package net.consensys.pier.impl.ethereum.vm;

import java.io.File;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Stack;

import com.fasterxml.jackson.databind.ObjectMapper;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;

import static org.junit.Assert.assertArrayEquals;

/**
 * The VM operation testing framework entry point.
 */
@RunWith(Parameterized.class)
public class OperationTest {

  /**
   * The JSON test specification files to generate tests for.
   */
  private static String[] TEST_CONFIG_FILES = {
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/add.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/and0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/and1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/and2.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/addMod.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/addModZero.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/byte0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/byte1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/byte2.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/byte3.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/divide.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/divideZero.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/dup.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/eq0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/eq1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/exp0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/exp1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/exp2.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/exp3.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/exp4.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/gt0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/gt1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/gas.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/isZero0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/isZero1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/jump.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/jumpdest.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/jumpiDoJump.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/jumpiDoNotJump.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/lt0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/lt1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mloadAlignedExistent.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mloadAlignedNonexistent.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mloadUnalignedExistent.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mloadUnalignedNonexistent.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mloadUnalignedPartialExistent.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mod.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/modZero.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/msize0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/msize1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mstore8LSBExistent.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mstore8LSBNonexistent.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mstore8MSBExistent.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mstore8MSBNonexistent.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mstoreAlignedExistent.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mstoreAlignedNonexistent.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mstoreUnalignedExistent.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mstoreUnalignedNonexistent.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mstoreUnalignedPartialExistent.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mulMod0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mulMod1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/mulMod2.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/multiply.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/not0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/not1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/or0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/or1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/or2.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/pc0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/pc1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/pop.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/pushAllCases.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/sDivide0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/sDivide1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/sDivide2.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/signExtend0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/signExtend1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/signExtend2.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/signExtend3.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/signExtend4.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/signExtend5.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/signExtend6.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/sgt0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/sgt1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/sLt0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/sLt1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/sLt2.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/sLt3.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/sLt4.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/sLt5.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/sMod0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/sMod1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/sMod2.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/stop.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/subtract.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/swap.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/xor0.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/xor1.json",
    "src/test/resource/net/consensys/pier/impl/ethereum/vm/xor2.json"
  };

  /**
   * The test case name.
   */
  private final String name;

  /**
   * The test case specification.
   */
  private final OperationTestCaseSpec spec;

  /**
   * Returns a collection of parameter sets to execute operation tests.
   *
   * @return a collection of parameter sets to execute operation tests
   */
  @Parameters(name="Name: {0}")
  public static Collection<Object[]> getTestParametersForConfig() throws Exception {
    ObjectMapper mapper = new ObjectMapper();

    Collection<Object[]> testCaseSpecs = new ArrayList<Object[]>();

    for (String testConfigFile : TEST_CONFIG_FILES) {
      OperationTestSuiteSpec testSuiteSpec  = mapper.readValue(
          new File(testConfigFile), OperationTestSuiteSpec.class);

      testCaseSpecs.addAll(testSuiteSpec.getTestCaseSpecParameters());
    }

    return testCaseSpecs;
  }

  /**
   * Public constructor.
   *
   * @param name - the test name
   * @param spec - the test specification
   */
  public OperationTest(String name, OperationTestCaseSpec spec) {
    this.name = name;
    this.spec = spec;
  }

  /**
   * Run the test case.
   */
  @Test
  public void testExecution() {
    OperationTraceEntry initExecState = spec.getInitialExecutionState().clone();

    WorldState worldState = new WorldState();
    MachineState machState = new MachineState(initExecState.getGas(),
                                              initExecState.getPC(),
                                              initExecState.getMemory(),
                                              initExecState.getOperandStack());
    TransactionSubstate substate = new TransactionSubstate();
    EnvironmentInformation execEnv = new EnvironmentInformation(
      spec.getCode(), spec.getDepth());

    VM vm = new VM(worldState, machState, substate, execEnv);

    while (!vm.hasHalted()) {
      vm.step();
    }

    // the state must be updated somewhere, somehow between
    // there and here

    assertArrayEquals(spec.getExecutionTrace(), vm.getExecutionTrace());
  }

}