import json
import sys
import sacrebleu

# Check command-line arguments
if len(sys.argv) != 2:
    print("Usage: python script.py <jsonl_file>")
    sys.exit(1)

# Initialize lists to store targets and predictions
targets = []
predictions = []

# Read the JSON lines file
filename = sys.argv[1]
with open(filename, 'r') as f:
    for line in f:
        obj = json.loads(line)
        targets.append(obj['target'])
        predictions.append(obj['prediction'])

# Joining sentences for BLEU score calculation
targets_str = ' '.join(targets)
predictions_str = ' '.join(predictions)

# Calculate BLEU score
bleu = sacrebleu.sentence_bleu(predictions_str, [targets_str])

# Print results
print(f"BLEU Score: {bleu.score}")