import { useEffect, useRef, type KeyboardEvent } from 'react';
import type { AgentMessage, AssistantMessage, ToolCall, ToolResultMessage } from '../shared/types';
import { PiLogo } from './TopBar';

function ToolCallView({ call }: { call: ToolCall }) {
  const entries = Object.entries(call.arguments);
  return (
    <div className="tool">
      <div className="tool-head">{call.name}</div>
      {call.name === 'bash' && typeof call.arguments.command === 'string' ? (
        <pre>$ {call.arguments.command}</pre>
      ) : (
        entries.map(([k, v]) => (
          <div className="kv" key={k}>
            <b>{k}</b>
            <pre>{String(v)}</pre>
          </div>
        ))
      )}
    </div>
  );
}

function ResultView({ m }: { m: ToolResultMessage }) {
  const text = m.content.map((c) => c.text).join('\n');
  return (
    <details className={`result${m.isError ? ' bad' : ''}`} open={text.length < 400}>
      <summary>
        {m.toolName} result{m.details.exitCode !== undefined ? ` · exit ${m.details.exitCode}` : ''}
        {m.isError ? ' · error' : ''}
      </summary>
      <pre>{text}</pre>
    </details>
  );
}

function AssistantView({ m, live }: { m: AssistantMessage; live?: boolean }) {
  return (
    <div className="msg assistant">
      {m.content.map((c, i) =>
        c.type === 'thinking' ? (
          <details key={i} className="thinking" open={live}>
            <summary>Thinking</summary>
            <pre>{c.thinking}</pre>
          </details>
        ) : c.type === 'text' ? (
          <p key={i} className="text">
            {c.text}
          </p>
        ) : (
          <ToolCallView key={i} call={c} />
        ),
      )}
      {live && m.content.length === 0 && <span className="typing" aria-label="Working"><i /><i /><i /></span>}
      {m.stopReason === 'error' && <p className="err">{m.errorMessage}</p>}
      {m.stopReason === 'aborted' && <p className="muted">Stopped.</p>}
      {m.stopReason === 'length' && <p className="muted">Stopped at the output limit.</p>}
    </div>
  );
}

interface Props {
  messages: AgentMessage[];
  streaming: AssistantMessage | null;
  busy: string | null;
  draft: string;
  contextTokens: number;
  onDraft: (v: string) => void;
  onSend: () => void;
  onStop: () => void;
  onNewChat: () => void;
}

export function ChatPanel({ messages, streaming, busy, draft, contextTokens, onDraft, onSend, onStop, onNewChat }: Props) {
  const logRef = useRef<HTMLDivElement>(null);
  const working = busy === 'prompt';
  const last = messages[messages.length - 1];

  useEffect(() => {
    const el = logRef.current;
    if (el) el.scrollTop = el.scrollHeight;
  }, [messages, streaming]);

  const onKey = (e: KeyboardEvent<HTMLTextAreaElement>) => {
    // Không gửi khi đang gõ dấu bằng bộ gõ (tiếng Việt, tiếng Trung…).
    if (e.key === 'Enter' && !e.shiftKey && !e.nativeEvent.isComposing) {
      e.preventDefault();
      onSend();
    }
  };

  return (
    <section className="chat" aria-label="Agent conversation">
      <div className="log" ref={logRef} role="log" aria-live="polite">
        {messages.length === 0 && !working && (
          <div className="empty">
            <PiLogo />
            <h2>Ask Pi to work in your workspace</h2>
            <p>Pi can read, write and edit files and run shell commands. Everything stays in this browser.</p>
            <button onClick={() => onDraft("What's our total sales revenue?")}>What&apos;s our total sales revenue?</button>
          </div>
        )}
        {messages.map((m, i) =>
          m.role === 'user' ? (
            <div key={i} className="msg user">{m.content}</div>
          ) : m.role === 'assistant' ? (
            <AssistantView key={i} m={m} />
          ) : (
            <ResultView key={i} m={m} />
          ),
        )}
        {working && streaming && <AssistantView m={streaming} live />}
        {working && !streaming && last && last.role !== 'assistant' && (
          <div className="msg assistant"><span className="typing" aria-label="Working"><i /><i /><i /></span></div>
        )}
      </div>
      <div className="composer">
        <label className="sr" htmlFor="prompt">Message Pi</label>
        <textarea
          id="prompt"
          value={draft}
          onChange={(e) => onDraft(e.target.value)}
          onKeyDown={onKey}
          placeholder="Message Pi…  (Enter to send, Shift+Enter for a new line)"
          rows={2}
        />
        <div className="controls">
          <button onClick={onNewChat} disabled={busy !== null || messages.length === 0}>New chat</button>
          <span className="grow">{contextTokens > 0 ? `${contextTokens.toLocaleString()} / 8,192 tokens` : 'Model and tools run in your browser'}</span>
          {busy !== null && <button onClick={onStop}>Stop</button>}
          <button className="send" onClick={onSend} disabled={busy !== null || !draft.trim()}>Send ↑</button>
        </div>
      </div>
    </section>
  );
}