fukurow-engine 0.1.0

//! Processing pipelines for complex reasoning workflows

use super::orchestration::{ReasoningEngine, EngineResult, ProcessingOptions, EngineError};
use fukurow_store::store::RdfStore;
use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use chrono::{DateTime, Utc};

/// Processing pipeline stage
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PipelineStage {
    pub name: String,
    pub description: String,
    pub engine: PipelineEngine,
    pub conditions: Vec<PipelineCondition>,
    pub on_success: Vec<String>, // Next stages to execute
    pub on_failure: Vec<String>, // Alternative stages
}

/// Engine configuration for pipeline
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum PipelineEngine {
    Rdfs,
    OwlLite,
    OwlDl,
    Custom(String),
}

/// Pipeline execution conditions
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum PipelineCondition {
    MinTriples(usize),
    MaxTriples(usize),
    HasViolations(bool),
    Custom(String),
}

/// Processing pipeline
pub struct ProcessingPipeline {
    stages: HashMap<String, PipelineStage>,
    current_stage: Option<String>,
    execution_history: Vec<PipelineExecution>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PipelineExecution {
    pub stage_name: String,
    pub started_at: DateTime<Utc>,
    pub completed_at: Option<DateTime<Utc>>,
    pub result: Option<EngineResult>,
    pub error: Option<String>,
    pub next_stages: Vec<String>,
}

impl ProcessingPipeline {
    pub fn new() -> Self {
        Self {
            stages: HashMap::new(),
            current_stage: None,
            execution_history: Vec::new(),
        }
    }

    /// Add a processing stage
    pub fn add_stage(&mut self, stage: PipelineStage) {
        self.stages.insert(stage.name.clone(), stage);
    }

    /// Set the entry point stage
    pub fn set_entry_point(&mut self, stage_name: String) {
        self.current_stage = Some(stage_name);
    }

    /// Execute the pipeline
    pub async fn execute(&mut self, store: &RdfStore) -> Result<PipelineResult, PipelineError> {
        let mut results = Vec::new();
        let mut current_stages = match &self.current_stage {
            Some(stage) => vec![stage.clone()],
            None => return Err(PipelineError::NoEntryPoint),
        };

        while !current_stages.is_empty() {
            let mut next_stages = Vec::new();

            for stage_name in current_stages {
                let stage = self.stages.get(&stage_name)
                    .ok_or_else(|| PipelineError::StageNotFound(stage_name.clone()))?;

                // Check conditions
                if !self.check_conditions(&stage.conditions, store).await {
                    continue;
                }

                // Execute stage
                let execution = self.execute_stage(&stage, store).await;
                self.execution_history.push(execution.clone());

                match execution.result {
                    Some(result) => {
                        results.push(result);
                        next_stages.extend(execution.next_stages);
                    }
                    None => {
                        // Stage failed
                        if !stage.on_failure.is_empty() {
                            next_stages.extend(stage.on_failure.clone());
                        }
                    }
                }
            }

            current_stages = next_stages;
        }

        Ok(PipelineResult {
            stage_results: results,
            execution_history: self.execution_history.clone(),
        })
    }

    async fn execute_stage(&self, stage: &PipelineStage, store: &RdfStore) -> PipelineExecution {
        let started_at = Utc::now();
        let mut execution = PipelineExecution {
            stage_name: stage.name.clone(),
            started_at,
            completed_at: None,
            result: None,
            error: None,
            next_stages: Vec::new(),
        };

        // Create engine based on configuration
        let engine_result: Result<ReasoningEngine, PipelineError> = match &stage.engine {
            PipelineEngine::Rdfs => {
                // TODO: Create RDFS engine
                Err(PipelineError::EngineNotImplemented("RDFS".to_string()))
            }
            PipelineEngine::OwlLite => {
                // TODO: Create OWL Lite engine
                Err(PipelineError::EngineNotImplemented("OWL Lite".to_string()))
            }
            PipelineEngine::OwlDl => {
                // TODO: Create OWL DL engine
                Err(PipelineError::EngineNotImplemented("OWL DL".to_string()))
            }
            PipelineEngine::Custom(name) => {
                Err(PipelineError::EngineNotImplemented(format!("Custom: {}", name)))
            }
        };

        execution.completed_at = Some(Utc::now());

        match engine_result {
            Ok(engine) => {
                match engine.process(store).await {
                    Ok(result) => {
                        execution.result = Some(result);
                        execution.next_stages = stage.on_success.clone();
                    }
                    Err(e) => {
                        execution.error = Some(e.to_string());
                        execution.next_stages = stage.on_failure.clone();
                    }
                }
            }
            Err(e) => {
                execution.error = Some(e.to_string());
            }
        }

        execution
    }

    async fn check_conditions(&self, conditions: &[PipelineCondition], store: &RdfStore) -> bool {
        for condition in conditions {
            match condition {
                PipelineCondition::MinTriples(min) => {
                    if store.statistics().total_triples < *min {
                        return false;
                    }
                }
                PipelineCondition::MaxTriples(max) => {
                    if store.statistics().total_triples > *max {
                        return false;
                    }
                }
                PipelineCondition::HasViolations(expected) => {
                    // TODO: Check for violations
                    // For now, assume no violations
                    if *expected {
                        return false;
                    }
                }
                PipelineCondition::Custom(_) => {
                    // TODO: Implement custom conditions
                    return true;
                }
            }
        }
        true
    }

    /// Get execution history
    pub fn execution_history(&self) -> &[PipelineExecution] {
        &self.execution_history
    }

    /// Get available stages
    pub fn stages(&self) -> &HashMap<String, PipelineStage> {
        &self.stages
    }
}

/// Pipeline execution result
#[derive(Debug, Clone)]
pub struct PipelineResult {
    pub stage_results: Vec<EngineResult>,
    pub execution_history: Vec<PipelineExecution>,
}

/// Pipeline errors
#[derive(Debug, thiserror::Error)]
pub enum PipelineError {
    #[error("No entry point defined")]
    NoEntryPoint,

    #[error("Stage not found: {0}")]
    StageNotFound(String),

    #[error("Engine not implemented: {0}")]
    EngineNotImplemented(String),

    #[error("Pipeline execution failed: {0}")]
    ExecutionError(String),
}

impl Default for ProcessingPipeline {
    fn default() -> Self {
        Self::new()
    }
}

/// Builder for creating processing pipelines
pub struct PipelineBuilder {
    pipeline: ProcessingPipeline,
}

impl PipelineBuilder {
    pub fn new() -> Self {
        Self {
            pipeline: ProcessingPipeline::new(),
        }
    }

    /// Add an RDFS reasoning stage
    pub fn add_rdfs_stage(mut self, name: &str, description: &str) -> Self {
        let stage = PipelineStage {
            name: name.to_string(),
            description: description.to_string(),
            engine: PipelineEngine::Rdfs,
            conditions: vec![],
            on_success: vec![],
            on_failure: vec![],
        };
        self.pipeline.add_stage(stage);
        self
    }

    /// Add an OWL Lite reasoning stage
    pub fn add_owl_lite_stage(mut self, name: &str, description: &str) -> Self {
        let stage = PipelineStage {
            name: name.to_string(),
            description: description.to_string(),
            engine: PipelineEngine::OwlLite,
            conditions: vec![],
            on_success: vec![],
            on_failure: vec![],
        };
        self.pipeline.add_stage(stage);
        self
    }

    /// Add an OWL DL reasoning stage
    pub fn add_owl_dl_stage(mut self, name: &str, description: &str) -> Self {
        let stage = PipelineStage {
            name: name.to_string(),
            description: description.to_string(),
            engine: PipelineEngine::OwlDl,
            conditions: vec![],
            on_success: vec![],
            on_failure: vec![],
        };
        self.pipeline.add_stage(stage);
        self
    }

    /// Set entry point
    pub fn entry_point(mut self, stage_name: &str) -> Self {
        self.pipeline.set_entry_point(stage_name.to_string());
        self
    }

    /// Build the pipeline
    pub fn build(self) -> ProcessingPipeline {
        self.pipeline
    }
}

impl Default for PipelineBuilder {
    fn default() -> Self {
        Self::new()
    }
}