import { LitElement, html, css } from './plugins.js';
import type { CSSResult, TemplateResult } from './plugins.js';

export class SmartchatInput extends LitElement {
  declare disabled: boolean;
  declare placeholder: string;
  private value = '';

  static properties = {
    disabled: { type: Boolean },
    placeholder: { type: String },
  };

  static styles: CSSResult = css`
    :host {
      display: block;
    }

    .input-wrap {
      display: flex;
      align-items: flex-end;
      gap: 8px;
      padding: 10px 12px;
      background: rgba(255, 255, 255, 0.04);
      border-radius: 16px;
      border: 1px solid rgba(255, 255, 255, 0.07);
      transition: border-color 0.2s ease, box-shadow 0.2s ease;
    }

    .input-wrap:focus-within {
      border-color: rgba(99, 102, 241, 0.45);
      box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.08);
    }

    .input-wrap.disabled {
      opacity: 0.45;
      pointer-events: none;
    }

    textarea {
      flex: 1;
      background: transparent;
      border: none;
      outline: none;
      color: #e4e4e7;
      font-size: 14px;
      font-family: inherit;
      line-height: 1.5;
      resize: none;
      min-height: 22px;
      max-height: 110px;
      padding: 2px 0;
    }

    textarea::placeholder {
      color: rgba(255, 255, 255, 0.22);
    }

    .send-btn {
      width: 32px;
      height: 32px;
      border-radius: 50%;
      border: none;
      background: linear-gradient(135deg, #6366f1, #7c3aed);
      color: #fff;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
      transition: transform 0.12s ease, opacity 0.12s ease, box-shadow 0.12s ease;
      box-shadow: 0 2px 8px rgba(99, 102, 241, 0.3);
    }

    .send-btn:hover:not(:disabled) {
      transform: scale(1.08);
      box-shadow: 0 3px 12px rgba(99, 102, 241, 0.45);
    }

    .send-btn:active:not(:disabled) {
      transform: scale(0.94);
    }

    .send-btn:disabled {
      opacity: 0.25;
      cursor: default;
      box-shadow: none;
    }

    .send-btn svg {
      width: 15px;
      height: 15px;
    }

    .hint {
      display: flex;
      justify-content: flex-end;
      padding: 5px 2px 0;
    }

    .hint-text {
      font-size: 10.5px;
      color: rgba(255, 255, 255, 0.13);
    }

    kbd {
      padding: 0 3px;
      border-radius: 3px;
      background: rgba(255, 255, 255, 0.05);
      border: 1px solid rgba(255, 255, 255, 0.07);
      font-family: inherit;
      font-size: 10px;
    }
  `;

  constructor() {
    super();
    this.disabled = false;
    this.placeholder = 'Type a message...';
  }

  private handleKeydown(e: KeyboardEvent) {
    if (e.key === 'Enter' && !e.shiftKey) {
      e.preventDefault();
      this.submit();
    }
  }

  private handleInput(e: Event) {
    const textarea = e.target as HTMLTextAreaElement;
    this.value = textarea.value;
    textarea.style.height = 'auto';
    textarea.style.height = Math.min(textarea.scrollHeight, 110) + 'px';
  }

  private submit() {
    if (!this.value.trim() || this.disabled) return;
    this.dispatchEvent(
      new CustomEvent('send', {
        detail: { text: this.value.trim() },
        bubbles: true,
        composed: true,
      }),
    );
    this.value = '';
    const textarea = this.shadowRoot?.querySelector('textarea');
    if (textarea) {
      textarea.value = '';
      textarea.style.height = 'auto';
    }
  }

  render(): TemplateResult {
    const canSend = !this.disabled && !!this.value.trim();
    return html`
      <div class="input-wrap ${this.disabled ? 'disabled' : ''}">
        <textarea
          rows="1"
          .value=${this.value}
          @input=${this.handleInput}
          @keydown=${this.handleKeydown}
          placeholder=${this.disabled ? 'Waiting for response...' : this.placeholder}
          ?disabled=${this.disabled}
        ></textarea>
        <button
          class="send-btn"
          @click=${this.submit}
          ?disabled=${!canSend}
          aria-label="Send message"
        >
          <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round">
            <line x1="12" y1="19" x2="12" y2="5"></line>
            <polyline points="5 12 12 5 19 12"></polyline>
          </svg>
        </button>
      </div>
      <div class="hint">
        <span class="hint-text"><kbd>Enter</kbd> send · <kbd>Shift+Enter</kbd> new line</span>
      </div>
    `;
  }
}

customElements.define('smartchat-input', SmartchatInput);