import React, { useState, useRef, useEffect } from 'react';

interface ChatInputProps {
    onSendMessage: (content: string) => void;
    isSending: boolean;
    disabled: boolean;
}

const ChatInput: React.FC<ChatInputProps> = ({ onSendMessage, isSending, disabled }) => {
    const [message, setMessage] = useState('');
    const textareaRef = useRef<HTMLTextAreaElement>(null);

    // Auto-resize textarea
    useEffect(() => {
        if (textareaRef.current) {
            textareaRef.current.style.height = 'auto';
            textareaRef.current.style.height = `${Math.min(textareaRef.current.scrollHeight, 200)}px`;
        }
    }, [message]);

    const handleSubmit = () => {
        const trimmed = message.trim();
        if (trimmed && !isSending && !disabled) {
            onSendMessage(trimmed);
            setMessage('');
            if (textareaRef.current) {
                textareaRef.current.style.height = 'auto';
            }
        }
    };

    const handleKeyDown = (e: React.KeyboardEvent) => {
        if (e.key === 'Enter' && !e.shiftKey) {
            e.preventDefault();
            handleSubmit();
        }
    };

    return (
        <div className="border-t border-gray-200 bg-white p-4">


            <div className="max-w-4xl mx-auto">
                <div className="relative flex items-end gap-3 bg-gray-50 border border-gray-200 rounded-2xl p-2 focus-within:border-indigo-300 focus-within:ring-2 focus-within:ring-indigo-100 transition-all">
                    <textarea
                        ref={textareaRef}
                        value={message}
                        onChange={(e) => setMessage(e.target.value)}
                        onKeyDown={handleKeyDown}
                        placeholder={disabled ? "Select or create a chat to start..." : "Ask a question..."}
                        disabled={disabled || isSending}
                        rows={1}
                        className="flex-1 resize-none bg-transparent px-3 py-2 text-gray-800 placeholder-gray-400 focus:outline-none text-sm leading-relaxed max-h-[200px] disabled:cursor-not-allowed"
                    />
                    <button
                        onClick={onsubmit}
                        disabled={!message.trim() || isSending || disabled}
                        className={`flex-shrink-0 p-3 rounded-xl transition-all duration-200 ${message.trim() && !isSending && !disabled
                                ? 'bg-gradient-to-r from-indigo-600 to-purple-600 text-white shadow-lg hover:shadow-indigo-500/30 hover:scale-105 active:scale-95'
                                : 'bg-gray-200 text-gray-400 cursor-not-allowed'
                            }`}
                    >
                        {isSending ? (
                            <svg className="w-5 h-5 animate-spin" fill="none" viewBox="0 0 24 24">
                                <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4"></circle>
                                <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"></path>
                            </svg>
                        ) : (
                            <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 19l9 2-9-18-9 18 9-2zm0 0v-8" />
                            </svg>
                        )}
                    </button>
                </div>
                <p className="text-xs text-gray-400 text-center mt-2">
                    Press Enter to send, Shift+Enter for new line
                </p>
            </div>
        </div>
    );
};

export default ChatInput;
