"""Inference script for QED Math with strict stdout compliance.

This script emits only [START], [STEP], and [END] lines to stdout.
"""

from __future__ import annotations

import asyncio
import json
import os
import re
import sys
import traceback
from pathlib import Path
from typing import Any, Optional, cast

from openai import OpenAI

from client import QEDMathEnv


def _load_local_dotenv() -> None:
    """Load .env values if present without overriding exported env vars."""
    candidates = [Path.cwd() / ".env", Path(__file__).resolve().parent / ".env"]
    seen: set[Path] = set()
    for env_path in candidates:
        resolved = env_path.resolve()
        if resolved in seen or not resolved.is_file():
            continue
        seen.add(resolved)

        for raw_line in resolved.read_text(encoding="utf-8").splitlines():
            line = raw_line.strip()
            if not line or line.startswith("#"):
                continue
            if line.startswith("export "):
                line = line[len("export ") :].strip()

            key, sep, value = line.partition("=")
            if not sep:
                continue

            key = key.strip()
            value = value.strip()
            if len(value) >= 2 and value[0] == value[-1] and value[0] in {'"', "'"}:
                value = value[1:-1]

            if key:
                os.environ.setdefault(key, value)


_load_local_dotenv()

API_BASE_URL = os.getenv("API_BASE_URL", "https://router.huggingface.co/v1")
MODEL_NAME = os.getenv("MODEL_NAME", "openai/gpt-oss-120b:novita")
HF_TOKEN = os.getenv("HF_TOKEN") or os.getenv("API_KEY")

_raw_qed_math_url = os.getenv("QED_MATH_URL")
QED_MATH_URL = (
    _raw_qed_math_url.strip()
    if _raw_qed_math_url is not None
    else "https://rycerzes-qed-math-openenv.hf.space"
)
TASK_NAME = os.getenv("TASK_NAME", "solve-qed-math")
BENCHMARK = os.getenv("BENCHMARK", "qed-math")
TASK_COUNT = max(3, int(os.getenv("TASK_COUNT", "3")))
MIN_SUBMISSION_SCORE = float(os.getenv("MIN_SUBMISSION_SCORE", "0.01"))
MAX_SUBMISSION_SCORE = float(os.getenv("MAX_SUBMISSION_SCORE", "0.99"))

MAX_STEPS = int(os.getenv("MAX_STEPS", "8"))
TEMPERATURE = float(os.getenv("TEMPERATURE", "0.2"))
MAX_TOKENS = int(os.getenv("MAX_TOKENS", "4096"))

SYSTEM_PROMPT = (
    "You are an expert mathematician. Always call get_problem first, then reason "
    "carefully and call submit_proof with a complete solution. Use "
    "get_grading_guidelines if helpful."
)


def _single_line(value: Any) -> str:
    """Normalize text values so each log record stays on one line."""
    return re.sub(r"\s+", " ", str(value)).strip()


def _strict_open_interval_score(score: float) -> float:
    """Clamp score for submission output so it remains strictly in (0, 1)."""
    lo = max(0.01, min(MIN_SUBMISSION_SCORE, MAX_SUBMISSION_SCORE))
    hi = min(0.99, max(MIN_SUBMISSION_SCORE, MAX_SUBMISSION_SCORE))
    if hi <= lo:
        lo, hi = 0.01, 0.99
    return min(max(float(score), lo), hi)


def log_start(task: str, env: str, model: str) -> None:
    print(
        f"[START] task={_single_line(task)} env={_single_line(env)} model={_single_line(model)}",
        flush=True,
    )


def log_step(step: int, action: str, reward: float, done: bool, error: Optional[str]) -> None:
    error_val = str(error) if error else "null"
    print(
        f"[STEP] step={step} action={_single_line(action)} reward={reward:.2f} "
        f"done={str(done).lower()} error={error_val}",
        flush=True,
    )


def log_end(success: bool, steps: int, score: float, rewards: list[float]) -> None:
    rewards_str = ",".join(f"{reward:.2f}" for reward in rewards)
    score = _strict_open_interval_score(score)
    end_line = (
        f"[END] success={str(success).lower()} steps={steps} "
        f"score={score:.2f} rewards={rewards_str}"
    )
    print(
        end_line,
        flush=True,
    )


def _coerce_float(value: object) -> float | None:
    """Best-effort float coercion that never raises."""
    if value is None:
        return None
    if isinstance(value, bool):
        return float(value)
    if isinstance(value, (int, float)):
        return float(value)
    if isinstance(value, str):
        text = value.strip()
        if not text:
            return None
        try:
            return float(text)
        except ValueError:
            return None
    return None


def _normalize_episode_score(result_dict: dict[str, Any], reward: float) -> float:
    """Return a score in [0, 1] from tool payload fields."""
    score = _coerce_float(result_dict.get("reward"))
    if score is None:
        parsed_raw = _coerce_float(result_dict.get("score"))
        if parsed_raw is None:
            score = reward
        else:
            score = parsed_raw / 7.0 if parsed_raw > 1.0 else parsed_raw

    return min(max(score, 0.0), 1.0)


def _extract_task_ids(payload: Any) -> list[str]:
    result = _as_mapping(payload)
    task_ids = result.get("task_ids")
    if not isinstance(task_ids, list):
        return []

    normalized: list[str] = []
    for value in task_ids:
        task_id = str(value).strip()
        if task_id:
            normalized.append(task_id)
    return normalized


def _select_task_ids(task_ids: list[str], task_count: int) -> list[str]:
    if task_count <= 0:
        return []
    if not task_ids:
        return [TASK_NAME for _ in range(task_count)]
    if len(task_ids) >= task_count:
        return task_ids[:task_count]

    selected: list[str] = []
    for idx in range(task_count):
        selected.append(task_ids[idx % len(task_ids)])
    return selected


def _tools_to_openai_format(tools: list[Any]) -> list[dict[str, Any]]:
    openai_tools: list[dict[str, Any]] = []
    for tool in tools:
        properties: dict[str, Any] = {}
        required: list[str] = []
        input_schema = (
            getattr(tool, "input_schema", None) or getattr(tool, "inputSchema", None) or {}
        )
        if input_schema and "properties" in input_schema:
            for name, schema in input_schema["properties"].items():
                properties[name] = {
                    "type": schema.get("type", "string"),
                    "description": schema.get("description", ""),
                }
            required = input_schema.get("required", [])

        openai_tools.append(
            {
                "type": "function",
                "function": {
                    "name": tool.name,
                    "description": tool.description or "",
                    "parameters": {
                        "type": "object",
                        "properties": properties,
                        "required": required,
                    },
                },
            }
        )
    return openai_tools


def _extract_tool_call(response: Any) -> tuple[str, dict[str, Any], str]:
    message = response.choices[0].message
    if message.tool_calls:
        tool_call_obj = cast(Any, message.tool_calls[0])
        function_payload = getattr(tool_call_obj, "function", None)
        tool_call_id = str(getattr(tool_call_obj, "id", "fallback"))

        if function_payload is not None:
            tool_name = str(getattr(function_payload, "name", "submit_proof"))
            raw_arguments = str(getattr(function_payload, "arguments", "{}"))
            try:
                tool_args = json.loads(raw_arguments)
            except json.JSONDecodeError:
                tool_args = {"proof": raw_arguments}
        else:
            tool_name = "submit_proof"
            raw_input = getattr(tool_call_obj, "input", "")
            tool_args = {"proof": str(raw_input)}
    else:
        tool_name = "submit_proof"
        tool_args = {"proof": message.content or ""}
        tool_call_id = "fallback"

    return tool_name, tool_args, tool_call_id


def _as_mapping(value: Any) -> dict[str, Any]:
    if hasattr(value, "model_dump"):
        return value.model_dump()
    if isinstance(value, dict):
        return value
    return {"result": str(value)}


async def run_episode(
    env: QEDMathEnv,
    client: OpenAI,
    tools: list[dict[str, Any]],
    problem_id: str | None = None,
) -> tuple[bool, int, float, list[float]]:
    tool_names = {tool["function"]["name"] for tool in tools}

    if problem_id is not None:
        await env.reset(problem_id=problem_id)
    else:
        await env.reset()

    chat_history: list[dict[str, Any]] = [
        {"role": "system", "content": SYSTEM_PROMPT},
        {"role": "user", "content": "Solve the current QED math problem."},
    ]

    rewards: list[float] = []
    steps_taken = 0
    score = 0.0
    success = False
    grader_called = False

    for step in range(1, MAX_STEPS + 1):
        response = client.chat.completions.create(
            model=MODEL_NAME,
            messages=cast(Any, chat_history),
            tools=cast(Any, tools),
            tool_choice="required",
            temperature=TEMPERATURE,
            max_tokens=MAX_TOKENS,
            stream=False,
        )

        tool_name, tool_args, tool_call_id = _extract_tool_call(response)

        if tool_name not in tool_names:
            tool_name = "submit_proof"
            tool_args = {"proof": tool_args.get("proof", str(tool_args))}

        call_kwargs = dict(tool_args)

        step_result = await env.call_tool(tool_name, **call_kwargs)
        if tool_name == "submit_proof":
            grader_called = True

        result_dict = _as_mapping(step_result)

        reward = float(result_dict.get("reward") or 0.0)
        done = bool(result_dict.get("done", False))
        error_raw = result_dict.get("last_action_error")
        error = str(error_raw) if error_raw is not None else None

        action_str = json.dumps({"tool": tool_name, "args": tool_args}, ensure_ascii=True)
        log_step(step=step, action=action_str, reward=reward, done=done, error=error)

        rewards.append(reward)
        steps_taken = step

        if done:
            score = _normalize_episode_score(result_dict, reward)
            success = bool(result_dict.get("is_correct", score > 0.0))
            break

        chat_history.append(
            {
                "role": "assistant",
                "content": None,
                "tool_calls": [
                    {
                        "id": tool_call_id,
                        "type": "function",
                        "function": {
                            "name": tool_name,
                            "arguments": json.dumps(tool_args),
                        },
                    }
                ],
            }
        )
        chat_history.append(
            {
                "role": "tool",
                "tool_call_id": tool_call_id,
                "content": json.dumps(result_dict),
            }
        )

    # Ensure each task reaches the grader at least once for submission validation.
    if not grader_called:
        forced_proof = "I attempted a complete proof but could not finish within the step budget."
        step_result = await env.call_tool("submit_proof", proof=forced_proof)
        result_dict = _as_mapping(step_result)
        reward = float(result_dict.get("reward") or 0.0)
        done = bool(result_dict.get("done", True))
        error_raw = result_dict.get("last_action_error")
        error = str(error_raw) if error_raw is not None else None
        forced_step = steps_taken + 1
        action_str = json.dumps(
            {
                "tool": "submit_proof",
                "args": {"proof": forced_proof},
                "forced": True,
            },
            ensure_ascii=True,
        )
        log_step(step=forced_step, action=action_str, reward=reward, done=done, error=error)
        rewards.append(reward)
        steps_taken = forced_step
        score = _normalize_episode_score(result_dict, reward)
        success = bool(result_dict.get("is_correct", score > 0.0))

    if not rewards:
        score = 0.0
    elif score == 0.0:
        score = min(max(float(rewards[-1]), 0.0), 1.0)

    return success, steps_taken, score, rewards


async def async_main() -> None:
    if not HF_TOKEN:
        raise SystemExit("HF_TOKEN must be set.\nOptional fallback: API_KEY.")
    if not QED_MATH_URL:
        raise SystemExit("QED_MATH_URL must be set (for example: https://<space>.hf.space/).")

    client = OpenAI(base_url=API_BASE_URL, api_key=HF_TOKEN)

    caught_error: Exception | None = None

    try:
        async with QEDMathEnv(base_url=QED_MATH_URL) as raw_env:
            env = cast(QEDMathEnv, raw_env)
            mcp_tools = await env.list_tools()
            tools = _tools_to_openai_format(mcp_tools)

            try:
                task_payload = await env.call_tool("list_task_ids")
            except Exception:
                task_payload = {"task_ids": []}
            available_task_ids = _extract_task_ids(task_payload)
            selected_task_ids = _select_task_ids(available_task_ids, TASK_COUNT)

            for task_index, problem_id in enumerate(selected_task_ids, start=1):
                task_name = f"{TASK_NAME}:{problem_id}:run{task_index}"
                log_start(task=task_name, env=BENCHMARK, model=MODEL_NAME)
                success, steps_taken, score, rewards = await run_episode(
                    env=env,
                    client=client,
                    tools=tools,
                    problem_id=problem_id if problem_id != TASK_NAME else None,
                )
                log_end(success=success, steps=steps_taken, score=score, rewards=rewards)
    except Exception as exc:
        caught_error = exc
        print(
            f"[ERROR] type={type(exc).__name__} message={exc}",
            file=sys.stderr,
            flush=True,
        )
        print(
            f"[ERROR] QED_MATH_URL={QED_MATH_URL}",
            file=sys.stderr,
            flush=True,
        )
        traceback.print_exc(file=sys.stderr)

    if caught_error is not None:
        raise SystemExit(1) from caught_error


def main() -> None:
    asyncio.run(async_main())


if __name__ == "__main__":
    main()