from __future__ import annotations

import json
from collections.abc import AsyncIterator
from dataclasses import dataclass
from typing import TYPE_CHECKING, Any, Literal, overload

from openai import NOT_GIVEN, AsyncOpenAI, AsyncStream, NotGiven
from openai.types import ChatModel
from openai.types.responses import (
    Response,
    ResponseCompletedEvent,
    ResponseStreamEvent,
    ResponseTextConfigParam,
    ToolParam,
    WebSearchToolParam,
    response_create_params,
)

from .. import _debug
from ..agent_output import AgentOutputSchema
from ..exceptions import UserError
from ..handoffs import Handoff
from ..items import ItemHelpers, ModelResponse, TResponseInputItem
from ..logger import logger
from ..tool import ComputerTool, FileSearchTool, FunctionTool, Tool, WebSearchTool
from ..tracing import SpanError, response_span
from ..usage import Usage
from ..version import __version__
from .interface import Model, ModelTracing

if TYPE_CHECKING:
    from ..model_settings import ModelSettings


_USER_AGENT = f"Agents/Python {__version__}"
_HEADERS = {"User-Agent": _USER_AGENT}

# From the Responses API
IncludeLiteral = Literal[
    "file_search_call.results",
    "message.input_image.image_url",
    "computer_call_output.output.image_url",
]


class OpenAIResponsesModel(Model):
    """
    Implementation of `Model` that uses the OpenAI Responses API.
    """

    def __init__(
        self,
        model: str | ChatModel,
        openai_client: AsyncOpenAI,
    ) -> None:
        self.model = model
        self._client = openai_client

    def _non_null_or_not_given(self, value: Any) -> Any:
        return value if value is not None else NOT_GIVEN

    async def get_response(
        self,
        system_instructions: str | None,
        input: str | list[TResponseInputItem],
        model_settings: ModelSettings,
        tools: list[Tool],
        output_schema: AgentOutputSchema | None,
        handoffs: list[Handoff],
        tracing: ModelTracing,
    ) -> ModelResponse:
        with response_span(disabled=tracing.is_disabled()) as span_response:
            try:
                response = await self._fetch_response(
                    system_instructions,
                    input,
                    model_settings,
                    tools,
                    output_schema,
                    handoffs,
                    stream=False,
                )

                if _debug.DONT_LOG_MODEL_DATA:
                    logger.debug("LLM responsed")
                else:
                    logger.debug(
                        "LLM resp:\n"
                        f"{json.dumps([x.model_dump() for x in response.output], indent=2)}\n"
                    )

                usage = (
                    Usage(
                        requests=1,
                        input_tokens=response.usage.input_tokens,
                        output_tokens=response.usage.output_tokens,
                        total_tokens=response.usage.total_tokens,
                    )
                    if response.usage
                    else Usage()
                )

                if tracing.include_data():
                    span_response.span_data.response = response
                    span_response.span_data.input = input
            except Exception as e:
                span_response.set_error(
                    SpanError(
                        message="Error getting response",
                        data={
                            "error": str(e) if tracing.include_data() else e.__class__.__name__,
                        },
                    )
                )
                logger.error(f"Error getting response: {e}")
                raise

        return ModelResponse(
            output=response.output,
            usage=usage,
            referenceable_id=response.id,
        )

    async def stream_response(
        self,
        system_instructions: str | None,
        input: str | list[TResponseInputItem],
        model_settings: ModelSettings,
        tools: list[Tool],
        output_schema: AgentOutputSchema | None,
        handoffs: list[Handoff],
        tracing: ModelTracing,
    ) -> AsyncIterator[ResponseStreamEvent]:
        """
        Yields a partial message as it is generated, as well as the usage information.
        """
        with response_span(disabled=tracing.is_disabled()) as span_response:
            try:
                stream = await self._fetch_response(
                    system_instructions,
                    input,
                    model_settings,
                    tools,
                    output_schema,
                    handoffs,
                    stream=True,
                )

                final_response: Response | None = None

                async for chunk in stream:
                    if isinstance(chunk, ResponseCompletedEvent):
                        final_response = chunk.response
                    yield chunk

                if final_response and tracing.include_data():
                    span_response.span_data.response = final_response
                    span_response.span_data.input = input

            except Exception as e:
                span_response.set_error(
                    SpanError(
                        message="Error streaming response",
                        data={
                            "error": str(e) if tracing.include_data() else e.__class__.__name__,
                        },
                    )
                )
                logger.error(f"Error streaming response: {e}")
                raise

    @overload
    async def _fetch_response(
        self,
        system_instructions: str | None,
        input: str | list[TResponseInputItem],
        model_settings: ModelSettings,
        tools: list[Tool],
        output_schema: AgentOutputSchema | None,
        handoffs: list[Handoff],
        stream: Literal[True],
    ) -> AsyncStream[ResponseStreamEvent]: ...

    @overload
    async def _fetch_response(
        self,
        system_instructions: str | None,
        input: str | list[TResponseInputItem],
        model_settings: ModelSettings,
        tools: list[Tool],
        output_schema: AgentOutputSchema | None,
        handoffs: list[Handoff],
        stream: Literal[False],
    ) -> Response: ...

    async def _fetch_response(
        self,
        system_instructions: str | None,
        input: str | list[TResponseInputItem],
        model_settings: ModelSettings,
        tools: list[Tool],
        output_schema: AgentOutputSchema | None,
        handoffs: list[Handoff],
        stream: Literal[True] | Literal[False] = False,
    ) -> Response | AsyncStream[ResponseStreamEvent]:
        list_input = ItemHelpers.input_to_new_input_list(input)

        parallel_tool_calls = (
            True if model_settings.parallel_tool_calls and tools and len(tools) > 0 else NOT_GIVEN
        )

        tool_choice = Converter.convert_tool_choice(model_settings.tool_choice)
        converted_tools = Converter.convert_tools(tools, handoffs)
        response_format = Converter.get_response_format(output_schema)

        if _debug.DONT_LOG_MODEL_DATA:
            logger.debug("Calling LLM")
        else:
            logger.debug(
                f"Calling LLM {self.model} with input:\n"
                f"{json.dumps(list_input, indent=2)}\n"
                f"Tools:\n{json.dumps(converted_tools.tools, indent=2)}\n"
                f"Stream: {stream}\n"
                f"Tool choice: {tool_choice}\n"
                f"Response format: {response_format}\n"
            )

        return await self._client.responses.create(
            instructions=self._non_null_or_not_given(system_instructions),
            model=self.model,
            input=list_input,
            include=converted_tools.includes,
            tools=converted_tools.tools,
            temperature=self._non_null_or_not_given(model_settings.temperature),
            top_p=self._non_null_or_not_given(model_settings.top_p),
            truncation=self._non_null_or_not_given(model_settings.truncation),
            tool_choice=tool_choice,
            parallel_tool_calls=parallel_tool_calls,
            stream=stream,
            extra_headers=_HEADERS,
            text=response_format,
        )

    def _get_client(self) -> AsyncOpenAI:
        if self._client is None:
            self._client = AsyncOpenAI()
        return self._client


@dataclass
class ConvertedTools:
    tools: list[ToolParam]
    includes: list[IncludeLiteral]


class Converter:
    @classmethod
    def convert_tool_choice(
        cls, tool_choice: Literal["auto", "required", "none"] | str | None
    ) -> response_create_params.ToolChoice | NotGiven:
        if tool_choice is None:
            return NOT_GIVEN
        elif tool_choice == "required":
            return "required"
        elif tool_choice == "auto":
            return "auto"
        elif tool_choice == "none":
            return "none"
        elif tool_choice == "file_search":
            return {
                "type": "file_search",
            }
        elif tool_choice == "web_search_preview":
            return {
                "type": "web_search_preview",
            }
        elif tool_choice == "computer_use_preview":
            return {
                "type": "computer_use_preview",
            }
        else:
            return {
                "type": "function",
                "name": tool_choice,
            }

    @classmethod
    def get_response_format(
        cls, output_schema: AgentOutputSchema | None
    ) -> ResponseTextConfigParam | NotGiven:
        if output_schema is None or output_schema.is_plain_text():
            return NOT_GIVEN
        else:
            return {
                "format": {
                    "type": "json_schema",
                    "name": "final_output",
                    "schema": output_schema.json_schema(),
                    "strict": output_schema.strict_json_schema,
                }
            }

    @classmethod
    def convert_tools(
        cls,
        tools: list[Tool],
        handoffs: list[Handoff[Any]],
    ) -> ConvertedTools:
        converted_tools: list[ToolParam] = []
        includes: list[IncludeLiteral] = []

        computer_tools = [tool for tool in tools if isinstance(tool, ComputerTool)]
        if len(computer_tools) > 1:
            raise UserError(f"You can only provide one computer tool. Got {len(computer_tools)}")

        for tool in tools:
            converted_tool, include = cls._convert_tool(tool)
            converted_tools.append(converted_tool)
            if include:
                includes.append(include)

        for handoff in handoffs:
            converted_tools.append(cls._convert_handoff_tool(handoff))

        return ConvertedTools(tools=converted_tools, includes=includes)

    @classmethod
    def _convert_tool(cls, tool: Tool) -> tuple[ToolParam, IncludeLiteral | None]:
        """Returns converted tool and includes"""

        if isinstance(tool, FunctionTool):
            converted_tool: ToolParam = {
                "name": tool.name,
                "parameters": tool.params_json_schema,
                "strict": tool.strict_json_schema,
                "type": "function",
                "description": tool.description,
            }
            includes: IncludeLiteral | None = None
        elif isinstance(tool, WebSearchTool):
            ws: WebSearchToolParam = {
                "type": "web_search_preview",
                "user_location": tool.user_location,
                "search_context_size": tool.search_context_size,
            }
            converted_tool = ws
            includes = None
        elif isinstance(tool, FileSearchTool):
            converted_tool = {
                "type": "file_search",
                "vector_store_ids": tool.vector_store_ids,
            }
            if tool.max_num_results:
                converted_tool["max_num_results"] = tool.max_num_results
            if tool.ranking_options:
                converted_tool["ranking_options"] = tool.ranking_options
            if tool.filters:
                converted_tool["filters"] = tool.filters

            includes = "file_search_call.results" if tool.include_search_results else None
        elif isinstance(tool, ComputerTool):
            converted_tool = {
                "type": "computer-preview",
                "environment": tool.computer.environment,
                "display_width": tool.computer.dimensions[0],
                "display_height": tool.computer.dimensions[1],
            }
            includes = None

        else:
            raise UserError(f"Unknown tool type: {type(tool)}, tool")

        return converted_tool, includes

    @classmethod
    def _convert_handoff_tool(cls, handoff: Handoff) -> ToolParam:
        return {
            "name": handoff.tool_name,
            "parameters": handoff.input_json_schema,
            "strict": handoff.strict_json_schema,
            "type": "function",
            "description": handoff.tool_description,
        }
