/*******************************************************************************
 * Copyright (C) 2026, Leo Galambos
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 
 * 3. All advertising materials mentioning features or use of this software must
 *    display the following acknowledgement:
 *    This product includes software developed by the Egothor project.
 * 
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 *    may be used to endorse or promote products derived from this software without
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package zeroecho.pki.impl.audit;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;

/**
 * Internal utilities for enumerating persisted audit files.
 */
final class FileAuditSinkFiles {

    private FileAuditSinkFiles() {
    }

    /**
     * Lists all {@code *.audit.log.gz} files under {@code baseDir}
     * deterministically.
     *
     * @param baseDir base directory (must not be null)
     * @return immutable, lexicographically sorted list of paths
     * @throws IllegalArgumentException if {@code baseDir} is null
     * @throws IllegalStateException    if filesystem traversal fails
     */
    /* default */ static List<Path> listDailyFiles(Path baseDir) {
        if (baseDir == null) {
            throw new IllegalArgumentException("baseDir must not be null");
        }
        if (!Files.isDirectory(baseDir)) {
            return List.of();
        }

        List<Path> out = new ArrayList<>();
        try {
            Files.walk(baseDir).filter(Files::isRegularFile)
                    .filter(p -> p.getFileName().toString().endsWith(".audit.log.gz")).forEach(out::add);
        } catch (IOException ex) {
            throw new IllegalStateException("Failed to list audit files.", ex);
        }

        out.sort(Comparator.naturalOrder());
        return List.copyOf(out);
    }
}
