import logging
from dataclasses import dataclass
from typing import Any, List, Optional, cast

import llama_index
from llama_index.bridge.pydantic import BaseModel
from llama_index.callbacks.base import CallbackManager
from llama_index.core.embeddings.base import BaseEmbedding
from llama_index.indices.prompt_helper import PromptHelper
from llama_index.llm_predictor import LLMPredictor
from llama_index.llm_predictor.base import BaseLLMPredictor, LLMMetadata
from llama_index.llms.llm import LLM
from llama_index.llms.utils import LLMType, resolve_llm
from llama_index.logger import LlamaLogger
from llama_index.node_parser.interface import NodeParser, TextSplitter
from llama_index.node_parser.text.sentence import (
    DEFAULT_CHUNK_SIZE,
    SENTENCE_CHUNK_OVERLAP,
    SentenceSplitter,
)
from llama_index.prompts.base import BasePromptTemplate
from llama_index.schema import TransformComponent
from llama_index.types import PydanticProgramMode

logger = logging.getLogger(__name__)


def _get_default_node_parser(
    chunk_size: int = DEFAULT_CHUNK_SIZE,
    chunk_overlap: int = SENTENCE_CHUNK_OVERLAP,
    callback_manager: Optional[CallbackManager] = None,
) -> NodeParser:
    """Get default node parser."""
    return SentenceSplitter(
        chunk_size=chunk_size,
        chunk_overlap=chunk_overlap,
        callback_manager=callback_manager or CallbackManager(),
    )


def _get_default_prompt_helper(
    llm_metadata: LLMMetadata,
    context_window: Optional[int] = None,
    num_output: Optional[int] = None,
) -> PromptHelper:
    """Get default prompt helper."""
    if context_window is not None:
        llm_metadata.context_window = context_window
    if num_output is not None:
        llm_metadata.num_output = num_output
    return PromptHelper.from_llm_metadata(llm_metadata=llm_metadata)


class ServiceContextData(BaseModel):
    llm: dict
    llm_predictor: dict
    prompt_helper: dict
    embed_model: dict
    transformations: List[dict]


@dataclass
class ServiceContext:
    """Service Context container.

    The service context container is a utility container for LlamaIndex
    index and query classes. It contains the following:
    - llm_predictor: BaseLLMPredictor
    - prompt_helper: PromptHelper
    - embed_model: BaseEmbedding
    - node_parser: NodeParser
    - llama_logger: LlamaLogger (deprecated)
    - callback_manager: CallbackManager

    """

    llm_predictor: BaseLLMPredictor
    prompt_helper: PromptHelper
    embed_model: BaseEmbedding
    transformations: List[TransformComponent]
    llama_logger: LlamaLogger
    callback_manager: CallbackManager

    @classmethod
    def from_defaults(
        cls,
        llm_predictor: Optional[BaseLLMPredictor] = None,
        llm: Optional[LLMType] = "default",
        prompt_helper: Optional[PromptHelper] = None,
        embed_model: Optional[Any] = "default",
        node_parser: Optional[NodeParser] = None,
        text_splitter: Optional[TextSplitter] = None,
        transformations: Optional[List[TransformComponent]] = None,
        llama_logger: Optional[LlamaLogger] = None,
        callback_manager: Optional[CallbackManager] = None,
        system_prompt: Optional[str] = None,
        query_wrapper_prompt: Optional[BasePromptTemplate] = None,
        # pydantic program mode (used if output_cls is specified)
        pydantic_program_mode: PydanticProgramMode = PydanticProgramMode.DEFAULT,
        # node parser kwargs
        chunk_size: Optional[int] = None,
        chunk_overlap: Optional[int] = None,
        # prompt helper kwargs
        context_window: Optional[int] = None,
        num_output: Optional[int] = None,
        # deprecated kwargs
        chunk_size_limit: Optional[int] = None,
    ) -> "ServiceContext":
        """Create a ServiceContext from defaults.
        If an argument is specified, then use the argument value provided for that
        parameter. If an argument is not specified, then use the default value.

        You can change the base defaults by setting llama_index.global_service_context
        to a ServiceContext object with your desired settings.

        Args:
            llm_predictor (Optional[BaseLLMPredictor]): LLMPredictor
            prompt_helper (Optional[PromptHelper]): PromptHelper
            embed_model (Optional[BaseEmbedding]): BaseEmbedding
                or "local" (use local model)
            node_parser (Optional[NodeParser]): NodeParser
            llama_logger (Optional[LlamaLogger]): LlamaLogger (deprecated)
            chunk_size (Optional[int]): chunk_size
            callback_manager (Optional[CallbackManager]): CallbackManager
            system_prompt (Optional[str]): System-wide prompt to be prepended
                to all input prompts, used to guide system "decision making"
            query_wrapper_prompt (Optional[BasePromptTemplate]): A format to wrap
                passed-in input queries.

        Deprecated Args:
            chunk_size_limit (Optional[int]): renamed to chunk_size

        """
        from llama_index.embeddings.utils import EmbedType, resolve_embed_model

        embed_model = cast(EmbedType, embed_model)

        if chunk_size_limit is not None and chunk_size is None:
            logger.warning(
                "chunk_size_limit is deprecated, please specify chunk_size instead"
            )
            chunk_size = chunk_size_limit

        if llama_index.global_service_context is not None:
            return cls.from_service_context(
                llama_index.global_service_context,
                llm=llm,
                llm_predictor=llm_predictor,
                prompt_helper=prompt_helper,
                embed_model=embed_model,
                node_parser=node_parser,
                text_splitter=text_splitter,
                llama_logger=llama_logger,
                callback_manager=callback_manager,
                context_window=context_window,
                chunk_size=chunk_size,
                chunk_size_limit=chunk_size_limit,
                chunk_overlap=chunk_overlap,
                num_output=num_output,
                system_prompt=system_prompt,
                query_wrapper_prompt=query_wrapper_prompt,
                transformations=transformations,
            )

        callback_manager = callback_manager or CallbackManager([])
        if llm != "default":
            if llm_predictor is not None:
                raise ValueError("Cannot specify both llm and llm_predictor")
            llm = resolve_llm(llm)
            llm.system_prompt = llm.system_prompt or system_prompt
            llm.query_wrapper_prompt = llm.query_wrapper_prompt or query_wrapper_prompt
            llm.pydantic_program_mode = (
                llm.pydantic_program_mode or pydantic_program_mode
            )

        if llm_predictor is not None:
            print("LLMPredictor is deprecated, please use LLM instead.")
        llm_predictor = llm_predictor or LLMPredictor(
            llm=llm, pydantic_program_mode=pydantic_program_mode
        )
        if isinstance(llm_predictor, LLMPredictor):
            llm_predictor.llm.callback_manager = callback_manager
            if system_prompt:
                llm_predictor.system_prompt = system_prompt
            if query_wrapper_prompt:
                llm_predictor.query_wrapper_prompt = query_wrapper_prompt

        # NOTE: the embed_model isn't used in all indices
        # NOTE: embed model should be a transformation, but the way the service
        # context works, we can't put in there yet.
        embed_model = resolve_embed_model(embed_model)
        embed_model.callback_manager = callback_manager

        prompt_helper = prompt_helper or _get_default_prompt_helper(
            llm_metadata=llm_predictor.metadata,
            context_window=context_window,
            num_output=num_output,
        )

        if text_splitter is not None and node_parser is not None:
            raise ValueError("Cannot specify both text_splitter and node_parser")

        node_parser = (
            text_splitter  # text splitter extends node parser
            or node_parser
            or _get_default_node_parser(
                chunk_size=chunk_size or DEFAULT_CHUNK_SIZE,
                chunk_overlap=chunk_overlap or SENTENCE_CHUNK_OVERLAP,
                callback_manager=callback_manager,
            )
        )

        transformations = transformations or [node_parser]

        llama_logger = llama_logger or LlamaLogger()

        return cls(
            llm_predictor=llm_predictor,
            embed_model=embed_model,
            prompt_helper=prompt_helper,
            transformations=transformations,
            llama_logger=llama_logger,  # deprecated
            callback_manager=callback_manager,
        )

    @classmethod
    def from_service_context(
        cls,
        service_context: "ServiceContext",
        llm_predictor: Optional[BaseLLMPredictor] = None,
        llm: Optional[LLMType] = "default",
        prompt_helper: Optional[PromptHelper] = None,
        embed_model: Optional[Any] = "default",
        node_parser: Optional[NodeParser] = None,
        text_splitter: Optional[TextSplitter] = None,
        transformations: Optional[List[TransformComponent]] = None,
        llama_logger: Optional[LlamaLogger] = None,
        callback_manager: Optional[CallbackManager] = None,
        system_prompt: Optional[str] = None,
        query_wrapper_prompt: Optional[BasePromptTemplate] = None,
        # node parser kwargs
        chunk_size: Optional[int] = None,
        chunk_overlap: Optional[int] = None,
        # prompt helper kwargs
        context_window: Optional[int] = None,
        num_output: Optional[int] = None,
        # deprecated kwargs
        chunk_size_limit: Optional[int] = None,
    ) -> "ServiceContext":
        """Instantiate a new service context using a previous as the defaults."""
        from llama_index.embeddings.utils import EmbedType, resolve_embed_model

        embed_model = cast(EmbedType, embed_model)

        if chunk_size_limit is not None and chunk_size is None:
            logger.warning(
                "chunk_size_limit is deprecated, please specify chunk_size",
                DeprecationWarning,
            )
            chunk_size = chunk_size_limit

        callback_manager = callback_manager or service_context.callback_manager
        if llm != "default":
            if llm_predictor is not None:
                raise ValueError("Cannot specify both llm and llm_predictor")
            llm = resolve_llm(llm)
            llm_predictor = LLMPredictor(llm=llm)

        llm_predictor = llm_predictor or service_context.llm_predictor
        if isinstance(llm_predictor, LLMPredictor):
            llm_predictor.llm.callback_manager = callback_manager
            if system_prompt:
                llm_predictor.system_prompt = system_prompt
            if query_wrapper_prompt:
                llm_predictor.query_wrapper_prompt = query_wrapper_prompt

        # NOTE: the embed_model isn't used in all indices
        # default to using the embed model passed from the service context
        if embed_model == "default":
            embed_model = service_context.embed_model
        embed_model = resolve_embed_model(embed_model)
        embed_model.callback_manager = callback_manager

        prompt_helper = prompt_helper or service_context.prompt_helper
        if context_window is not None or num_output is not None:
            prompt_helper = _get_default_prompt_helper(
                llm_metadata=llm_predictor.metadata,
                context_window=context_window,
                num_output=num_output,
            )

        transformations = transformations or []
        node_parser_found = False
        for transform in service_context.transformations:
            if isinstance(transform, NodeParser):
                node_parser_found = True
                node_parser = transform
                break

        if text_splitter is not None and node_parser is not None:
            raise ValueError("Cannot specify both text_splitter and node_parser")

        if not node_parser_found:
            node_parser = (
                text_splitter  # text splitter extends node parser
                or node_parser
                or _get_default_node_parser(
                    chunk_size=chunk_size or DEFAULT_CHUNK_SIZE,
                    chunk_overlap=chunk_overlap or SENTENCE_CHUNK_OVERLAP,
                    callback_manager=callback_manager,
                )
            )

        transformations = transformations or service_context.transformations

        llama_logger = llama_logger or service_context.llama_logger

        return cls(
            llm_predictor=llm_predictor,
            embed_model=embed_model,
            prompt_helper=prompt_helper,
            transformations=transformations,
            llama_logger=llama_logger,  # deprecated
            callback_manager=callback_manager,
        )

    @property
    def llm(self) -> LLM:
        return self.llm_predictor.llm

    @property
    def node_parser(self) -> NodeParser:
        """Get the node parser."""
        for transform in self.transformations:
            if isinstance(transform, NodeParser):
                return transform
        raise ValueError("No node parser found.")

    def to_dict(self) -> dict:
        """Convert service context to dict."""
        llm_dict = self.llm_predictor.llm.to_dict()
        llm_predictor_dict = self.llm_predictor.to_dict()

        embed_model_dict = self.embed_model.to_dict()

        prompt_helper_dict = self.prompt_helper.to_dict()

        tranform_list_dict = [x.to_dict() for x in self.transformations]

        return ServiceContextData(
            llm=llm_dict,
            llm_predictor=llm_predictor_dict,
            prompt_helper=prompt_helper_dict,
            embed_model=embed_model_dict,
            transformations=tranform_list_dict,
        ).dict()

    @classmethod
    def from_dict(cls, data: dict) -> "ServiceContext":
        from llama_index.embeddings.loading import load_embed_model
        from llama_index.extractors.loading import load_extractor
        from llama_index.llm_predictor.loading import load_predictor
        from llama_index.node_parser.loading import load_parser

        service_context_data = ServiceContextData.parse_obj(data)

        llm_predictor = load_predictor(service_context_data.llm_predictor)

        embed_model = load_embed_model(service_context_data.embed_model)

        prompt_helper = PromptHelper.from_dict(service_context_data.prompt_helper)

        transformations: List[TransformComponent] = []
        for transform in service_context_data.transformations:
            try:
                transformations.append(load_parser(transform))
            except ValueError:
                transformations.append(load_extractor(transform))

        return cls.from_defaults(
            llm_predictor=llm_predictor,
            prompt_helper=prompt_helper,
            embed_model=embed_model,
            transformations=transformations,
        )


def set_global_service_context(service_context: Optional[ServiceContext]) -> None:
    """Helper function to set the global service context."""
    llama_index.global_service_context = service_context
