"""
Mordor - Wine Tower

Neural network that encodes wine characteristics from embedding + categorical features.
"""

import torch
import torch.nn as nn
import torch.nn.functional as F
from typing import Dict

from .config import (
    EMBEDDING_DIM,
    WINE_VECTOR_DIM,
    HIDDEN_DIM,
    CATEGORICAL_ENCODING_DIM,
)


class WineTower(nn.Module):
    """
    Mordor: Encodes wine characteristics from embedding and metadata.

    Architecture:
        1. Concatenate wine embedding + categorical one-hot encoding
        2. MLP: (768 + 31) → 256 → 128
        3. L2 normalization to unit sphere

    Input:
        wine_embedding: (batch, 768) - google-text-embedding-004 vector
        categorical_features: (batch, 31) - one-hot encoded categoricals

    Output:
        wine_vector: (batch, 128) - normalized wine embedding
    """

    def __init__(
        self,
        embedding_dim: int = EMBEDDING_DIM,
        categorical_dim: int = CATEGORICAL_ENCODING_DIM,
        hidden_dim: int = HIDDEN_DIM,
        output_dim: int = WINE_VECTOR_DIM,
    ):
        super().__init__()

        self.embedding_dim = embedding_dim
        self.categorical_dim = categorical_dim
        self.output_dim = output_dim

        # Input dimension: embedding + categorical
        input_dim = embedding_dim + categorical_dim

        # MLP layers
        self.fc1 = nn.Linear(input_dim, hidden_dim)
        self.fc2 = nn.Linear(hidden_dim, output_dim)

        # Dropout for regularization
        self.dropout = nn.Dropout(0.1)

    def forward(
        self,
        wine_embedding: torch.Tensor,
        categorical_features: torch.Tensor,
    ) -> torch.Tensor:
        """
        Forward pass through the wine tower.

        Args:
            wine_embedding: (batch, embedding_dim)
            categorical_features: (batch, categorical_dim) - one-hot encoded

        Returns:
            wine_vector: (batch, output_dim) - L2 normalized
        """
        # Concatenate embedding and categorical features
        x = torch.cat([wine_embedding, categorical_features], dim=-1)

        # MLP projection
        x = F.relu(self.fc1(x))
        x = self.dropout(x)
        wine_vector = self.fc2(x)

        # L2 normalize to unit sphere
        wine_vector = F.normalize(wine_vector, p=2, dim=-1)

        return wine_vector


def encode_categorical_features(wine_data: Dict) -> torch.Tensor:
    """
    Convert wine metadata dict to one-hot encoded tensor.

    Args:
        wine_data: Dict with keys: color, type, style, climate_type,
                   climate_band, vintage_band

    Returns:
        Tensor of shape (categorical_dim,) with one-hot encoding
    """
    from .config import CATEGORICAL_VOCAB_SIZES, CATEGORICAL_FEATURES

    # Vocabulary mappings (could be loaded from config)
    vocab_maps = {
        "color": {
            "red": 0,
            "white": 1,
            "rosé": 2,
            "rose": 2,
            "orange": 3,
            "sparkling": 4,
        },
        "type": {"still": 0, "sparkling": 1, "fortified": 2, "dessert": 3},
        "style": {
            "natural": 0,
            "organic": 1,
            "biodynamic": 2,
            "conventional": 3,
            "sustainable": 4,
            "vegan": 5,
            "other": 6,
        },
        "climate_type": {"cool": 0, "moderate": 1, "warm": 2, "hot": 3},
        "climate_band": {"cool": 0, "moderate": 1, "warm": 2, "hot": 3},
        "vintage_band": {"young": 0, "developing": 1, "mature": 2, "non_vintage": 3},
    }

    encoded = []

    for feature in CATEGORICAL_FEATURES:
        vocab_size = CATEGORICAL_VOCAB_SIZES[feature]
        one_hot = torch.zeros(vocab_size)

        value = wine_data.get(feature)
        if value and feature in vocab_maps:
            value_lower = str(value).lower()
            if value_lower in vocab_maps[feature]:
                idx = vocab_maps[feature][value_lower]
                one_hot[idx] = 1.0

        encoded.append(one_hot)

    return torch.cat(encoded, dim=0)