"""
batch_parser.py
Parse multiple NX Nastran cases in batch

AtomizerField Batch Parser v1.0.0
Efficiently processes multiple FEA cases for neural network training dataset creation.

Usage:
    python batch_parser.py <root_directory>

Example:
    python batch_parser.py ./training_data

Directory structure expected:
    training_data/
    ├── case_001/
    │   ├── input/model.bdf
    │   └── output/model.op2
    ├── case_002/
    │   ├── input/model.bdf
    │   └── output/model.op2
    └── ...
"""

import os
import sys
import json
from pathlib import Path
from datetime import datetime
import traceback

from neural_field_parser import NastranToNeuralFieldParser
from validate_parsed_data import NeuralFieldDataValidator


class BatchParser:
    """
    Batch parser for processing multiple FEA cases

    This enables rapid dataset creation for neural network training.
    Processes each case sequentially and generates a summary report.
    """

    def __init__(self, root_directory, validate=True, continue_on_error=True):
        """
        Initialize batch parser

        Args:
            root_directory (str or Path): Root directory containing case subdirectories
            validate (bool): Run validation after parsing each case
            continue_on_error (bool): Continue processing if a case fails
        """
        self.root_dir = Path(root_directory)
        self.validate = validate
        self.continue_on_error = continue_on_error
        self.results = []

    def find_cases(self):
        """
        Find all case directories in root directory

        A valid case directory contains:
        - input/ subdirectory with .bdf or .dat file
        - output/ subdirectory with .op2 file

        Returns:
            list: List of Path objects for valid case directories
        """
        cases = []

        for item in self.root_dir.iterdir():
            if not item.is_dir():
                continue

            # Check for required subdirectories and files
            input_dir = item / "input"
            output_dir = item / "output"

            if not input_dir.exists() or not output_dir.exists():
                continue

            # Check for BDF file
            bdf_files = list(input_dir.glob("*.bdf")) + list(input_dir.glob("*.dat"))
            if not bdf_files:
                continue

            # Check for OP2 file
            op2_files = list(output_dir.glob("*.op2"))
            if not op2_files:
                continue

            cases.append(item)

        return sorted(cases)

    def parse_case(self, case_dir):
        """
        Parse a single case

        Args:
            case_dir (Path): Path to case directory

        Returns:
            dict: Result dictionary with status and metadata
        """
        result = {
            "case": case_dir.name,
            "status": "unknown",
            "timestamp": datetime.now().isoformat()
        }

        try:
            print(f"\n{'='*60}")
            print(f"Processing: {case_dir.name}")
            print(f"{'='*60}")

            # Parse
            parser = NastranToNeuralFieldParser(case_dir)
            data = parser.parse_all()

            result["status"] = "parsed"
            result["nodes"] = data["mesh"]["statistics"]["n_nodes"]
            result["elements"] = data["mesh"]["statistics"]["n_elements"]

            # Get max displacement and stress if available
            if "displacement" in data.get("results", {}):
                result["max_displacement"] = data["results"]["displacement"].get("max_translation")

            if "stress" in data.get("results", {}):
                for stress_type, stress_data in data["results"]["stress"].items():
                    if "max_von_mises" in stress_data and stress_data["max_von_mises"] is not None:
                        result["max_stress"] = stress_data["max_von_mises"]
                        break

            # Validate if requested
            if self.validate:
                print(f"\nValidating {case_dir.name}...")
                validator = NeuralFieldDataValidator(case_dir)
                validation_passed = validator.validate()

                result["validated"] = validation_passed
                if validation_passed:
                    result["status"] = "success"
                else:
                    result["status"] = "validation_failed"
                    result["message"] = "Validation failed (see output above)"

            else:
                result["status"] = "success"

        except Exception as e:
            result["status"] = "failed"
            result["error"] = str(e)
            result["traceback"] = traceback.format_exc()

            print(f"\n✗ ERROR: {e}")
            if not self.continue_on_error:
                raise

        return result

    def batch_parse(self):
        """
        Parse all cases in root directory

        Returns:
            list: List of result dictionaries
        """
        print("\n" + "="*60)
        print("AtomizerField Batch Parser v1.0")
        print("="*60)
        print(f"\nRoot directory: {self.root_dir}")

        # Find all cases
        cases = self.find_cases()

        if not cases:
            print(f"\n✗ No valid cases found in {self.root_dir}")
            print("\nCase directories should contain:")
            print("  input/model.bdf (or model.dat)")
            print("  output/model.op2")
            return []

        print(f"\nFound {len(cases)} case(s) to process:")
        for case in cases:
            print(f"  - {case.name}")

        # Process each case
        self.results = []
        start_time = datetime.now()

        for i, case in enumerate(cases, 1):
            print(f"\n[{i}/{len(cases)}] Processing {case.name}...")

            result = self.parse_case(case)
            self.results.append(result)

            # Show progress
            success_count = sum(1 for r in self.results if r["status"] == "success")
            print(f"\nProgress: {i}/{len(cases)} processed, {success_count} successful")

        end_time = datetime.now()
        elapsed = (end_time - start_time).total_seconds()

        # Print summary
        self._print_summary(elapsed)

        # Save summary to JSON
        self._save_summary()

        return self.results

    def _print_summary(self, elapsed_time):
        """Print batch processing summary"""
        print("\n" + "="*60)
        print("BATCH PROCESSING COMPLETE")
        print("="*60)

        success_count = sum(1 for r in self.results if r["status"] == "success")
        failed_count = sum(1 for r in self.results if r["status"] == "failed")
        validation_failed = sum(1 for r in self.results if r["status"] == "validation_failed")

        print(f"\nTotal cases: {len(self.results)}")
        print(f"  ✓ Successful: {success_count}")
        if validation_failed > 0:
            print(f"  ⚠ Validation failed: {validation_failed}")
        if failed_count > 0:
            print(f"  ✗ Failed: {failed_count}")

        print(f"\nProcessing time: {elapsed_time:.1f} seconds")
        if len(self.results) > 0:
            print(f"Average time per case: {elapsed_time/len(self.results):.1f} seconds")

        # Detailed results
        print("\nDetailed Results:")
        print("-" * 60)
        for result in self.results:
            status_symbol = {
                "success": "✓",
                "failed": "✗",
                "validation_failed": "⚠",
                "parsed": "•"
            }.get(result["status"], "?")

            case_info = f"{status_symbol} {result['case']}: {result['status']}"

            if "nodes" in result and "elements" in result:
                case_info += f" ({result['nodes']:,} nodes, {result['elements']:,} elements)"

            if "max_stress" in result:
                case_info += f" | Max VM: {result['max_stress']:.2f} MPa"

            if result["status"] == "failed" and "error" in result:
                case_info += f"\n    Error: {result['error']}"

            print(f"  {case_info}")

        print("\n" + "="*60)

        if success_count == len(self.results):
            print("✓ ALL CASES PROCESSED SUCCESSFULLY")
        elif success_count > 0:
            print(f"⚠ {success_count}/{len(self.results)} CASES SUCCESSFUL")
        else:
            print("✗ ALL CASES FAILED")

        print("="*60 + "\n")

    def _save_summary(self):
        """Save batch processing summary to JSON file"""
        summary_file = self.root_dir / "batch_processing_summary.json"

        summary = {
            "batch_info": {
                "root_directory": str(self.root_dir),
                "timestamp": datetime.now().isoformat(),
                "total_cases": len(self.results),
                "successful_cases": sum(1 for r in self.results if r["status"] == "success"),
                "failed_cases": sum(1 for r in self.results if r["status"] == "failed"),
                "validation_enabled": self.validate
            },
            "cases": self.results
        }

        with open(summary_file, 'w') as f:
            json.dump(summary, f, indent=2)

        print(f"Summary saved to: {summary_file}\n")


def main():
    """
    Main entry point for batch parser
    """
    if len(sys.argv) < 2:
        print("\nAtomizerField Batch Parser v1.0")
        print("="*60)
        print("\nUsage:")
        print("  python batch_parser.py <root_directory> [options]")
        print("\nOptions:")
        print("  --no-validate     Skip validation step")
        print("  --stop-on-error   Stop processing if a case fails")
        print("\nExample:")
        print("  python batch_parser.py ./training_data")
        print("\nDirectory structure:")
        print("  training_data/")
        print("    ├── case_001/")
        print("    │   ├── input/model.bdf")
        print("    │   └── output/model.op2")
        print("    ├── case_002/")
        print("    │   ├── input/model.bdf")
        print("    │   └── output/model.op2")
        print("    └── ...")
        print()
        sys.exit(1)

    root_dir = sys.argv[1]

    # Parse options
    validate = "--no-validate" not in sys.argv
    continue_on_error = "--stop-on-error" not in sys.argv

    if not Path(root_dir).exists():
        print(f"ERROR: Directory not found: {root_dir}")
        sys.exit(1)

    # Create batch parser
    batch_parser = BatchParser(
        root_dir,
        validate=validate,
        continue_on_error=continue_on_error
    )

    # Process all cases
    try:
        results = batch_parser.batch_parse()

        # Exit with appropriate code
        if not results:
            sys.exit(1)

        success_count = sum(1 for r in results if r["status"] == "success")
        if success_count == len(results):
            sys.exit(0)  # All successful
        elif success_count > 0:
            sys.exit(2)  # Partial success
        else:
            sys.exit(1)  # All failed

    except KeyboardInterrupt:
        print("\n\nBatch processing interrupted by user")
        sys.exit(130)
    except Exception as e:
        print(f"\n\nFATAL ERROR: {e}")
        traceback.print_exc()
        sys.exit(1)


if __name__ == "__main__":
    main()