import { BaseBlockHandler, type IBlockEventHandlers } from '../block.base.js';
import type { IBlock } from '../../wysiwyg.types.js';
import { cssManager } from '@design.estate/dees-element';
import { WysiwygBlocks } from '../../wysiwyg.blocks.js';
import { WysiwygSelection } from '../../wysiwyg.selection.js';

export class CodeBlockHandler extends BaseBlockHandler {
  type = 'code';
  
  // Track cursor position
  private lastKnownCursorPosition: number = 0;
  
  render(block: IBlock, isSelected: boolean): string {
    const language = block.metadata?.language || 'plain text';
    const selectedClass = isSelected ? ' selected' : '';
    
    console.log('CodeBlockHandler.render:', { blockId: block.id, isSelected, content: block.content, language });
    
    return `
      <div class="code-block-container">
        <div class="code-language">${language}</div>
        <div
          class="block code${selectedClass}"
          contenteditable="true"
          data-block-id="${block.id}"
          data-block-type="${block.type}"
          spellcheck="false"
        ></div>
      </div>
    `;
  }
  
  setup(element: HTMLElement, block: IBlock, handlers: IBlockEventHandlers): void {
    const codeBlock = element.querySelector('.block.code') as HTMLDivElement;
    if (!codeBlock) {
      console.error('CodeBlockHandler.setup: No code block element found');
      return;
    }
    
    console.log('CodeBlockHandler.setup: Setting up code block', { blockId: block.id });
    
    // Set initial content if needed - use textContent for code blocks
    if (block.content && !codeBlock.textContent) {
      codeBlock.textContent = block.content;
    }
    
    // Input handler
    codeBlock.addEventListener('input', (e) => {
      console.log('CodeBlockHandler: Input event', { blockId: block.id });
      handlers.onInput(e as InputEvent);
      
      // Track cursor position after input
      const pos = this.getCursorPosition(element);
      if (pos !== null) {
        this.lastKnownCursorPosition = pos;
      }
    });
    
    // Keydown handler
    codeBlock.addEventListener('keydown', (e) => {
      // Track cursor position before keydown
      const pos = this.getCursorPosition(element);
      if (pos !== null) {
        this.lastKnownCursorPosition = pos;
      }
      
      // Special handling for Tab key in code blocks
      if (e.key === 'Tab') {
        e.preventDefault();
        // Insert two spaces for tab
        const selection = window.getSelection();
        if (selection && selection.rangeCount > 0) {
          const range = selection.getRangeAt(0);
          range.deleteContents();
          const textNode = document.createTextNode('  ');
          range.insertNode(textNode);
          range.setStartAfter(textNode);
          range.setEndAfter(textNode);
          selection.removeAllRanges();
          selection.addRange(range);
          
          // Trigger input event
          handlers.onInput(new InputEvent('input'));
        }
        return;
      }
      
      handlers.onKeyDown(e);
    });
    
    // Focus handler
    codeBlock.addEventListener('focus', () => {
      console.log('CodeBlockHandler: Focus event', { blockId: block.id });
      handlers.onFocus();
    });
    
    // Blur handler
    codeBlock.addEventListener('blur', () => {
      console.log('CodeBlockHandler: Blur event', { blockId: block.id });
      handlers.onBlur();
    });
    
    // Composition handlers for IME support
    codeBlock.addEventListener('compositionstart', () => {
      console.log('CodeBlockHandler: Composition start', { blockId: block.id });
      handlers.onCompositionStart();
    });
    
    codeBlock.addEventListener('compositionend', () => {
      console.log('CodeBlockHandler: Composition end', { blockId: block.id });
      handlers.onCompositionEnd();
    });
    
    // Mouse up handler
    codeBlock.addEventListener('mouseup', (e) => {
      const pos = this.getCursorPosition(element);
      if (pos !== null) {
        this.lastKnownCursorPosition = pos;
      }
      handlers.onMouseUp?.(e);
    });
    
    // Click handler with delayed cursor tracking
    codeBlock.addEventListener('click', (e: MouseEvent) => {
      setTimeout(() => {
        const pos = this.getCursorPosition(element);
        if (pos !== null) {
          this.lastKnownCursorPosition = pos;
        }
      }, 0);
    });
    
    // Keyup handler for cursor tracking
    codeBlock.addEventListener('keyup', (e) => {
      const pos = this.getCursorPosition(element);
      if (pos !== null) {
        this.lastKnownCursorPosition = pos;
      }
    });
    
    // Paste handler - handle as plain text
    codeBlock.addEventListener('paste', (e) => {
      e.preventDefault();
      const text = e.clipboardData?.getData('text/plain');
      if (text) {
        const selection = window.getSelection();
        if (selection && selection.rangeCount > 0) {
          const range = selection.getRangeAt(0);
          range.deleteContents();
          const textNode = document.createTextNode(text);
          range.insertNode(textNode);
          range.setStartAfter(textNode);
          range.setEndAfter(textNode);
          selection.removeAllRanges();
          selection.addRange(range);
          
          // Trigger input event
          handlers.onInput(new InputEvent('input'));
        }
      }
    });
  }
  
  getStyles(): string {
    return `
      /* Code block specific styles */
      .code-block-container {
        position: relative;
        margin: 20px 0;
      }
      
      .block.code {
        font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', monospace;
        font-size: 14px;
        background: ${cssManager.bdTheme('#f8f8f8', '#0d0d0d')};
        border: 1px solid ${cssManager.bdTheme('#e0e0e0', '#2a2a2a')};
        padding: 16px 20px;
        padding-top: 32px;
        border-radius: 6px;
        white-space: pre-wrap;
        color: ${cssManager.bdTheme('#24292e', '#e1e4e8')};
        line-height: 1.5;
        overflow-x: auto;
        margin: 0;
      }
      
      .code-language {
        position: absolute;
        top: 0;
        right: 0;
        background: ${cssManager.bdTheme('#e1e4e8', '#333333')};
        color: ${cssManager.bdTheme('#586069', '#8b949e')};
        padding: 4px 12px;
        font-size: 12px;
        border-radius: 0 6px 0 6px;
        font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
        text-transform: lowercase;
        z-index: 1;
      }
    `;
  }
  
  getPlaceholder(): string {
    return '';
  }
  
  // Helper methods for code functionality
  
  getCursorPosition(element: HTMLElement, context?: any): number | null {
    // Get the actual code element
    const codeBlock = element.querySelector('.block.code') as HTMLDivElement;
    if (!codeBlock) {
      console.log('CodeBlockHandler.getCursorPosition: No code element found');
      return null;
    }
    
    // Get shadow roots from context
    const wysiwygBlock = context?.component;
    const parentComponent = wysiwygBlock?.closest('dees-input-wysiwyg');
    const parentShadowRoot = parentComponent?.shadowRoot;
    const blockShadowRoot = context?.shadowRoot;
    
    // Get selection info with both shadow roots for proper traversal
    const shadowRoots: ShadowRoot[] = [];
    if (parentShadowRoot) shadowRoots.push(parentShadowRoot);
    if (blockShadowRoot) shadowRoots.push(blockShadowRoot);
    
    const selectionInfo = WysiwygSelection.getSelectionInfo(...shadowRoots);
    
    if (!selectionInfo) {
      return null;
    }
    
    if (!WysiwygSelection.containsAcrossShadowDOM(codeBlock, selectionInfo.startContainer)) {
      return null;
    }
    
    // Create a range from start of element to cursor position
    const preCaretRange = document.createRange();
    preCaretRange.selectNodeContents(codeBlock);
    preCaretRange.setEnd(selectionInfo.startContainer, selectionInfo.startOffset);
    
    // Get the text content length up to cursor
    const position = preCaretRange.toString().length;
    
    return position;
  }
  
  getContent(element: HTMLElement, context?: any): string {
    const codeBlock = element.querySelector('.block.code') as HTMLDivElement;
    if (!codeBlock) return '';
    
    // For code blocks, get textContent to avoid HTML formatting
    const content = codeBlock.textContent || '';
    console.log('CodeBlockHandler.getContent:', content);
    return content;
  }
  
  setContent(element: HTMLElement, content: string, context?: any): void {
    const codeBlock = element.querySelector('.block.code') as HTMLDivElement;
    if (!codeBlock) return;
    
    // Store if we have focus
    const hadFocus = document.activeElement === codeBlock || 
                     element.shadowRoot?.activeElement === codeBlock;
    
    // Use textContent for code blocks
    codeBlock.textContent = content;
    
    // Restore focus if we had it
    if (hadFocus) {
      codeBlock.focus();
    }
  }
  
  setCursorToStart(element: HTMLElement, context?: any): void {
    const codeBlock = element.querySelector('.block.code') as HTMLDivElement;
    if (codeBlock) {
      WysiwygBlocks.setCursorToStart(codeBlock);
    }
  }
  
  setCursorToEnd(element: HTMLElement, context?: any): void {
    const codeBlock = element.querySelector('.block.code') as HTMLDivElement;
    if (codeBlock) {
      WysiwygBlocks.setCursorToEnd(codeBlock);
    }
  }
  
  focus(element: HTMLElement, context?: any): void {
    const codeBlock = element.querySelector('.block.code') as HTMLDivElement;
    if (!codeBlock) return;
    
    // Ensure the element is focusable
    if (!codeBlock.hasAttribute('contenteditable')) {
      codeBlock.setAttribute('contenteditable', 'true');
    }
    
    codeBlock.focus();
    
    // If focus failed, try again after a microtask
    if (document.activeElement !== codeBlock && element.shadowRoot?.activeElement !== codeBlock) {
      Promise.resolve().then(() => {
        codeBlock.focus();
      });
    }
  }
  
  focusWithCursor(element: HTMLElement, position: 'start' | 'end' | number = 'end', context?: any): void {
    const codeBlock = element.querySelector('.block.code') as HTMLDivElement;
    if (!codeBlock) return;
    
    // Ensure element is focusable first
    if (!codeBlock.hasAttribute('contenteditable')) {
      codeBlock.setAttribute('contenteditable', 'true');
    }
    
    // Focus the element
    codeBlock.focus();
    
    // Set cursor position after focus is established
    const setCursor = () => {
      if (position === 'start') {
        this.setCursorToStart(element, context);
      } else if (position === 'end') {
        this.setCursorToEnd(element, context);
      } else if (typeof position === 'number') {
        // Use the selection utility to set cursor position
        WysiwygSelection.setCursorPosition(codeBlock, position);
      }
    };
    
    // Ensure cursor is set after focus
    if (document.activeElement === codeBlock || element.shadowRoot?.activeElement === codeBlock) {
      setCursor();
    } else {
      // Wait for focus to be established
      Promise.resolve().then(() => {
        if (document.activeElement === codeBlock || element.shadowRoot?.activeElement === codeBlock) {
          setCursor();
        }
      });
    }
  }
  
  getSplitContent(element: HTMLElement, context?: any): { before: string; after: string } | null {
    const codeBlock = element.querySelector('.block.code') as HTMLDivElement;
    if (!codeBlock) {
      return null;
    }
    
    // Get shadow roots from context
    const wysiwygBlock = context?.component;
    const parentComponent = wysiwygBlock?.closest('dees-input-wysiwyg');
    const parentShadowRoot = parentComponent?.shadowRoot;
    const blockShadowRoot = context?.shadowRoot;
    
    // Get selection info with both shadow roots for proper traversal
    const shadowRoots: ShadowRoot[] = [];
    if (parentShadowRoot) shadowRoots.push(parentShadowRoot);
    if (blockShadowRoot) shadowRoots.push(blockShadowRoot);
    
    const selectionInfo = WysiwygSelection.getSelectionInfo(...shadowRoots);
    
    if (!selectionInfo) {
      // Try using last known cursor position
      if (this.lastKnownCursorPosition !== null) {
        const fullText = codeBlock.textContent || '';
        const pos = Math.min(this.lastKnownCursorPosition, fullText.length);
        return {
          before: fullText.substring(0, pos),
          after: fullText.substring(pos)
        };
      }
      return null;
    }
    
    // Make sure the selection is within this block
    if (!WysiwygSelection.containsAcrossShadowDOM(codeBlock, selectionInfo.startContainer)) {
      // Try using last known cursor position
      if (this.lastKnownCursorPosition !== null) {
        const fullText = codeBlock.textContent || '';
        const pos = Math.min(this.lastKnownCursorPosition, fullText.length);
        return {
          before: fullText.substring(0, pos),
          after: fullText.substring(pos)
        };
      }
      return null;
    }
    
    // Get cursor position
    const cursorPos = this.getCursorPosition(element, context);
    
    if (cursorPos === null || cursorPos === 0) {
      // If cursor is at start or can't determine position, move all content
      return {
        before: '',
        after: codeBlock.textContent || ''
      };
    }
    
    // For code blocks, split based on text content only
    const fullText = codeBlock.textContent || '';
    
    return { 
      before: fullText.substring(0, cursorPos), 
      after: fullText.substring(cursorPos) 
    };
  }
}