"""OpenAI-compatible request and response models."""

from typing import Any, Dict, List, Literal, Optional, Union
from pydantic import BaseModel, Field


# ============================================================================
# Chat Completions Models
# ============================================================================

class ChatMessage(BaseModel):
    """A chat message in the conversation."""
    role: Literal["system", "user", "assistant", "function", "tool", "developer"]
    content: Optional[str] = None
    name: Optional[str] = None
    function_call: Optional[Dict[str, Any]] = None
    tool_calls: Optional[List[Dict[str, Any]]] = None


class FunctionCall(BaseModel):
    """Function call specification."""
    name: str
    arguments: str


class ToolCall(BaseModel):
    """Tool call specification."""
    id: str
    type: Literal["function"]
    function: FunctionCall


class ChatCompletionRequest(BaseModel):
    """OpenAI chat completion request."""
    model: str
    messages: List[ChatMessage]
    temperature: Optional[float] = Field(default=1.0, ge=0, le=2)
    top_p: Optional[float] = Field(default=1.0, ge=0, le=1)
    n: Optional[int] = Field(default=1, ge=1)
    stream: Optional[bool] = False
    stop: Optional[Union[str, List[str]]] = None
    max_tokens: Optional[int] = Field(default=None, ge=1)
    presence_penalty: Optional[float] = Field(default=0, ge=-2, le=2)
    frequency_penalty: Optional[float] = Field(default=0, ge=-2, le=2)
    logit_bias: Optional[Dict[str, float]] = None
    user: Optional[str] = None
    functions: Optional[List[Dict[str, Any]]] = None
    function_call: Optional[Union[str, Dict[str, str]]] = None
    tools: Optional[List[Dict[str, Any]]] = None
    tool_choice: Optional[Union[str, Dict[str, Any]]] = None


class ChatCompletionChoice(BaseModel):
    """A single chat completion choice."""
    index: int
    message: ChatMessage
    finish_reason: Optional[str] = None
    logprobs: Optional[Dict[str, Any]] = None


class ChatCompletionUsage(BaseModel):
    """Token usage information."""
    prompt_tokens: int
    completion_tokens: int
    total_tokens: int


class ChatCompletionResponse(BaseModel):
    """OpenAI chat completion response."""
    id: str
    object: Literal["chat.completion"] = "chat.completion"
    created: int
    model: str
    choices: List[ChatCompletionChoice]
    usage: ChatCompletionUsage
    system_fingerprint: Optional[str] = None


class ChatCompletionChunkDelta(BaseModel):
    """Delta content in streaming response."""
    role: Optional[str] = None
    content: Optional[str] = None
    function_call: Optional[Dict[str, Any]] = None
    tool_calls: Optional[List[Dict[str, Any]]] = None


class ChatCompletionChunkChoice(BaseModel):
    """A single streaming chunk choice."""
    index: int
    delta: ChatCompletionChunkDelta
    finish_reason: Optional[str] = None
    logprobs: Optional[Dict[str, Any]] = None


class ChatCompletionChunk(BaseModel):
    """OpenAI streaming chat completion chunk."""
    id: str
    object: Literal["chat.completion.chunk"] = "chat.completion.chunk"
    created: int
    model: str
    choices: List[ChatCompletionChunkChoice]
    system_fingerprint: Optional[str] = None


# ============================================================================
# Completions Models (Legacy)
# ============================================================================

class CompletionRequest(BaseModel):
    """OpenAI completion request (legacy)."""
    model: str
    prompt: Union[str, List[str], List[int], List[List[int]]]
    suffix: Optional[str] = None
    max_tokens: Optional[int] = Field(default=16, ge=1)
    temperature: Optional[float] = Field(default=1.0, ge=0, le=2)
    top_p: Optional[float] = Field(default=1.0, ge=0, le=1)
    n: Optional[int] = Field(default=1, ge=1)
    stream: Optional[bool] = False
    logprobs: Optional[int] = Field(default=None, ge=0, le=5)
    echo: Optional[bool] = False
    stop: Optional[Union[str, List[str]]] = None
    presence_penalty: Optional[float] = Field(default=0, ge=-2, le=2)
    frequency_penalty: Optional[float] = Field(default=0, ge=-2, le=2)
    best_of: Optional[int] = Field(default=1, ge=1)
    logit_bias: Optional[Dict[str, float]] = None
    user: Optional[str] = None


class CompletionChoice(BaseModel):
    """A single completion choice."""
    text: str
    index: int
    logprobs: Optional[Dict[str, Any]] = None
    finish_reason: Optional[str] = None


class CompletionResponse(BaseModel):
    """OpenAI completion response."""
    id: str
    object: Literal["text_completion"] = "text_completion"
    created: int
    model: str
    choices: List[CompletionChoice]
    usage: ChatCompletionUsage


# ============================================================================
# Embeddings Models
# ============================================================================

class EmbeddingRequest(BaseModel):
    """OpenAI embedding request."""
    model: str
    input: Union[str, List[str], List[int], List[List[int]]]
    encoding_format: Optional[Literal["float", "base64"]] = "float"
    dimensions: Optional[int] = None
    user: Optional[str] = None


class EmbeddingData(BaseModel):
    """A single embedding result."""
    object: Literal["embedding"] = "embedding"
    embedding: List[float]
    index: int


class EmbeddingUsage(BaseModel):
    """Token usage for embeddings."""
    prompt_tokens: int
    total_tokens: int


class EmbeddingResponse(BaseModel):
    """OpenAI embedding response."""
    object: Literal["list"] = "list"
    data: List[EmbeddingData]
    model: str
    usage: EmbeddingUsage


# ============================================================================
# Models List
# ============================================================================

class ModelInfo(BaseModel):
    """Information about a single model."""
    id: str
    object: Literal["model"] = "model"
    created: int
    owned_by: str


class ModelsResponse(BaseModel):
    """List of available models."""
    object: Literal["list"] = "list"
    data: List[ModelInfo]


# ============================================================================
# Error Models
# ============================================================================

class ErrorDetail(BaseModel):
    """Error detail information."""
    message: str
    type: str
    param: Optional[str] = None
    code: Optional[str] = None


class ErrorResponse(BaseModel):
    """OpenAI error response."""
    error: ErrorDetail