aiha 0.0.4

//! Module for the Bert model
use serde::Deserialize;
use serde_json::Value;

use crate::models::{ModelConfigTrait, ModelError, ModelLibraries};

/// A struct representing the Bert architecture parameters
#[derive(Clone, Debug, Deserialize)]
pub struct BertParams {
    /// Bert model hidden_size
    hidden_size: i32,
    /// Bert model intermediate_size
    intermediate_size: i32,
    /// Bert model max_position_embeddings
    max_position_embeddings: i32,
    /// Bert model num_attention_heads
    num_attention_heads: i32,
    /// Bert model num_hidden_layers
    num_hidden_layers: i32,
}

/// Bert model parameters implementation
impl BertParams {
    /// Build a new `BertParams` struct based on the provided parameters
    pub fn new(
        hidden_size: i32,
        intermediate_size: i32,
        max_position_embeddings: i32,
        num_attention_heads: i32,
        num_hidden_layers: i32,
    ) -> BertParams {
        BertParams {
            hidden_size,
            intermediate_size,
            max_position_embeddings,
            num_attention_heads,
            num_hidden_layers,
        }
    }
    /// Build from a JSON value
    pub fn from_json(value: Value) -> Result<BertParams, ModelError> {
        let hidden_size = value["hidden_size"]
            .as_i64()
            .ok_or(ModelError::MissingField("hidden_size".to_string()))?
            as i32;

        let intermediate_size = value["intermediate_size"]
            .as_i64()
            .ok_or(ModelError::MissingField("intermediate_size".to_string()))?
            as i32;

        let max_position_embeddings =
            value["max_position_embeddings"]
                .as_i64()
                .ok_or(ModelError::MissingField(
                    "max_position_embeddings".to_string(),
                ))? as i32;

        let num_attention_heads = value["num_attention_heads"]
            .as_i64()
            .ok_or(ModelError::MissingField("num_attention_heads".to_string()))?
            as i32;

        let num_hidden_layers = value["num_hidden_layers"]
            .as_i64()
            .ok_or(ModelError::MissingField("num_hidden_layers".to_string()))?
            as i32;

        Ok(BertParams {
            hidden_size,
            intermediate_size,
            max_position_embeddings,
            num_attention_heads,
            num_hidden_layers,
        })
    }
}

/// A struct representing a Bert model configuration
#[derive(Clone, Debug, Deserialize)]
pub struct BertModelConfig {
    /// Bert model parameters
    params: BertParams,
    /// Bert model type
    model_type: String,
    /// Bert model available libraries
    available_libraries: Vec<ModelLibraries>,
}

/// Bert model implementation
impl BertModelConfig {
    /// Build a new `BertModelConfig` struct based on the provided parameters
    pub fn new(
        params: BertParams,
        model_type: String,
        available_libraries: Vec<ModelLibraries>,
    ) -> BertModelConfig {
        BertModelConfig {
            params,
            model_type,
            available_libraries,
        }
    }
}

/// Implementation of the `ModelConfigTrait` trait for `BertModelConfig`
impl ModelConfigTrait for BertModelConfig {
    fn hidden_size(&self) -> i32 {
        self.params.hidden_size
    }

    fn intermediate_size(&self) -> i32 {
        self.params.intermediate_size
    }

    fn max_position_embeddings(&self) -> i32 {
        self.params.max_position_embeddings
    }

    fn num_attention_heads(&self) -> i32 {
        self.params.num_attention_heads
    }

    fn num_hidden_layers(&self) -> i32 {
        self.params.num_hidden_layers
    }

    fn model_type(&self) -> &str {
        &self.model_type
    }

    fn available_libraries(&self) -> &[ModelLibraries] {
        &self.available_libraries
    }

    fn from_json(value: Value) -> Result<Self, ModelError> {
        let params = BertParams::from_json(value.clone())?;

        let model_type = match value["model_type"].as_str() {
            Some(model_type) => model_type.to_string(),
            None => return Err(ModelError::MissingField("model_type".to_string())),
        };

        // TODO: Implement this
        let available_libraries = vec![ModelLibraries::PyTorch];
        // let available_libraries = match value["available_libraries"].as_array() {
        //     Some(al) => al.iter().map(|v| ModelLibraries::from_str(v.as_str().unwrap()).unwrap()).collect(),
        //     None => return Err(ModelError::MissingField("available_libraries".to_string())),
        // };

        Ok(BertModelConfig {
            params,
            model_type,
            available_libraries,
        })
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_bert_model_params() {
        let bert_params = BertParams::new(768, 3072, 512, 12, 12);

        assert_eq!(bert_params.hidden_size, 768);
        assert_eq!(bert_params.intermediate_size, 3072);
        assert_eq!(bert_params.max_position_embeddings, 512);
        assert_eq!(bert_params.num_attention_heads, 12);
        assert_eq!(bert_params.num_hidden_layers, 12);
    }

    #[test]
    fn test_bert_model_config() {
        let bert_params = BertParams::new(768, 3072, 512, 12, 12);
        let bert_model_config = BertModelConfig::new(
            bert_params,
            "bert".to_string(),
            vec![ModelLibraries::PyTorch],
        );
        assert_eq!(bert_model_config.params.hidden_size, 768);
        assert_eq!(bert_model_config.params.intermediate_size, 3072);
        assert_eq!(bert_model_config.params.max_position_embeddings, 512);
        assert_eq!(bert_model_config.params.num_attention_heads, 12);
        assert_eq!(bert_model_config.params.num_hidden_layers, 12);
        assert_eq!(bert_model_config.model_type, "bert");
        assert_eq!(
            bert_model_config.available_libraries,
            vec![ModelLibraries::PyTorch]
        );
    }

    #[test]
    fn test_bert_model_trait_implementation() {
        let bert_params = BertParams::new(768, 3072, 512, 12, 12);
        let bert_model_config = BertModelConfig::new(
            bert_params,
            "bert".to_string(),
            vec![ModelLibraries::PyTorch],
        );
        assert_eq!(bert_model_config.hidden_size(), 768);
        assert_eq!(bert_model_config.intermediate_size(), 3072);
        assert_eq!(bert_model_config.max_position_embeddings(), 512);
        assert_eq!(bert_model_config.num_attention_heads(), 12);
        assert_eq!(bert_model_config.num_hidden_layers(), 12);
        assert_eq!(bert_model_config.model_type(), "bert");
        assert_eq!(
            bert_model_config.available_libraries(),
            vec![ModelLibraries::PyTorch]
        );
    }
}