/**
 * TestDrive-JSUI - JavaScript-First Markdown Editor
 *
 * Main entry point for the TestDrive-JSUI library.
 * This is a pure JavaScript library for interactive markdown editing.
 * Language adapters (Python, Ruby, Java) are optional integration helpers.
 *
 * @version 1.0.0
 * @license MIT
 */

/**
 * TestDriveJSUI - Main library class
 *
 * Usage:
 * ```javascript
 * const editor = new TestDriveJSUI({
 *     container: '#editor',
 *     markdown: '# Hello World\n\nEdit me!',
 *     mode: 'edit',
 *     theme: 'github',
 *     autosave: false
 * });
 * ```
 */
class TestDriveJSUI {
    constructor(options = {}) {
        // Validate required options
        if (!options.container) {
            throw new Error('TestDriveJSUI: container option is required');
        }

        // Configuration
        this.config = {
            container: options.container,
            markdown: options.markdown || '# Welcome\n\nStart editing...',
            mode: options.mode || 'edit',  // 'edit' or 'view'
            theme: options.theme || 'github',
            autosave: options.autosave || false,
            shortcuts: options.shortcuts !== false,  // default true
            sections: options.sections !== false,    // default true
            debug: options.debug || false,
            ...options
        };

        // Internal state
        this.container = null;
        this.sectionManager = null;
        this.domRenderer = null;
        this.documentControls = null;
        this.isInitialized = false;
        this.listeners = new Map();

        // Initialize
        this.init();
    }

    /**
     * Initialize the editor
     */
    init() {
        if (this.isInitialized) {
            console.warn('TestDriveJSUI: Already initialized');
            return;
        }

        // Resolve container
        this.container = this.resolveContainer(this.config.container);
        if (!this.container) {
            throw new Error('TestDriveJSUI: Could not resolve container');
        }

        // Check for marked.js dependency
        if (typeof marked === 'undefined') {
            console.warn('TestDriveJSUI: marked.js not loaded. Markdown rendering will be limited.');
        }

        // Apply theme
        this.applyTheme(this.config.theme);

        // Initialize components based on mode
        if (this.config.mode === 'edit') {
            this.initEditMode();
        } else {
            this.initViewMode();
        }

        this.isInitialized = true;

        // Emit initialized event
        this.emit('initialized', {
            mode: this.config.mode,
            theme: this.config.theme,
            sections: this.sectionManager ? this.sectionManager.sections.size : 0
        });
    }

    /**
     * Initialize edit mode with full interactivity
     */
    initEditMode() {
        // Load required components
        if (typeof SectionManager === 'undefined') {
            console.error('TestDriveJSUI: SectionManager not loaded');
            return;
        }
        if (typeof DOMRenderer === 'undefined') {
            console.error('TestDriveJSUI: DOMRenderer not loaded');
            return;
        }
        if (typeof DocumentControls === 'undefined') {
            console.error('TestDriveJSUI: DocumentControls not loaded');
            return;
        }

        // Create section manager
        this.sectionManager = new SectionManager();

        // Create DOM renderer
        this.domRenderer = new DOMRenderer(this.sectionManager, this.container);

        // Create document controls
        this.documentControls = new DocumentControls();
        this.documentControls.create();

        // Set up event handlers for controls
        this.setupControlHandlers();

        // Parse markdown into sections and render
        this.sectionManager.createSectionsFromMarkdown(this.config.markdown);

        // Setup keyboard shortcuts if enabled
        if (this.config.shortcuts) {
            this.setupKeyboardShortcuts();
        }

        // Setup autosave if enabled
        if (this.config.autosave) {
            this.setupAutosave();
        }
    }

    /**
     * Initialize view mode (read-only rendering)
     */
    initViewMode() {
        // Clear container
        this.container.innerHTML = '';

        // Render markdown directly using marked.js or simple renderer
        const html = this.renderMarkdown(this.config.markdown);

        // Create content wrapper
        const contentWrapper = document.createElement('div');
        contentWrapper.className = 'testdrive-view-content';
        contentWrapper.innerHTML = html;

        this.container.appendChild(contentWrapper);

        // Apply view mode styling
        contentWrapper.style.cssText = `
            padding: 20px;
            max-width: 800px;
            margin: 0 auto;
            line-height: 1.6;
        `;
    }

    /**
     * Setup control panel event handlers
     */
    setupControlHandlers() {
        this.documentControls.setEventHandlers({
            'save-document': () => {
                const markdown = this.getMarkdown();
                this.emit('save', { markdown });

                // If autosave is enabled and we have a save handler, call it
                if (this.listeners.has('save')) {
                    // User has registered a save handler
                } else {
                    // Default: save to localStorage
                    this.saveToLocalStorage(markdown);
                    alert('Document saved to browser localStorage');
                }
            },
            'reset-all': () => {
                if (confirm('Reset all sections to original content?')) {
                    this.resetAll();
                }
            },
            'show-status': () => {
                const status = this.getStatus();
                this.showStatus(status);
            },
            'toggle-debug': () => {
                this.toggleDebug();
            }
        });
    }

    /**
     * Setup keyboard shortcuts
     */
    setupKeyboardShortcuts() {
        document.addEventListener('keydown', (event) => {
            // Ctrl+S or Cmd+S - Save
            if ((event.ctrlKey || event.metaKey) && event.key === 's') {
                event.preventDefault();
                this.save();
            }

            // Escape - Close editor
            if (event.key === 'Escape') {
                if (this.domRenderer && this.domRenderer.currentFloatingMenu) {
                    this.domRenderer.hideCurrentEditor();
                }
            }
        });
    }

    /**
     * Setup autosave functionality
     */
    setupAutosave() {
        // Save every 30 seconds
        this.autosaveInterval = setInterval(() => {
            const markdown = this.getMarkdown();
            this.saveToLocalStorage(markdown);
            this.emit('autosave', { markdown });
        }, 30000);
    }

    /**
     * Resolve container from selector or element
     */
    resolveContainer(container) {
        if (typeof container === 'string') {
            return document.querySelector(container);
        } else if (container instanceof HTMLElement) {
            return container;
        }
        return null;
    }

    /**
     * Render markdown to HTML
     */
    renderMarkdown(markdown) {
        if (typeof marked !== 'undefined') {
            // Use marked.js for full markdown support
            marked.setOptions({
                gfm: true,
                breaks: true,
                headerIds: true,
                mangle: false,
                sanitize: false
            });
            return marked.parse(markdown);
        } else {
            // Fallback to simple rendering
            return this.simpleMarkdownRender(markdown);
        }
    }

    /**
     * Simple markdown renderer (fallback)
     */
    simpleMarkdownRender(markdown) {
        return markdown
            .replace(/^# (.*$)/gim, '<h1>$1</h1>')
            .replace(/^## (.*$)/gim, '<h2>$1</h2>')
            .replace(/^### (.*$)/gim, '<h3>$1</h3>')
            .replace(/!\[(.*?)\]\((.*?)\)/gim, '<img src="$2" alt="$1" style="max-width: 100%; height: auto;" />')
            .replace(/\[([^\]]+)\]\(([^)]+)\)/gim, '<a href="$2" target="_blank">$1</a>')
            .replace(/\*\*(.*?)\*\*/gim, '<strong>$1</strong>')
            .replace(/\*(.*?)\*/gim, '<em>$1</em>')
            .replace(/`([^`]+)`/gim, '<code>$1</code>')
            .replace(/\n/gim, '<br>');
    }

    /**
     * Apply theme to the editor
     */
    applyTheme(themeName) {
        // Remove existing theme classes
        this.container.className = this.container.className
            .split(' ')
            .filter(c => !c.startsWith('theme-'))
            .join(' ');

        // Add new theme class
        this.container.classList.add(`theme-${themeName}`);

        // Apply base styles
        this.container.style.cssText = `
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
            line-height: 1.6;
            color: #24292e;
            background: #ffffff;
            min-height: 300px;
        `;
    }

    /**
     * Get current markdown content
     */
    getMarkdown() {
        if (this.sectionManager) {
            return this.sectionManager.getDocumentMarkdown();
        }
        return this.config.markdown;
    }

    /**
     * Set markdown content
     */
    setMarkdown(markdown) {
        this.config.markdown = markdown;

        if (this.config.mode === 'edit' && this.sectionManager) {
            // Re-parse and render sections
            this.sectionManager.sections.clear();
            this.sectionManager.createSectionsFromMarkdown(markdown);
        } else {
            // Re-render view mode
            this.container.innerHTML = '';
            this.initViewMode();
        }

        this.emit('content-changed', { markdown });
    }

    /**
     * Get editor status
     */
    getStatus() {
        if (this.sectionManager) {
            const sections = this.sectionManager.getAllSections();
            const editingSections = sections.filter(s => s.isEditing());
            const modifiedSections = sections.filter(s => s.hasChanges());

            return {
                mode: this.config.mode,
                totalSections: sections.length,
                editingSections: editingSections.length,
                modifiedSections: modifiedSections.length,
                wordCount: this.getWordCount(),
                characterCount: this.getMarkdown().length
            };
        }

        return {
            mode: this.config.mode,
            wordCount: this.getWordCount(),
            characterCount: this.config.markdown.length
        };
    }

    /**
     * Get word count
     */
    getWordCount() {
        const text = this.getMarkdown();
        return text.split(/\s+/).filter(word => word.length > 0).length;
    }

    /**
     * Show status dialog
     */
    showStatus(status) {
        const message = [
            `Mode: ${status.mode}`,
            `Total Sections: ${status.totalSections || 0}`,
            `Editing: ${status.editingSections || 0}`,
            `Modified: ${status.modifiedSections || 0}`,
            `Words: ${status.wordCount}`,
            `Characters: ${status.characterCount}`
        ].join('\n');

        alert(message);
    }

    /**
     * Save current content
     */
    save() {
        const markdown = this.getMarkdown();
        this.emit('save', { markdown });

        // Default: save to localStorage
        this.saveToLocalStorage(markdown);
    }

    /**
     * Save to browser localStorage
     */
    saveToLocalStorage(markdown) {
        try {
            localStorage.setItem('testdrive-jsui-content', markdown);
            localStorage.setItem('testdrive-jsui-timestamp', new Date().toISOString());
        } catch (e) {
            console.error('Failed to save to localStorage:', e);
        }
    }

    /**
     * Load from browser localStorage
     */
    loadFromLocalStorage() {
        try {
            const markdown = localStorage.getItem('testdrive-jsui-content');
            if (markdown) {
                this.setMarkdown(markdown);
                return true;
            }
        } catch (e) {
            console.error('Failed to load from localStorage:', e);
        }
        return false;
    }

    /**
     * Download markdown as file
     */
    download(filename = 'document.md') {
        const markdown = this.getMarkdown();
        const blob = new Blob([markdown], { type: 'text/markdown' });
        const url = URL.createObjectURL(blob);
        const a = document.createElement('a');
        a.href = url;
        a.download = filename;
        document.body.appendChild(a);
        a.click();
        document.body.removeChild(a);
        URL.revokeObjectURL(url);

        this.emit('download', { filename, markdown });
    }

    /**
     * Reset all sections to original content
     */
    resetAll() {
        if (this.sectionManager) {
            const sections = this.sectionManager.getAllSections();
            sections.forEach(section => {
                this.sectionManager.resetSection(section.id);
            });
        }

        this.emit('reset');
    }

    /**
     * Toggle debug mode
     */
    toggleDebug() {
        this.config.debug = !this.config.debug;

        const debugContainer = document.getElementById('debug-messages-container');
        if (debugContainer) {
            debugContainer.style.display = this.config.debug ? 'block' : 'none';
        }

        this.emit('debug-toggled', { enabled: this.config.debug });
    }

    /**
     * Event listener system
     */
    on(event, callback) {
        if (!this.listeners.has(event)) {
            this.listeners.set(event, []);
        }
        this.listeners.get(event).push(callback);
        return this;
    }

    /**
     * Remove event listener
     */
    off(event, callback) {
        if (this.listeners.has(event)) {
            const callbacks = this.listeners.get(event);
            const index = callbacks.indexOf(callback);
            if (index > -1) {
                callbacks.splice(index, 1);
            }
        }
        return this;
    }

    /**
     * Emit event
     */
    emit(event, data) {
        if (this.listeners.has(event)) {
            this.listeners.get(event).forEach(callback => {
                try {
                    callback(data);
                } catch (e) {
                    console.error(`Error in event listener for '${event}':`, e);
                }
            });
        }
    }

    /**
     * Destroy the editor and clean up
     */
    destroy() {
        // Clear autosave interval
        if (this.autosaveInterval) {
            clearInterval(this.autosaveInterval);
        }

        // Destroy document controls
        if (this.documentControls) {
            this.documentControls.destroy();
        }

        // Clear container
        if (this.container) {
            this.container.innerHTML = '';
        }

        // Clear references
        this.sectionManager = null;
        this.domRenderer = null;
        this.documentControls = null;
        this.listeners.clear();
        this.isInitialized = false;

        this.emit('destroyed');
    }
}

// Export for CommonJS (Node.js, Jest)
if (typeof module !== 'undefined' && module.exports) {
    module.exports = { TestDriveJSUI };
}

// Export for browser use
if (typeof window !== 'undefined') {
    window.TestDriveJSUI = TestDriveJSUI;
}