import hashlib
import json
import os
import queue
import signal
import subprocess
from collections.abc import Iterator
from contextlib import contextmanager
from pathlib import Path
from typing import TYPE_CHECKING, Final, Literal

import httpx
import psutil
from pydantic import BaseModel, Field, JsonValue, TypeAdapter

if TYPE_CHECKING:
    from integration._support.mcp import McpPeer


class ConformanceCheck(BaseModel):
    id: str
    status: Literal["SUCCESS", "FAILURE", "WARNING", "INFO"]
    errorMessage: str | None = None
    details: dict[str, JsonValue] = Field(default_factory=dict)


def verify_archive(archive: Path, expected_sha256: str) -> None:
    actual: Final = hashlib.sha256(archive.read_bytes()).hexdigest()
    assert actual == expected_sha256, f"SHA-256 mismatch for {archive.name}: {actual}"


def read_checks(directory: Path, scenario: str) -> tuple[ConformanceCheck, ...]:
    reports: Final = tuple(directory.rglob("checks.json"))
    assert len(reports) == 1, f"conformance {scenario}: expected one fresh report, found {len(reports)}"
    checks: Final = TypeAdapter(tuple[ConformanceCheck, ...]).validate_json(reports[0].read_bytes())
    assert len({check.id for check in checks}) == len(checks), f"conformance {scenario}: duplicate checks"
    required: Final = {
        "server-initialize": ("server-initialize", "server-session-id-visible-ascii", "wire-schema-valid"),
        "tools-list": ("tools-list", "tools-name-format", "wire-schema-valid"),
        "tools-call-image": ("tools-call-image", "wire-schema-valid"),
    }.get(scenario, (scenario,))
    for identity in required:
        assert tuple(check.status for check in checks if check.id == identity) == ("SUCCESS",), (
            f"conformance {scenario}: required check {identity} did not pass: {checks}"
        )
    assert all(check.status != "FAILURE" for check in checks), f"conformance {scenario}: failed checks: {checks}"
    if scenario == "tools-call-simple-text":
        result: Final = next(check for check in checks if check.id == scenario).details.get("result")
        # The official scenario accepts any nonempty text, including tool errors.
        assert isinstance(result, dict) and result.get("isError", False) is False, f"reference payload: {result}"
        assert result.get("content") == [{"type": "text", "text": "This is a simple text response for testing."}], (
            f"reference payload: {result}"
        )
    return checks


def run_scenario(root: Path, url: str, scenario: str, directory: Path) -> tuple[ConformanceCheck, ...]:
    directory.mkdir(parents=True, exist_ok=False)
    with (directory / "runner.log").open("w") as log:
        result: Final = subprocess.run(
            [
                "node",
                "--import",
                "tsx",
                "src/index.ts",
                "server",
                "--url",
                url,
                "--scenario",
                scenario,
                "--spec-version",
                "2025-11-25",
                "--output-dir",
                str(directory.resolve()),
                "--timeout",
                "30000",
            ],
            cwd=root,
            stdout=log,
            stderr=subprocess.STDOUT,
            timeout=45,
            check=False,
        )
    assert result.returncode == 0, (directory / "runner.log").read_text()
    return read_checks(directory, scenario)


@contextmanager
def reference_server(root: Path, directory: Path, port: int) -> Iterator["McpPeer"]:
    from integration._support.client import eventually
    from integration._support.mcp import McpPeer
    from integration._support.process import group_members, signal_group, stop_root_process

    directory.mkdir(parents=True, exist_ok=True)
    url: Final = f"http://127.0.0.1:{port}"
    with (directory / "reference.log").open("w") as log:
        process: Final = subprocess.Popen(
            ["node", "--import", "tsx", "everything-server.ts"],
            cwd=root / "legacy-reference/examples/servers/typescript",
            env={"PATH": os.environ["PATH"], "PORT": str(port)},
            stdout=log,
            stderr=subprocess.STDOUT,
            start_new_session=True,
        )
        try:
            with httpx.Client(timeout=1, trust_env=False) as client:

                def ready() -> bool:
                    assert process.poll() is None, (directory / "reference.log").read_text()
                    try:
                        return client.get(url + "/mcp").status_code == 400
                    except httpx.TransportError:
                        return False

                eventually(ready, bool, seconds=15)
            yield McpPeer(url + "/mcp", queue.Queue())
        finally:
            stopped: Final = stop_root_process(process)
            residual: Final = group_members(process.pid)
            if residual:
                signal_group(process.pid, signal.SIGTERM)
                psutil.wait_procs(residual, timeout=5)
            remaining: Final = group_members(process.pid)
            if remaining:
                signal_group(process.pid, signal.SIGKILL)
                psutil.wait_procs(remaining, timeout=3)
            process.wait(timeout=3)
            assert not group_members(process.pid), "Official reference child survived cleanup"
            assert stopped and not remaining, "Official reference required forced cleanup"


@contextmanager
def authenticated_endpoint(target: str, key: str, alias: str) -> Iterator[str]:
    from integration._support.asgi import asgi_server
    from starlette.applications import Starlette
    from starlette.requests import Request
    from starlette.responses import StreamingResponse
    from starlette.routing import Mount
    from starlette.types import Receive, Scope, Send

    async def forward(scope: Scope, receive: Receive, send: Send) -> None:
        request: Final = Request(scope, receive)
        original: Final = await request.body()
        body: Final = prefixed_request(original, alias)
        headers: Final = tuple(
            (name, value)
            for name, value in request.headers.raw
            if name.lower() != b"authorization" and (name.lower() != b"content-length" or body == original)
        ) + ((b"authorization", f"Bearer {key}".encode()),)
        async with httpx.AsyncClient(timeout=35, trust_env=False) as client:
            async with client.stream(request.method, target, headers=headers, content=body) as response:
                streamed: Final = StreamingResponse(response.aiter_raw(), status_code=response.status_code)
                streamed.raw_headers = [
                    (name, value)
                    for name, value in response.headers.raw
                    if name.lower() not in (b"transfer-encoding", b"connection")
                ]
                await streamed(scope, receive, send)

    with asgi_server(Starlette(routes=[Mount("/mcp", app=forward)])) as url:
        yield url + "/mcp/"


def prefixed_request(body: bytes, alias: str) -> bytes:
    try:
        request: Final = json.loads(body)
    except (ValueError, UnicodeDecodeError):
        return body
    if not isinstance(request, dict) or request.get("method") not in ("tools/call", "prompts/get"):
        return body
    params: Final = request.get("params")
    if not isinstance(params, dict) or not isinstance(params.get("name"), str):
        return body
    return json.dumps({**request, "params": {**params, "name": f"{alias}-{params['name']}"}}).encode()