# models/schemas.py
"""Pydantic models for request/response validation"""

from pydantic import BaseModel, Field, validator
from typing import List, Optional, Literal

class EmbeddingRequest(BaseModel):
    """Request model for embedding generation"""
    texts: List[str] = Field(
        ..., 
        description="List of texts to embed",
        example=["Hola mundo", "¿Cómo estás?"]
    )
    normalize: bool = Field(
        default=True,
        description="Whether to normalize embeddings to unit length"
    )
    max_length: Optional[int] = Field(
        default=None,
        description="Maximum sequence length (uses model default if not specified)"
    )
    
    @validator('texts')
    def validate_texts(cls, v):
        if not v:
            raise ValueError("At least one text must be provided")
        if len(v) > 50:
            raise ValueError("Maximum 50 texts per request")
        # Check for empty strings
        if any(not text.strip() for text in v):
            raise ValueError("Empty texts are not allowed")
        return v
    
    @validator('max_length')
    def validate_max_length(cls, v):
        if v is not None:
            if v < 1:
                raise ValueError("Max length must be positive")
            if v > 8192:
                raise ValueError("Max length cannot exceed 8192")
        return v

class EmbeddingResponse(BaseModel):
    """Response model for embedding generation"""
    embeddings: List[List[float]] = Field(
        ...,
        description="List of embedding vectors"
    )
    model_used: str = Field(
        ...,
        description="Model that was used"
    )
    dimensions: int = Field(
        ...,
        description="Dimension of embedding vectors"
    )
    num_texts: int = Field(
        ...,
        description="Number of texts processed"
    )

class ModelInfo(BaseModel):
    """Information about available models"""
    model_id: str = Field(
        ...,
        description="Model identifier for API calls"
    )
    name: str = Field(
        ...,
        description="Full Hugging Face model name"
    )
    dimensions: int = Field(
        ...,
        description="Output embedding dimensions"
    )
    max_sequence_length: int = Field(
        ...,
        description="Maximum input sequence length"
    )
    languages: List[str] = Field(
        ...,
        description="Supported languages"
    )
    model_type: str = Field(
        ...,
        description="Type/domain of model"
    )
    description: str = Field(
        ...,
        description="Model description"
    )

class ErrorResponse(BaseModel):
    """Error response model"""
    detail: str = Field(
        ...,
        description="Error message"
    )
    error_type: Optional[str] = Field(
        default=None,
        description="Type of error"
    )