package Torello.Java.Build;

import Torello.JavaDoc.Upgrade;

import Torello.Java.Verbosity;
import Torello.Java.StrCmpr;
import Torello.Java.EmptyListException;
import Torello.Java.WritableDirectoryException;
import Torello.Java.GSUTIL; // Needed for a javadoc '@link'

import Torello.Java.ReadOnly.ReadOnlyList;

import Torello.HTML.Tools.Images.IF;

import java.io.File;
import java.io.FileNotFoundException;

import java.util.Objects;
import java.util.regex.Pattern;

import java.util.function.Consumer;
import java.util.function.Predicate;

/**
 * This class provides a list of fields, all of which may be modified and configured, for providing
 * any needed settings to class {@link Builder}.
 * 
 * <BR /><BR />Use the {@code public} constructor offered by this class, and then set and change
 * the values of any of the Configuration-Fields.  Once this class Configuration-Fields have been
 * appropriately set to contain your project's data, pass the instance to the {@link Builder} class
 * only constructor (along with an argv {@code String[]}-Array).
 * 
 * <BR /><BR />This will inform the {@code Builder}-Constructor of all of your nedded settings, and
 * once built, will make running your project's build script very easy.
 */
public final class Config
{
    // ********************************************************************************************
    // ********************************************************************************************
    // Validator Constants
    // ********************************************************************************************
    // ********************************************************************************************


    /**
     * Project-Name validation {@code String}.  The value passed to configuration field/parameter
     * must match this regular expression.  This is used in this class {@link #validate()} method.
     * 
     * @see #PROJECT_NAME
     * @see Builder#PROJECT_NAME
     * @see #validate()
     */
    public static final Predicate<String> projectNameValidator =
        Pattern.compile("^\\w[\\w\\d]*$").asPredicate();


    // ********************************************************************************************
    // ********************************************************************************************
    // Configuration Instance Fields
    // ********************************************************************************************
    // ********************************************************************************************


    /**
     * To-Do, Explain This
     * @see Builder#HOME_DIR
     */
    public String HOME_DIR = null;

    /**
     * The File-System Directory-Location where Java-Doc Output is sent for storage.  Also the 
     * directory that the Upgrader searches to retrieve and parse JavaDoc Files.
     *  
     * @see Builder#LOCAL_JAVADOC_DIR
     */
    public String LOCAL_JAVADOC_DIR = "javadoc" + java.io.File.separator;

    /**
     * A simple name for this Project.  Name must pass the {@link #projectNameValidator}
     * Regular-Expression.
     * 
     * @see Builder#PROJECT_NAME
     * @see #projectNameValidator
     */
    public String PROJECT_NAME = null;

    /**
     * The Major Version Number of the Current Build.  This class {@link #validate()} method checks
     * to ensure that this field contains a positive integer / byte value.
     * 
     * @see Builder#VERSION_MAJOR_NUMBER
     */
    public byte VERSION_MAJOR_NUMBER = 1;

    /**
     * The Minor Version Number of the Current Build.  This class {@link #validate()} method checks
     * to ensure that this field contains a positive integer / byte value.
     * 
     * @see Builder#VERSION_MINOR_NUMBER
     */
    public byte VERSION_MINOR_NUMBER = 0;

    /**
     * The full or partial Path-Name of the {@code 'javac'} binary to use for compiling this
     * project.  This parameter / field may not be null, or a {@code NullPointerException} will
     * throw.
     * 
     * <BR /><BR /><B CLASS=JDDescLabel>Default Setting:</B>
     * 
     * <BR />The default setting for this Configuration-Field is just the command name, which
     * is to presume that the {@code PATH} environment-variable has been set to facilitate finding
     * {@code 'javac'}
     * 
     * @see Builder#JAVAC_BIN
     */
    public String JAVAC_BIN = "javac";

    /**
     * The full or partial Path-Name of the {@code 'javac'} binary to use for compiling this
     * project.  This parameter / field may not be null, or a {@code NullPointerException} will
     * throw.
     * 
     * <BR /><BR /><B CLASS=JDDescLabel>Default Setting:</B>
     * 
     * <BR />The default setting for this Configuration-Field is just the command name, which
     * is to presume that the {@code PATH} environment-variable has been set to facilitate finding
     * {@code 'javadoc'}.
     * 
     * @see Builder#JAVADOC_BIN
     */
    public String JAVADOC_BIN = "javadoc";

    /**
     * The number to provide to the {@code --release} switch to {@code javac}.  This number may be
     * set to any negative value, and it will prevent the {@code Builder} from using this switch at
     * all
     * 
     * @see Builder#JAVA_RELEASE_NUM_SWITCH
     */
    public byte JAVA_RELEASE_NUM_SWITCH = -1;

    /**
     * Currently unused, but originally used to indicate the {@code javadoc} version being used
     * @see Builder#JAVADOC_VER
     */
    public byte JAVADOC_VER = 11;

    /**
     * If the <B>Stage 3</B> {@link Upgrade}-Process utilizes a favicon on its Web-Pages, then this
     * field may be assigned to the location on disk where that favicon is located.
     * 
     * <BR /><BR />When this field contains a non-null Image-File, that image will be copied (after
     * upgrade has completed) directly to the {@code 'javadoc'} output directory.  When this field
     * is left null, it will be ignored and no favicon image is copied.
     * 
     * @see Builder#FAVICON
     */
    public String FAVICON = null;

    /**
     * Source-Directory to be used as root directory for archiving
     * @see Builder#TAR_SOURCE_DIR
     */
    public String TAR_SOURCE_DIR = null;

    /**
     * The Google Cloud Platform Storage-Bucket into which jar, log &amp; documentation files will
     * be copied by this Build-Tool.  This Storage-Bucket Directory is intended for use with a
     * boiler-plate &amp; "still under development" {@code URL}.
     * 
     * <BR /><BR />If this parameter remains null, several of the user menu options will be
     * removed, because several are designed for coying data to the Developer Site.  When it is
     * null such options are removed, and this Configuration-Field is ignored.
     * 
     * @see Builder#GCS_DIR_DEV
     * @see #GCS_DIR_RELEASE
     * @see Builder#GCS_DIR_RELEASE
     */
    public String GCS_DIR_DEV = null;

    /**
     * Another Google Cloud Platform Storage-Bucket for storing and providing jar, log &amp;
     * Code-Documentation Files.
     * 
     * <BR /><BR />Similary to Configuration-Field {@link #GCS_DIR_DEV}, this parameter may also be
     * null, and when it is it will be ignored, but a few User-Interface Menu-Options will not be 
     * present at the Build-Menu.
     * 
     * @see Builder#GCS_DIR_RELEASE
     * @see #GCS_DIR_DEV
     * @see Builder#GCS_DIR_DEV
     */
    public String GCS_DIR_RELEASE = null;

    /**
     * Informs the Build-Tool whether or not the {@link GSUTIL} method for making the output
     * directory content public needs to be run.  This {@code boolean} controls whether or not
     * {@code javadoc} content synchronized / copied to the {@link #GCS_DIR_DEV} is assigned the
     * public read-only access level.
     * 
     * <BR /><BR />When {@link #GCS_DIR_DEV} is left null, thi flag is ignored.
     * 
     * <BR /><BR />There is also a {@code boolean} setting for the {@link #GCS_DIR_RELEASE} flag.
     * 
     * <BR /><BR />The default setting for both of these flags is {@code FALSE}.
     * 
     * @see #GCS_DIR_DEV
     * @see Builder#GCS_DIR_DEV
     * @see #RUN_MAKE_PUBLIC_RELEASE
     */
    public boolean RUN_MAKE_PUBLIC_DEV = false;

    /**
     * Informs the Build-Tool whether or not the {@link GSUTIL} method for making the output
     * directory content public needs to be run.  This {@code boolean} controls whether or not
     * {@code javadoc} content synchronized / copied to the {@link #GCS_DIR_RELEASE} is assigned
     * the public read-only access level.
     * 
     * <BR /><BR />When {@link #GCS_DIR_RELEASE} is left null, thi flag is ignored.
     * 
     * <BR /><BR />There is also a {@code boolean} setting for the {@link #GCS_DIR_DEV} flag.
     * 
     * <BR /><BR />The default setting for both of these flags is {@code FALSE}.
     * 
     * @see #GCS_DIR_RELEASE
     * @see Builder#GCS_DIR_RELEASE
     * @see #RUN_MAKE_PUBLIC_DEV
     */
    public boolean RUN_MAKE_PUBLIC_RELEASE = false;

    /**
     * A Storage-Bucket on Google Cloud Platform for saving the generated backup {@code '.tar'}
     * File.  This Configuration-Field may remain null, and if it is it will be silently ignored.
     * In this case, the generated backup {@code '.tar'} File will not be copied onto any Google
     * Cloud Platform Storage-Buckets.
     * 
     * @see Builder#BACKUP_TAR_FILE_GCS_DIR
     */
    public String BACKUP_TAR_FILE_GCS_DIR = null;

    /**
     * This optional configuration field is optional, and may be used to move / relocate the
     * {@code '.jar'} File after it's built by this Build-Processor.  If there is a diretory or
     * location on the File-System into which the {@code '.jar'} should be moved, then provide that
     * directory's name here.
     * 
     * <BR /><BR />When this field is left null, it will be silently ignored; furthermore, the
     * {@code '.jar'} File which the Build-Processor creates will be left in the Current Working
     * Directory.
     */
    public String JAR_FILE_MOVE_DIR = null;

    /**
     * The directory location where log information will be saved.  This configuration field may
     * not be null, or a {@code NullPointerException} will throw.
     */
    public String LOG_DIR = null;

    /**
     * The <B>Stage 3</B> {@link Upgrade} instance to invoke.  This parameter-field configuration
     * may not be null, or a {@code NullPointerException} will throw.
     */
    public Upgrade upgrader = null;

    /**
     * The script invoked <B STYLE='color: red'><I>before</I></B> the <B>Stage 3</B> call to
     * {@link Upgrade}.  This configuration may be assigned null, and in such cases, no script will
     * be invoked before the upgrader runs.
     * 
     * @see Builder#preUpgraderScript
     */
    public UpgradeProcessor preUpgraderScript = null;

    /**
     * The script invoked <B STYLE='color: red'><I>after</I></B> the <B>Stage 3</B> call to
     * {@link Upgrade}.  This configuration may be assigned null, and in such cases, no script will
     * be invoked before the upgrader runs.
     * 
     * @see Builder#postUpgraderScript
     */
    public UpgradeProcessor postUpgraderScript = null;

    /**
     * For Stage 1, the Java-Compiler Stage, this Configuration-Field may be assigned any
     * switch-{@code String's}, and they will be passed to the {@code javac} invocation.
     * 
     * <BR /><BR />This field's value may be left null, or assigned a zero-length 
     * {@code String[]}-Array and, in both cases, it shall be ignored.
     * 
     * @see Builder#extraSwitchesJAVAC
     */
    public String[] extraSwitchesJAVAC = null;

    /**
     * For Stage 2, the {@code javadoc} Stage, this Configuration-Field may be assigned any
     * switch-{@code String's}, and they will be passed to the {@code javadoc} invocation.
     * 
     * <BR /><BR />This field's value may be left or null, or assigned a zero-length 
     * {@code String[]}-Array, and, in both cases, it shall be ignored.
     * 
     * @see Builder#extraSwitchesJAVADOC
     */
    public String[] extraSwitchesJAVADOC = null;

    /**
     * The list of Java Packages to compile.  This list may be neither empty nor null, or an
     * exception will throw.
     * 
     * @see Builder#packageList
     */
    public BuildPackage[] packageList = null;

    /**
     * The Root Class-File Directories to use with {@code 'javac'}.  This is used to generate the
     * value passed to the {@code -cp} switch passed when <B>Stage 1</B> invokes the Java-Compiler.
     * This parameter / field may be empty or null, and if it is, it will be ignored.
     */
    public String[] CLASS_PATH = null;

    /**
     * This allows for specifying a list of files to manually add into the {@code '.jar'} that is
     * built by this package.
     * 
     * <BR /><BR /><B CLASS=JDDescLabel>Constructor Call:</B>
     * 
     * <BR />Because it isn't necessary to include any "Extra Files" into the {@code '.jar'}, there
     * is some likelihood that this Configuration-Field wouldn't ever be needed / used.  Make sure
     * to call the {@link JarInclude} constructor, first, to build an instance of this Config-Field
     * before attempting to use it.  Notice that it is initially initialized to null!
     * 
     * <BR /><BR /><B CLASS=JDDescLabel>Common Usess:</B>
     * 
     * <BR />Java-HTML has quite a few Data-Files that are inserted into the Jar-File, manually,
     * using this class.  There may also be the need to insert {@code META-INF/} directory files
     * that name things like Annotation-Processor locations, taglets, or other Java Services.
     * 
     * @see Builder#jarIncludes
     */
    public JarInclude jarIncludes = null;

    /**
     * Requests that when {@code 'javac'} is invoked, the switch {@code -Xlint:all,-processing} is
     * included in the command-line invocation.
     * 
     * @see Builder#USE_XLINT_SWITCH
     */
    public boolean USE_XLINT_SWITCH = true;

    /**
     * Requests that when {@code 'javac'} is invoked, the switch {@code -Xdiags:verbose} is
     * included in the command-line invocation.
     * 
     * @see Builder#USE_XDIAGS_SWITCH
     */
    public boolean USE_XDIAGS_SWITCH = true;

    /**
     * JavaDoc Frames were a true majesty that should never have been eliminated.  If you would
     * prefer to remove them, or you are using JDK 21+ which no longer accepts the {@code --frames}
     * switch, then set this Configuration-Field to {@code FALSE}.
     * 
     * @see Builder#NO_JAVADOC_FRAMES_SWITCH
     */
    public boolean NO_JAVADOC_FRAMES_SWITCH = false;


    // ********************************************************************************************
    // ********************************************************************************************
    // Configuration Instance Fields
    // ********************************************************************************************
    // ********************************************************************************************


    /**
     * Creates an instance of this class, with all default values assigned to the parameter /
     * fields.
     * 
     * <BR /><BR />The intention is that an instance of this class will have its
     * Configuration-Fields property assigned, according to the needs of the Project being built.
     * Afterwards, the {@code 'Config'} instance may be passed to the {@code 'Builder'}-Constructor
     * and then that instance may be used to build the project.
     * 
     * @see Builder#Builder(Config, String...)
     * @see Builder#build()
     */
    public Config() { }


    // ********************************************************************************************
    // ********************************************************************************************
    // Configuration Instance Fields
    // ********************************************************************************************
    // ********************************************************************************************


    /**
     * Used by class {@link Builder} to validate all user-provided data on a best efforts basis.
     * 
     * @throws NullPointerException If any of the configuration parameter/fields listed here have
     * been assigned null
     * 
     * <BR /><UL CLASS=JDUL>
     * <LI>{@link #LOCAL_JAVADOC_DIR}</LI>
     * <LI>{@link #PROJECT_NAME}</LI>
     * <LI>{@link #JAVAC_BIN}</LI>
     * <LI>{@link #JAVADOC_BIN}</LI>
     * <LI>{@link #TAR_SOURCE_DIR}</LI>
     * <LI>{@link #LOG_DIR}</LI>
     * <LI>{@link #upgrader}</LI>
     * <LI>{@link #packageList}</LI>
     * </UL>
     * 
     * <BR />This exception will also be thrown if these lists contain any null-valued
     * entries:
     * <BR /><UL CLASS=JDUL>
     * <LI>{@link #packageList}</LI>
     * <LI>{@link #CLASS_PATH}</LI>
     * </UL>
     * 
     * @throws IllegalArgumentException If any of these configuration fields were assigned a 
     * negative number:
     * <BR /><UL CLASS=JDUL>
     * <LI>{@link VERSION_MAJOR_NUMBER}</LI>
     * <LI>{@link VERSION_MINOR_NUMBER}</LI>
     * <LI>{@link JAVADOC_VER}</LI>
     * </UL>
     * 
     * <BR />This exception will also be thrown if:
     * <BR /><UL CLASS=JDUL>
     * <LI> {@link #PROJECT_NAME} does not pass the {@link #projectNameValidator} test.</LI>
     * </UL>
     * 
     * @throws FileNotFoundException This exception will throw if either of these fields are not
     * assigned a valid File-System Directory-Name:
     * <BR /><UL CLASS=JDUL>
     * <LI> {@link #FAVICON}</LI>
     * <LI> {@link #TAR_SOURCE_DIR}</LI>
     * </UL>
     * 
     * @throws UnrecognizedImageExtException If the {@link #FAVICON} Image-Format cannot be 
     * properly "guessed" by class {@link IF}.
     * 
     * @throws EmptyListException If {@link #packageList} has been assigned an empty list.
     * 
     * @throws WriteableDirectoryException If parameter {@link #JAR_FILE_MOVE_DIR} is assigned a 
     * non-null value, but the {@code String} assigned it does not point to a File-System
     * directory, or that directory is not writeable.
     * 
     * <BR /><BR />Also throws if {@link #LOG_DIR} is not a valid directory-name, that allows
     * write-access.
     */
    public final void validate() throws java.io.FileNotFoundException
    {
        Objects.requireNonNull(LOCAL_JAVADOC_DIR,   M1 + "LOCAL_JAVADOC_DIR" + M2);
        Objects.requireNonNull(PROJECT_NAME,        M1 + "PROJECT_NAME" + M2);
        Objects.requireNonNull(JAVAC_BIN,           M1 + "JAVAC_BIN" + M2);
        Objects.requireNonNull(JAVADOC_BIN,         M1 + "JAVADOC_BIN" + M2);
        Objects.requireNonNull(TAR_SOURCE_DIR,      M1 + "TAR_SOURCE_DIR" + M2);
        Objects.requireNonNull(LOG_DIR,             M1 + "LOG_DIR" + M2);
        Objects.requireNonNull(upgrader,            M1 + "upgrader" + M2);
        Objects.requireNonNull(packageList,         M1 + "packageList" + M2);

        if (! projectNameValidator.test(PROJECT_NAME)) throw new IllegalArgumentException
            (M1 + "PROJECT_NAME] was not passed a valid name.");

        if (VERSION_MAJOR_NUMBER < 0) throw new IllegalArgumentException
            (M1 + "VERSION_MAJOR_NUMBER" + M3 + VERSION_MAJOR_NUMBER);

        if (VERSION_MINOR_NUMBER < 0) throw new IllegalArgumentException
            (M1 + "VERSION_MINOR_NUMBER" + M3 + VERSION_MINOR_NUMBER);

        if (JAVADOC_VER < 0) throw new IllegalArgumentException
            (M1 + "JAVADOC_VER" + M3 + JAVADOC_VER);

        if (FAVICON != null)
        {
            File f = new File(FAVICON);

            if ((! f.exists()) || (! f.isFile())) throw new FileNotFoundException(
                "Field 'FAVICON' [" + FAVICON + "] points to a file that was not found, or " +
                "isn't a File"
            );

            IF.guessOrThrow(FAVICON);
        }

        if (packageList.length == 0) throw new EmptyListException
            (M1 + "packageList] was passed a list of size 0.");

        for (BuildPackage bp : packageList) if (bp == null) throw new NullPointerException
            (M1 + "packageList] contains a null value.");

        for (String p : CLASS_PATH) if (p == null) throw new NullPointerException
            (M1 + "CLASS_PATH] contains a null value.");

        File f = new File(TAR_SOURCE_DIR);
        if (! (f.exists() && f.isDirectory())) throw new FileNotFoundException
            (M1 + "] was not passed a vaild File-System Directory-Name.");

        if (JAR_FILE_MOVE_DIR != null)
        {
            WritableDirectoryException.check(JAR_FILE_MOVE_DIR);

            if (! JAR_FILE_MOVE_DIR.endsWith(File.separator))
                JAR_FILE_MOVE_DIR = JAR_FILE_MOVE_DIR + File.separator;
        }

        WritableDirectoryException.check(LOG_DIR);

        if (! LOG_DIR.endsWith(File.separator)) LOG_DIR = LOG_DIR + File.separator;
    }

    private static final String M1 = "The Parameter-Field Configuration [";
    private static final String M2 = "] was ultimately assigned null.";
    private static final String M3 = "] was passed a negative number: ";

    final String classPathStr(boolean INCLUDE_JAR_IN_CP, String JAR_FILE_NAME)
    {
        if (CLASS_PATH == null) return INCLUDE_JAR_IN_CP ? JAR_FILE_NAME : null;

        final String sep = StrCmpr.containsIgnoreCase(System.getProperty("os.name"), "win")
            ? ";"
            : ":";

        final StringBuilder sb  = new StringBuilder();

        for (int i=0; i < CLASS_PATH.length; i++) sb.append(((i==0) ? "" : sep) + CLASS_PATH[i]);

        if (INCLUDE_JAR_IN_CP) sb.append(sep + JAR_FILE_NAME);

        return sb.toString();
    }
}