cqfn/eo

/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2016-2024 Objectionary.com
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package org.eolang.maven.footprint;

import com.jcabi.log.Logger;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;
import org.cactoos.Scalar;
import org.cactoos.scalar.IoChecked;
import org.cactoos.text.IoCheckedText;
import org.cactoos.text.TextOf;
import org.eolang.maven.Place;
import org.eolang.maven.util.HmBase;

/**
 * Program footprint of EO compilation process.
 * <p>The footprint optionally cached in {@link #cache} folder.</p>
 * Caching is applied if {@link #version} is not empty otherwise caching is ignored.
 *
 * @since 1.0
 */
public final class FtCached implements Footprint {

    /**
     * Version tag.
     */
    private final CacheVersion version;

    /**
     * Path to cache root.
     */
    private final Path cache;

    /**
     * Path to main root.
     */
    private final Footprint origin;

    /**
     * Ctor.
     * @param hash Version tag or hash
     * @param cache Cache root
     * @param origin Origin
     */
    public FtCached(
        final String hash,
        final Path cache,
        final Footprint origin
    ) {
        this(new CacheVersion("", hash), cache, origin);
    }

    /**
     * Ctor.
     * @param ver Version
     * @param cache Cache root
     * @param origin Origin
     */
    public FtCached(
        final CacheVersion ver,
        final Path cache,
        final Footprint origin
    ) {
        this.version = ver;
        this.cache = cache;
        this.origin = origin;
    }

    @Override
    public String load(final String program, final String ext) throws IOException {
        final String content;
        if (this.version.cacheable() && this.isCached(program, ext)) {
            content = new IoCheckedText(
                new TextOf(
                    this.cache.resolve(this.path(program, ext))
                )
            ).asString();
        } else {
            content = this.origin.load(program, ext);
        }
        return content;
    }

    @Override
    public void save(final String program, final String ext, final Scalar<String> content)
        throws IOException {
        final String text;
        if (this.version.cacheable()) {
            if (this.isCached(program, ext)) {
                text = this.load(program, ext);
            } else {
                text = new IoChecked<>(content).value();
                new HmBase(this.cache).save(text, this.path(program, ext));
            }
        } else {
            text = new IoChecked<>(content).value();
        }
        this.origin.save(program, ext, () -> text);
    }

    @Override
    public List<Path> list(final String ext) throws IOException {
        return this.origin.list(ext);
    }

    /**
     * Is cached?
     * @param program Program name
     * @param ext Extension
     * @return TRUE if cached
     */
    private boolean isCached(final String program, final String ext) {
        final Path relative = this.path(program, ext);
        final boolean res;
        if (Files.exists(this.cache.resolve(relative))) {
            Logger.debug(
                this,
                "Program %s.%s is found in cache: %s",
                program, ext, relative
            );
            res = true;
        } else {
            res = false;
        }
        return res;
    }

    /**
     * Relative path to cached file.
     * @param program Program name
     * @param ext Extension
     * @return Path
     */
    private Path path(final String program, final String ext) {
        return new Place(program).make(this.version.path(), ext);
    }
}