//! # RTX Model Merging
//!
//! Advanced model merging algorithms and strategies for RustyTorch.
//!
//! This crate provides comprehensive model merging capabilities including:
//! - TIES (Task-specific Interference Elimination)
//! - DARE (Drop And REscale) merging
//! - SLERP (Spherical Linear Interpolation)
//! - Model soups and ensemble methods
//! - Frankenmerging techniques
//! - Dynamic expert selection and routing
//! - Merge conflict resolution
//! - Performance evaluation and benchmarking
//!
//! # Features
//!
//! - **Mathematical Precision**: Exact implementations from research papers
//! - **Memory Efficiency**: Streaming parameter processing for large models
//! - **Performance Optimization**: Parallel processing and GPU acceleration
//! - **Robustness**: Comprehensive error handling and validation
//! - **Configuration**: Flexible YAML/TOML configuration system
//!
//! # Example
//!
//! ```rust
//! use rtx_model_merging::{MergeStrategy, ModelMerger, TiesConfig};
//!
//! # async fn example() -> anyhow::Result<()> {
//! let merger = ModelMerger::new()?;
//! let strategy = MergeStrategy::Ties(TiesConfig::default());
//!
//! let merged_model = merger
//!     .merge_models(&["model1.safetensors", "model2.safetensors"], &strategy)
//!     .await?;
//! # Ok(())
//! # }
//! ```

pub mod algorithms;
pub mod config;
pub mod conflict_resolution;
pub mod error;
pub mod evaluation;
pub mod expert_selection;
pub mod model_loader;
pub mod planning;
pub mod strategies;
pub mod types;

// Re-export core types and functions for convenience
pub use algorithms::*;
pub use config::*;
pub use conflict_resolution::*;
pub use error::{MergeError, Result};
pub use evaluation::*;
pub use expert_selection::*;
pub use model_loader::*;
pub use planning::*;
pub use strategies::*;
pub use types::*;

use std::path::Path;
use std::sync::Arc;

/// Main model merging orchestrator
pub struct ModelMerger {
    loader: Arc<ModelLoader>,
    validator: Arc<MergeValidator>,
    evaluator: Arc<PerformanceEvaluator>,
}

impl ModelMerger {
    /// Create a new model merger with default configuration
    pub fn new() -> Result<Self> {
        let loader = Arc::new(ModelLoader::new()?);
        let validator = Arc::new(MergeValidator::new());
        let evaluator = Arc::new(PerformanceEvaluator::new()?);

        Ok(Self {
            loader,
            validator,
            evaluator,
        })
    }

    /// Create a new model merger with custom configuration
    pub fn with_config(config: MergeConfig) -> Result<Self> {
        let loader = Arc::new(ModelLoader::with_config(config.loader)?);
        let validator = Arc::new(MergeValidator::with_config(config.validation));
        let evaluator = Arc::new(PerformanceEvaluator::with_config(config.evaluation)?);

        Ok(Self {
            loader,
            validator,
            evaluator,
        })
    }

    /// Merge multiple models using the specified strategy
    pub async fn merge_models<P: AsRef<Path>>(
        &self,
        model_paths: &[P],
        strategy: &MergeStrategy,
    ) -> Result<MergedModel> {
        tracing::info!("Starting model merge with strategy: {:?}", strategy);

        // Load all models
        let models = self.loader.load_models(model_paths).await?;

        // Validate compatibility
        self.validator.validate_compatibility(&models)?;

        // Execute merge strategy
        let merged = match strategy {
            MergeStrategy::Ties(config) => algorithms::ties::merge_models(&models, config).await?,
            MergeStrategy::Dare(config) => algorithms::dare::merge_models(&models, config).await?,
            MergeStrategy::Slerp(config) => {
                algorithms::slerp::merge_models(&models, config).await?
            }
            MergeStrategy::TaskArithmetic(config) => {
                algorithms::task_arithmetic::merge_models(&models, config).await?
            }
            MergeStrategy::Fisher(config) => {
                algorithms::fisher::merge_models(&models, config).await?
            }
            MergeStrategy::ModelSoup(config) => {
                strategies::model_soup::merge_models(&models, config).await?
            }
            MergeStrategy::Frankenmerge(config) => {
                strategies::frankenmerge::merge_models(&models, config).await?
            }
            MergeStrategy::Progressive(config) => {
                strategies::progressive::merge_models(&models, config).await?
            }
        };

        // Validate the merged model
        self.validator.validate_merged_model(&merged)?;

        tracing::info!("Model merge completed successfully");
        Ok(merged)
    }

    /// Evaluate the performance of a merged model
    pub async fn evaluate_model(&self, model: &MergedModel) -> Result<EvaluationResults> {
        self.evaluator.evaluate(model).await
    }

    /// Recommend the best merge strategy for given models
    pub async fn recommend_strategy<P: AsRef<Path>>(
        &self,
        model_paths: &[P],
    ) -> Result<MergeStrategy> {
        let models = self.loader.load_model_metadata(model_paths).await?;
        let planner = MergePlanner::new();
        planner.recommend_strategy(&models)
    }
}

impl Default for ModelMerger {
    fn default() -> Self {
        Self::new().expect("Failed to create default ModelMerger")
    }
}

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

    #[tokio::test]
    async fn test_model_merger_creation() {
        let merger = ModelMerger::new();
        assert!(merger.is_ok());
    }

    #[tokio::test]
    async fn test_model_merger_with_config() {
        let config = MergeConfig::default();
        let merger = ModelMerger::with_config(config);
        assert!(merger.is_ok());
    }
}