/*
 * Copyright (c) 2019, 2020, Oracle and/or its affiliates.
 *
 * 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. Neither the name of the copyright holder nor the names of its contributors may be used to
 * endorse or promote products derived from this software without specific prior written
 * permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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 */
package com.oracle.truffle.llvm.runtime;

import com.oracle.truffle.api.TruffleFile;

import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.List;

Locates libraries based on the global library paths. /**
 * Locates libraries based on the global {@link LLVMContext#getLibraryPaths() library paths}.
 */
public final class DefaultLibraryLocator extends LibraryLocator {

    public static final DefaultLibraryLocator INSTANCE = new DefaultLibraryLocator();

    private DefaultLibraryLocator() {
    }

    @Override
    public TruffleFile locateLibrary(LLVMContext context, String lib, Object reason) {
        Path libPath = Paths.get(lib);
        if (libPath.isAbsolute()) {
            return locateAbsolute(context, libPath);
        }
        return locateGlobal(context, lib);
    }

    public static TruffleFile locateGlobal(LLVMContext context, String lib) {
        // search global paths
        List<Path> libraryPaths = context.getLibraryPaths();
        traceSearchPath(context, libraryPaths);
        for (Path p : libraryPaths) {
            Path absPath = Paths.get(p.toString(), lib);
            traceTry(context, absPath);
            TruffleFile file = context.getEnv().getInternalTruffleFile(absPath.toUri());
            if (file.exists()) {
                return file;
            }
        }
        return null;
    }

    public static TruffleFile locateAbsolute(LLVMContext context, Path libPath) {
        assert libPath.isAbsolute();
        traceTry(context, libPath);
        TruffleFile file = context.getEnv().getInternalTruffleFile(libPath.toUri());
        if (file.exists()) {
            return file;
        } else {
            /*
             * On OSX Big Sur, some system libraries don't exist as a file. These libraries are
             * native libraries anyway, Sulong can do nothing with these libraries, so we can just
             * return null here. The NFI will later re-try locating these libraries, and they will
             * be found via the dlopen cache.
             */
            return null;
        }
    }

}