lambdust 0.1.1

//! Application service for orchestrating monadic evaluations.
//!
//! This layer coordinates between domain services and handles
//! business use cases without containing domain logic itself.

use crate::eval::{
    Value, Environment, 
    operational_semantics::{EvaluationContext, ComputationState},
    continuation_domain::{CapturedContinuation, ContinuationId},
};
use crate::ast::{Expr, Spanned};
use crate::diagnostics::{Result, Error, Span};
use crate::effects::{
    Effect, EffectContext, Maybe, Either, IO, State, Reader,
    ContinuationMonad, EffectfulComputation,
};
use std::rc::Rc;
use std::sync::Arc;
use std::collections::HashMap;
use async_trait::async_trait;

use super::{
    monadic_computation::MonadicComputation,
    monad_service::MonadService,
    orchestrator_configuration::OrchestratorConfiguration,
    monadic_evaluation_input::MonadicEvaluationInput,
    monadic_evaluation_result::MonadicEvaluationResult,
    evaluation_metadata::EvaluationMetadata,
    evaluation_metrics::EvaluationMetrics,
    continuation_repository::ContinuationRepository,
    effect_interpreter::EffectInterpreter,
    environment_manager::EnvironmentManager,
};

/// Application service for orchestrating monadic evaluations.
///
/// This layer coordinates between domain services and handles
/// business use cases without containing domain logic itself.
#[derive(Debug)]
pub struct MonadicEvaluationOrchestrator {
    /// Domain service for monadic operations
    monad_service: MonadService,
    
    /// Repository for continuations (injected dependency)
    continuation_repository: Box<dyn ContinuationRepository>,
    
    /// Effect interpreter (injected dependency)
    effect_interpreter: Box<dyn EffectInterpreter>,
    
    /// Environment manager (injected dependency)
    environment_manager: Box<dyn EnvironmentManager>,
    
    /// Configuration
    orchestrator_config: OrchestratorConfiguration,
}

impl MonadicEvaluationOrchestrator {
    /// Create a new orchestrator with dependencies injected
    pub fn new(
        continuation_repository: Box<dyn ContinuationRepository>,
        effect_interpreter: Box<dyn EffectInterpreter>,
        environment_manager: Box<dyn EnvironmentManager>,
    ) -> Self {
        Self {
            monad_service: MonadService::new(),
            continuation_repository,
            effect_interpreter,
            environment_manager,
            orchestrator_config: OrchestratorConfiguration::default(),
        }
    }
    
    /// Evaluate a monadic expression (main orchestration method)
    pub async fn evaluate(
        &mut self,
        input: MonadicEvaluationInput,
    ) -> Result<MonadicEvaluationResult> {
        let start_time = std::time::Instant::now();
        let mut steps_taken = 0;
        let mut max_stack_depth = 0;
        let mut monads_used = Vec::new();
        let mut effects = Vec::new();
        let mut continuations_captured = 0;
        let mut io_operations = 0;
        
        // Main evaluation loop
        let computation = self.evaluate_expression(&input.expression, &input.environment).await?;
        
        // Create result with metrics
        let evaluation_time_ns = start_time.elapsed().as_nanos() as u64;
        
        Ok(MonadicEvaluationResult {
            computation,
            metadata: EvaluationMetadata {
                steps_taken,
                max_stack_depth,
                monads_used,
                tail_call_optimized: false, // Would be set by actual evaluation
            },
            effects,
            metrics: EvaluationMetrics {
                evaluation_time_ns,
                memory_allocated: 0, // Would be measured by actual implementation
                continuations_captured,
                io_operations,
            },
        })
    }
    
    /// Evaluate a single expression (private helper)
    async fn evaluate_expression(
        &mut self,
        expr: &Spanned<Expr>,
        env: &Rc<Environment>,
    ) -> Result<MonadicComputation<Value>> {
        match &expr.inner {
            Expr::CallCC(proc_expr) => {
                // Handle call/cc by capturing continuation
                self.handle_call_cc(proc_expr, env).await
            }
            
            Expr::Application { operator, operands } => {
                // Check if this is a monadic operation
                if self.is_monadic_operation(operator) {
                    self.handle_monadic_operation(operator, operands, env).await
                } else {
                    // Regular function application
                    Ok(MonadicComputation::Pure(Value::Unspecified)) // Simplified
                }
            }
            
            _ => {
                // For other expressions, return pure computation
                Ok(MonadicComputation::Pure(Value::Unspecified)) // Simplified
            }
        }
    }
    
    /// Handle call/cc expression
    async fn handle_call_cc(
        &mut self,
        _proc_expr: &Spanned<Expr>,
        _env: &Rc<Environment>,
    ) -> Result<MonadicComputation<Value>> {
        // Capture current continuation and create monadic computation
        Ok(MonadicComputation::Continuation(
            ContinuationMonad::pure(Value::Unspecified)
        ))
    }
    
    /// Handle monadic operations
    async fn handle_monadic_operation(
        &mut self,
        _operator: &Spanned<Expr>,
        _operands: &[Spanned<Expr>],
        _env: &Rc<Environment>,
    ) -> Result<MonadicComputation<Value>> {
        // Detect and handle specific monadic operations
        Ok(MonadicComputation::Pure(Value::Unspecified)) // Simplified
    }
    
    /// Check if an expression represents a monadic operation
    fn is_monadic_operation(&self, expr: &Spanned<Expr>) -> bool {
        if let Expr::Identifier(name) = &expr.inner {
            matches!(name.as_str(), "map" | "bind" | "pure" | "lift" | "just" | "nothing" | "left" | "right")
        } else {
            false
        }
    }
}