import os
from typing import Literal, TypedDict, Unpack

from langchain.chat_models import init_chat_model

from ..dashboard.options import DEFAULT_MODEL_ID
from .gateway import gateway_env_default, gateway_overrides

OPENAI_RESPONSES_WS_BASE_URL = "wss://api.openai.com/v1"

# Anthropic SDK default is 2; a 529 burst can outlive that. Bump to give the
# primary provider a fair chance before the fallback middleware kicks in.
DEFAULT_MAX_RETRIES = 6

OpenAIReasoningEffort = Literal["none", "low", "medium", "high", "xhigh"]
# OpenAI's Responses API only returns human-readable reasoning text when a
# summary is requested; without it, reasoning happens silently (billed in
# output tokens) and the reasoning content block arrives empty.
OpenAIReasoningSummary = Literal["auto", "concise", "detailed"]
AnthropicThinkingType = Literal["adaptive"]
AnthropicThinkingDisplay = Literal["summarized", "omitted"]
AnthropicEffort = Literal["low", "medium", "high", "xhigh", "max"]
GoogleThinkingLevel = Literal["minimal", "low", "medium", "high"]
FireworksReasoningEffort = Literal["none", "low", "medium", "high", "xhigh", "max"]


class OpenAIReasoning(TypedDict, total=False):
    effort: OpenAIReasoningEffort
    summary: OpenAIReasoningSummary


DEFAULT_LLM_REASONING: "OpenAIReasoning" = {"effort": "medium", "summary": "auto"}


class AnthropicThinking(TypedDict, total=False):
    type: AnthropicThinkingType
    display: AnthropicThinkingDisplay


class ModelKwargs(TypedDict, total=False):
    max_tokens: int | None
    reasoning: OpenAIReasoning | None
    reasoning_effort: OpenAIReasoningEffort | None
    thinking: AnthropicThinking | None
    effort: AnthropicEffort | None
    thinking_level: GoogleThinkingLevel | None
    temperature: float | None
    max_retries: int | None
    store: bool | None
    include: list[str] | None
    model_kwargs: dict[str, object] | None
    additional_model_request_fields: dict[str, object] | None
    region_name: str | None


_ANTHROPIC_EFFORTS: set[AnthropicEffort] = {"low", "medium", "high", "xhigh", "max"}


def _coerce_openai_chat_completions_kwargs(model_kwargs: dict[str, object]) -> None:
    if model_kwargs.get("use_responses_api") is not False:
        return
    reasoning = model_kwargs.pop("reasoning", None)
    if isinstance(reasoning, dict):
        effort = reasoning.get("effort")
        if isinstance(effort, str):
            model_kwargs.setdefault("reasoning_effort", effort)


def _configure_openai_responses_kwargs(model_kwargs: dict[str, object]) -> None:
    if model_kwargs.get("use_responses_api") is False:
        return
    model_kwargs.setdefault("store", False)
    include = model_kwargs.get("include")
    if include is None:
        model_kwargs["include"] = ["reasoning.encrypted_content"]
    elif isinstance(include, list) and "reasoning.encrypted_content" not in include:
        include.append("reasoning.encrypted_content")


def make_model(model_id: str, *, use_gateway: bool | None = None, **kwargs: Unpack[ModelKwargs]):
    """Build a chat model, optionally routed through the LangSmith LLM Gateway.

    ``use_gateway`` resolves the deployment default (``LANGSMITH_GATEWAY_ENABLED``)
    when ``None``; async callers pass the team-settings-resolved value. When on,
    gateway ``base_url``/``api_key``/``use_responses_api`` override the direct
    provider defaults below (see :mod:`agent.utils.gateway`).
    """
    model_kwargs: dict[str, object] = kwargs.copy()
    model_kwargs.setdefault("max_retries", DEFAULT_MAX_RETRIES)

    if model_id.startswith("openai:"):
        # Direct-provider default: Responses API over the OpenAI websocket base.
        # Gateway routing overrides this below (an HTTP(S) proxy can't carry wss).
        model_kwargs["base_url"] = OPENAI_RESPONSES_WS_BASE_URL
        model_kwargs["use_responses_api"] = True
    elif model_id.startswith("bedrock_converse:"):
        # Resolve region with the same precedence validate_local_dev_llm_config
        # accepts (AWS_REGION or AWS_DEFAULT_REGION), so the validated value
        # is the one actually used.
        model_kwargs.setdefault(
            "region_name",
            os.environ.get("AWS_REGION") or os.environ.get("AWS_DEFAULT_REGION") or "us-east-1",
        )

    enabled = gateway_env_default() if use_gateway is None else use_gateway
    if enabled:
        overrides = gateway_overrides(model_id)
        if overrides is not None:
            model_kwargs.update(overrides)

    if model_id.startswith("openai:"):
        _configure_openai_responses_kwargs(model_kwargs)
        _coerce_openai_chat_completions_kwargs(model_kwargs)

    return init_chat_model(model=model_id, **model_kwargs)


def fallback_model_id_for(primary_model_id: str) -> str | None:
    """Return the cross-provider fallback model id for a given primary, if any.

    Bedrock (Claude) primaries fall back to Fireworks and vice versa. Returns
    ``None`` when the provider has no configured cross-provider fallback (e.g.
    local or self-hosted providers we don't want to silently route off-host).
    """
    if primary_model_id.startswith("bedrock_converse:"):
        return "fireworks:accounts/fireworks/models/deepseek-v4-pro"
    if primary_model_id.startswith("fireworks:"):
        return "bedrock_converse:us.anthropic.claude-opus-4-8"
    return None


def is_gemini_3_family(model_id: str) -> bool:
    model_name = model_id.split(":", 1)[-1]
    return model_name.startswith("gemini-3")


def openai_reasoning_for(
    profile_effort: str | None,
    *,
    default_effort: OpenAIReasoningEffort | None = None,
) -> OpenAIReasoning | None:
    """Return an OpenAI reasoning kwarg from a profile effort string.

    Requests ``summary: "auto"`` for every reasoning effort so the Responses
    API emits visible reasoning text. ``effort: "none"`` disables reasoning
    entirely, so no summary is attached.
    """
    effort = profile_effort or default_effort or DEFAULT_LLM_REASONING.get("effort")
    if effort == "none":
        return {"effort": "none"}
    if effort == "low":
        return {"effort": "low", "summary": "auto"}
    if effort == "medium":
        return {"effort": "medium", "summary": "auto"}
    if effort == "high":
        return {"effort": "high", "summary": "auto"}
    if effort == "xhigh":
        return {"effort": "xhigh", "summary": "auto"}
    return None


def anthropic_thinking_for(profile_effort: str | None) -> AnthropicThinking | None:
    if profile_effort in _ANTHROPIC_EFFORTS:
        # `display: "summarized"` makes Opus 4.7+ return the (summarized) reasoning
        # text in the response. The adaptive default is "omitted", which streams a
        # reasoning block carrying only a signature and no visible thinking — so the
        # dashboard never has any text to render.
        return {"type": "adaptive", "display": "summarized"}
    return None


def anthropic_effort_for(profile_effort: str | None) -> AnthropicEffort | None:
    if profile_effort in _ANTHROPIC_EFFORTS:
        return profile_effort
    return None


def fireworks_reasoning_effort_for(profile_effort: str | None) -> FireworksReasoningEffort | None:
    """Map profile effort to a Fireworks ``reasoning_effort`` value.

    Fireworks' OpenAI-compatible API accepts ``reasoning_effort`` on its reasoning
    models. ``none`` disables reasoning; ``xhigh``/``max`` are only honored by models
    that advertise them (e.g. DeepSeek V4 Pro). The per-model ``efforts`` lists in
    ``dashboard/options.py`` gate which values can actually reach this function.
    """
    if profile_effort == "none":
        return "none"
    if profile_effort == "low":
        return "low"
    if profile_effort == "medium":
        return "medium"
    if profile_effort == "high":
        return "high"
    if profile_effort == "xhigh":
        return "xhigh"
    if profile_effort == "max":
        return "max"
    return None


def google_thinking_level_for(profile_effort: str | None) -> GoogleThinkingLevel | None:
    """Map profile effort to Gemini 3+ ``thinking_level``."""
    if profile_effort in ("minimal", "none"):
        return "minimal"
    if profile_effort == "low":
        return "low"
    if profile_effort == "medium":
        return "medium"
    if profile_effort in ("high", "xhigh", "max"):
        return "high"
    return None


def provider_model_kwargs(
    model_id: str,
    profile_effort: str | None,
    *,
    max_tokens: int,
    openai_reasoning_default: OpenAIReasoning | None = None,
) -> ModelKwargs:
    """Build provider-specific kwargs for ``make_model`` from a model id and effort."""
    kwargs: ModelKwargs = {"max_tokens": max_tokens}
    if model_id.startswith("openai:"):
        reasoning = openai_reasoning_for(profile_effort)
        if reasoning is not None:
            kwargs["reasoning"] = reasoning
        elif openai_reasoning_default is not None:
            kwargs["reasoning"] = openai_reasoning_default
    elif model_id.startswith("anthropic:"):
        thinking = anthropic_thinking_for(profile_effort)
        if thinking is not None:
            kwargs["thinking"] = thinking
        effort = anthropic_effort_for(profile_effort)
        if effort is not None:
            kwargs["effort"] = effort
    elif model_id.startswith("bedrock_converse:"):
        # Opus 4.7+ on Bedrock rejects thinking.type "enabled"/budget_tokens with a
        # ValidationException; it requires adaptive thinking plus output_config.effort,
        # passed through Converse's additional_model_request_fields.
        fields: dict[str, object] = {}
        thinking = anthropic_thinking_for(profile_effort)
        if thinking is not None:
            fields["thinking"] = thinking
        effort = anthropic_effort_for(profile_effort)
        if effort is not None:
            fields["output_config"] = {"effort": effort}
        if fields:
            kwargs["additional_model_request_fields"] = fields
    elif model_id.startswith("google_genai:") and is_gemini_3_family(model_id):
        thinking_level = google_thinking_level_for(profile_effort)
        if thinking_level is not None:
            kwargs["thinking_level"] = thinking_level
    elif model_id.startswith("fireworks:"):
        effort = fireworks_reasoning_effort_for(profile_effort)
        if effort is not None:
            kwargs["model_kwargs"] = {"reasoning_effort": effort}
    return kwargs


def validate_local_dev_llm_config() -> None:
    """Validate API keys for the locally configured default model.

    This check only runs in localhost development environments and is
    intended to catch missing credentials for the default model specified
    via LLM_MODEL_ID/DEFAULT_MODEL_ID. Runtime model selection may come
    from team, profile, or thread configuration and is not validated here.
    """
    dashboard_url = os.environ.get("DASHBOARD_BASE_URL", "")
    if not dashboard_url.startswith("http://localhost"):
        return

    model_id = os.environ.get("LLM_MODEL_ID", DEFAULT_MODEL_ID)

    if model_id.startswith("bedrock_converse:") and not (
        os.environ.get("AWS_REGION") or os.environ.get("AWS_DEFAULT_REGION")
    ):
        raise ValueError(f"AWS_REGION is required for configured model {model_id}")
    elif model_id.startswith("fireworks:") and not os.environ.get("FIREWORKS_API_KEY"):
        raise ValueError(f"FIREWORKS_API_KEY is required for configured model {model_id}")