"""
Saxon Worker Pool - Persistente JVM-Prozesse für schnelle XSLT-Transformationen.

Eliminiert JVM-Startup-Overhead durch Vorinitialisierung von N Worker-Prozessen.
Jeder Worker läuft als Daemon und verarbeitet mehrere Transformationen nacheinander.
"""

import logging
import subprocess
import threading
import time
import psutil
from pathlib import Path
from typing import Optional
import tempfile

from worker_metrics import WorkerPoolMetrics

logger = logging.getLogger(__name__)

# Java-Worker-Code (wird zur Laufzeit kompiliert)
SAXON_WORKER_JAVA = """
import javax.xml.transform.*;
import javax.xml.transform.stream.*;
import java.io.*;
import java.util.*;

public class SaxonWorker {
    public static void main(String[] args) {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        String line;

        // Create TransformerFactory once and reuse
        TransformerFactory factory = TransformerFactory.newInstance();

        // Cache für kompilierte Stylesheets (Performance-Optimierung)
        Map<String, Templates> templatesCache = new HashMap<>();

        System.err.println("SaxonWorker started and ready (using JAXP Transformer API with stylesheet caching)");
        System.err.flush();

        try {
            while ((line = reader.readLine()) != null) {
                System.err.println("DEBUG: Received line: " + line.substring(0, Math.min(100, line.length())));
                System.err.flush();

                if ("EXIT".equals(line.trim())) {
                    System.err.println("SaxonWorker exiting");
                    break;
                }

                try {
                    // Parse job
                    System.err.println("DEBUG: Parsing job...");
                    System.err.flush();

                    String[] parts = line.split("\\t");
                    System.err.println("DEBUG: Parts count: " + parts.length);
                    System.err.flush();

                    if (parts.length < 3) {
                        System.out.println("ERROR: Invalid job format");
                        System.out.flush();
                        continue;
                    }

                    String sourceXml = parts[0];
                    String xslStylesheet = parts[1];
                    String outputFo = parts[2];

                    // Prüfe ob Stylesheet bereits im Cache ist
                    Templates templates;
                    if (templatesCache.containsKey(xslStylesheet)) {
                        templates = templatesCache.get(xslStylesheet);
                        System.err.println("DEBUG: Using cached stylesheet: " + xslStylesheet);
                        System.err.flush();
                    } else {
                        System.err.println("DEBUG: Compiling and caching stylesheet: " + xslStylesheet);
                        System.err.flush();

                        StreamSource xslSource = new StreamSource(new File(xslStylesheet));
                        templates = factory.newTemplates(xslSource);
                        templatesCache.put(xslStylesheet, templates);

                        System.err.println("DEBUG: Stylesheet compiled and cached (cache size: " + templatesCache.size() + ")");
                        System.err.flush();
                    }

                    System.err.println("DEBUG: Creating transformer from cached template...");
                    System.err.flush();

                    // Create Source and Result objects
                    StreamSource xmlSource = new StreamSource(new File(sourceXml));
                    StreamResult result = new StreamResult(new File(outputFo));

                    // Create transformer from templates
                    Transformer transformer = templates.newTransformer();

                    // Set parameters if present
                    if (parts.length > 3 && !parts[3].isEmpty()) {
                        String[] params = parts[3].split("\\\\|\\\\|\\\\|");
                        for (String param : params) {
                            if (!param.isEmpty() && param.contains("=")) {
                                String[] kv = param.split("=", 2);
                                transformer.setParameter(kv[0], kv[1]);
                                System.err.println("DEBUG: Set parameter: " + kv[0] + " = " + kv[1]);
                            }
                        }
                        System.err.flush();
                    }

                    System.err.println("DEBUG: Running transformation...");
                    System.err.flush();

                    // Capture errors via ErrorListener
                    final StringBuilder errors = new StringBuilder();
                    transformer.setErrorListener(new ErrorListener() {
                        @Override
                        public void warning(TransformerException e) {
                            errors.append("WARNING: ").append(e.getMessage()).append("\\n");
                        }

                        @Override
                        public void error(TransformerException e) {
                            errors.append("ERROR: ").append(e.getMessage()).append("\\n");
                        }

                        @Override
                        public void fatalError(TransformerException e) throws TransformerException {
                            errors.append("FATAL: ").append(e.getMessage()).append("\\n");
                            throw e;
                        }
                    });

                    // Run transformation
                    transformer.transform(xmlSource, result);

                    System.err.println("DEBUG: Transformation completed");
                    System.err.flush();

                    // Check for errors
                    if (errors.length() > 0) {
                        System.out.println("ERROR: " + errors.toString().trim());
                    } else {
                        System.out.println("OK");
                    }
                    System.out.flush();

                } catch (TransformerException e) {
                    System.err.println("DEBUG: Transformer exception: " + e.getClass().getName());
                    System.err.flush();
                    e.printStackTrace(System.err);

                    String errorMsg = e.getMessage();
                    if (errorMsg == null || errorMsg.isEmpty()) {
                        errorMsg = e.getClass().getSimpleName();
                    }
                    System.out.println("ERROR: " + errorMsg);
                    System.out.flush();

                } catch (Exception e) {
                    System.err.println("DEBUG: Job processing exception: " + e.getClass().getName());
                    System.err.flush();
                    e.printStackTrace(System.err);
                    System.out.println("ERROR: " + (e.getMessage() != null ? e.getMessage() : e.getClass().getName()));
                    System.out.flush();
                }
            }
        } catch (IOException e) {
            System.err.println("SaxonWorker I/O error: " + e.getMessage());
            e.printStackTrace(System.err);
        }
    }
}
"""


class SaxonWorkerPool:
    """
    Pool von lang-laufenden JVM-Prozessen für Saxon-Transformationen.

    Eliminiert JVM-Startup-Overhead durch Wiederverwendung von N Worker-Prozessen.
    """

    def __init__(
        self,
        num_workers: int,
        java_vm_path: Path,
        saxon_jar_path: Path,
        classpath_cache: dict[Path, str],
        log_dir: Optional[Path] = None,
    ):
        """
        Initialisiert den Saxon-Worker-Pool.

        Args:
            num_workers: Anzahl der Worker-Prozesse
            java_vm_path: Pfad zur Java VM Binary
            saxon_jar_path: Pfad zur Saxon JAR-Datei
            classpath_cache: Cache für Saxon-Classpaths
            log_dir: Optionales Verzeichnis für Worker-Logs (Standard: temp_dir/tmp)
        """
        self.num_workers = num_workers
        self.java_vm_path = java_vm_path
        self.saxon_jar_path = saxon_jar_path
        self.classpath_cache = classpath_cache
        self.log_dir = log_dir

        # Worker-Prozesse
        self.workers: list[subprocess.Popen] = []
        self.worker_locks: list[threading.Lock] = []

        # Temporäres Verzeichnis für kompilierte Java-Klasse
        self.temp_dir: Optional[Path] = None
        self.worker_class_path: Optional[Path] = None
        self.worker_log_dir: Optional[Path] = None

        # Performance-Metriken
        self.metrics = WorkerPoolMetrics()

        # Initialisierung
        self._compile_worker_class()
        self._start_workers()

        logger.info(f"SaxonWorkerPool initialisiert mit {num_workers} Workern")

    def _compile_worker_class(self):
        """Kompiliert die SaxonWorker-Java-Klasse."""
        start_time = time.time()
        try:
            # Erstelle temporäres Verzeichnis
            self.temp_dir = Path(tempfile.mkdtemp(prefix="saxon_worker_"))

            # Schreibe Java-Quellcode
            java_file = self.temp_dir / "SaxonWorker.java"
            java_file.write_text(SAXON_WORKER_JAVA, encoding="utf-8")

            # Hole Classpath
            saxon_dir = self.saxon_jar_path.parent
            if saxon_dir in self.classpath_cache:
                classpath = self.classpath_cache[saxon_dir]
            else:
                # Fallback: Baue Classpath neu
                import glob
                import sys

                all_jars = glob.glob(str(saxon_dir / "*.jar"))
                lib_dir = saxon_dir / "lib"
                if lib_dir.exists():
                    all_jars.extend(glob.glob(str(lib_dir / "*.jar")))

                classpath_separator = ";" if sys.platform == "win32" else ":"
                classpath = classpath_separator.join(all_jars)

            # Kompiliere Java-Klasse
            javac_cmd = [str(self.java_vm_path).replace("java", "javac"), "-cp", classpath, str(java_file)]

            logger.debug(f"Kompiliere SaxonWorker: {' '.join(javac_cmd)}")

            result = subprocess.run(javac_cmd, capture_output=True, text=True, timeout=30)

            if result.returncode != 0:
                raise RuntimeError(f"Java-Kompilierung fehlgeschlagen: {result.stderr}")

            self.worker_class_path = self.temp_dir

            # Speichere Kompilierungszeit
            self.metrics.compilation_time_seconds = time.time() - start_time

            logger.info(
                f"SaxonWorker erfolgreich kompiliert: {self.temp_dir} " f"({self.metrics.compilation_time_seconds:.3f}s)"
            )

        except Exception as e:
            logger.error(f"Fehler beim Kompilieren von SaxonWorker: {e}")
            raise

    def _start_workers(self):
        """Startet N Worker-Prozesse."""
        # Hole Classpath
        saxon_dir = self.saxon_jar_path.parent
        classpath = self.classpath_cache.get(saxon_dir, "")

        # Füge Worker-Classpath hinzu
        import sys

        classpath_separator = ";" if sys.platform == "win32" else ":"
        full_classpath = str(self.worker_class_path) + classpath_separator + classpath

        # Bestimme Log-Verzeichnis
        self.worker_log_dir = self.log_dir if self.log_dir else self.temp_dir
        if self.log_dir:
            self.worker_log_dir.mkdir(parents=True, exist_ok=True)

        for i in range(self.num_workers):
            worker_start_time = time.time()
            try:
                # Starte JVM-Prozess mit SaxonWorker
                cmd = [str(self.java_vm_path), "-cp", full_classpath, "SaxonWorker"]

                # Öffne stderr-Log-Datei für diesen Worker
                stderr_log = self.worker_log_dir / f"worker_{i}_stderr.log"
                stderr_file = open(stderr_log, "w", encoding="utf-8")

                process = subprocess.Popen(
                    cmd,
                    stdin=subprocess.PIPE,
                    stdout=subprocess.PIPE,
                    stderr=stderr_file,  # Redirect stderr to file
                    text=True,
                    bufsize=1,  # Line buffered
                )

                self.workers.append(process)
                self.worker_locks.append(threading.Lock())

                logger.debug(f"Worker {i} gestartet (PID: {process.pid}, stderr: {stderr_log})")

                # Warte kurz damit Worker initialisieren kann
                time.sleep(0.1)

                # Prüfe ob Worker noch läuft
                if process.poll() is not None:
                    # Worker ist bereits beendet - Fehler!
                    stderr_file.close()
                    with open(stderr_log, "r") as f:
                        stderr_content = f.read()
                    raise RuntimeError(
                        f"Worker {i} ist sofort beendet (Exit Code: {process.returncode})\nstderr:\n{stderr_content}"
                    )

                # Speichere Worker-Startzeit
                worker_elapsed = time.time() - worker_start_time
                self.metrics.worker_start_times.append(worker_elapsed)

            except Exception as e:
                logger.error(f"Fehler beim Starten von Worker {i}: {e}")
                raise

        # Berechne Aggregat-Werte für Worker-Startzeiten
        self.metrics.calculate_aggregates()

        logger.info(
            f"{len(self.workers)} Saxon-Worker erfolgreich gestartet "
            f"(Summe: {self.metrics.total_worker_start_time_seconds:.3f}s, "
            f"Durchschnitt: {self.metrics.average_worker_start_time_seconds:.3f}s)"
        )

    def transform(
        self, source_xml: Path, xsl_stylesheet: Path, output_fo: Path, xslt_params: dict[str, str]
    ) -> tuple[bool, str]:
        """
        Führt eine XSLT-Transformation mit einem Worker aus dem Pool aus.

        Args:
            source_xml: Pfad zur XML-Eingabedatei
            xsl_stylesheet: Pfad zur XSL-Stylesheet-Datei
            output_fo: Pfad zur FO-Ausgabedatei
            xslt_params: Dictionary mit XSLT-Parametern

        Returns:
            tuple[bool, str]: (Erfolg, Fehlermeldung/Info)
        """
        # Finde freien Worker
        worker_idx = None
        for i, lock in enumerate(self.worker_locks):
            if lock.acquire(blocking=False):
                worker_idx = i
                break

        if worker_idx is None:
            # Kein freier Worker, warte auf ersten verfügbaren
            for i, lock in enumerate(self.worker_locks):
                lock.acquire()
                worker_idx = i
                break

        try:
            worker = self.workers[worker_idx]

            # Prüfe ob Worker noch läuft
            if worker.poll() is not None:
                # Worker ist tot!
                stderr_log = self.worker_log_dir / f"worker_{worker_idx}_stderr.log"
                try:
                    with open(stderr_log, "r") as f:
                        stderr_content = f.read()
                    error_msg = (
                        f"Worker {worker_idx} ist beendet (Exit: {worker.returncode})\nstderr:\n{stderr_content}"
                    )
                except Exception:
                    error_msg = f"Worker {worker_idx} ist beendet (Exit: {worker.returncode})"
                logger.error(error_msg)
                return False, error_msg

            # Formatiere Parameter
            params_str = "|||".join([f"{key}={value}" for key, value in xslt_params.items()])

            # Erstelle Job-String (Tab-separated)
            job = f"{source_xml}\t{xsl_stylesheet}\t{output_fo}\t{params_str}\n"

            logger.debug(f"Sende Job an Worker {worker_idx}: {source_xml.name}")

            # Sende Job an Worker
            worker.stdin.write(job)
            worker.stdin.flush()

            # Warte auf Antwort
            response = worker.stdout.readline().strip()

            logger.debug(f"Worker {worker_idx} Antwort: '{response}'")

            if response == "OK":
                return True, "Erfolgreich"
            elif response.startswith("ERROR:"):
                error_msg = response[6:].strip()
                return False, f"Saxon-Fehler: {error_msg}"
            else:
                # Leere Antwort bedeutet Worker ist crashed
                if not response:
                    stderr_log = self.worker_log_dir / f"worker_{worker_idx}_stderr.log"
                    try:
                        with open(stderr_log, "r") as f:
                            stderr_content = f.read()[-500:]  # Letzte 500 Zeichen
                        return False, f"Worker {worker_idx} crashed (keine Antwort)\nstderr:\n{stderr_content}"
                    except Exception:
                        return False, f"Worker {worker_idx} crashed (keine Antwort)"
                return False, f"Unerwartete Antwort: {response}"

        except Exception as e:
            logger.error(f"Fehler bei Worker {worker_idx}: {e}")
            return False, f"Worker-Fehler: {str(e)}"

        finally:
            # Gebe Worker-Lock frei
            self.worker_locks[worker_idx].release()

    def measure_ram_usage(self) -> tuple[float, float, list[float]]:
        """
        Misst den aktuellen RAM-Verbrauch aller Worker-Prozesse.

        Returns:
            tuple: (total_mb, average_mb, per_worker_mb_list)
        """
        ram_per_worker = []

        for i, worker in enumerate(self.workers):
            try:
                if worker.poll() is None:  # Worker läuft noch
                    process = psutil.Process(worker.pid)
                    # Hole Speicherinfo (RSS = Resident Set Size in Bytes)
                    mem_info = process.memory_info()
                    ram_mb = mem_info.rss / (1024 * 1024)  # Konvertiere zu MB
                    ram_per_worker.append(ram_mb)
                else:
                    logger.warning(f"Worker {i} ist nicht mehr aktiv (kann RAM nicht messen)")
            except (psutil.NoSuchProcess, psutil.AccessDenied) as e:
                logger.warning(f"Konnte RAM für Worker {i} nicht messen: {e}")

        total_ram = sum(ram_per_worker)
        average_ram = total_ram / len(ram_per_worker) if ram_per_worker else 0.0

        return total_ram, average_ram, ram_per_worker

    def capture_ram_before_transform(self):
        """Erfasst RAM-Verbrauch vor der ersten Transformation."""
        total, average, per_worker = self.measure_ram_usage()
        self.metrics.ram_before_transform_mb_per_worker = per_worker
        self.metrics.total_ram_before_mb = total
        self.metrics.average_ram_before_mb = average

        logger.info(
            f"RAM vor Transformation: {self.metrics.total_ram_before_mb:.1f} MB "
            f"(Durchschnitt: {self.metrics.average_ram_before_mb:.1f} MB/Worker)"
        )

    def capture_ram_after_transform(self):
        """Erfasst RAM-Verbrauch nach allen Transformationen."""
        total, average, per_worker = self.measure_ram_usage()
        self.metrics.ram_after_transform_mb_per_worker = per_worker
        self.metrics.total_ram_after_mb = total
        self.metrics.average_ram_after_mb = average

        logger.info(
            f"RAM nach Transformation: {self.metrics.total_ram_after_mb:.1f} MB "
            f"(Durchschnitt: {self.metrics.average_ram_after_mb:.1f} MB/Worker)"
        )

    def shutdown(self):
        """Beendet alle Worker-Prozesse sauber."""
        logger.info("Beende Saxon-Worker-Pool...")

        for i, worker in enumerate(self.workers):
            try:
                # Sende EXIT-Befehl
                if worker.stdin and not worker.stdin.closed:
                    worker.stdin.write("EXIT\n")
                    worker.stdin.flush()

                # Warte auf Beendigung (max 2 Sekunden)
                worker.wait(timeout=2)
                logger.debug(f"Worker {i} beendet")

            except subprocess.TimeoutExpired:
                # Force kill falls nötig
                worker.kill()
                logger.warning(f"Worker {i} musste gekillt werden")

            except Exception as e:
                logger.error(f"Fehler beim Beenden von Worker {i}: {e}")

        # Lösche temporäres Verzeichnis
        if self.temp_dir and self.temp_dir.exists():
            try:
                import shutil

                shutil.rmtree(self.temp_dir)
                logger.debug(f"Temporäres Verzeichnis gelöscht: {self.temp_dir}")
            except Exception as e:
                logger.warning(f"Konnte temporäres Verzeichnis nicht löschen: {e}")

        logger.info("Saxon-Worker-Pool beendet")

    def __enter__(self):
        """Context manager entry."""
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        """Context manager exit."""
        self.shutdown()