/**
 * File Editor with CodeMirror 6
 * Supports: Multi-file tabs, syntax highlighting, dirty state tracking
 */

import { EditorState, Compartment } from '@codemirror/state';
import { EditorView, keymap, highlightSpecialChars, drawSelection, dropCursor, lineNumbers, rectangularSelection, crosshairCursor, highlightActiveLine, highlightSelectionMatches, EditorView as cmEditorView } from '@codemirror/view';
import { defaultKeymap, history, historyKeymap } from '@codemirror/commands';
import { searchKeymap, highlightSelectionMatches as searchHighlightMatches } from '@codemirror/search';
import { autocompletion, completionKeymap, closeBrackets, closeBracketsKeymap } from '@codemirror/autocomplete';
import { bracketMatching, codeFolding, foldGutter, syntaxHighlighting, defaultHighlightStyle } from '@codemirror/language';
import { tags } from '@lezer/highlight';

// Language support
import { javascript } from '@codemirror/lang-javascript';
import { python } from '@codemirror/lang-python';
import { html } from '@codemirror/lang-html';
import { css } from '@codemirror/lang-css';
import { json } from '@codemirror/lang-json';
import { markdown } from '@codemirror/lang-markdown';

// Custom dark theme matching GitHub's dark theme
const customDarkTheme = cmEditorView.theme({
    '&': {
        backgroundColor: '#0d1117',
        color: '#c9d1d9',
        fontSize: '14px',
        fontFamily: "'Fira Code', 'JetBrains Mono', 'SF Mono', 'Menlo', 'Consolas', monospace"
    },
    '.cm-scroller': {
        fontFamily: 'inherit',
        overflow: 'auto'
    },
    '.cm-content': {
        padding: '12px 0',
        minHeight: '100%'
    },
    '.cm-line': {
        padding: '0 12px'
    },
    '.cm-gutters': {
        backgroundColor: '#0d1117',
        color: '#484f58',
        border: 'none'
    },
    '.cm-activeLineGutter': {
        backgroundColor: 'transparent',
        color: '#c9d1d9'
    },
    '.cm-activeLine': {
        backgroundColor: '#161b22'
    },
    '.cm-focused': {
        outline: 'none'
    },
    '.cm-selectionBackground': {
        backgroundColor: '#264f78'
    },
    '&.cm-focused .cm-selectionBackground': {
        backgroundColor: '#264f78'
    },
    '.cm-selectionMatch': {
        backgroundColor: '#264f7855'
    },
    '.cm-cursor': {
        borderLeftColor: '#58a6ff'
    },
    '.cm-foldPlaceholder': {
        backgroundColor: 'transparent',
        border: 'none',
        color: '#484f58'
    },
    '.cm-tooltip': {
        border: '1px solid #30363d',
        backgroundColor: '#161b22',
        boxShadow: '0 4px 12px rgba(0, 0, 0, 0.5)'
    },
    '.cm-tooltip-autocomplete': {
        '& > ul': {
            maxHeight: '200px',
            fontFamily: 'inherit',
            '& > li': {
                padding: '4px 8px',
                '&[aria-selected]': {
                    backgroundColor: '#1f6feb',
                    color: '#ffffff'
                }
            }
        }
    }
}, {
    dark: true
});

// State compartments for dynamic reconfiguration
const languageCompartment = new Compartment();
const tabSizeCompartment = new Compartment();

/**
 * Get language extension based on file extension
 */
function getLanguageExtension(filePath) {
    const ext = filePath.split('.').pop().toLowerCase();

    const languageMap = {
        'js': javascript(),
        'jsx': javascript({ jsx: true }),
        'ts': javascript({ typescript: true }),
        'tsx': javascript({ typescript: true, jsx: true }),
        'mjs': javascript(),
        'cjs': javascript(),
        'py': python(),
        'html': html(),
        'htm': html(),
        'css': css(),
        'scss': css(),
        'sass': css(),
        'json': json(),
        'md': markdown(),
        'markdown': markdown(),
        'txt': null
    };

    return languageMap[ext] || javascript();
}

/**
 * Create CodeMirror editor state
 */
function createEditorState(filePath, content, onChange) {
    const language = getLanguageExtension(filePath);

    return EditorState.create({
        doc: content || '',
        extensions: [
            lineNumbers(),
            highlightSpecialChars(),
            history(),
            foldGutter(),
            drawSelection(),
            dropCursor(),
            codeFolding(),
            bracketMatching(),
            closeBrackets(),
            autocompletion(),
            rectangularSelection(),
            crosshairCursor(),
            highlightActiveLine(),
            highlightSelectionMatches(),
            syntaxHighlighting(defaultHighlightStyle, { fallback: true }),
            keymap.of([
                ...closeBracketsKeymap,
                ...defaultKeymap,
                ...searchKeymap,
                ...historyKeymap,
                ...completionKeymap,
                {
                    key: 'Mod-s',
                    run: () => {
                        // Trigger save - will be handled by the component
                        const event = new CustomEvent('editor-save', { bubbles: true });
                        document.dispatchEvent(event);
                        return true;
                    }
                },
                {
                    key: 'Mod-w',
                    run: (view) => {
                        // Trigger close tab - will be handled by the component
                        const event = new CustomEvent('editor-close-tab', { bubbles: true });
                        document.dispatchEvent(event);
                        return true;
                    }
                }
            ]),
            customDarkTheme,
            languageCompartment.of(language || []),
            tabSizeCompartment.of(EditorState.tabSize.of(4)),
            cmEditorView.updateListener.of((update) => {
                if (update.docChanged) {
                    // Notify that content changed
                    if (onChange) onChange();
                }
            })
        ]
    });
}

/**
 * FileEditor Class
 */
class FileEditor {
    constructor(container) {
        this.container = container;
        this.editors = new Map(); // tabId -> EditorView
        this.activeTab = null;
        this.tabs = [];
        this.nextTabId = 1;

        this.initialize();
    }

    initialize() {
        // Create editor container structure
        this.container.innerHTML = `
            <div class="file-editor-container">
                <div class="editor-header">
                    <div class="editor-tabs" id="editor-tabs">
                        <!-- Tabs will be rendered here -->
                    </div>
                    <div class="editor-actions">
                        <button class="btn-icon" id="btn-save-all" title="Save All (Ctrl+S)">💾</button>
                        <button class="btn-icon" id="btn-close-all" title="Close All">✕</button>
                    </div>
                </div>
                <div class="editor-content" id="editor-content">
                    <div class="editor-placeholder">
                        <div class="placeholder-icon">📄</div>
                        <h2>No file open</h2>
                        <p>Select a file from the sidebar to start editing</p>
                    </div>
                </div>
            </div>
        `;

        // Set up event listeners
        this.setupEventListeners();
    }

    setupEventListeners() {
        // Save all button
        const saveAllBtn = this.container.querySelector('#btn-save-all');
        if (saveAllBtn) {
            saveAllBtn.addEventListener('click', () => this.saveAllFiles());
        }

        // Close all button
        const closeAllBtn = this.container.querySelector('#btn-close-all');
        if (closeAllBtn) {
            closeAllBtn.addEventListener('click', () => this.closeAllTabs());
        }

        // Keyboard shortcuts
        document.addEventListener('editor-save', () => this.saveCurrentFile());
        document.addEventListener('editor-close-tab', () => this.closeCurrentTab());

        // Handle window resize
        window.addEventListener('resize', () => this.refreshActiveEditor());
    }

    /**
     * Open a file in the editor
     */
    async openFile(filePath, content) {
        // Check if file is already open
        const existingTab = this.tabs.find(tab => tab.path === filePath);
        if (existingTab) {
            this.activateTab(existingTab.id);
            return;
        }

        // Create new tab
        const tabId = `tab-${this.nextTabId++}`;
        const tab = {
            id: tabId,
            path: filePath,
            name: filePath.split('/').pop(),
            dirty: false,
            originalContent: content || ''
        };

        this.tabs.push(tab);

        // Create CodeMirror editor instance
        const editorContainer = document.createElement('div');
        editorContainer.className = 'cm-editor-instance';
        editorContainer.style.display = 'none';

        const contentArea = this.container.querySelector('#editor-content');

        // Remove placeholder if it exists
        const placeholder = contentArea.querySelector('.editor-placeholder');
        if (placeholder) {
            placeholder.remove();
        }

        contentArea.appendChild(editorContainer);

        const state = createEditorState(filePath, content || '', () => {
            this.markDirty(tabId);
        });

        const editor = new EditorView({
            state: state,
            parent: editorContainer
        });

        this.editors.set(tabId, editor);

        // Activate the new tab
        this.activateTab(tabId);

        return tabId;
    }

    /**
     * Activate a tab
     */
    activateTab(tabId) {
        if (!this.editors.has(tabId)) {
            console.error('[FileEditor] Tab not found:', tabId);
            return;
        }

        // Hide all editors
        this.editors.forEach((editor, id) => {
            const container = editor.dom.parentElement;
            if (container) {
                container.style.display = id === tabId ? 'block' : 'none';
            }
        });

        this.activeTab = tabId;
        this.renderTabs();

        // Refresh the active editor to ensure proper rendering
        setTimeout(() => this.refreshActiveEditor(), 10);
    }

    /**
     * Close a tab
     */
    async closeTab(tabId) {
        const tab = this.tabs.find(t => t.id === tabId);
        if (!tab) return;

        // Check for unsaved changes
        if (tab.dirty) {
            const shouldSave = confirm(`Save changes to ${tab.name} before closing?`);
            if (shouldSave) {
                await this.saveFile(tabId);
            }
        }

        // Destroy editor
        const editor = this.editors.get(tabId);
        if (editor) {
            editor.destroy();
            this.editors.delete(tabId);
        }

        // Remove tab from list
        this.tabs = this.tabs.filter(t => t.id !== tabId);

        // If we closed the active tab, activate another one
        if (this.activeTab === tabId) {
            if (this.tabs.length > 0) {
                this.activateTab(this.tabs[0].id);
            } else {
                this.activeTab = null;
                this.showPlaceholder();
            }
        }

        this.renderTabs();
    }

    /**
     * Close current tab
     */
    closeCurrentTab() {
        if (this.activeTab) {
            this.closeTab(this.activeTab);
        }
    }

    /**
     * Close all tabs
     */
    async closeAllTabs() {
        if (this.tabs.length === 0) return;

        const hasUnsaved = this.tabs.some(t => t.dirty);
        if (hasUnsaved) {
            const shouldSaveAll = confirm('Some files have unsaved changes. Save all before closing?');
            if (shouldSaveAll) {
                await this.saveAllFiles();
            }
        }

        // Destroy all editors
        this.editors.forEach(editor => editor.destroy());
        this.editors.clear();

        this.tabs = [];
        this.activeTab = null;

        this.renderTabs();
        this.showPlaceholder();
    }

    /**
     * Save a file
     */
    async saveFile(tabId) {
        const tab = this.tabs.find(t => t.id === tabId);
        if (!tab) return;

        const editor = this.editors.get(tabId);
        if (!editor) return;

        const content = editor.state.doc.toString();

        try {
            const response = await fetch(`/claude/api/file/${encodeURIComponent(tab.path)}`, {
                method: 'PUT',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({ content })
            });

            if (!response.ok) {
                throw new Error(`HTTP ${response.status}: ${response.statusText}`);
            }

            const data = await response.json();
            if (data.error) {
                throw new Error(data.error);
            }

            // Update tab state
            tab.dirty = false;
            tab.originalContent = content;

            this.renderTabs();

            // Show success toast
            if (typeof showToast === 'function') {
                showToast(`✅ Saved ${tab.name}`, 'success', 2000);
            }

            return true;
        } catch (error) {
            console.error('[FileEditor] Error saving file:', error);
            if (typeof showToast === 'function') {
                showToast(`❌ Failed to save ${tab.name}: ${error.message}`, 'error', 3000);
            }
            return false;
        }
    }

    /**
     * Save current file
     */
    async saveCurrentFile() {
        if (this.activeTab) {
            await this.saveFile(this.activeTab);
        }
    }

    /**
     * Save all files
     */
    async saveAllFiles() {
        const dirtyTabs = this.tabs.filter(t => t.dirty);

        if (dirtyTabs.length === 0) {
            if (typeof showToast === 'function') {
                showToast('No unsaved changes', 'info', 2000);
            }
            return;
        }

        let saved = 0;
        let failed = 0;

        for (const tab of dirtyTabs) {
            const result = await this.saveFile(tab.id);
            if (result) {
                saved++;
            } else {
                failed++;
            }
        }

        if (typeof showToast === 'function') {
            if (failed === 0) {
                showToast(`✅ Saved ${saved} file${saved > 1 ? 's' : ''}`, 'success', 2000);
            } else {
                showToast(`⚠️ Saved ${saved} file${saved > 1 ? 's' : ''}, ${failed} failed`, 'warning', 3000);
            }
        }
    }

    /**
     * Mark tab as dirty (unsaved changes)
     */
    markDirty(tabId) {
        const tab = this.tabs.find(t => t.id === tabId);
        if (tab && !tab.dirty) {
            tab.dirty = true;
            this.renderTabs();
        }
    }

    /**
     * Check if any tab is dirty
     */
    hasUnsavedChanges() {
        return this.tabs.some(t => t.dirty);
    }

    /**
     * Get current file content
     */
    getCurrentContent() {
        if (!this.activeTab) return null;

        const editor = this.editors.get(this.activeTab);
        return editor ? editor.state.doc.toString() : null;
    }

    /**
     * Get current file path
     */
    getCurrentFilePath() {
        if (!this.activeTab) return null;

        const tab = this.tabs.find(t => t.id === this.activeTab);
        return tab ? tab.path : null;
    }

    /**
     * Refresh active editor
     */
    refreshActiveEditor() {
        if (!this.activeTab) return;

        const editor = this.editors.get(this.activeTab);
        if (editor) {
            editor.requestMeasure();
        }
    }

    /**
     * Show placeholder when no files are open
     */
    showPlaceholder() {
        const contentArea = this.container.querySelector('#editor-content');
        if (contentArea) {
            contentArea.innerHTML = `
                <div class="editor-placeholder">
                    <div class="placeholder-icon">📄</div>
                    <h2>No file open</h2>
                    <p>Select a file from the sidebar to start editing</p>
                </div>
            `;
        }
    }

    /**
     * Render tabs
     */
    renderTabs() {
        const tabsContainer = this.container.querySelector('#editor-tabs');
        if (!tabsContainer) return;

        if (this.tabs.length === 0) {
            tabsContainer.innerHTML = '';
            return;
        }

        tabsContainer.innerHTML = this.tabs.map(tab => `
            <div class="editor-tab ${tab.id === this.activeTab ? 'active' : ''} ${tab.dirty ? 'dirty' : ''}"
                 data-tab-id="${tab.id}">
                <span class="tab-name">${this.escapeHtml(tab.name)}</span>
                ${tab.dirty ? '<span class="tab-dirty-indicator">●</span>' : ''}
                <button class="tab-close" title="Close tab">×</button>
            </div>
        `).join('');

        // Tab click handlers
        tabsContainer.querySelectorAll('.editor-tab').forEach(tabEl => {
            tabEl.addEventListener('click', (e) => {
                if (!e.target.classList.contains('tab-close')) {
                    this.activateTab(tabEl.dataset.tabId);
                }
            });

            const closeBtn = tabEl.querySelector('.tab-close');
            if (closeBtn) {
                closeBtn.addEventListener('click', (e) => {
                    e.stopPropagation();
                    this.closeTab(tabEl.dataset.tabId);
                });
            }
        });
    }

    /**
     * Escape HTML to prevent XSS
     */
    escapeHtml(text) {
        const div = document.createElement('div');
        div.textContent = text;
        return div.innerHTML;
    }

    /**
     * Get tab count
     */
    getTabCount() {
        return this.tabs.length;
    }

    /**
     * Get dirty tab count
     */
    getDirtyTabCount() {
        return this.tabs.filter(t => t.dirty).length;
    }

    /**
     * Destroy editor and cleanup
     */
    destroy() {
        // Destroy all editors
        this.editors.forEach(editor => editor.destroy());
        this.editors.clear();

        this.tabs = [];
        this.activeTab = null;
    }
}

// Export for use in other scripts
if (typeof module !== 'undefined' && module.exports) {
    module.exports = { FileEditor };
}

// Export to window for use from non-module scripts
if (typeof window !== 'undefined') {
    window.FileEditor = FileEditor;
    console.log('[FileEditor] Component loaded and available globally');
}

// Auto-initialize when DOM is ready
if (typeof document !== 'undefined') {
    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', () => {
            // Create global file editor instance
            if (!window.fileEditor) {
                window.fileEditor = new FileEditor(document.getElementById('file-editor'));
                console.log('[FileEditor] Auto-initialized on DOMContentLoaded');
            }
        });
    } else {
        // DOM is already ready
        if (!window.fileEditor) {
            window.fileEditor = new FileEditor(document.getElementById('file-editor'));
            console.log('[FileEditor] Auto-initialized (DOM already ready)');
        }
    }
}