# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project

from collections.abc import Iterable, Sequence

from transformers import PreTrainedTokenizerBase

from vllm.entrypoints.openai.chat_completion.protocol import (
    ChatCompletionRequest,
)
from vllm.entrypoints.openai.engine.protocol import DeltaMessage
from vllm.logger import init_logger
from vllm.reasoning import ReasoningParser
from vllm.reasoning.deepseek_r1_reasoning_parser import DeepSeekR1ReasoningParser

from .identity_reasoning_parser import IdentityReasoningParser

logger = init_logger(__name__)


class DeepSeekV3ReasoningParser(ReasoningParser):
    """
    V3 parser that delegates to either DeepSeekR1ReasoningParser or
    IdentityReasoningParser based on `thinking` and `separate_reasoning`.
    """

    def __init__(self, tokenizer: PreTrainedTokenizerBase, *args, **kwargs):
        super().__init__(tokenizer, *args, **kwargs)

        chat_kwargs = kwargs.get("chat_template_kwargs", {}) or {}
        thinking = bool(chat_kwargs.get("thinking", False))
        enable_thinking = bool(chat_kwargs.get("enable_thinking", False))
        thinking = thinking or enable_thinking

        if thinking:
            self._parser = DeepSeekR1ReasoningParser(tokenizer, *args, **kwargs)
        else:
            self._parser = IdentityReasoningParser(tokenizer, *args, **kwargs)

    def is_reasoning_end(self, input_ids: Sequence[int]) -> bool:
        return self._parser.is_reasoning_end(input_ids)

    def is_reasoning_end_streaming(
        self, input_ids: Sequence[int], delta_ids: Iterable[int]
    ) -> bool:
        return self._parser.is_reasoning_end_streaming(input_ids, delta_ids)

    def extract_content_ids(self, input_ids: list[int]) -> list[int]:
        return self._parser.extract_content_ids(input_ids)

    def extract_reasoning(
        self, model_output: str, request: ChatCompletionRequest
    ) -> tuple[str | None, str | None]:
        return self._parser.extract_reasoning(model_output, request)

    def extract_reasoning_streaming(
        self,
        previous_text: str,
        current_text: str,
        delta_text: str,
        previous_token_ids: Sequence[int],
        current_token_ids: Sequence[int],
        delta_token_ids: Sequence[int],
    ) -> DeltaMessage | None:
        return self._parser.extract_reasoning_streaming(
            previous_text,
            current_text,
            delta_text,
            previous_token_ids,
            current_token_ids,
            delta_token_ids,
        )


class DeepSeekV3ReasoningWithThinkingParser(DeepSeekV3ReasoningParser):
    """
    DeepSeekV3ReasoningParser that defaults to thinking mode.
    """

    def __init__(self, tokenizer: PreTrainedTokenizerBase, *args, **kwargs):
        chat_kwargs = kwargs.get("chat_template_kwargs", {}) or {}
        thinking = chat_kwargs.get("thinking", None)
        enable_thinking = chat_kwargs.get("enable_thinking", None)
        if thinking is None and enable_thinking is None:
            chat_kwargs["thinking"] = True
            chat_kwargs["enable_thinking"] = True
            kwargs["chat_template_kwargs"] = chat_kwargs
        super().__init__(tokenizer, *args, **kwargs)
