import { Notice } from 'obsidian';

export class KeyboardNavigator {
  private container: HTMLElement | null = null;
  private table: HTMLTableElement | null = null;
  private row = 0;
  private col = 0;
  private rows: HTMLTableRowElement[] = [];
  private active = false;
  private searchMode = false;
  private searchOverlay: HTMLElement | null = null;
  private searchInput: HTMLInputElement | null = null;
  private searchQuery = '';
  private boundHandler: (e: KeyboardEvent) => void;

  constructor(private app: { workspace: { openLinkText(link: string, source: string): void } }) {
    this.boundHandler = this.handleKeydown.bind(this);
  }

  attach(container: HTMLElement): boolean {
    const table = container.querySelector<HTMLTableElement>('table.logfire-table');
    if (!table) return false;

    this.container = container;
    this.table = table;
    this.rows = Array.from(table.querySelectorAll('tbody tr'));
    if (this.rows.length === 0) return false;

    this.active = true;
    this.row = 0;
    this.col = 0;
    container.tabIndex = 0;
    container.focus();
    container.addEventListener('keydown', this.boundHandler);
    this.highlight();
    return true;
  }

  detach(): void {
    this.clearHighlight();
    this.closeSearch();
    if (this.container) {
      this.container.removeEventListener('keydown', this.boundHandler);
    }
    this.active = false;
    this.container = null;
    this.table = null;
    this.rows = [];
  }

  isActive(): boolean {
    return this.active;
  }

  // ---------------------------------------------------------------------------
  // Keydown handler
  // ---------------------------------------------------------------------------

  private handleKeydown(e: KeyboardEvent): void {
    if (!this.active) return;

    if (this.searchMode) {
      this.handleSearchKey(e);
      return;
    }

    switch (e.key) {
      case 'j': this.move(1, 0); break;
      case 'k': this.move(-1, 0); break;
      case 'l': this.move(0, 1); break;
      case 'h': this.move(0, -1); break;
      case 'g':
        if (this.pendingG) {
          this.goTop();
          this.pendingG = false;
        } else {
          this.pendingG = true;
          setTimeout(() => { this.pendingG = false; }, 500);
          return;
        }
        break;
      case 'G': this.goBottom(); break;
      case '/': this.openSearch(); break;
      case 'y': this.yankCell(); break;
      case 'Enter': this.openFile(); break;
      case 'Escape': this.detach(); break;
      default: return;
    }
    e.preventDefault();
    e.stopPropagation();
  }

  private pendingG = false;

  // ---------------------------------------------------------------------------
  // Movement
  // ---------------------------------------------------------------------------

  private move(dr: number, dc: number): void {
    this.clearHighlight();
    this.row = clamp(this.row + dr, 0, this.rows.length - 1);
    const cellCount = this.rows[this.row]?.cells.length ?? 1;
    this.col = clamp(this.col + dc, 0, cellCount - 1);
    this.highlight();
    this.scrollIntoView();
  }

  private goTop(): void {
    this.clearHighlight();
    this.row = 0;
    this.highlight();
    this.scrollIntoView();
  }

  private goBottom(): void {
    this.clearHighlight();
    this.row = this.rows.length - 1;
    this.highlight();
    this.scrollIntoView();
  }

  // ---------------------------------------------------------------------------
  // Highlight
  // ---------------------------------------------------------------------------

  private highlight(): void {
    const tr = this.rows[this.row];
    if (!tr) return;
    tr.classList.add('logfire-vim-row');
    const td = tr.cells[this.col];
    if (td) td.classList.add('logfire-vim-cell');
  }

  private clearHighlight(): void {
    for (const tr of this.rows) {
      tr.classList.remove('logfire-vim-row');
      for (const td of Array.from(tr.cells)) {
        td.classList.remove('logfire-vim-cell');
      }
    }
  }

  private scrollIntoView(): void {
    this.rows[this.row]?.scrollIntoView({ block: 'nearest' });
  }

  // ---------------------------------------------------------------------------
  // Yank
  // ---------------------------------------------------------------------------

  private yankCell(): void {
    const td = this.rows[this.row]?.cells[this.col];
    if (!td) return;
    navigator.clipboard.writeText(td.textContent ?? '');
    td.classList.add('logfire-vim-yanked');
    setTimeout(() => td.classList.remove('logfire-vim-yanked'), 600);
    new Notice('In Zwischenablage kopiert.');
  }

  // ---------------------------------------------------------------------------
  // Open file
  // ---------------------------------------------------------------------------

  private openFile(): void {
    const td = this.rows[this.row]?.cells[this.col];
    if (!td) return;
    const text = td.textContent?.trim() ?? '';
    if (text.endsWith('.md') || text.includes('/')) {
      this.app.workspace.openLinkText(text, '');
    }
  }

  // ---------------------------------------------------------------------------
  // Search
  // ---------------------------------------------------------------------------

  private openSearch(): void {
    if (!this.container) return;
    this.searchMode = true;
    this.searchQuery = '';

    this.searchOverlay = this.container.createDiv({ cls: 'logfire-vim-search' });
    this.searchOverlay.createEl('span', { text: '/' });
    this.searchInput = this.searchOverlay.createEl('input', {
      attr: { type: 'text', placeholder: 'Suche...' },
    });
    this.searchInput.focus();
  }

  private handleSearchKey(e: KeyboardEvent): void {
    if (e.key === 'Escape') {
      this.closeSearch();
      e.preventDefault();
      return;
    }
    if (e.key === 'Enter') {
      this.searchQuery = this.searchInput?.value ?? '';
      this.closeSearch();
      this.findNext();
      e.preventDefault();
      return;
    }
    // Let normal typing pass through to the input
  }

  private closeSearch(): void {
    this.searchOverlay?.remove();
    this.searchOverlay = null;
    this.searchInput = null;
    this.searchMode = false;
    this.container?.focus();
  }

  private findNext(): void {
    if (!this.searchQuery) return;
    const q = this.searchQuery.toLowerCase();
    for (let i = 1; i <= this.rows.length; i++) {
      const idx = (this.row + i) % this.rows.length;
      const text = this.rows[idx].textContent?.toLowerCase() ?? '';
      if (text.includes(q)) {
        this.clearHighlight();
        this.row = idx;
        this.highlight();
        this.scrollIntoView();
        return;
      }
    }
    new Notice('Nicht gefunden.');
  }
}

function clamp(val: number, min: number, max: number): number {
  return Math.max(min, Math.min(max, val));
}