchInput.value = tag;
        this.handleSearch(tag);
    }

    /* ============================================
       FAVORITE SOURCES
       ============================================ */

    loadFavorites() {
        try {
            return JSON.parse(localStorage.getItem("ivy-rss-favorites") || "[]");
        } catch {
            return [];
        }
    }

    saveFavorites() {
        localStorage.setItem("ivy-rss-favorites", JSON.stringify(this.favoriteSources));
    }

    toggleFavoriteSource(sourceId, sourceName, sourceIcon) {
        const index = this.favoriteSources.findIndex(f => f.id === sourceId);

        if (index >= 0) {
            this.favoriteSources.splice(index, 1);
        } else {
            this.favoriteSources.push({
                id: sourceId,
                name: sourceName,
                icon: sourceIcon
            });
        }

        this.saveFavorites();
        this.renderFavorites();
        return index < 0; // Returns true if added
    }

    isSourceFavorite(sourceId) {
        return this.favoriteSources.some(f => f.id === sourceId);
    }

    renderFavorites() {
        if (this.favoriteSources.length === 0) {
            this.elements.favoritesList.innerHTML =
                '<span class="empty-hint">No favorite sources. Click ⭐ on source headers.</span>';
            return;
        }

        // Get article counts per source
        const sourceCounts = {};
        this.allArticles.forEach(article => {
            sourceCounts[article.sourceId] = (sourceCounts[article.sourceId] || 0) + 1;
        });

        this.elements.favoritesList.innerHTML = this.favoriteSources
            .map(
                source => `
            <div class="favorite-source" onclick="sidebar.scrollToSource('${source.id}')" role="button" tabindex="0" onkeydown="if(event.key==='Enter'||event.key===' '){event.preventDefault();sidebar.scrollToSource('${source.id}')}">
                <span class="favorite-icon" aria-hidden="true">${source.icon}</span>
                <span class="favorite-name">${this.escapeHtml(source.name)}</span>
                <span class="favorite-count" aria-label="${sourceCounts[source.id] || 0} articles">${sourceCounts[source.id] || 0}</span>
                <button class="favorite-remove" onclick="event.stopPropagation(); sidebar.toggleFavoriteSource('${source.id}')" title="Remove from favorites" aria-label="Remove ${this.escapeHtml(source.name)} from favorites">×</button>
            </div>
        `
            )
            .join("");
    }

    scrollToSource(sourceId) {
        const section = document.querySelector(`.source-section[data-source="${sourceId}"]`);
        if (section) {
            section.scrollIntoView({ behavior: "smooth", block: "start" });
            // Flash effect
            section.style.boxShadow = "0 0 0 2px var(--ivy-green)";
            setTimeout(() => {
                section.style.boxShadow = "";
            }, 1500);
        }

        // Close sidebar on mobile
        if (window.innerWidth <= 1100) {
            this.elements.sidebar.classList.remove("open");
        }
    }

    /* ============================================
       CALENDAR
       ============================================ */

    renderCalendar() {
        const days = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];
        const today = new Date();
        today.setHours(0, 0, 0, 0); // Normalize to midnight for consistent comparison
        const dayCounts = {};

        // Initialize count for last 7 days
        for (let i = 0; i < 7; i++) {
            const date = new Date(today);
            date.setDate(date.getDate() - i);
            const dateKey = this.getDateKey(date);
            dayCounts[dateKey] = 0;
        }

        // Count articles per day
        this.allArticles.forEach(article => {
            if (article.pubDate) {
                const dateKey = this.getDateKey(article.pubDate);
                if (dateKey in dayCounts) {
                    dayCounts[dateKey]++;
                }
            }
        });

        // Build calendar HTML (last 7 days)
        const calendarHtml = [];
        for (let i = 6; i >= 0; i--) {
            const date = new Date(today);
            date.setDate(date.getDate() - i);
            const dateKey = this.getDateKey(date);
            const count = dayCounts[dateKey] || 0;
            const isToday = i === 0;
            const dayName = days[date.getDay()];
            const dayOfMonth = date.getDate();

            calendarHtml.push(`
                <div class="calendar-day ${isToday ? "active" : ""}"
                     onclick="sidebar.filterByDay(${i})"
                     title="${date.toLocaleDateString()} - ${count} articles"
                     role="button"
                     tabindex="0"
                     aria-pressed="${isToday}"
                     aria-label="${dayName} ${dayOfMonth}, ${count} articles"
                     onkeydown="if(event.key==='Enter'||event.key===' '){event.preventDefault();sidebar.filterByDay(${i})}">
                    <span class="day-name">${dayName}</span>
                    <span class="day-date">${dayOfMonth}</span>
                    <span class="day-count ${count === 0 ? "zero" : ""}">${count}</span>
                </div>
            `);
        }

        this.elements.calendarGrid.innerHTML = calendarHtml.join("");
    }

    /**
     * Get a normalized date key (YYYY-MM-DD) for consistent comparison
     */
    getDateKey(date) {
        const d = new Date(date);
        return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, "0")}-${String(d.getDate()).padStart(2, "0")}`;
    }

    filterByDay(daysAgo) {
        const today = new Date();
        today.setHours(0, 0, 0, 0);
        const targetDate = new Date(today);
        targetDate.setDate(targetDate.getDate() - daysAgo);
        const targetDateKey = this.getDateKey(targetDate);

        // Filter articles from that day using consistent date key
        const dayArticles = this.allArticles.filter(
            article => article.pubDate && this.getDateKey(article.pubDate) === targetDateKey
        );

        if (dayArticles.length === 0) {
            this.elements.searchResults.innerHTML = `<span class="search-hint">No articles from ${targetDate.toLocaleDateString()}</span>`;
        } else {
            this.elements.searchResults.innerHTML = dayArticles
                .slice(0, 20)
                .map(
                    article => `
                <a class="search-result-item" href="${this.escapeHtml(article.link)}" target="_blank" rel="noopener">
                    ${this.escapeHtml(this.truncate(article.title, 80))}
                    <div class="search-result-source">${article.sourceIcon} ${this.escapeHtml(article.sourceName)}</div>
                </a>
            `
                )
                .join("");
        }

        this.elements.searchInput.value = "";

        // Update calendar active state and aria-pressed
        document.querySelectorAll(".calendar-day").forEach((day, index) => {
            const isActive = index === 6 - daysAgo;
            day.classList.toggle("active", isActive);
            day.setAttribute("aria-pressed", isActive);
        });
    }

    /* ============================================
       UTILITIES
       ============================================ */

    escapeHtml(text) {
        return window.IvyUtils.escapeHtml(text);
    }

    /**
     * Escape text for use in HTML attributes (delegates to shared utility)
     */
    escapeAttr(text) {
        return window.IvyUtils.escapeAttr(text);
    }

    truncate(text, maxLength) {
        return window.IvyUtils.truncate(text, maxLength);
    }
}

// Export
window.SidebarManager = SidebarManager;