/* valaversionattribute.vala
 *
 * Copyright (C) 2013  Florian Brosch
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 *
 * Author:
 * 	Florian Brosch <flo.brosch@gmail.com>
 */

using GLib;


/**
 * Represents a [Version] attribute
 */
public class Vala.VersionAttribute {
	private weak Symbol symbol;

	private bool? _deprecated;
	private bool? _experimental;

	/**
	 * Constructs a new VersionAttribute.
	 *
	 * @param symbol the owner
	 * @return a new VersionAttribute
	 * @see Vala.Symbol
	 */
	public VersionAttribute (Symbol symbol) {
		this.symbol = symbol;
	}



	/**
	 * Specifies whether this symbol has been deprecated.
	 */
	public bool deprecated {
		get {
			if (_deprecated == null) {
				_deprecated = symbol.get_attribute_bool ("Version", "deprecated", false)
					|| symbol.get_attribute_string ("Version", "deprecated_since") != null
					|| symbol.get_attribute_string ("Version", "replacement") != null
					// [Deprecated] is deprecated
					|| symbol.get_attribute ("Deprecated") != null;
			}
			return _deprecated;
		}
		set {
			_deprecated = value;
			symbol.set_attribute_bool ("Version", "deprecated", _deprecated);
		}
	}

	/**
	 * Specifies what version this symbol has been deprecated since.
	 */
	public string? deprecated_since {
		owned get {
			return symbol.get_attribute_string ("Version", "deprecated_since")
				// [Deprecated] is deprecated
				?? symbol.get_attribute_string ("Deprecated", "since");
		}
		set {
			symbol.set_attribute_string ("Version", "deprecated_since", value);
		}
	}

	/**
	 * Specifies the replacement if this symbol has been deprecated.
	 */
	public string? replacement {
		owned get {
			return symbol.get_attribute_string ("Version", "replacement")
				// [Deprecated] is deprecated
				?? symbol.get_attribute_string ("Deprecated", "replacement");
		}
		set {
			symbol.set_attribute_string ("Version", "replacement", value);
		}
	}



	/**
	 * Specifies whether this symbol is experimental.
	 */
	public bool experimental {
		get {
			if (_experimental == null) {
				_experimental = symbol.get_attribute_bool ("Version", "experimental", false)
					|| symbol.get_attribute_string ("Version", "experimental_until") != null
					|| symbol.get_attribute ("Experimental") != null;
			}
			return _experimental;
		}
		set {
			_experimental = value;
			symbol.set_attribute_bool ("Version", "experimental", value);
		}
	}

	/**
	 * Specifies until which version this symbol is experimental.
	 */
	public string? experimental_until {
		owned get {
			return symbol.get_attribute_string ("Version", "experimental_until");
		}
		set {
			symbol.set_attribute_string ("Version", "experimental_until", value);
		}
	}



	/**
	 * The minimum version for {@link Vala.VersionAttribute.symbol}
	 */
	public string? since {
		owned get {
			return symbol.get_attribute_string ("Version", "since");
		}
		set {
			symbol.set_attribute_string ("Version", "since", value);
		}
	}



	/**
	 * Check to see if the symbol is experimental, deprecated or not available
	 * and emit a warning if it is.
	 */
	public bool check (CodeContext context, SourceReference? source_ref = null) {
		bool result = false;

		// deprecation:
		if (symbol.external_package && deprecated) {
			string? package_version = symbol.source_reference.file.installed_version;

			if (!context.deprecated && (package_version == null || deprecated_since == null || VersionAttribute.cmp_versions (package_version, deprecated_since) >= 0)) {
				Report.deprecated (source_ref, "`%s' %s%s", symbol.get_full_name (), (deprecated_since == null) ? "is deprecated" : "has been deprecated since %s".printf (deprecated_since), (replacement == null) ? "" : ". Use %s".printf (replacement));
			}
			result = true;
		}

		// availability:
		if (symbol.external_package && since != null) {
			string? package_version = symbol.source_reference.file.installed_version;

			if (context.since_check && package_version != null && VersionAttribute.cmp_versions (package_version, since) < 0) {
				unowned string filename = symbol.source_reference.file.filename;
				string pkg = Path.get_basename (filename[0:filename.last_index_of_char ('.')]);
				Report.error (source_ref, "`%s' is not available in %s %s. Use %s >= %s", symbol.get_full_name (), pkg, package_version, pkg, since);
			}
			result = true;
		}

		// experimental:
		if (symbol.external_package && experimental) {
			if (!context.experimental) {
				string? package_version = symbol.source_reference.file.installed_version;
				string? experimental_until = this.experimental_until;

				if (experimental_until == null || package_version == null || VersionAttribute.cmp_versions (package_version, experimental_until) < 0) {
					Report.experimental (source_ref, "`%s' is experimental%s", symbol.get_full_name (), (experimental_until != null) ? " until %s".printf (experimental_until) : "");
				}
			}
			result = true;
		}

		return result;
	}


	/**
	 * A simple version comparison function.
	 *
	 * @param v1str a version number
	 * @param v2str a version number
	 * @return an integer less than, equal to, or greater than zero, if v1str is <, == or > than v2str
	 * @see GLib.CompareFunc
	 */
	public static int cmp_versions (string v1str, string v2str) {
		string[] v1arr = v1str.split (".");
		string[] v2arr = v2str.split (".");
		int i = 0;

		while (v1arr[i] != null && v2arr[i] != null) {
			int v1num = int.parse (v1arr[i]);
			int v2num = int.parse (v2arr[i]);

			if (v1num < 0 || v2num < 0) {
				// invalid format
				return 0;
			}

			if (v1num > v2num) {
				return 1;
			}

			if (v1num < v2num) {
				return -1;
			}

			i++;
		}

		if (v1arr[i] != null && v2arr[i] == null) {
			return 1;
		}

		if (v1arr[i] == null && v2arr[i] != null) {
			return -1;
		}

		return 0;
	}
}