//! Optimization stage - applies performance optimizations using MoE routing.

use anyhow::Result;

#[cfg(feature = "native")]
use tracing::info;

// Stub macros for WASM build
#[cfg(not(feature = "native"))]
macro_rules! info {
    ($($arg:tt)*) => {{}};
}

use crate::pipeline::types::{PipelineContext, PipelineStage};

/// Optimization stage - applies performance optimizations using MoE routing
pub struct OptimizationStage {
    pub(crate) enable_gpu: bool,
    pub(crate) enable_simd: bool,
    pub(crate) gpu_threshold: usize,
    pub(crate) backend_selector: crate::backend::BackendSelector,
}

impl OptimizationStage {
    pub fn new(enable_gpu: bool, enable_simd: bool, gpu_threshold: usize) -> Self {
        Self {
            enable_gpu,
            enable_simd,
            gpu_threshold,
            backend_selector: crate::backend::BackendSelector::new(),
        }
    }

    /// Analyze code and recommend backend optimizations using MoE
    pub fn analyze_optimizations(&self) -> Vec<String> {
        contract_pre_analyze!(self);
        use crate::backend::OpComplexity;

        let mut recommendations = Vec::new();

        // Example workload analysis - in practice this would analyze the actual code
        let workloads = vec![
            ("Element-wise operations", OpComplexity::Low, 1_000_000),
            ("Vector reductions", OpComplexity::Medium, 50_000),
            ("Matrix multiplications", OpComplexity::High, 100_000),
        ];

        for (name, complexity, size) in workloads {
            let backend = self.backend_selector.select_with_moe(complexity, size);
            recommendations
                .push(format!("{}: {} backend recommended ({} elements)", name, backend, size));
        }

        recommendations
    }
}

#[async_trait::async_trait]
impl PipelineStage for OptimizationStage {
    fn name(&self) -> &'static str {
        "Optimization"
    }

    async fn execute(&self, mut ctx: PipelineContext) -> Result<PipelineContext> {
        info!(
            "Applying optimizations using MoE routing (GPU: {}, SIMD: {})",
            self.enable_gpu, self.enable_simd
        );

        // Use MoE to analyze and recommend backend optimizations
        let moe_recommendations = self.analyze_optimizations();

        info!("MoE backend recommendations:");
        for rec in &moe_recommendations {
            info!("  - {}", rec);
        }

        // Apply traditional optimizations
        if self.enable_simd {
            ctx.optimizations.push("SIMD vectorization enabled".to_string());
        }

        if self.enable_gpu {
            ctx.optimizations
                .push(format!("GPU dispatch enabled (threshold: {})", self.gpu_threshold));
        }

        // Add MoE recommendations
        ctx.optimizations.extend(moe_recommendations);

        // Store optimization strategy in metadata
        ctx.metadata
            .insert("optimizations_applied".to_string(), serde_json::json!(ctx.optimizations));

        ctx.metadata.insert("moe_routing_enabled".to_string(), serde_json::json!(true));

        Ok(ctx)
    }
}
