import os
import tos
from tos.exceptions import TosClientError, TosServerError

def create_client() -> tos.TosClientV2:
    """Initializes a TosClientV2 using AK/SK (and optional STS token) from environment variables."""
    try:
        ak = os.getenv('TOS_ACCESS_KEY')
        sk = os.getenv('TOS_SECRET_KEY')
        endpoint = os.getenv('TOS_ENDPOINT')
        region = os.getenv('TOS_REGION')
        security_token = os.getenv('TOS_SECURITY_TOKEN') # Optional, for STS

        if not all([ak, sk, endpoint, region]):
            raise ValueError("Required environment variables are missing (AK, SK, Endpoint, Region).")

        return tos.TosClientV2(
            ak=ak,
            sk=sk,
            endpoint=endpoint,
            region=region,
            security_token=security_token,
        )
    except (ValueError, ImportError) as e:
        print(f"Error initializing client: {e}")
        return None

# Create the client
client = create_client()

# (Assumes 'client' is initialized and 'bucket_name', 'object_key' are set)

# 1. Get Image Info
try:
    response = client.get_object(bucket_name, object_key, process="image/info")
    info_data = response.read()
    print("Image Info:", info_data.decode('utf-8'))
except TosServerError as e:
    print(f"Error getting image info: {e}")

# 2. Resize an Image and save locally
try:
    client.get_object_to_file(
        bucket_name,
        object_key,
        "resized_image.jpg",
        process="image/resize,w_500,m_lfit" # Resize to 500px width, lfit mode
    )
    print("Resized image saved to resized_image.jpg")
except TosServerError as e:
    print(f"Error resizing image: {e}")

# 3. Convert Image to WebP and save back to TOS
try:
    response = client.get_object(
        bucket_name,
        object_key,
        process="image/format,f_webp,q_80", # Convert to WebP, quality 80
        save_bucket="my-output-bucket",
        save_object="processed/image.webp"
    )
    save_result = response.read()
    print("Converted image saved to TOS:", save_result.decode('utf-8'))
except TosServerError as e:
    print(f"Error saving converted image to TOS: {e}")

response = client.get_object(bucket_name, object_key, process="image/info")
image_metadata = response.read().decode('utf-8')
print(image_metadata)

# Convert to PNG format
client.get_object_to_file(
    bucket_name,
    object_key,
    "output.png",
    process="image/format,f_png"
)

# Resize to a maximum width of 1024px, maintaining aspect ratio
client.get_object_to_file(
    bucket_name,
    object_key,
    "resized_1024.jpg",
    process="image/resize,w_1024"
)

# Example for a text watermark (parameters must be Base64-encoded)
# This is a conceptual example. Refer to official docs for exact keys.
import base64
text_b64 = base64.b64encode("My Watermark".encode()).decode()
process_rule = f"image/watermark,type_1,text_{text_b64},size_40,p_9"

client.get_object_to_file(
    bucket_name,
    object_key,
    "watermarked.jpg",
    process=process_rule
)

# Example: Apply a Gaussian blur (hypothetical parameters)
client.get_object_to_file(
    bucket_name,
    object_key,
    "blurred.jpg",
    process="image/blur,r_5,s_2"
)