from __future__ import annotations

import argparse
from dataclasses import dataclass, field
from collections import deque
from queue import SimpleQueue
from typing import Final

import uvicorn
from pydantic import JsonValue, TypeAdapter
from starlette.applications import Starlette
from starlette.requests import Request
from starlette.responses import JSONResponse, Response
from starlette.routing import Route

from _fake_openai_endpoint_server import chat_completions, completions, embeddings, health, moderations

JSON_OBJECT: Final = TypeAdapter(dict[str, JsonValue])
INTERNAL_FIELDS: Final = frozenset(
    {
        "litellm_params",
        "litellm_logging_obj",
        "litellm_call_id",
        "litellm_metadata",
        "proxy_server_request",
        "rpm",
        "tpm",
        "timeout",
        "stream_chunk_size",
    }
)


@dataclass(frozen=True, slots=True)
class Observation:
    path: str
    authorization: str
    body: dict[str, JsonValue]


@dataclass(frozen=True, slots=True)
class Provider:
    observations: SimpleQueue[Observation] = field(default_factory=SimpleQueue)
    scripts: dict[str, deque[int]] = field(default_factory=dict)

    async def chat(self, request: Request) -> Response:
        body: Final = JSON_OBJECT.validate_json(await request.body())
        self.observations.put(Observation(request.url.path, request.headers.get("authorization", ""), body))
        leaked: Final = tuple(sorted(INTERNAL_FIELDS.intersection(body)))
        if leaked:
            return JSONResponse({"error": {"message": f"Unexpected provider fields: {leaked}"}}, status_code=400)
        messages: Final = body.get("messages")
        if not isinstance(body.get("model"), str) or not isinstance(messages, list) or not messages:
            return JSONResponse({"error": {"message": "model and nonempty messages are required"}}, status_code=400)
        if any(
            not isinstance(message, dict)
            or message.get("role") not in {"system", "developer", "user", "assistant", "tool"}
            or "content" not in message
            for message in messages
        ):
            return JSONResponse({"error": {"message": "Invalid selected message contract"}}, status_code=400)
        script: Final = self.scripts.get(str(body["model"]))
        if script is not None:
            if not script:
                return JSONResponse({"error": {"message": "Script exhausted", "type": "api_error"}}, status_code=500)
            status: Final = script.popleft()
            if status != 200:
                return JSONResponse(
                    {"error": {"message": "Controlled provider failure", "type": "api_error", "code": str(status)}},
                    status_code=status,
                )
        return await chat_completions(request)

    async def script(self, request: Request) -> Response:
        name: Final = request.path_params["model"]
        if request.method in {"DELETE", "GET"} and name not in self.scripts:
            return JSONResponse({"error": "Script not found"}, status_code=404)
        if request.method == "GET":
            return JSONResponse({"remaining": list(self.scripts[name])})
        if request.method == "DELETE":
            remaining: Final = self.scripts.pop(name)
            return JSONResponse({"remaining": list(remaining)})
        body: Final = JSON_OBJECT.validate_json(await request.body())
        statuses: Final = body.get("statuses")
        if not isinstance(statuses, list) or not statuses or any(type(value) is not int for value in statuses):
            return JSONResponse({"error": "A nonempty list of HTTP status codes is required"}, status_code=400)
        self.scripts[name] = deque(int(str(value)) for value in statuses)
        return JSONResponse({"configured": len(statuses)})

    async def observed(self, _request: Request) -> Response:
        values: Final = tuple(self.observations.get() for _ in range(self.observations.qsize()))
        return JSONResponse(
            {
                "requests": [
                    {"path": value.path, "authorization": value.authorization, "body": value.body} for value in values
                ]
            }
        )

    def app(self) -> Starlette:
        return Starlette(
            routes=[
                Route("/health", health),
                Route("/__observations", self.observed),
                Route("/__scripts/{model}", self.script, methods=["POST", "DELETE", "GET"]),
                Route("/v1/chat/completions", self.chat, methods=["POST"]),
                Route("/v1/completions", completions, methods=["POST"]),
                Route("/v1/embeddings", embeddings, methods=["POST"]),
                Route("/v1/moderations", moderations, methods=["POST"]),
            ]
        )


def main() -> None:
    parser: Final = argparse.ArgumentParser()
    parser.add_argument("--port", type=int, default=8190)
    arguments: Final = parser.parse_args()
    uvicorn.run(Provider().app(), host="127.0.0.1", port=arguments.port, access_log=False)


if __name__ == "__main__":
    main()