import json
import time
from litellm._uuid import uuid
from typing import TYPE_CHECKING, Any, AsyncIterator, Iterator, List, Optional, Union

from httpx._models import Headers, Response

import litellm
from litellm._logging import verbose_proxy_logger
from litellm.litellm_core_utils.prompt_templates.common_utils import (
    get_str_from_messages,
)
from litellm.litellm_core_utils.prompt_templates.factory import (
    convert_to_ollama_image,
    custom_prompt,
    ollama_pt,
)
from litellm.llms.base_llm.base_model_iterator import BaseModelResponseIterator
from litellm.llms.base_llm.chat.transformation import BaseConfig, BaseLLMException
from litellm.secret_managers.main import get_secret_str
from litellm.types.llms.openai import AllMessageValues, ChatCompletionUsageBlock
from litellm.types.utils import (
    Delta,
    GenericStreamingChunk,
    ModelInfoBase,
    ModelResponse,
    ModelResponseStream,
    ProviderField,
    StreamingChoices,
)

from ..common_utils import OllamaError, _convert_image

if TYPE_CHECKING:
    from litellm.litellm_core_utils.litellm_logging import Logging as _LiteLLMLoggingObj

    LiteLLMLoggingObj = _LiteLLMLoggingObj
else:
    LiteLLMLoggingObj = Any


class OllamaConfig(BaseConfig):
    """
    Reference: https://github.com/ollama/ollama/blob/main/docs/api.md#parameters

    The class `OllamaConfig` provides the configuration for the Ollama's API interface. Below are the parameters:

    - `mirostat` (int): Enable Mirostat sampling for controlling perplexity. Default is 0, 0 = disabled, 1 = Mirostat, 2 = Mirostat 2.0. Example usage: mirostat 0

    - `mirostat_eta` (float): Influences how quickly the algorithm responds to feedback from the generated text. A lower learning rate will result in slower adjustments, while a higher learning rate will make the algorithm more responsive. Default: 0.1. Example usage: mirostat_eta 0.1

    - `mirostat_tau` (float): Controls the balance between coherence and diversity of the output. A lower value will result in more focused and coherent text. Default: 5.0. Example usage: mirostat_tau 5.0

    - `num_ctx` (int): Sets the size of the context window used to generate the next token. Default: 2048. Example usage: num_ctx 4096

    - `num_gqa` (int): The number of GQA groups in the transformer layer. Required for some models, for example it is 8 for llama2:70b. Example usage: num_gqa 1

    - `num_gpu` (int): The number of layers to send to the GPU(s). On macOS it defaults to 1 to enable metal support, 0 to disable. Example usage: num_gpu 0

    - `num_thread` (int): Sets the number of threads to use during computation. By default, Ollama will detect this for optimal performance. It is recommended to set this value to the number of physical CPU cores your system has (as opposed to the logical number of cores). Example usage: num_thread 8

    - `repeat_last_n` (int): Sets how far back for the model to look back to prevent repetition. Default: 64, 0 = disabled, -1 = num_ctx. Example usage: repeat_last_n 64

    - `repeat_penalty` (float): Sets how strongly to penalize repetitions. A higher value (e.g., 1.5) will penalize repetitions more strongly, while a lower value (e.g., 0.9) will be more lenient. Default: 1.1. Example usage: repeat_penalty 1.1

    - `temperature` (float): The temperature of the model. Increasing the temperature will make the model answer more creatively. Default: 0.8. Example usage: temperature 0.7

    - `seed` (int): Sets the random number seed to use for generation. Setting this to a specific number will make the model generate the same text for the same prompt. Example usage: seed 42

    - `stop` (string[]): Sets the stop sequences to use. Example usage: stop "AI assistant:"

    - `tfs_z` (float): Tail free sampling is used to reduce the impact of less probable tokens from the output. A higher value (e.g., 2.0) will reduce the impact more, while a value of 1.0 disables this setting. Default: 1. Example usage: tfs_z 1

    - `num_predict` (int): Maximum number of tokens to predict when generating text. Default: 128, -1 = infinite generation, -2 = fill context. Example usage: num_predict 42

    - `top_k` (int): Reduces the probability of generating nonsense. A higher value (e.g. 100) will give more diverse answers, while a lower value (e.g. 10) will be more conservative. Default: 40. Example usage: top_k 40

    - `top_p` (float): Works together with top-k. A higher value (e.g., 0.95) will lead to more diverse text, while a lower value (e.g., 0.5) will generate more focused and conservative text. Default: 0.9. Example usage: top_p 0.9

    - `system` (string): system prompt for model (overrides what is defined in the Modelfile)

    - `template` (string): the full prompt or prompt template (overrides what is defined in the Modelfile)
    """

    mirostat: Optional[int] = None
    mirostat_eta: Optional[float] = None
    mirostat_tau: Optional[float] = None
    num_ctx: Optional[int] = None
    num_gqa: Optional[int] = None
    num_gpu: Optional[int] = None
    num_thread: Optional[int] = None
    repeat_last_n: Optional[int] = None
    repeat_penalty: Optional[float] = None
    temperature: Optional[float] = None
    seed: Optional[int] = None
    stop: Optional[list] = (
        None  # stop is a list based on this - https://github.com/ollama/ollama/pull/442
    )
    tfs_z: Optional[float] = None
    num_predict: Optional[int] = None
    top_k: Optional[int] = None
    top_p: Optional[float] = None
    system: Optional[str] = None
    template: Optional[str] = None

    def __init__(
        self,
        mirostat: Optional[int] = None,
        mirostat_eta: Optional[float] = None,
        mirostat_tau: Optional[float] = None,
        num_ctx: Optional[int] = None,
        num_gqa: Optional[int] = None,
        num_gpu: Optional[int] = None,
        num_thread: Optional[int] = None,
        repeat_last_n: Optional[int] = None,
        repeat_penalty: Optional[float] = None,
        temperature: Optional[float] = None,
        seed: Optional[int] = None,
        stop: Optional[list] = None,
        tfs_z: Optional[float] = None,
        num_predict: Optional[int] = None,
        top_k: Optional[int] = None,
        top_p: Optional[float] = None,
        system: Optional[str] = None,
        template: Optional[str] = None,
    ) -> None:
        locals_ = locals().copy()
        for key, value in locals_.items():
            if key != "self" and value is not None:
                setattr(self.__class__, key, value)

    @classmethod
    def get_config(cls):
        return super().get_config()

    def get_required_params(self) -> List[ProviderField]:
        """For a given provider, return it's required fields with a description"""
        return [
            ProviderField(
                field_name="base_url",
                field_type="string",
                field_description="Your Ollama API Base",
                field_value="http://10.10.11.249:11434",
            )
        ]

    def get_supported_openai_params(self, model: str):
        return [
            "max_tokens",
            "stream",
            "top_p",
            "temperature",
            "seed",
            "frequency_penalty",
            "stop",
            "response_format",
            "max_completion_tokens",
            "reasoning_effort",
        ]

    def map_openai_params(
        self,
        non_default_params: dict,
        optional_params: dict,
        model: str,
        drop_params: bool,
    ) -> dict:
        for param, value in non_default_params.items():
            if param == "max_tokens" or param == "max_completion_tokens":
                optional_params["num_predict"] = value
            elif param == "stream":
                optional_params["stream"] = value
            elif param == "temperature":
                optional_params["temperature"] = value
            elif param == "seed":
                optional_params["seed"] = value
            elif param == "top_p":
                optional_params["top_p"] = value
            elif param == "frequency_penalty":
                optional_params["frequency_penalty"] = value
            elif param == "stop":
                optional_params["stop"] = value
            elif param == "reasoning_effort" and value is not None:
                if model.startswith("gpt-oss"):
                    optional_params["think"] = value
                else:
                    optional_params["think"] = value in {"low", "medium", "high"}
            elif param == "response_format" and isinstance(value, dict):
                if value["type"] == "json_object":
                    optional_params["format"] = "json"
                elif value["type"] == "json_schema":
                    optional_params["format"] = value["json_schema"]["schema"]

        return optional_params

    def _supports_function_calling(self, ollama_model_info: dict) -> bool:
        """
        Check if the 'template' field in the ollama_model_info contains a 'tools' or 'function' key.
        """
        _template: str = str(ollama_model_info.get("template", "") or "")
        return "tools" in _template.lower()

    def _get_max_tokens(self, ollama_model_info: dict) -> Optional[int]:
        _model_info: dict = ollama_model_info.get("model_info", {})

        for k, v in _model_info.items():
            if "context_length" in k:
                return v
        return None

    @staticmethod
    def get_api_key() -> Optional[str]:
        """Get API key from environment variables or litellm configuration"""
        import os

        import litellm
        from litellm.secret_managers.main import get_secret_str

        return (
            os.environ.get("OLLAMA_API_KEY")
            or litellm.api_key
            or litellm.openai_key
            or get_secret_str("OLLAMA_API_KEY")
        )

    def get_model_info(self, model: str) -> ModelInfoBase:
        """
        curl http://localhost:11434/api/show -d '{
          "name": "mistral"
        }'
        """
        if model.startswith("ollama/") or model.startswith("ollama_chat/"):
            model = model.split("/", 1)[1]
        api_base = get_secret_str("OLLAMA_API_BASE") or "http://localhost:11434"
        api_key = self.get_api_key()
        headers = {"Authorization": f"Bearer {api_key}"} if api_key else {}

        try:
            response = litellm.module_level_client.post(
                url=f"{api_base}/api/show",
                json={"name": model},
                headers=headers,
            )
        except Exception as e:
            raise Exception(
                f"OllamaError: Error getting model info for {model}. Set Ollama API Base via `OLLAMA_API_BASE` environment variable. Error: {e}"
            )

        model_info = response.json()

        _max_tokens: Optional[int] = self._get_max_tokens(model_info)

        return ModelInfoBase(
            key=model,
            litellm_provider="ollama",
            mode="chat",
            supports_function_calling=self._supports_function_calling(model_info),
            input_cost_per_token=0.0,
            output_cost_per_token=0.0,
            max_tokens=_max_tokens,
            max_input_tokens=_max_tokens,
            max_output_tokens=_max_tokens,
        )

    def get_error_class(
        self, error_message: str, status_code: int, headers: Union[dict, Headers]
    ) -> BaseLLMException:
        return OllamaError(
            status_code=status_code, message=error_message, headers=headers
        )

    def transform_response(
        self,
        model: str,
        raw_response: Response,
        model_response: ModelResponse,
        logging_obj: LiteLLMLoggingObj,
        request_data: dict,
        messages: List[AllMessageValues],
        optional_params: dict,
        litellm_params: dict,
        encoding: str,
        api_key: Optional[str] = None,
        json_mode: Optional[bool] = None,
    ) -> ModelResponse:
        from litellm.litellm_core_utils.prompt_templates.common_utils import (
            _parse_content_for_reasoning,
        )

        response_json = raw_response.json()
        ## RESPONSE OBJECT
        model_response.choices[0].finish_reason = "stop"
        if request_data.get("format", "") == "json":
            # Check if response field exists and is not empty before parsing JSON
            response_text = response_json.get("response", "")

            if not response_text or not response_text.strip():
                # Handle empty response gracefully - set empty content
                message = litellm.Message(content="")
                model_response.choices[0].message = message  # type: ignore
                model_response.choices[0].finish_reason = "stop"
            else:
                try:
                    response_content = json.loads(response_text)

                    # Check if this is a function call format with name/arguments structure
                    if (
                        isinstance(response_content, dict)
                        and "name" in response_content
                        and "arguments" in response_content
                    ):
                        # Handle as function call (original behavior)
                        function_call = response_content
                        message = litellm.Message(
                            content=None,
                            tool_calls=[
                                {
                                    "id": f"call_{str(uuid.uuid4())}",
                                    "function": {
                                        "name": function_call["name"],
                                        "arguments": json.dumps(
                                            function_call["arguments"]
                                        ),
                                    },
                                    "type": "function",
                                }
                            ],
                        )
                        model_response.choices[0].message = message  # type: ignore
                        model_response.choices[0].finish_reason = "tool_calls"
                    else:
                        # Handle as regular JSON (new behavior)
                        message = litellm.Message(
                            content=json.dumps(response_content),
                        )
                        model_response.choices[0].message = message  # type: ignore
                        model_response.choices[0].finish_reason = "stop"
                except json.JSONDecodeError:
                    # If JSON parsing fails, treat as regular text response
                    ## output parse reasoning content from response_text
                    reasoning_content: Optional[str] = None
                    content: Optional[str] = None
                    if response_text is not None:
                        reasoning_content, content = _parse_content_for_reasoning(
                            response_text
                        )
                    message = litellm.Message(
                        content=content, reasoning_content=reasoning_content
                    )
                    model_response.choices[0].message = message  # type: ignore
                    model_response.choices[0].finish_reason = "stop"
        else:
            response_text = response_json.get("response", "")
            content = None
            reasoning_content = None
            if response_text is not None and isinstance(response_text, str):
                reasoning_content, content = _parse_content_for_reasoning(response_text)
            else:
                content = response_text  # type: ignore
            model_response.choices[0].message.content = content  # type: ignore
            model_response.choices[0].message.reasoning_content = reasoning_content  # type: ignore
        model_response.created = int(time.time())
        model_response.model = "ollama/" + model
        _prompt = request_data.get("prompt", "")
        prompt_tokens = response_json.get(
            "prompt_eval_count", len(encoding.encode(_prompt, disallowed_special=()))  # type: ignore
        )
        completion_tokens = response_json.get(
            "eval_count", len(response_json.get("message", dict()).get("content", ""))
        )
        setattr(
            model_response,
            "usage",
            litellm.Usage(
                prompt_tokens=prompt_tokens,
                completion_tokens=completion_tokens,
                total_tokens=prompt_tokens + completion_tokens,
            ),
        )
        return model_response

    def transform_request(
        self,
        model: str,
        messages: List[AllMessageValues],
        optional_params: dict,
        litellm_params: dict,
        headers: dict,
    ) -> dict:
        custom_prompt_dict = (
            litellm_params.get("custom_prompt_dict") or litellm.custom_prompt_dict
        )

        text_completion_request = litellm_params.get("text_completion")
        if model in custom_prompt_dict:
            # check if the model has a registered custom prompt
            model_prompt_details = custom_prompt_dict[model]
            ollama_prompt = custom_prompt(
                role_dict=model_prompt_details["roles"],
                initial_prompt_value=model_prompt_details["initial_prompt_value"],
                final_prompt_value=model_prompt_details["final_prompt_value"],
                messages=messages,
            )
        elif text_completion_request:  # handle `/completions` requests
            ollama_prompt = get_str_from_messages(messages=messages)
        else:  # handle `/chat/completions` requests
            modified_prompt = ollama_pt(model=model, messages=messages)
            if isinstance(modified_prompt, dict):
                ollama_prompt, images = (
                    modified_prompt["prompt"],
                    modified_prompt["images"],
                )
                optional_params["images"] = images
            else:
                ollama_prompt = modified_prompt
        stream = optional_params.pop("stream", False)
        format = optional_params.pop("format", None)
        images = optional_params.pop("images", None)
        think = optional_params.pop("think", None)
        data = {
            "model": model,
            "prompt": ollama_prompt,
            "options": optional_params,
            "stream": stream,
        }

        if format is not None:
            data["format"] = format
        if images is not None:
            data["images"] = [
                _convert_image(convert_to_ollama_image(image)) for image in images
            ]
        if think is not None:
            data["think"] = think

        return data

    def validate_environment(
        self,
        headers: dict,
        model: str,
        messages: List[AllMessageValues],
        optional_params: dict,
        litellm_params: dict,
        api_key: Optional[str] = None,
        api_base: Optional[str] = None,
    ) -> dict:
        return headers

    def get_complete_url(
        self,
        api_base: Optional[str],
        api_key: Optional[str],
        model: str,
        optional_params: dict,
        litellm_params: dict,
        stream: Optional[bool] = None,
    ) -> str:
        """
        OPTIONAL

        Get the complete url for the request

        Some providers need `model` in `api_base`
        """
        if api_base is None:
            api_base = "http://localhost:11434"
        if api_base.endswith("/api/generate"):
            url = api_base
        else:
            url = f"{api_base}/api/generate"

        return url

    def get_model_response_iterator(
        self,
        streaming_response: Union[Iterator[str], AsyncIterator[str], ModelResponse],
        sync_stream: bool,
        json_mode: Optional[bool] = False,
    ):
        return OllamaTextCompletionResponseIterator(
            streaming_response=streaming_response,
            sync_stream=sync_stream,
            json_mode=json_mode,
        )


class OllamaTextCompletionResponseIterator(BaseModelResponseIterator):
    def __init__(
        self, streaming_response, sync_stream: bool, json_mode: Optional[bool] = False
    ):
        super().__init__(streaming_response, sync_stream, json_mode)
        self.started_reasoning_content: bool = False
        self.finished_reasoning_content: bool = False

    def _handle_string_chunk(
        self, str_line: str
    ) -> Union[GenericStreamingChunk, ModelResponseStream]:
        return self.chunk_parser(json.loads(str_line))

    def chunk_parser(
        self, chunk: dict
    ) -> Union[GenericStreamingChunk, ModelResponseStream]:
        try:
            if "error" in chunk:
                raise Exception(f"Ollama Error - {chunk}")

            text = ""
            is_finished = False
            finish_reason = None
            if chunk["done"] is True:
                text = ""
                is_finished = True
                finish_reason = "stop"
                prompt_eval_count: Optional[int] = chunk.get("prompt_eval_count", None)
                eval_count: Optional[int] = chunk.get("eval_count", None)

                usage: Optional[ChatCompletionUsageBlock] = None
                if prompt_eval_count is not None and eval_count is not None:
                    usage = ChatCompletionUsageBlock(
                        prompt_tokens=prompt_eval_count,
                        completion_tokens=eval_count,
                        total_tokens=prompt_eval_count + eval_count,
                    )
                return GenericStreamingChunk(
                    text=text,
                    is_finished=is_finished,
                    finish_reason=finish_reason,
                    usage=usage,
                )
            elif chunk["response"]:
                text = chunk["response"]
                reasoning_content: Optional[str] = None
                content: Optional[str] = None
                if text is not None:
                    if "<think>" in text:
                        text = text.replace("<think>", "")
                        self.started_reasoning_content = True
                    elif "</think>" in text:
                        text = text.replace("</think>", "")
                        self.finished_reasoning_content = True

                    if (
                        self.started_reasoning_content
                        and not self.finished_reasoning_content
                    ):
                        reasoning_content = text
                    else:
                        content = text

                return ModelResponseStream(
                    choices=[
                        StreamingChoices(
                            index=0,
                            delta=Delta(
                                reasoning_content=reasoning_content, content=content
                            ),
                        )
                    ],
                    finish_reason=finish_reason,
                    usage=None,
                )
                # return GenericStreamingChunk(
                #     text=text,
                #     is_finished=is_finished,
                #     finish_reason="stop",
                #     usage=None,
                # )
            elif "thinking" in chunk and not chunk["response"]:
                # Return reasoning content as ModelResponseStream so UIs can render it
                thinking_content = chunk.get("thinking") or ""
                return ModelResponseStream(
                    choices=[
                        StreamingChoices(
                            index=0,
                            delta=Delta(reasoning_content=thinking_content),
                        )
                    ]
                )
            else:
                # In this case, 'thinking' is not present in the chunk, chunk["done"] is false,
                # and chunk["response"] is falsy (None or empty string), 
                # but Ollama is just starting to stream, so it should be processed as a normal dict
                return ModelResponseStream(
                    choices=[
                        StreamingChoices(
                            index=0,
                            delta=Delta(reasoning_content=""),
                        )
                    ]
                )
                # raise Exception(f"Unable to parse ollama chunk - {chunk}")
        except Exception as e:
            verbose_proxy_logger.error(f"Unable to parse ollama chunk - {chunk}")
            raise e
