// Copyright (c) 2019, the R8 project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
package com.android.tools.r8.ir.optimize.string;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;

import com.android.tools.r8.TestParameters;
import com.android.tools.r8.TestParametersCollection;
import com.android.tools.r8.graph.AppView;
import com.android.tools.r8.ir.analysis.AnalysisTestBase;
import com.android.tools.r8.ir.code.IRCode;
import com.android.tools.r8.ir.code.Instruction;
import com.android.tools.r8.ir.code.InvokeMethod;
import com.android.tools.r8.ir.code.Value;
import com.android.tools.r8.ir.optimize.string.StringBuilderOptimizer.BuilderState;
import com.android.tools.r8.utils.AndroidApiLevel;
import com.android.tools.r8.utils.InternalOptions;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.function.Consumer;
import org.junit.Ignore;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;

@RunWith(Parameterized.class)
public class StringBuilderOptimizerAnalysisTest extends AnalysisTestBase {

  @Parameterized.Parameters(name = "{0}")
  public static TestParametersCollection data() {
    return getTestParameters().withDexRuntimes().withAllApiLevels().build();
  }

  public StringBuilderOptimizerAnalysisTest(TestParameters parameters) throws Exception {
    super(
        parameters,
        StringConcatenationTestClass.class.getTypeName(),
        StringConcatenationTestClass.class);
  }

  @Override
  public void configure(InternalOptions options) {}

  @Test
  public void testUnusedBuilder() {
    buildAndCheckIR(
        "unusedBuilder",
        code -> assertTrue(code.streamInstructions().allMatch(Instruction::isReturn)));
  }

  @Test
  public void testTrivialSequence() {
    buildAndCheckIR(
        "trivialSequence",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(1, optimizer.analysis.builderStates.size());
          for (Value builder : optimizer.analysis.builderStates.keySet()) {
            Map<Instruction, BuilderState> perBuilderState =
                optimizer.analysis.builderStates.get(builder);
            checkBuilderState(optimizer, perBuilderState, "xyz", true);
          }
          assertEquals(1, optimizer.analysis.simplifiedBuilders.size());
        }));
  }

  @Test
  public void testBuilderWithInitialValue() {
    buildAndCheckIR(
        "builderWithInitialValue",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(1, optimizer.analysis.builderStates.size());
          for (Value builder : optimizer.analysis.builderStates.keySet()) {
            Map<Instruction, BuilderState> perBuilderState =
                optimizer.analysis.builderStates.get(builder);
            checkBuilderState(optimizer, perBuilderState, "Hello,R8", true);
          }
          assertEquals(1, optimizer.analysis.simplifiedBuilders.size());
        }));
  }

  @Test
  public void testBuilderWithCapacity() {
    buildAndCheckIR(
        "builderWithCapacity",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(1, optimizer.analysis.builderStates.size());
          for (Value builder : optimizer.analysis.builderStates.keySet()) {
            Map<Instruction, BuilderState> perBuilderState =
                optimizer.analysis.builderStates.get(builder);
            checkBuilderState(optimizer, perBuilderState, "42", true);
          }
          assertEquals(1, optimizer.analysis.simplifiedBuilders.size());
        }));
  }

  @Test
  public void testNonStringArgs() {
    buildAndCheckIR(
        "nonStringArgs",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(1, optimizer.analysis.builderStates.size());
          for (Value builder : optimizer.analysis.builderStates.keySet()) {
            Map<Instruction, BuilderState> perBuilderState =
                optimizer.analysis.builderStates.get(builder);
            checkBuilderState(optimizer, perBuilderState, "42", true);
          }
          assertEquals(1, optimizer.analysis.simplifiedBuilders.size());
        }));
  }

  @Test
  public void testTypeConversion() {
    buildAndCheckIR(
        "typeConversion",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(1, optimizer.analysis.builderStates.size());
          for (Value builder : optimizer.analysis.builderStates.keySet()) {
            Map<Instruction, BuilderState> perBuilderState =
                optimizer.analysis.builderStates.get(builder);
            checkBuilderState(optimizer, perBuilderState, "0.14 0 false null", true);
          }
          assertEquals(1, optimizer.analysis.simplifiedBuilders.size());
        }));
  }

  @Test
  public void testTypeConversion_withPhis() {
    buildAndCheckIR(
        "typeConversion_withPhis",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(1, optimizer.analysis.builderStates.size());
          for (Value builder : optimizer.analysis.builderStates.keySet()) {
            Map<Instruction, BuilderState> perBuilderState =
                optimizer.analysis.builderStates.get(builder);
            checkBuilderState(optimizer, perBuilderState, null, true);
          }
          assertEquals(0, optimizer.analysis.simplifiedBuilders.size());
        }));
  }

  @Ignore("TODO(b/113859361): passed to another builder should be an eligible case.")
  @Test
  public void testNestedBuilders_appendBuilderItself() {
    buildAndCheckIR(
        "nestedBuilders_appendBuilderItself",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(1, optimizer.analysis.builderStates.size());
          for (Value builder : optimizer.analysis.builderStates.keySet()) {
            Map<Instruction, BuilderState> perBuilderState =
                optimizer.analysis.builderStates.get(builder);
            checkBuilderState(optimizer, perBuilderState, "Hello,R8", true);
          }
          assertEquals(1, optimizer.analysis.simplifiedBuilders.size());
          // TODO(b/113859361): check # of merged builders.
          // assertEquals(2, optimizer.analysis.mergedBuilders.size());
        }));
  }

  @Ignore("TODO(b/113859361): merge builder.")
  @Test
  public void testNestedBuilders_appendBuilderResult() {
    buildAndCheckIR(
        "nestedBuilders_appendBuilderResult",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(1, optimizer.analysis.builderStates.size());
          for (Value builder : optimizer.analysis.builderStates.keySet()) {
            Map<Instruction, BuilderState> perBuilderState =
                optimizer.analysis.builderStates.get(builder);
            checkBuilderState(optimizer, perBuilderState, "Hello,R8", true);
          }
          assertEquals(1, optimizer.analysis.simplifiedBuilders.size());
          // TODO(b/113859361): check # of merged builders.
          // assertEquals(2, optimizer.analysis.mergedBuilders.size());
        }));
  }

  @Ignore("TODO(b/113859361): merge builder.")
  @Test
  public void testNestedBuilders_conditional() {
    buildAndCheckIR(
        "nestedBuilders_conditional",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(1, optimizer.analysis.builderStates.size());
          for (Value builder : optimizer.analysis.builderStates.keySet()) {
            Map<Instruction, BuilderState> perBuilderState =
                optimizer.analysis.builderStates.get(builder);
            checkBuilderState(optimizer, perBuilderState, null, true);
          }
          assertEquals(0, optimizer.analysis.simplifiedBuilders.size());
          // TODO(b/113859361): check # of merged builders.
          // assertEquals(3, optimizer.analysis.mergedBuilders.size());
        }));
  }

  @Ignore("TODO(b/113859361): merge builder.")
  @Test
  public void testConcatenatedBuilders_init() {
    buildAndCheckIR(
        "concatenatedBuilders_init",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(1, optimizer.analysis.builderStates.size());
          for (Value builder : optimizer.analysis.builderStates.keySet()) {
            Map<Instruction, BuilderState> perBuilderState =
                optimizer.analysis.builderStates.get(builder);
            checkBuilderState(optimizer, perBuilderState, "Hello,R8", true);
          }
          assertEquals(1, optimizer.analysis.simplifiedBuilders.size());
          // TODO(b/113859361): check # of merged builders.
          // assertEquals(2, optimizer.analysis.mergedBuilders.size());
        }));
  }

  @Ignore("TODO(b/113859361): merge builder.")
  @Test
  public void testConcatenatedBuilders_append() {
    buildAndCheckIR(
        "concatenatedBuilders_append",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(1, optimizer.analysis.builderStates.size());
          for (Value builder : optimizer.analysis.builderStates.keySet()) {
            Map<Instruction, BuilderState> perBuilderState =
                optimizer.analysis.builderStates.get(builder);
            checkBuilderState(optimizer, perBuilderState, "Hello,R8", true);
          }
          assertEquals(1, optimizer.analysis.simplifiedBuilders.size());
          // TODO(b/113859361): check # of merged builders.
          // assertEquals(2, optimizer.analysis.mergedBuilders.size());
        }));
  }

  @Ignore("TODO(b/113859361): merge builder.")
  @Test
  public void testConcatenatedBuilders_conditional() {
    final Set<String> expectedConstStrings = new HashSet<>();
    expectedConstStrings.add("Hello,R8");
    expectedConstStrings.add("D8");
    buildAndCheckIR(
        "concatenatedBuilders_conditional",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(2, optimizer.analysis.builderStates.size());
          for (Value builder : optimizer.analysis.builderStates.keySet()) {
            Map<Instruction, BuilderState> perBuilderState =
                optimizer.analysis.builderStates.get(builder);
            checkBuilderStates(optimizer, perBuilderState, expectedConstStrings, true);
          }
          assertEquals(2, optimizer.analysis.simplifiedBuilders.size());
          // TODO(b/113859361): check # of merged builders.
          // assertEquals(2, optimizer.analysis.mergedBuilders.size());
        }));
  }

  @Test
  public void testSimplePhi() {
    buildAndCheckIR(
        "simplePhi",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(0, optimizer.analysis.builderStates.size());
          assertEquals(0, optimizer.analysis.simplifiedBuilders.size());
        }));
  }

  @Test
  public void testPhiAtInit() {
    int expectedNumOfNewBuilder = 0;
    boolean expectToMeetToString = false;
    if (parameters.isDexRuntime() && parameters.getApiLevel().isLessThan(AndroidApiLevel.M)) {
      expectedNumOfNewBuilder = 1;
      expectToMeetToString = true;
    }
    final int finalExpectedNumOfNewBuilder = expectedNumOfNewBuilder;
    final boolean finalExpectToMeetToString = expectToMeetToString;
    buildAndCheckIR(
        "phiAtInit",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(finalExpectedNumOfNewBuilder, optimizer.analysis.builderStates.size());
          for (Value builder : optimizer.analysis.builderStates.keySet()) {
            Map<Instruction, BuilderState> perBuilderState =
                optimizer.analysis.builderStates.get(builder);
            checkBuilderState(optimizer, perBuilderState, null, finalExpectToMeetToString);
          }
          assertEquals(0, optimizer.analysis.simplifiedBuilders.size());
        }));
  }

  @Test
  public void testPhiWithDifferentInits() {
    buildAndCheckIR(
        "phiWithDifferentInits",
        checkOptimizerStates(
            appView,
            optimizer -> {
              assertEquals(0, optimizer.analysis.builderStates.size());
              for (Value builder : optimizer.analysis.builderStates.keySet()) {
                Map<Instruction, BuilderState> perBuilderState =
                    optimizer.analysis.builderStates.get(builder);
                checkBuilderState(optimizer, perBuilderState, null, false);
              }
              assertEquals(0, optimizer.analysis.simplifiedBuilders.size());
            }));
  }

  @Test
  public void testConditionalPhiWithoutAppend() {
    buildAndCheckIR(
        "conditionalPhiWithoutAppend",
        checkOptimizerStates(
            appView,
            optimizer -> {
              assertEquals(1, optimizer.analysis.builderStates.size());
              for (Value builder : optimizer.analysis.builderStates.keySet()) {
                Map<Instruction, BuilderState> perBuilderState =
                    optimizer.analysis.builderStates.get(builder);
                checkBuilderState(optimizer, perBuilderState, "initial:suffix", true);
              }
              assertEquals(1, optimizer.analysis.simplifiedBuilders.size());
            }));
  }

  @Test
  public void testLoop() {
    buildAndCheckIR(
        "loop",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(2, optimizer.analysis.builderStates.size());
          for (Value builder : optimizer.analysis.builderStates.keySet()) {
            Map<Instruction, BuilderState> perBuilderState =
                optimizer.analysis.builderStates.get(builder);
            checkBuilderState(optimizer, perBuilderState, null, true);
          }
          assertEquals(0, optimizer.analysis.simplifiedBuilders.size());
        }));
  }

  @Test
  public void testLoopWithBuilder() {
    buildAndCheckIR(
        "loopWithBuilder",
        checkOptimizerStates(appView, optimizer -> {
          assertEquals(1, optimizer.analysis.builderStates.size());
          for (Value builder : optimizer.analysis.builderStates.keySet()) {
            Map<Instruction, BuilderState> perBuilderState =
                optimizer.analysis.builderStates.get(builder);
            checkBuilderState(optimizer, perBuilderState, null, true);
          }
          assertEquals(0, optimizer.analysis.simplifiedBuilders.size());
        }));
  }

  static Consumer<IRCode> checkOptimizerStates(
      AppView<?> appView, Consumer<StringBuilderOptimizer> optimizerConsumer) {
    return code -> {
      StringBuilderOptimizer optimizer = new StringBuilderOptimizer(appView);
      optimizer.computeTrivialStringConcatenation(code);
      optimizerConsumer.accept(optimizer);
    };
  }

  static void checkBuilderState(
      StringBuilderOptimizer optimizer,
      Map<Instruction, BuilderState> perBuilderState,
      String expectedConstString,
      boolean expectToSeeMethodToString) {
    boolean seenMethodToString = false;
    for (Map.Entry<Instruction, BuilderState> entry : perBuilderState.entrySet()) {
      InvokeMethod invoke = entry.getKey().asInvokeMethod();
      if (invoke != null
          && optimizer.optimizationConfiguration.isToStringMethod(invoke.getInvokedMethod())) {
        seenMethodToString = true;
        Value builder = invoke.getArgument(0).getAliasedValue();
        assertEquals(
            expectedConstString, optimizer.analysis.toCompileTimeString(builder, entry.getValue()));
      }
    }
    assertEquals(expectToSeeMethodToString, seenMethodToString);
  }

  static void checkBuilderStates(
      StringBuilderOptimizer optimizer,
      Map<Instruction, BuilderState> perBuilderState,
      Set<String> expectedConstStrings,
      boolean expectToSeeMethodToString) {
    boolean seenMethodToString = false;
    for (Map.Entry<Instruction, BuilderState> entry : perBuilderState.entrySet()) {
      InvokeMethod invoke = entry.getKey().asInvokeMethod();
      if (invoke != null
          && optimizer.optimizationConfiguration.isToStringMethod(invoke.getInvokedMethod())) {
        seenMethodToString = true;
        Value builder = invoke.getArgument(0).getAliasedValue();
        String computedString = optimizer.analysis.toCompileTimeString(builder, entry.getValue());
        assertNotNull(computedString);
        assertTrue(expectedConstStrings.contains(computedString));
        expectedConstStrings.remove(computedString);
      }
    }
    assertEquals(expectToSeeMethodToString, seenMethodToString);
  }
}