package net.bmahe.genetics4j.gpu.opencl;
   
   import java.util.Map;
   
   import org.immutables.value.Value;
   import org.jocl.cl_command_queue;
   import org.jocl.cl_context;
   import org.jocl.cl_kernel;
   import org.jocl.cl_program;
  
  import net.bmahe.genetics4j.gpu.opencl.model.Device;
  import net.bmahe.genetics4j.gpu.opencl.model.KernelInfo;
  import net.bmahe.genetics4j.gpu.opencl.model.Platform;
  
  /**
   * Encapsulates a complete OpenCL execution environment for a specific device with compiled kernels and runtime context.
   * 
   * <p>OpenCLExecutionContext represents a fully initialized OpenCL execution environment tied to a specific
   * device and containing all the resources needed for kernel execution. This includes the OpenCL context,
   * command queue, compiled program, and kernel objects, along with associated metadata about platform
   * and device capabilities.
   * 
   * <p>The execution context serves as the primary interface between high-level fitness evaluation code
   * and low-level OpenCL operations. It provides access to:
   * <ul>
   * <li><strong>Device information</strong>: Platform and device metadata for optimization decisions</li>
   * <li><strong>OpenCL runtime</strong>: Context and command queue for memory and execution management</li>
   * <li><strong>Compiled kernels</strong>: Ready-to-execute kernel objects with associated metadata</li>
   * <li><strong>Execution parameters</strong>: Kernel work group information for optimal kernel launch</li>
   * </ul>
   * 
   * <p>Context lifecycle and management:
   * <ol>
   * <li><strong>Creation</strong>: Built by {@link net.bmahe.genetics4j.gpu.GPUFitnessEvaluator} during initialization</li>
   * <li><strong>Usage</strong>: Passed to fitness functions for kernel execution and memory operations</li>
   * <li><strong>Cleanup</strong>: Resources automatically released by the fitness evaluator</li>
   * </ol>
   * 
   * <p>Key usage patterns in fitness evaluation:
   * <pre>{@code
   * public CompletableFuture<List<Double>> compute(OpenCLExecutionContext context, 
   *         ExecutorService executor, long generation, List<Genotype> genotypes) {
   *     
   *     return CompletableFuture.supplyAsync(() -> {
   *         // Access device capabilities for optimization
   *         Device device = context.device();
   *         int maxWorkGroupSize = device.maxWorkGroupSize();
   *         
   *         // Get compiled kernel for execution
   *         cl_kernel fitnessKernel = context.kernels().get("fitness_evaluation");
   *         
   *         // Get kernel execution parameters
   *         KernelInfo kernelInfo = context.kernelInfo("fitness_evaluation");
   *         int preferredWorkGroupSize = kernelInfo.preferredWorkGroupSizeMultiple();
   *         
   *         // Execute kernel with optimal work group configuration
   *         executeKernel(context, fitnessKernel, genotypes.size(), preferredWorkGroupSize);
   *         
   *         // Extract results using the execution context
   *         return extractResults(context, genotypes.size());
   *     }, executor);
   * }
   * }</pre>
   * 
   * <p>Memory management considerations:
   * <ul>
   * <li><strong>Context ownership</strong>: The execution context owns OpenCL resources</li>
   * <li><strong>Thread safety</strong>: OpenCL contexts are not thread-safe; use appropriate synchronization</li>
   * <li><strong>Resource lifecycle</strong>: Resources are managed by the parent fitness evaluator</li>
   * <li><strong>Command queue usage</strong>: Use the provided command queue for all operations</li>
   * </ul>
   * 
   * <p>Performance optimization capabilities:
   * <ul>
   * <li><strong>Device-specific tuning</strong>: Access device capabilities for optimal kernel configuration</li>
   * <li><strong>Kernel information</strong>: Use kernel metadata for work group size optimization</li>
   * <li><strong>Memory hierarchy</strong>: Leverage device memory characteristics for data layout</li>
   * <li><strong>Compute capabilities</strong>: Adapt algorithms based on device compute units and features</li>
   * </ul>
   * 
   * <p>Error handling and robustness:
   * <ul>
   * <li><strong>Resource validation</strong>: All OpenCL objects are validated during context creation</li>
   * <li><strong>Device compatibility</strong>: Context ensures device supports required kernels</li>
   * <li><strong>Kernel availability</strong>: All specified kernels are guaranteed to be compiled and available</li>
   * <li><strong>Exception safety</strong>: Context provides consistent state even if operations fail</li>
   * </ul>
   * 
   * @see net.bmahe.genetics4j.gpu.GPUFitnessEvaluator
   * @see net.bmahe.genetics4j.gpu.spec.fitness.OpenCLFitness
   * @see Platform
   * @see Device
   * @see KernelInfo
   */
  @Value.Immutable
  public interface OpenCLExecutionContext {
  
  	/**
  	 * Returns the OpenCL platform associated with this execution context.
 	 * 
 	 * @return the platform containing the device for this context
 	 */
 	@Value.Parameter
 	Platform platform();
 
 	/**
 	 * Returns the OpenCL device associated with this execution context.
 	 * 
 	 * @return the device on which kernels will be executed
 	 */
 	@Value.Parameter
 	Device device();
 
 	/**
 	 * Returns the OpenCL context for this execution environment.
 	 * 
 	 * @return the OpenCL context for memory and resource management
 	 */
 	@Value.Parameter
 	cl_context clContext();
 
 	/**
 	 * Returns the OpenCL command queue for kernel execution and memory operations.
 	 * 
 	 * @return the command queue for submitting OpenCL operations
 	 */
 	@Value.Parameter
 	cl_command_queue clCommandQueue();
 
 	/**
 	 * Returns the compiled OpenCL program containing all kernels.
 	 * 
 	 * @return the compiled OpenCL program object
 	 */
 	@Value.Parameter
 	cl_program clProgram();
 
 	/**
 	 * Returns a map of kernel names to compiled kernel objects.
 	 * 
 	 * @return map from kernel names to executable kernel objects
 	 */
 	@Value.Parameter
 	Map<String, cl_kernel> kernels();
 
 	/**
 	 * Returns a map of kernel names to kernel execution information.
 	 * 
 	 * @return map from kernel names to kernel metadata and execution parameters
 	 */
 	@Value.Parameter
 	Map<String, KernelInfo> kernelInfos();
 
 	/**
 	 * Convenience method to retrieve kernel execution information by name.
 	 * 
 	 * @param kernelName the name of the kernel to get information for
 	 * @return the kernel execution information, or null if not found
 	 */
 	default KernelInfo kernelInfo(final String kernelName) {
 		return kernelInfos().get(kernelName);
 	}
 
 	public static class Builder extends ImmutableOpenCLExecutionContext.Builder {
 	}
 
 	/**
 	 * Creates a new builder for constructing OpenCL execution contexts.
 	 * 
 	 * @return a new builder instance
 	 */
 	public static Builder builder() {
 		return new Builder();
 	}
 }