"""Offline tests for the Dragonchain Python SDK.

No network access required. The HMAC test independently recomputes the expected
Authorization header to guard the byte-for-byte contract with the prime-node
authorizer.
"""

import base64
import hashlib
import hmac
import json

import pytest

from prime_sdk import (
    Block,
    DragonchainAPIError,
    DragonchainSDK,
    InterchainTrace,
    SmartContractCreateRequest,
    Transaction,
    TransactionCreateRequest,
)
from prime_sdk.client import Client
from prime_sdk.credentials import load_config_from_string

PUBLIC_ID = "test-public-id"
AUTH_KEY_ID = "test-key-id"
AUTH_KEY = "test-secret-key"
BASE_URL = "https://chains.dragonchain.com"


def _expected_auth_header(method, path, timestamp, content_type, body: bytes) -> str:
    """Recompute the expected header from scratch, independent of the SDK."""
    b64_content = base64.b64encode(hashlib.sha256(body).digest()).decode()
    message = "\n".join([method.upper(), path, PUBLIC_ID, timestamp, content_type, b64_content])
    digest = hmac.new(AUTH_KEY.encode(), message.encode(), hashlib.sha256).digest()
    return f"DC1-HMAC-SHA256 {AUTH_KEY_ID}:{base64.b64encode(digest).decode()}"


# --------------------------------------------------------------------------- #
# HMAC signing
# --------------------------------------------------------------------------- #


def test_hmac_message_format():
    c = Client(PUBLIC_ID, AUTH_KEY_ID, AUTH_KEY, BASE_URL)
    msg = c._hmac_message("post", "/api/v1/transaction", "1700000000", "application/json", b"hello")
    lines = msg.split("\n")
    assert len(lines) == 6
    assert lines[0] == "POST"  # method uppercased
    assert lines[1] == "/api/v1/transaction"
    assert lines[2] == PUBLIC_ID
    assert lines[3] == "1700000000"
    assert lines[4] == "application/json"
    assert lines[5] == base64.b64encode(hashlib.sha256(b"hello").digest()).decode()
    assert not msg.endswith("\n")  # no trailing newline


def test_auth_header_matches_independent_computation():
    c = Client(PUBLIC_ID, AUTH_KEY_ID, AUTH_KEY, BASE_URL)
    body = b'{"txn_type":"x","payload":"y"}'
    got = c._generate_auth_header("POST", "/api/v1/transaction", "1700000000", "application/json", body)
    want = _expected_auth_header("POST", "/api/v1/transaction", "1700000000", "application/json", body)
    assert got == want


def test_empty_body_signs_sha256_of_empty():
    c = Client(PUBLIC_ID, AUTH_KEY_ID, AUTH_KEY, BASE_URL)
    got = c._generate_auth_header("GET", "/api/v1/status", "1700000000", "", b"")
    want = _expected_auth_header("GET", "/api/v1/status", "1700000000", "", b"")
    assert got == want


def test_base_url_trailing_slash_stripped():
    c = Client(PUBLIC_ID, AUTH_KEY_ID, AUTH_KEY, BASE_URL + "/")
    assert c.endpoint() == BASE_URL


# --------------------------------------------------------------------------- #
# Request plumbing (with a fake session)
# --------------------------------------------------------------------------- #


class _FakeResponse:
    def __init__(self, status_code, text):
        self.status_code = status_code
        self.text = text


class _FakeSession:
    def __init__(self, response):
        self.response = response
        self.calls = []

    def request(self, method, url, data=None, headers=None, timeout=None, allow_redirects=None):
        self.calls.append(
            {
                "method": method,
                "url": url,
                "data": data,
                "headers": headers,
                "allow_redirects": allow_redirects,
            }
        )
        return self.response


def test_create_sends_correct_request_and_parses_response():
    sdk = DragonchainSDK(PUBLIC_ID, AUTH_KEY_ID, AUTH_KEY, BASE_URL)
    fake = _FakeSession(_FakeResponse(200, json.dumps({"transaction_id": "txn-123"})))
    sdk.get_client()._session = fake

    resp = sdk.transaction.create(
        TransactionCreateRequest(txn_type="my-type", payload='{"a":1}', tag="t")
    )

    assert resp.transaction_id == "txn-123"
    call = fake.calls[0]
    assert call["method"] == "POST"
    assert call["url"] == BASE_URL + "/api/v1/transaction"
    # headers present and consistent
    headers = call["headers"]
    assert headers["Dragonchain"] == PUBLIC_ID
    assert headers["Content-Type"] == "application/json"
    assert headers["Authorization"].startswith(f"DC1-HMAC-SHA256 {AUTH_KEY_ID}:")
    # the bytes sent are exactly the bytes that were signed
    sent = call["data"]
    expected_auth = _expected_auth_header(
        "POST", "/api/v1/transaction", headers["Timestamp"], "application/json", sent
    )
    assert headers["Authorization"] == expected_auth
    # omitempty: version dropped, tag kept
    body = json.loads(sent)
    assert body == {"txn_type": "my-type", "payload": '{"a":1}', "tag": "t"}


def test_error_status_raises():
    sdk = DragonchainSDK(PUBLIC_ID, AUTH_KEY_ID, AUTH_KEY, BASE_URL)
    sdk.get_client()._session = _FakeSession(_FakeResponse(404, "  not found  "))
    with pytest.raises(DragonchainAPIError) as exc:
        sdk.transaction.get("missing")
    assert exc.value.status_code == 404
    assert exc.value.body == "not found"


def test_get_sends_no_content_type_header():
    sdk = DragonchainSDK(PUBLIC_ID, AUTH_KEY_ID, AUTH_KEY, BASE_URL)
    fake = _FakeSession(_FakeResponse(200, json.dumps({"id": "chain", "level": 1})))
    sdk.get_client()._session = fake
    sdk.system.status()
    headers = fake.calls[0]["headers"]
    assert "Content-Type" not in headers
    assert fake.calls[0]["data"] == b""


# --------------------------------------------------------------------------- #
# Model (de)serialization
# --------------------------------------------------------------------------- #


def test_transaction_from_dict_nested():
    raw = {
        "version": "1",
        "header": {"txn_id": "abc", "block_id": "42", "txn_type": "t"},
        "proof": {"full": "ff", "stripped": "ss"},
        "payload": "{}",
    }
    txn = Transaction.from_dict(raw)
    assert txn.header.txn_id == "abc"
    assert txn.header.block_id == "42"
    assert txn.proof.full == "ff"
    assert txn.payload == "{}"


def test_block_from_dict_nested_header():
    # Real server shape: id/prev/timestamp nested under "header" with camelCase
    # keys; proof carries only "proof" on a trust-scheme chain.
    raw = {
        "version": "1",
        "header": {
            "blockId": "69569983",
            "dcId": "chain-xyz",
            "prevId": "69186326",
            "prevProof": "MEUCIQ...",
            "timestamp": "1780088135",
        },
        "proof": {"proof": "MEQCIF..."},
        "transactions": ["{...}", "{...}", "{...}"],
    }
    blk = Block.from_dict(raw)
    assert blk.version == "1"
    assert blk.header.block_id == "69569983"
    assert blk.header.dc_id == "chain-xyz"
    assert blk.header.prev_id == "69186326"
    assert blk.header.prev_proof == "MEUCIQ..."
    assert blk.header.timestamp == "1780088135"
    assert blk.proof.proof == "MEQCIF..."
    assert blk.proof.scheme == ""  # absent on trust-scheme chain
    assert len(blk.transactions) == 3


def test_interchain_trace_from_dict_nested():
    # Server shape: validatorBlocks + interchainTransactions arrays, camelCase.
    raw = {
        "blockId": "69636602",
        "validatorBlocks": [
            {
                "version": "1",
                "primeChainId": "zDYr",
                "primeBlockId": "69636602",
                "verifierPublicKey": "02c4...",
                "verifierSignature": "MEUC...",
            }
        ],
        "interchainTransactions": [
            {
                "id": 19,
                "chainId": "1",
                "transHash": "0xd46e",
                "validatorBlocks": ["69636602"],
                "coveredPrimeChainIds": ["zDYr"],
            }
        ],
    }
    trace = InterchainTrace.from_dict(raw)
    assert trace.block_id == "69636602"
    assert len(trace.validator_blocks) == 1
    assert trace.validator_blocks[0].prime_block_id == "69636602"
    assert trace.validator_blocks[0].verifier_public_key == "02c4..."
    assert len(trace.interchain_transactions) == 1
    assert trace.interchain_transactions[0].id == 19
    assert trace.interchain_transactions[0].trans_hash == "0xd46e"
    assert trace.interchain_transactions[0].chain_id == "1"
    assert trace.interchain_transactions[0].validator_blocks == ["69636602"]
    assert trace.interchain_transactions[0].covered_prime_chain_ids == ["zDYr"]


def test_contract_create_request_omitempty():
    req = SmartContractCreateRequest(
        environment="python3.8",
        transaction_type="my-type",
        execution_order="parallel",
    )
    d = req.to_dict()
    assert d == {
        "environment": "python3.8",
        "transactionType": "my-type",
        "executionOrder": "parallel",
    }
    # remote False is dropped; envvars/secrets absent
    assert "remote" not in d
    assert "environmentVariables" not in d
    assert "secret" not in d


def test_contract_create_request_with_optionals():
    req = SmartContractCreateRequest(
        environment="python3.8",
        transaction_type="my-type",
        execution_order="serial",
        environment_variables={"K": "V"},
        secrets={"S": "v"},
        remote=True,
    )
    d = req.to_dict()
    assert d["environmentVariables"] == {"K": "V"}
    assert d["secret"] == {"S": "v"}
    assert d["remote"] is True


def test_credentials_round_trip():
    yaml_text = """
default: pub-1
chains:
  - name: alpha
    publicId: pub-1
    authKeyId: kid-1
    authKey: secret-1
    endpoint: https://chains.dragonchain.com
  - name: beta
    publicId: pub-2
    authKeyId: kid-2
    authKey: secret-2
    endpoint: https://dev-chains.dragonchain.com
"""
    cfg = load_config_from_string(yaml_text)
    assert cfg.default == "pub-1"
    assert cfg.list_chains() == ["alpha", "beta"]
    default = cfg.get_default_chain()
    assert default is not None and default.auth_key_id == "kid-1"
    assert cfg.get_chain_by_public_id("pub-2").endpoint.endswith("dev-chains.dragonchain.com")
    with pytest.raises(ValueError):
        cfg.delete_chain("pub-1")  # default
    cfg.delete_chain("pub-2")
    assert cfg.list_chains() == ["alpha"]