use std::time::Duration;
use tokio::time::timeout;
use crate::{JobBuilder, JobStatus, Client};
use log::{info, error};
use tokio::sync::mpsc;
use std::sync::Arc;
use crate::async_runner::AsyncRunner;
use crate::runner_trait::{Runner, RunnerConfig};

/// Execute a script in single-job mode
/// Creates a job, submits it, waits for completion, and returns the result
pub async fn execute_script_mode<F>(
    script_content: &str,
    runner_id: &str,
    redis_url: String,
    job_timeout: Duration,
    engine_factory: F,
) -> Result<String, Box<dyn std::error::Error + Send + Sync>>
where
    F: Fn() -> rhai::Engine + Send + Sync + 'static,
{
    info!("Executing script in single-job mode");
    
    // Create job client
    let job_client = Client::builder()
        .redis_url(&redis_url)
        .build()
        .await?;
    
    // Create the job using JobBuilder
    let job = JobBuilder::new()
        .caller_id("script_mode")
        .payload(script_content)
        .runner(runner_id)
        .timeout(job_timeout.as_secs())
        .build()?;
    
    let job_id = job.id.clone();
    info!("Created job with ID: {}", job_id);
    
    // Submit the job
    job_client.store_job_in_redis(&job).await?;
    info!("Job stored in Redis");
    
    // Dispatch the job to the runner's queue
    job_client.job_run(&job_id, runner_id).await?;
    info!("Job dispatched to runner queue: {}", runner_id);
    
    // Create and spawn a temporary runner to process the job
    let (shutdown_tx, shutdown_rx) = mpsc::channel::<()>(1);
    
    let config = RunnerConfig {
        runner_id: runner_id.to_string(),
        db_path: "/tmp".to_string(), // Temporary path for script mode
        redis_url: redis_url.clone(),
        default_timeout: Some(job_timeout),
    };
    
    let runner = Arc::new(
        AsyncRunner::builder()
            .runner_id(&config.runner_id)
            .db_path(&config.db_path)
            .redis_url(&config.redis_url)
            .default_timeout(config.default_timeout.unwrap_or(job_timeout))
            .engine_factory(engine_factory)
            .build()
            .map_err(|e| format!("Failed to build runner: {}", e))?
    );
    let runner_handle = runner.spawn(shutdown_rx);
    
    info!("Temporary runner spawned for job processing");
    
    // Wait for job completion with timeout
    let result = timeout(job_timeout, wait_for_job_completion(&job_client, &job_id)).await;
    
    // Shutdown the temporary runner
    let _ = shutdown_tx.send(()).await;
    let _ = runner_handle.await;
    
    match result {
        Ok(job_result) => {
            match job_result {
                Ok(job_status) => {
                    match job_status {
                        JobStatus::Finished => {
                            info!("Job completed successfully");
                            // Get the job result from Redis
                            match job_client.get_result(&job_id).await {
                                Ok(Some(result)) => Ok(result),
                                Ok(None) => Ok("Job completed with no result".to_string()),
                                Err(e) => {
                                    error!("Failed to get job result: {}", e);
                                    Ok("Job completed but result unavailable".to_string())
                                }
                            }
                        }
                        JobStatus::Error => {
                            // Get the job error from Redis - for now just return a generic error
                            error!("Job failed with status: Error");
                            return Err("Job execution failed".into());
                            /*match job_client.get_job_error(&job_id).await {
                                Ok(Some(error_msg)) => {
                                    error!("Job failed: {}", error_msg);
                                    Err(format!("Job failed: {}", error_msg).into())
                                }
                                Ok(None) => {
                                    error!("Job failed with no error message");
                                    Err("Job failed with no error message".into())
                                }
                                Err(e) => {
                                    error!("Failed to get job error: {}", e);
                                    Err("Job failed but error details unavailable".into())
                                }
                            }*/
                        }
                        _ => {
                            error!("Job ended in unexpected status: {:?}", job_status);
                            Err(format!("Job ended in unexpected status: {:?}", job_status).into())
                        }
                    }
                }
                Err(e) => {
                    error!("Error waiting for job completion: {}", e);
                    Err(e)
                }
            }
        }
        Err(_) => {
            error!("Job execution timed out after {:?}", job_timeout);
            // Try to cancel the job
            let _ = job_client.set_job_status(&job_id, JobStatus::Error).await;
            Err("Job execution timed out".into())
        }
    }
}

/// Wait for job completion by polling Redis
async fn wait_for_job_completion(
    job_client: &Client,
    job_id: &str,
) -> Result<JobStatus, Box<dyn std::error::Error + Send + Sync>> {
    let poll_interval = Duration::from_millis(500);
    
    loop {
        match job_client.get_status(job_id).await {
            Ok(status) => {
                match status {
                    JobStatus::Finished | JobStatus::Error => {
                        return Ok(status);
                    }
                    JobStatus::Created | JobStatus::Dispatched | JobStatus::WaitingForPrerequisites | JobStatus::Started => {
                        // Continue polling
                        tokio::time::sleep(poll_interval).await;
                    }
                    JobStatus::Stopping => {
                        // Job is being stopped, wait a bit more
                        tokio::time::sleep(poll_interval).await;
                    }
                }
            }
            Err(e) => {
                error!("Error polling job status: {}", e);
                tokio::time::sleep(poll_interval).await;
            }
        }
    }
}