import { useState, useRef } from 'react';
import { Send, Upload, FileText, X, Loader2 } from 'lucide-react';

export default function QueryInput({ onQuery, onCsvUpload, loading, csvMode = false, selectedNeon = [], selectedComparison = [], comparisonProviders = [] }) {
  const [query, setQuery] = useState('');
  const [selectedFile, setSelectedFile] = useState(null);
  const fileInputRef = useRef(null);

  const handleSubmit = (e) => {
    e.preventDefault();
    if (csvMode && selectedFile) {
      onCsvUpload(selectedFile);
    } else if (!csvMode && query.trim()) {
      onQuery(query.trim());
      setQuery('');
    }
  };

  const handleFileDrop = (e) => {
    e.preventDefault();
    const file = e.dataTransfer?.files?.[0];
    if (file && file.name.endsWith('.csv')) {
      setSelectedFile(file);
    }
  };

  const handleFileSelect = (e) => {
    const file = e.target.files?.[0];
    if (file) setSelectedFile(file);
  };

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

  const neonDisplayName = (sel) => {
    const name = sel.model_id.split('@')[0].split('/').pop();
    return `${name} - ${sel.persona_name}`;
  };

  const comparisonDisplayName = (modelId) => {
    for (const provider of comparisonProviders) {
      const model = provider.models.find(m => m.id === modelId);
      if (model) return model.name;
    }
    return modelId.split('/').pop();
  };

  return (
    <div className="query-input-container">
      <form onSubmit={handleSubmit} className="query-form">
        {csvMode ? (
          <div
            className={`csv-drop-zone ${selectedFile ? 'has-file' : ''}`}
            onDragOver={e => e.preventDefault()}
            onDrop={handleFileDrop}
            onClick={() => fileInputRef.current?.click()}
          >
            <input
              ref={fileInputRef}
              type="file"
              accept=".csv"
              onChange={handleFileSelect}
              style={{ display: 'none' }}
            />
            {selectedFile ? (
              <div className="csv-file-info">
                <FileText size={20} />
                <span>{selectedFile.name}</span>
                <button
                  type="button"
                  className="csv-clear"
                  onClick={(e) => { e.stopPropagation(); setSelectedFile(null); }}
                >
                  <X size={14} />
                </button>
              </div>
            ) : (
              <div className="csv-placeholder">
                <Upload size={24} />
                <span>Drop a CSV file here or click to browse</span>
                <span className="csv-hint">Single column of questions</span>
              </div>
            )}
          </div>
        ) : (
          <textarea
            className="query-textarea"
            value={query}
            onChange={e => setQuery(e.target.value)}
            onKeyDown={handleKeyDown}
            placeholder="Ask a question to compare across models..."
            rows={2}
            disabled={loading}
          />
        )}
        <div className="query-submit-row">
          <button
            type="submit"
            className="query-submit"
            disabled={loading || (csvMode ? !selectedFile : !query.trim())}
          >
            {loading ? <Loader2 size={18} className="spin" /> : <Send size={18} />}
            {csvMode ? 'Run Batch' : 'Compare'}
          </button>
          {(selectedNeon.length > 0 || selectedComparison.length > 0) && (
            <div className="selection-summary">
              {selectedNeon.length > 0 && (
                <div className="selection-line">
                  <span className="selection-label">Neon.ai Models Selected:</span>{' '}
                  {selectedNeon.map(s => neonDisplayName(s)).join(', ')} <span className="selection-count">({selectedNeon.length})</span>
                </div>
              )}
              {selectedComparison.length > 0 && (
                <div className="selection-line">
                  <span className="selection-label">Comparison Models Selected:</span>{' '}
                  {selectedComparison.map(id => comparisonDisplayName(id)).join(', ')} <span className="selection-count">({selectedComparison.length})</span>
                </div>
              )}
            </div>
          )}
        </div>
      </form>

      <style>{`
        .query-input-container {
          display: flex;
          flex-direction: column;
          gap: 8px;
        }
        .query-form {
          display: flex;
          flex-direction: column;
          gap: 8px;
        }
        .query-textarea {
          flex: 1;
          padding: 10px 14px;
          border: 2px solid var(--query-accent);
          border-radius: 10px;
          background: var(--card-bg);
          color: var(--text-primary);
          font-family: inherit;
          font-size: 14px;
          resize: vertical;
          min-height: 44px;
          outline: none;
          transition: border-color 0.15s;
        }
        .query-textarea:focus {
          border-color: var(--query-accent);
        }
        .query-textarea::placeholder {
          color: var(--text-muted);
        }
        .csv-drop-zone {
          flex: 1;
          border: 2px dashed var(--border-primary);
          border-radius: 10px;
          padding: 20px;
          text-align: center;
          cursor: pointer;
          transition: border-color 0.15s, background 0.15s;
          background: var(--card-bg);
        }
        .csv-drop-zone:hover {
          border-color: var(--accent-primary);
          background: var(--accent-light);
        }
        .csv-drop-zone.has-file {
          border-style: solid;
          border-color: var(--neon-accent);
        }
        .csv-placeholder {
          display: flex;
          flex-direction: column;
          align-items: center;
          gap: 6px;
          color: var(--text-tertiary);
          font-size: 13px;
        }
        .csv-hint {
          font-size: 11px;
          color: var(--text-muted);
        }
        .csv-file-info {
          display: flex;
          align-items: center;
          gap: 8px;
          color: var(--neon-accent);
          font-size: 14px;
          font-weight: 500;
          justify-content: center;
        }
        .csv-clear {
          display: flex;
          align-items: center;
          justify-content: center;
          width: 22px;
          height: 22px;
          border: none;
          border-radius: 50%;
          background: var(--bg-tertiary);
          color: var(--text-muted);
        }
        .csv-clear:hover {
          background: #FEE2E2;
          color: #EF4444;
        }
        .query-submit-row {
          display: flex;
          align-items: flex-end;
          gap: 16px;
        }
        .query-submit {
          display: flex;
          align-items: center;
          gap: 6px;
          padding: 10px 20px;
          border: none;
          border-radius: 10px;
          background: var(--accent-gradient);
          color: #FFFFFF;
          font-size: 14px;
          font-weight: 600;
          white-space: nowrap;
          transition: opacity 0.15s, transform 0.1s;
          flex-shrink: 0;
        }
        .selection-summary {
          display: flex;
          flex-direction: column;
          gap: 2px;
          padding-top: 2px;
          min-width: 0;
        }
        .selection-line {
          font-size: 14px;
          font-family: inherit;
          color: var(--text-muted);
          line-height: 1.5;
          word-break: break-word;
        }
        .selection-label {
          font-weight: 600;
          color: var(--text-secondary);
        }
        .selection-count {
          font-weight: 600;
          color: var(--text-secondary);
        }
        .query-submit:hover:not(:disabled) {
          opacity: 0.9;
          transform: translateY(-1px);
        }
        .query-submit:disabled {
          opacity: 0.5;
          cursor: not-allowed;
        }

        @media (max-width: 480px) {
          .query-textarea {
            min-height: 48px;
            font-size: 16px;
          }
          .query-submit-row {
            flex-direction: column;
            gap: 8px;
          }
          .query-submit {
            align-self: stretch;
            justify-content: center;
            padding: 12px 20px;
            font-size: 15px;
          }
          .selection-line {
            font-size: 13px;
          }
          .csv-drop-zone {
            padding: 16px;
          }
        }
      `}</style>
    </div>
  );
}