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}")
        # Handle initialization failure
        return None

# Create the client
client = create_client()

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

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


# 2. Take a Single Snapshot and save locally
try:
    client.get_object_to_file(
        bucket_name,
        object_key,
        "snapshot_1000ms.jpg",
        process="video/snapshot,t_1000,f_jpg,w_720"
    )
    print("Snapshot saved to snapshot_1000ms.jpg")
except TosServerError as e:
    print(f"Error taking snapshot: {e}")

# 3. Take a Snapshot and save back to TOS
try:
    response = client.get_object(
        bucket_name,
        object_key,
        process="video/snapshot,t_5000,f_jpg",
        save_bucket=bucket_name,
        save_object="processed/snapshot_5000ms.jpg"
    )
    save_result = response.read()
    print("Snapshot saved to TOS:", save_result.decode('utf-8'))
except TosServerError as e:
    print(f"Error saving snapshot to TOS: {e}")

# 'client', 'bucket_name', and 'object_key' must be defined
try:
    response = client.get_object(bucket_name, object_key, process="video/info")
    # The response body is a JSON string
    video_metadata = response.read().decode('utf-8')
    print(video_metadata)
except TosServerError as e:
    print(f"Server Error: {e.code} - {e.message}")

# Example: Take a snapshot at 10 seconds, resize to 720p width, and save locally
try:
    client.get_object_to_file(
        bucket_name,
        object_key,
        file_path="local_snapshot.jpg",
        process="video/snapshot,t_10000,w_720,f_jpg"
    )
    print("Snapshot saved successfully to local_snapshot.jpg")
except (TosClientError, TosServerError) as e:
    print(f"An error occurred: {e}")

# (Assumes 'client', 'bucket_name', 'object_key' are set)
timestamps = [1000, 5000, 10000]  # In milliseconds

for i, ts in enumerate(timestamps):
    output_filename = f'snapshot_{i+1}_at_{ts}ms.jpg'
    process_rule = f"video/snapshot,t_{ts},w_720,f_jpg"
    try:
        client.get_object_to_file(
            bucket_name,
            object_key,
            output_filename,
            process=process_rule
        )
        print(f"Saved snapshot to {output_filename}")
    except (TosClientError, TosServerError) as e:
        print(f"Failed for timestamp {ts}: {e}")