import boto3
import pandas as pd

# AWS credentials
aws_access_key_id = "YOUR_S3_ACCESS_KEY"
aws_secret_access_key = "YOUR_SECRET_KEY"
region_name = "ap-south-1"

# Excel output
output_file = "s3bucket_size.xlsx"

# Connect to S3
s3 = boto3.client(
    "s3",
    aws_access_key_id=aws_access_key_id,
    aws_secret_access_key=aws_secret_access_key,
    region_name=region_name
)

# Get all S3 buckets
response = s3.list_buckets()
buckets = response.get("Buckets", [])

print(f"Found {len(buckets)} S3 buckets.\n")

report = []

# Process each bucket
for bucket in buckets:

    bucket_name = bucket["Name"]

    print(f"Scanning: {bucket_name}")

    file_count = 0
    total_size = 0

    try:
        paginator = s3.get_paginator("list_objects_v2")

        for page in paginator.paginate(Bucket=bucket_name):

            for obj in page.get("Contents", []):

                key = obj["Key"]

                # Ignore folder placeholders
                if key.endswith("/"):
                    continue

                file_count += 1
                total_size += obj["Size"]

        total_size_gb = total_size / (1024 ** 3)
        total_size_tb = total_size / (1024 ** 4)

        report.append({
            "Bucket": bucket_name,
            "File Count": file_count,
            "Total Size (Bytes)": total_size,
            "Total Size (GB)": round(total_size_gb, 2),
            "Total Size (TB)": round(total_size_tb, 4)
        })

        print(
            f"  Files: {file_count:,} | "
            f"Size: {total_size_gb:.2f} GB"
        )

    except Exception as e:

        print(f"  ERROR: {e}")

        report.append({
            "Bucket": bucket_name,
            "File Count": "ERROR",
            "Total Size (Bytes)": "ERROR",
            "Total Size (GB)": "ERROR",
            "Total Size (TB)": "ERROR"
        })

# Create Excel report
df = pd.DataFrame(report)
df = df.sort_values(by="Bucket")

df.to_excel(
    output_file,
    index=False
)

print("\n===================================")
print("S3 BUCKET REPORT COMPLETED")
print("===================================")
print(f"Report saved to: {output_file}")