#!/usr/bin/env python3
"""x402 Buyer Quickstart — Pay $0.01 for crypto price data

Prerequisites:
  pip install x402 httpx eth-account
  export PRIVATE_KEY=0x...  # your Base mainnet wallet key (must hold USDC)

API: https://x402.167-172-95-184.nip.io/price
Cost: $0.01 USDC per call (Base mainnet, chain ID 8453)
Facilitator: https://api.cdp.coinbase.com/platform/v2/x402 (CDP, x402scan-indexed)
Pay to: 0x68614873C5d624c07DCAA3aFF5243DD5027c3910
Asset: USDC on Base (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913)
"""
import os, json
from eth_account import Account
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact import register_exact_evm_client
from x402.client import x402ClientSync
from x402.http import x402HTTPClientSync
import httpx

API_URL = 'https://x402.167-172-95-184.nip.io/price'

def main():
    pk = os.environ.get('PRIVATE_KEY', '')
    if not pk:
        print('ERROR: Set PRIVATE_KEY env var to your EVM private key')
        return
    if not pk.startswith('0x'): pk = '0x' + pk

    account = Account.from_key(pk)
    print(f'Payer: {account.address}')
    print(f'Paying $0.01 USDC on Base for crypto prices...')

    signer = EthAccountSigner(account)
    client = x402ClientSync()
    register_exact_evm_client(client, signer)
    http_client = x402HTTPClientSync(client)

    # Step 1: Get 402 payment challenge
    r = httpx.get(API_URL, timeout=15)
    print(f'Initial request: HTTP {r.status_code}')
    if r.status_code != 402:
        print(f'Expected 402, got {r.status_code}: {r.text[:200]}')
        return

    # Step 2: Parse payment requirements and sign
    payment_headers, payload = http_client.handle_402_response(dict(r.headers), r.content)
    print(f'Payment signed for {payload.amount} {payload.asset}')

    # Step 3: Retry with payment
    r2 = httpx.get(API_URL, headers=dict(payment_headers), timeout=30)
    print(f'Paid request: HTTP {r2.status_code}')
    if r2.status_code == 200:
        data = r2.json()
        print(f'\n✅ Payment settled! Received:')
        print(json.dumps(data, indent=2))
    else:
        print(f'Payment failed: {r2.text[:300]}')

if __name__ == '__main__':
    main()