/**
 * Copyright (C) 2022 Adrien Hopkins
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
package sevenUnits.utils;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static sevenUnits.utils.SemanticVersionNumber.BUILD_METADATA_COMPARATOR;
import static sevenUnits.utils.SemanticVersionNumber.builder;
import static sevenUnits.utils.SemanticVersionNumber.fromString;
import static sevenUnits.utils.SemanticVersionNumber.isValidVersionString;
import static sevenUnits.utils.SemanticVersionNumber.preRelease;
import static sevenUnits.utils.SemanticVersionNumber.stableVersion;

import java.util.List;

import org.junit.jupiter.api.Test;

/**
 * Tests for {@link SemanticVersionNumber}
 *
 * @since 2022-02-19
 */
public final class SemanticVersionTest {
	/**
	 * Test for {@link SemanticVersionNumber#compatible}
	 * 
	 * @since 2022-02-20
	 */
	@Test
	public void testCompatibility() {
		assertTrue(stableVersion(1, 0, 0).compatibleWith(stableVersion(1, 0, 5)),
				"1.0.0 not compatible with 1.0.5");
		assertTrue(stableVersion(1, 3, 1).compatibleWith(stableVersion(1, 4, 0)),
				"1.3.1 not compatible with 1.4.0");
		
		// 0.y.z should not be compatible with any other version
		assertFalse(stableVersion(0, 4, 0).compatibleWith(stableVersion(0, 4, 1)),
				"0.4.0 compatible with 0.4.1 (0.y.z versions should be treated as unstable/incompatbile)");
		
		// upgrading major version should = incompatible
		assertFalse(stableVersion(1, 0, 0).compatibleWith(stableVersion(2, 0, 0)),
				"1.0.0 compatible with 2.0.0");
		
		// dowgrade should = incompatible
		assertFalse(stableVersion(1, 1, 0).compatibleWith(stableVersion(1, 0, 0)),
				"1.1.0 compatible with 1.0.0");
	}
	
	/**
	 * Tests {@link SemanticVersionNumber#toString} for complex version numbers
	 * 
	 * @since 2022-02-19
	 */
	@Test
	public void testComplexToString() {
		final SemanticVersionNumber v1 = builder(1, 2, 3).preRelease(1, 2, 3)
				.build();
		assertEquals("1.2.3-1.2.3", v1.toString());
		final SemanticVersionNumber v2 = builder(4, 5, 6).preRelease("abc", 123)
				.buildMetadata("2022-02-19").build();
		assertEquals("4.5.6-abc.123+2022-02-19", v2.toString());
		final SemanticVersionNumber v3 = builder(1, 0, 0)
				.preRelease("x-y-z", "--").build();
		assertEquals("1.0.0-x-y-z.--", v3.toString());
	}
	
	/**
	 * Tests that complex version can be created and their parts read
	 * 
	 * @since 2022-02-19
	 */
	@Test
	public void testComplexVersions() {
		final SemanticVersionNumber v1 = builder(1, 2, 3).preRelease(1, 2, 3)
				.build();
		assertEquals(1, v1.majorVersion());
		assertEquals(2, v1.minorVersion());
		assertEquals(3, v1.patchVersion());
		assertEquals(List.of("1", "2", "3"), v1.preReleaseIdentifiers());
		assertEquals(List.of(), v1.buildMetadata());
		
		final SemanticVersionNumber v2 = builder(4, 5, 6).preRelease("abc", 123)
				.buildMetadata("2022-02-19").build();
		assertEquals(4, v2.majorVersion());
		assertEquals(5, v2.minorVersion());
		assertEquals(6, v2.patchVersion());
		assertEquals(List.of("abc", "123"), v2.preReleaseIdentifiers());
		assertEquals(List.of("2022-02-19"), v2.buildMetadata());
		
		final SemanticVersionNumber v3 = builder(1, 0, 0)
				.preRelease("x-y-z", "--").build();
		assertEquals(1, v3.majorVersion());
		assertEquals(0, v3.minorVersion());
		assertEquals(0, v3.patchVersion());
		assertEquals(List.of("x-y-z", "--"), v3.preReleaseIdentifiers());
		assertEquals(List.of(), v3.buildMetadata());
	}
	
	/**
	 * Test that semantic version strings can be parsed correctly
	 * 
	 * @since 2022-02-19
	 * @see SemanticVersionNumber#fromString
	 * @see SemanticVersionNumber#isValidVersionString
	 */
	@Test
	public void testFromString() {
		// test that the regex can match version strings
		assertTrue(isValidVersionString("1.0.0"), "1.0.0 is treated as invalid");
		assertTrue(isValidVersionString("1.3.9"), "1.3.9 is treated as invalid");
		assertTrue(isValidVersionString("2.0.0-a.1"),
				"2.0.0-a.1 is treated as invalid");
		assertTrue(isValidVersionString("1.0.0-a.b.c.d"),
				"1.0.0-a.b.c.d is treated as invalid");
		assertTrue(isValidVersionString("1.0.0+abc"),
				"1.0.0+abc is treated as invalid");
		assertTrue(isValidVersionString("1.0.0-abc+def"),
				"1.0.0-abc+def is treated as invalid");
		
		// test that invalid versions don't match
		assertFalse(isValidVersionString("1.0"),
				"1.0 is treated as valid (patch should be required)");
		assertFalse(isValidVersionString("1.A.0"),
				"1.A.0 is treated as valid (main versions must be numbers)");
		assertFalse(isValidVersionString("1.0.0-"),
				"1.0.0- is treated as valid (pre-release must not be empty)");
		assertFalse(isValidVersionString("1.0.0+"),
				"1.0.0+ is treated as valid (build metadata must not be empty)");
		
		// test that versions can be parsed
		assertEquals(stableVersion(1, 0, 0), fromString("1.0.0"),
				"Could not parse 1.0.0");
		assertEquals(
				builder(1, 2, 3).preRelease("abc", "56", "def")
						.buildMetadata("2022abc99").build(),
				fromString("1.2.3-abc.56.def+2022abc99"),
				"Could not parse 1.2.3-abc.56.def+2022abc99");
	}
	
	/**
	 * Ensures it is impossible to create invalid version numbers
	 */
	@Test
	public void testInvalidVersionNumbers() {
		// stableVersion()
		assertThrows(IllegalArgumentException.class,
				() -> stableVersion(1, 0, -1),
				"Negative patch tolerated by stableVersion");
		assertThrows(IllegalArgumentException.class,
				() -> stableVersion(1, -2, 1),
				"Negative minor version number tolerated by stableVersion");
		assertThrows(IllegalArgumentException.class,
				() -> stableVersion(-3, 0, 7),
				"Negative major version number tolerated by stableVersion");
		
		// preRelease()
		assertThrows(IllegalArgumentException.class,
				() -> preRelease(1, 0, -1, "test", 2),
				"Negative patch tolerated by preRelease");
		assertThrows(IllegalArgumentException.class,
				() -> preRelease(1, -2, 1, "test", 2),
				"Negative minor version number tolerated by preRelease");
		assertThrows(IllegalArgumentException.class,
				() -> preRelease(-3, 0, 7, "test", 2),
				"Negative major version number tolerated by preRelease");
		assertThrows(IllegalArgumentException.class,
				() -> preRelease(1, 0, 0, "test", -1),
				"Negative pre release number tolerated by preRelease");
		assertThrows(NullPointerException.class,
				() -> preRelease(1, 0, 0, null, 1), "Null tolerated by preRelease");
		assertThrows(IllegalArgumentException.class,
				() -> preRelease(1, 0, 0, "", 1),
				"Empty string tolerated by preRelease");
		assertThrows(IllegalArgumentException.class,
				() -> preRelease(1, 0, 0, "abc+cde", 1),
				"Invalid string tolerated by preRelease");
		
		// builder()
		assertThrows(IllegalArgumentException.class, () -> builder(1, 0, -1),
				"Negative patch tolerated by builder");
		assertThrows(IllegalArgumentException.class, () -> builder(1, -2, 1),
				"Negative minor version number tolerated by builder");
		assertThrows(IllegalArgumentException.class, () -> builder(-3, 0, 7),
				"Negative major version number tolerated by builder");
		
		final SemanticVersionNumber.Builder testBuilder = builder(1, 2, 3);
		// note: builder.buildMetadata(null) doesn't even compile lol
		// builder.buildMetadata
		assertThrows(NullPointerException.class,
				() -> testBuilder.buildMetadata(null, "abc"),
				"Null tolerated by builder.buildMetadata(String...)");
		assertThrows(IllegalArgumentException.class,
				() -> testBuilder.buildMetadata(""),
				"Empty string tolerated by builder.buildMetadata(String...)");
		assertThrows(IllegalArgumentException.class,
				() -> testBuilder.buildMetadata("c%4"),
				"Invalid string tolerated by builder.buildMetadata(String...)");
		assertThrows(NullPointerException.class,
				() -> testBuilder.buildMetadata(List.of("abc", null)),
				"Null tolerated by builder.buildMetadata(List<String>)");
		assertThrows(IllegalArgumentException.class,
				() -> testBuilder.buildMetadata(List.of("")),
				"Empty string tolerated by builder.buildMetadata(List<String>)");
		assertThrows(IllegalArgumentException.class,
				() -> testBuilder.buildMetadata(List.of("")),
				"Invalid string tolerated by builder.buildMetadata(List<String>)");
		
		// builder.preRelease
		assertThrows(NullPointerException.class,
				() -> testBuilder.preRelease(null, "abc"),
				"Null tolerated by builder.preRelease(String...)");
		assertThrows(IllegalArgumentException.class,
				() -> testBuilder.preRelease(""),
				"Empty string tolerated by builder.preRelease(String...)");
		assertThrows(IllegalArgumentException.class,
				() -> testBuilder.preRelease("c%4"),
				"Invalid string tolerated by builder.preRelease(String...)");
		assertThrows(NullPointerException.class,
				() -> testBuilder.preRelease(List.of("abc", null)),
				"Null tolerated by builder.preRelease(List<String>)");
		assertThrows(IllegalArgumentException.class,
				() -> testBuilder.preRelease(List.of("")),
				"Empty string tolerated by builder.preRelease(List<String>)");
		assertThrows(IllegalArgumentException.class,
				() -> testBuilder.preRelease(List.of("")),
				"Invalid string tolerated by builder.preRelease(List<String>)");
		
		// the overloadings that accept numeric arguments
		assertThrows(IllegalArgumentException.class,
				() -> testBuilder.preRelease(-1),
				"Negative number tolerated by builder.preRelease(int...)");
		assertThrows(IllegalArgumentException.class,
				() -> testBuilder.preRelease("abc", -1),
				"Negative number tolerated by builder.preRelease(String, int)");
		assertThrows(NullPointerException.class,
				() -> testBuilder.preRelease(null, 1),
				"Null tolerated by builder.preRelease(String, int)");
		assertThrows(IllegalArgumentException.class,
				() -> testBuilder.preRelease("", 1),
				"Empty string tolerated by builder.preRelease(String, int)");
		assertThrows(IllegalArgumentException.class,
				() -> testBuilder.preRelease("#$#c", 1),
				"Invalid string tolerated by builder.preRelease(String, int)");
		
		// ensure all these attempts didn't change the builder
		assertEquals(builder(1, 2, 3), testBuilder,
				"Attempts at making invalid version number succeeded despite throwing errors");
	}
	
	/**
	 * Test for {@link SemanticVersionNumber#isStable}
	 * 
	 * @since 2022-02-19
	 */
	@Test
	public void testIsStable() {
		assertTrue(stableVersion(1, 0, 0).isStable(),
				"1.0.0 should be stable but is not");
		assertFalse(stableVersion(0, 1, 2).isStable(),
				"0.1.2 should not be stable but is");
		assertFalse(preRelease(1, 2, 3, "alpha", 5).isStable(),
				"1.2.3a5 should not be stable but is");
		assertTrue(
				builder(9, 9, 99)
						.buildMetadata("lots-of-metadata", "abc123", "2022").build()
						.isStable(),
				"9.9.99+lots-of-metadata.abc123.2022 should be stable but is not");
	}
	
	/**
	 * Tests that the versions are ordered by
	 * {@link SemanticVersionNumber#compareTo} according to official rules. Tests
	 * all of the versions compared in section 11 of the SemVer 2.0.0 document
	 * and some more.
	 * 
	 * @since 2022-02-19
	 */
	@Test
	public void testOrder() {
		final SemanticVersionNumber v100a = builder(1, 0, 0).preRelease("alpha")
				.build(); // 1.0.0-alpha
		final SemanticVersionNumber v100a1 = preRelease(1, 0, 0, "alpha", 1); // 1.0.0-alpha.1
		final SemanticVersionNumber v100ab = builder(1, 0, 0)
				.preRelease("alpha", "beta").build(); // 1.0.0-alpha.beta
		final SemanticVersionNumber v100b = builder(1, 0, 0).preRelease("beta")
				.build(); // 1.0.0-alpha
		final SemanticVersionNumber v100b2 = preRelease(1, 0, 0, "beta", 2); // 1.0.0-beta.2
		final SemanticVersionNumber v100b11 = preRelease(1, 0, 0, "beta", 11); // 1.0.0-beta.11
		final SemanticVersionNumber v100rc1 = preRelease(1, 0, 0, "rc", 1); // 1.0.0-rc.1
		final SemanticVersionNumber v100 = stableVersion(1, 0, 0);
		final SemanticVersionNumber v100plus = builder(1, 0, 0)
				.buildMetadata("blah", "blah", "blah").build(); // 1.0.0+blah.blah.blah
		final SemanticVersionNumber v200 = stableVersion(2, 0, 0);
		final SemanticVersionNumber v201 = stableVersion(2, 0, 1);
		final SemanticVersionNumber v210 = stableVersion(2, 1, 0);
		final SemanticVersionNumber v211 = stableVersion(2, 1, 1);
		final SemanticVersionNumber v300 = stableVersion(3, 0, 0);
		
		// test order of version numbers
		assertTrue(v100a.compareTo(v100a1) < 0, "1.0.0-alpha >= 1.0.0-alpha.1");
		assertTrue(v100a1.compareTo(v100ab) < 0,
				"1.0.0-alpha.1 >= 1.0.0-alpha.beta");
		assertTrue(v100ab.compareTo(v100b) < 0, "1.0.0-alpha.beta >= 1.0.0-beta");
		assertTrue(v100b.compareTo(v100b2) < 0, "1.0.0-beta >= 1.0.0-beta.2");
		assertTrue(v100b2.compareTo(v100b11) < 0,
				"1.0.0-beta.2 >= 1.0.0-beta.11");
		assertTrue(v100b11.compareTo(v100rc1) < 0, "1.0.0-beta.11 >= 1.0.0-rc.1");
		assertTrue(v100rc1.compareTo(v100) < 0, "1.0.0-rc.1 >= 1.0.0");
		assertTrue(v100.compareTo(v200) < 0, "1.0.0 >= 2.0.0");
		assertTrue(v200.compareTo(v201) < 0, "2.0.0 >= 2.0.1");
		assertTrue(v201.compareTo(v210) < 0, "2.0.1 >= 2.1.0");
		assertTrue(v210.compareTo(v211) < 0, "2.1.0 >= 2.1.1");
		assertTrue(v211.compareTo(v300) < 0, "2.1.1 >= 3.0.0");
		
		// test symmetry - assume previous tests passed
		assertTrue(v100a1.compareTo(v100a) > 0, "1.0.0-alpha.1 <= 1.0.0-alpha");
		assertTrue(v100.compareTo(v100rc1) > 0, "1.0.0 <= 1.0.0-rc.1");
		assertTrue(v300.compareTo(v211) > 0, "3.0.0 <= 2.1.1");
		
		// test transitivity
		assertTrue(v100a.compareTo(v100b11) < 0, "1.0.0-alpha >= 1.0.0-beta.11");
		assertTrue(v100b.compareTo(v200) < 0, "1.0.0-beta >= 2.0.0");
		assertTrue(v100.compareTo(v300) < 0, "1.0.0 >= 3.0.0");
		assertTrue(v100a.compareTo(v300) < 0, "1.0.0-alpha >= 3.0.0");
		
		// test metadata is ignored
		assertEquals(0, v100.compareTo(v100plus), "Build metadata not ignored");
		// test metadata is NOT ignored by alternative comparator
		assertTrue(BUILD_METADATA_COMPARATOR.compare(v100, v100plus) > 0,
				"Build metadata ignored by BUILD_METADATA_COMPARATOR");
	}
	
	/**
	 * Tests that simple stable versions can be created and their parts read
	 * 
	 * @since 2022-02-19
	 */
	@Test
	public void testSimpleStableVersions() {
		final SemanticVersionNumber v100 = stableVersion(1, 0, 0);
		assertEquals(1, v100.majorVersion());
		assertEquals(0, v100.minorVersion());
		assertEquals(0, v100.patchVersion());
		
		final SemanticVersionNumber v925 = stableVersion(9, 2, 5);
		assertEquals(9, v925.majorVersion());
		assertEquals(2, v925.minorVersion());
		assertEquals(5, v925.patchVersion());
	}
	
	/**
	 * Tests that {@link SemanticVersionNumber#toString} works for simple version
	 * numbers
	 * 
	 * @since 2022-02-19
	 */
	@Test
	public void testSimpleToString() {
		final SemanticVersionNumber v100 = stableVersion(1, 0, 0);
		assertEquals("1.0.0", v100.toString());
		
		final SemanticVersionNumber v845a1 = preRelease(8, 4, 5, "alpha", 1);
		assertEquals("8.4.5-alpha.1", v845a1.toString());
	}
	
	/**
	 * Tests that simple unstable versions can be created and their parts read
	 * 
	 * @since 2022-02-19
	 */
	@Test
	public void testSimpleUnstableVersions() {
		final SemanticVersionNumber v350a1 = preRelease(3, 5, 0, "alpha", 1);
		assertEquals(3, v350a1.majorVersion(),
				"Incorrect major version for v3.5.0a1");
		assertEquals(5, v350a1.minorVersion(),
				"Incorrect minor version for v3.5.0a1");
		assertEquals(0, v350a1.patchVersion(),
				"Incorrect patch version for v3.5.0a1");
		assertEquals(List.of("alpha", "1"), v350a1.preReleaseIdentifiers(),
				"Incorrect pre-release identifiers for v3.5.0a1");
	}
}