/* Copyright (C) 2017-2025 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.grails.datastore.gorm.transactions.transform

import java.lang.reflect.Modifier

import groovy.transform.CompileStatic
import org.codehaus.groovy.ast.AnnotatedNode
import org.codehaus.groovy.ast.AnnotationNode
import org.codehaus.groovy.ast.ClassNode
import org.codehaus.groovy.ast.FieldNode
import org.codehaus.groovy.ast.MethodNode
import org.codehaus.groovy.ast.Parameter
import org.codehaus.groovy.ast.expr.ClassExpression
import org.codehaus.groovy.ast.expr.ConstantExpression
import org.codehaus.groovy.ast.expr.Expression
import org.codehaus.groovy.ast.expr.ListExpression
import org.codehaus.groovy.ast.expr.MethodCallExpression
import org.codehaus.groovy.ast.expr.VariableExpression
import org.codehaus.groovy.ast.stmt.BlockStatement
import org.codehaus.groovy.ast.stmt.Statement
import org.codehaus.groovy.control.CompilePhase
import org.codehaus.groovy.control.SourceUnit
import org.codehaus.groovy.transform.GroovyASTTransformation

import org.springframework.transaction.PlatformTransactionManager
import org.springframework.transaction.TransactionStatus
import org.springframework.transaction.annotation.Propagation
import org.springframework.transaction.interceptor.NoRollbackRuleAttribute
import org.springframework.transaction.interceptor.RollbackRuleAttribute

import grails.gorm.transactions.GrailsTransactionTemplate
import grails.gorm.transactions.NotTransactional
import grails.gorm.transactions.ReadOnly
import grails.gorm.transactions.Rollback
import grails.gorm.transactions.Transactional
import org.apache.grails.common.compiler.GroovyTransformOrder
import org.grails.datastore.gorm.GormEnhancer
import org.grails.datastore.gorm.multitenancy.transform.TenantTransform
import org.grails.datastore.gorm.transform.AbstractDatastoreMethodDecoratingTransformation
import org.grails.datastore.mapping.core.connections.MultipleConnectionSourceCapableDatastore
import org.grails.datastore.mapping.multitenancy.MultiTenantCapableDatastore
import org.grails.datastore.mapping.transactions.CustomizableRollbackTransactionAttribute
import org.grails.datastore.mapping.transactions.TransactionCapableDatastore

import static org.codehaus.groovy.ast.ClassHelper.CLASS_Type
import static org.codehaus.groovy.ast.ClassHelper.STRING_TYPE
import static org.codehaus.groovy.ast.ClassHelper.VOID_TYPE
import static org.codehaus.groovy.ast.ClassHelper.make
import static org.codehaus.groovy.ast.tools.GeneralUtils.args
import static org.codehaus.groovy.ast.tools.GeneralUtils.assignS
import static org.codehaus.groovy.ast.tools.GeneralUtils.block
import static org.codehaus.groovy.ast.tools.GeneralUtils.callX
import static org.codehaus.groovy.ast.tools.GeneralUtils.castX
import static org.codehaus.groovy.ast.tools.GeneralUtils.classX
import static org.codehaus.groovy.ast.tools.GeneralUtils.ctorX
import static org.codehaus.groovy.ast.tools.GeneralUtils.declS
import static org.codehaus.groovy.ast.tools.GeneralUtils.ifElseS
import static org.codehaus.groovy.ast.tools.GeneralUtils.ifS
import static org.codehaus.groovy.ast.tools.GeneralUtils.notNullX
import static org.codehaus.groovy.ast.tools.GeneralUtils.param
import static org.codehaus.groovy.ast.tools.GeneralUtils.params
import static org.codehaus.groovy.ast.tools.GeneralUtils.propX
import static org.codehaus.groovy.ast.tools.GeneralUtils.returnS
import static org.codehaus.groovy.ast.tools.GeneralUtils.stmt
import static org.codehaus.groovy.ast.tools.GeneralUtils.varX
import static org.grails.datastore.gorm.transform.AstMethodDispatchUtils.callD
import static org.grails.datastore.gorm.transform.AstMethodDispatchUtils.callThisD
import static org.grails.datastore.mapping.reflect.AstUtils.ZERO_ARGUMENTS
import static org.grails.datastore.mapping.reflect.AstUtils.ZERO_PARAMETERS
import static org.grails.datastore.mapping.reflect.AstUtils.buildGetPropertyExpression
import static org.grails.datastore.mapping.reflect.AstUtils.copyParameters
import static org.grails.datastore.mapping.reflect.AstUtils.findAnnotation
import static org.grails.datastore.mapping.reflect.AstUtils.hasOrInheritsProperty
import static org.grails.datastore.mapping.reflect.AstUtils.implementsInterface
import static org.grails.datastore.mapping.reflect.AstUtils.isSubclassOf
import static org.grails.datastore.mapping.reflect.AstUtils.nonGeneric
import static org.grails.datastore.mapping.reflect.AstUtils.varThis

/**
 * <p>This AST transform reads the {@link Transactional} annotation and transforms method calls by
 * wrapping the body of the method in an execution of {@link GrailsTransactionTemplate}.</p>
 *
 * <p>In other words given the following class:</p>
 *
 *
 * <pre>
 * class FooService {
 *   {@code @Transactional}
 *   void updateFoo() {
 *       ...
 *   }
 * }
 * </pre>
 *
 *
 * <p>The resulting byte code produced will be (more or less):</p>
 *
 * <pre>
 * class FooService {
 *   PlatformTransactionManager $transactionManager
 *
 *   PlatformTransactionManager getTransactionManager() { $transactionManager }
 *
 *   void updateFoo() {
 *       GrailsTransactionTemplate template = new GrailsTransactionTemplate(getTransactionManager())
 *       template.execute { TransactionStatus status ->
 *           $tt_updateFoo(status)
 *       }
 *   }
 *
 *   private void $tt_updateFoo(TransactionStatus status) {
 *       ...
 *   }
 * }
 * </pre>
 *
 * <p>
 *     The body of the method is moved to a new method prefixed with "$tt_" and which receives the arguments of the method and the TransactionStatus object
 * </p>
 *
 * @author Graeme Rocher
 * @since 6.1
 */
@CompileStatic
@GroovyASTTransformation(phase = CompilePhase.CANONICALIZATION)
class TransactionalTransform extends AbstractDatastoreMethodDecoratingTransformation {

    private static final Set<String> ANNOTATION_NAME_EXCLUDES = new HashSet<String>([Transactional.getName(), 'grails.transaction.Rollback', Rollback.getName(), NotTransactional.getName(), 'grails.transaction.NotTransactional', 'grails.gorm.transactions.ReadOnly'])
    public static final ClassNode MY_TYPE = new ClassNode(Transactional)
    public static final ClassNode READ_ONLY_TYPE = new ClassNode(ReadOnly)
    private static final String PROPERTY_TRANSACTION_MANAGER = 'transactionManager'
    private static final String METHOD_EXECUTE = 'execute'
    private static final Object APPLIED_MARKER = new Object()
    private static final String SET_TRANSACTION_MANAGER = 'setTransactionManager'
    private static final Set<String> VALID_ANNOTATION_NAMES = Collections.unmodifiableSet(
        new HashSet<String>([Transactional.simpleName, Rollback.simpleName, ReadOnly.simpleName])
    )
    public static final String GET_TRANSACTION_MANAGER_METHOD = 'getTransactionManager'

    public static final String RENAMED_METHOD_PREFIX = '$tt__'

    /**
     * Finds the transactional annotation for the given method node
     *
     * @param methodNode The method node
     * @return The annotation or null
     */
    static AnnotationNode findTransactionalAnnotation(MethodNode methodNode) {
        AnnotationNode ann = findAnnotation(methodNode, Transactional)
        if (ann != null) {
            return ann
        }
        ann = findAnnotation(methodNode, ReadOnly)
        if (ann != null) {
            return ann
        }
        ann = findAnnotation(methodNode.getDeclaringClass(), Transactional)
        if (ann != null) {
            return ann
        }
        ann = findAnnotation(methodNode.getDeclaringClass(), ReadOnly)
        return ann
    }

    @Override
    protected boolean isValidAnnotation(AnnotationNode annotationNode, AnnotatedNode classNode) {
        return VALID_ANNOTATION_NAMES.contains(annotationNode.classNode.nameWithoutPackage)
    }

    @Override
    protected ClassNode getAnnotationType() {
        return MY_TYPE
    }

    @Override
    protected Object getAppliedMarker() {
        return APPLIED_MARKER
    }

    @Override
    protected Parameter[] prepareNewMethodParameters(MethodNode methodNode, Map<String, ClassNode> genericsSpec, ClassNode classNode = null) {
        final Parameter transactionStatusParameter = param(make(TransactionStatus), 'transactionStatus')
        Parameter[] parameters = methodNode.getParameters()
        Parameter[] newParameters = parameters.length > 0 ? (copyParameters(((parameters as List) + [transactionStatusParameter]) as Parameter[], genericsSpec)) : [transactionStatusParameter] as Parameter[]
        return newParameters
    }

    @Override
    protected void enhanceClassNode(SourceUnit source, AnnotationNode annotationNode, ClassNode declaringClassNode) {
        weaveTransactionManagerAware(sourceUnit, annotationNode, declaringClassNode)
        super.enhanceClassNode(source, annotationNode, declaringClassNode)
    }

    @Override
    protected void weaveTestSetupMethod(SourceUnit sourceUnit, AnnotationNode annotationNode, ClassNode classNode, MethodNode methodNode, Map<String, ClassNode> genericsSpec) {
        def requiresNewTransaction = new AnnotationNode(annotationNode.classNode)
        requiresNewTransaction.addMember('propagation', propX(classX(Propagation), 'REQUIRES_NEW'))
        weaveNewMethod(sourceUnit, requiresNewTransaction, classNode, methodNode, genericsSpec)
    }

    @Override
    protected void weaveSetTargetDatastoreBody(SourceUnit source, AnnotationNode annotationNode, ClassNode declaringClassNode, Expression datastoreVar, BlockStatement setTargetDatastoreBody) {
        String transactionManagerFieldName = '$' + PROPERTY_TRANSACTION_MANAGER
        VariableExpression transactionManagerPropertyExpr = varX(transactionManagerFieldName)
        Statement assignConditional = ifS(notNullX(datastoreVar),
                assignS(transactionManagerPropertyExpr, callX(castX(make(TransactionCapableDatastore), datastoreVar), GET_TRANSACTION_MANAGER_METHOD)))
        setTargetDatastoreBody.addStatement(assignConditional)

    }

    protected void weaveTransactionManagerAware(SourceUnit source, AnnotationNode annotationNode, ClassNode declaringClassNode) {
        if (declaringClassNode.getNodeMetaData(APPLIED_MARKER) == APPLIED_MARKER) {
            return
        }

        Expression connectionName = annotationNode.getMember('connection')
        if (connectionName == null) {
            connectionName = annotationNode.getMember('value')
        }
        boolean hasDataSourceProperty = connectionName != null

        //add the transactionManager property
        if (!hasOrInheritsProperty(declaringClassNode, PROPERTY_TRANSACTION_MANAGER)) {

            ClassNode transactionManagerClassNode = make(PlatformTransactionManager)

            // build a static lookup in the case of no property set
            ClassExpression gormEnhancerExpr = classX(GormEnhancer)
            Expression val = annotationNode.getMember('datastore')
            MethodCallExpression transactionManagerLookupExpr
            if (val instanceof ClassExpression) {
                transactionManagerLookupExpr = hasDataSourceProperty ? callX(gormEnhancerExpr, 'findTransactionManager', args(val, connectionName)) : callX(gormEnhancerExpr, 'findTransactionManager', val)
                Parameter typeParameter = param(CLASS_Type, 'type')
                Parameter[] params = hasDataSourceProperty ? params(typeParameter, param(STRING_TYPE, 'connectionName')) : params(typeParameter)

                transactionManagerLookupExpr.setMethodTarget(
                        gormEnhancerExpr.getType().getDeclaredMethod('findTransactionManager', params)
                )
            }
            else {
                transactionManagerLookupExpr = hasDataSourceProperty ? callX(gormEnhancerExpr, 'findSingleTransactionManager', connectionName) : callX(gormEnhancerExpr, 'findSingleTransactionManager')
                Parameter[] params = hasDataSourceProperty ? params(param(STRING_TYPE, 'connectionName')) : ZERO_PARAMETERS
                transactionManagerLookupExpr.setMethodTarget(
                        gormEnhancerExpr.getType().getDeclaredMethod('findSingleTransactionManager', params)
                )
            }

            // simply logic for classes that implement Service
            if (implementsInterface(declaringClassNode, 'org.grails.datastore.mapping.services.Service')) {
                // Add Method: PlatformTransactionManager getTransactionManager()
                // if(datastore != null)
                //     return datastore.transactionManager
                // else
                //     return GormEnhancer.findSingleTransactionManager()
                ClassNode transactionCapableDatastore = make(TransactionCapableDatastore)
                Expression datastoreVar = castX(transactionCapableDatastore, varX('datastore'))
                Expression datastoreLookupExpr = datastoreVar
                if (hasDataSourceProperty) {
                    datastoreLookupExpr = callD(castX(make(MultipleConnectionSourceCapableDatastore), datastoreVar), 'getDatastoreForConnection', connectionName)
                }
                Statement ifElse = ifElseS(
                        notNullX(datastoreVar),
                        returnS(propX(castX(transactionCapableDatastore, datastoreLookupExpr), PROPERTY_TRANSACTION_MANAGER)),
                        returnS(transactionManagerLookupExpr)
                )

                declaringClassNode.addMethod(GET_TRANSACTION_MANAGER_METHOD,
                        Modifier.PUBLIC,
                        transactionManagerClassNode,
                        ZERO_PARAMETERS, null,
                        ifElse)

            }
            else {
                /// Add field: PlatformTransactionManager $transactionManager
                String transactionManagerFieldName = '$' + PROPERTY_TRANSACTION_MANAGER
                FieldNode transactionManagerField = declaringClassNode.addField(transactionManagerFieldName, Modifier.PROTECTED, transactionManagerClassNode, null)

                VariableExpression transactionManagerPropertyExpr = varX(transactionManagerField)
                BlockStatement getterBody = block()

                // this is a hacky workaround that ensures the transaction manager is also set on the spock shared instance which seems to differ for
                // some reason
                if (isSubclassOf(declaringClassNode, 'spock.lang.Specification')) {
                    getterBody.addStatement(
                            stmt(
                                    callX(propX(propX(varThis(), 'specificationContext'), 'sharedInstance'),
                                            SET_TRANSACTION_MANAGER,
                                            transactionManagerPropertyExpr)
                            )
                    )
                }

                // Prepare the getTransactionManager() method body
                // if($transactionManager != null)
                //     return $transactionManager
                // else
                //     return GormEnhancer.findSingleTransactionManager()
                Statement ifElse = ifElseS(
                        notNullX(transactionManagerPropertyExpr),
                        returnS(transactionManagerPropertyExpr),
                        returnS(transactionManagerLookupExpr)
                )

                getterBody.addStatement(ifElse)

                // Add Method: PlatformTransactionManager getTransactionManager()
                declaringClassNode.addMethod(GET_TRANSACTION_MANAGER_METHOD,
                        Modifier.PUBLIC,
                        transactionManagerClassNode,
                        ZERO_PARAMETERS, null,
                        getterBody)

                // Prepare setter parameters
                Parameter p = param(transactionManagerClassNode, PROPERTY_TRANSACTION_MANAGER)
                Parameter[] parameters = params(p)
                if (declaringClassNode.getMethod(SET_TRANSACTION_MANAGER, parameters) == null) {
                    Statement setterBody = assignS(transactionManagerPropertyExpr, varX(p))

                    // Add Setter Method: void setTransactionManager(PlatformTransactionManager transactionManager)
                    declaringClassNode.addMethod(SET_TRANSACTION_MANAGER,
                            Modifier.PUBLIC,
                            VOID_TYPE,
                            parameters,
                            null,
                            setterBody)
                }
            }

        }
    }

    MethodCallExpression buildDelegatingMethodCall(SourceUnit sourceUnit, AnnotationNode annotationNode, ClassNode classNode, MethodNode methodNode, MethodCallExpression originalMethodCall, BlockStatement newMethodBody) {
        String executeMethodName = isTestSetupOrCleanup(classNode, methodNode) ? METHOD_EXECUTE : getTransactionTemplateMethodName()
        // CustomizableRollbackTransactionAttribute $transactionAttribute = new CustomizableRollbackTransactionAttribute()
        final ClassNode transactionAttributeClassNode = make(CustomizableRollbackTransactionAttribute)
        final VariableExpression transactionAttributeVar = varX('$transactionAttribute', transactionAttributeClassNode)
        newMethodBody.addStatement(
            declS(transactionAttributeVar, ctorX(transactionAttributeClassNode, ZERO_ARGUMENTS))
        )

        // apply @Transaction attributes to properties of $transactionAttribute
        applyTransactionalAttributeSettings(annotationNode, transactionAttributeVar, newMethodBody, classNode, methodNode)

        boolean isMultiTenant = TenantTransform.hasTenantAnnotation(methodNode)

        Expression connectionName = annotationNode.getMember('connection')
        if (connectionName == null) {
            connectionName = annotationNode.getMember('value')
        }
        if (connectionName == null) {
            if (isMultiTenant) {
                connectionName = varX('tenantId')
            }
        }
        final boolean hasDataSourceProperty = connectionName != null

        // $transactionManager = connection != null ? getTargetDatastore(connection).getTransactionManager() : getTransactionManager()
        Expression transactionManagerExpression
        if (isMultiTenant && hasDataSourceProperty) {
            Expression targetDatastoreExpr = castX(make(MultiTenantCapableDatastore), callThisD(classNode, 'getTargetDatastore', ZERO_ARGUMENTS))
            targetDatastoreExpr = castX(make(TransactionCapableDatastore), callX(targetDatastoreExpr, 'getDatastoreForTenantId', connectionName))
            transactionManagerExpression = castX(make(PlatformTransactionManager), propX(targetDatastoreExpr, PROPERTY_TRANSACTION_MANAGER))

        }
        else if (hasDataSourceProperty) {
            // callX(varX("this"), "getTargetDatastore", connectionName)
            def targetDatastoreExpr = castX(make(TransactionCapableDatastore), callThisD(classNode, 'getTargetDatastore', connectionName))
            transactionManagerExpression = castX(make(PlatformTransactionManager), propX(targetDatastoreExpr, PROPERTY_TRANSACTION_MANAGER))
        }
        else {
            transactionManagerExpression = propX(varX('this'), PROPERTY_TRANSACTION_MANAGER)
        }

        // GrailsTransactionTemplate $transactionTemplate
        //           = new GrailsTransactionTemplate(getTransactionManager(), $transactionAttribute )
        final ClassNode transactionTemplateClassNode = make(GrailsTransactionTemplate)
        final VariableExpression transactionTemplateVar = varX('$transactionTemplate', transactionTemplateClassNode)

        newMethodBody.addStatement(
            declS(
                transactionTemplateVar,
                ctorX(transactionTemplateClassNode, args(
                    transactionManagerExpression,
                    transactionAttributeVar
                ))
            )
        )

        // Wrap original method in closure that executes within the context of a transaction
        // return $transactionTemplate.execute { TransactionStatus transactionStatus ->
        //       return $tt_myMethod(transactionStatus)
        // }
        Parameter transactionStatusParam = param(make(TransactionStatus), 'transactionStatus')
        Parameter[] parameters = params(transactionStatusParam)
        return makeDelegatingClosureCall(transactionTemplateVar, executeMethodName, parameters, originalMethodCall, methodNode.getVariableScope())
    }

    protected String getTransactionTemplateMethodName() {
        return 'execute'
    }

    protected applyTransactionalAttributeSettings(AnnotationNode annotationNode, VariableExpression transactionAttributeVar, BlockStatement methodBody, ClassNode classNode, MethodNode methodNode) {
        final ClassNode rollbackRuleAttributeClassNode = make(RollbackRuleAttribute)
        final ClassNode noRollbackRuleAttributeClassNode = make(NoRollbackRuleAttribute)
        final Map<String, Expression> members = annotationNode.getMembers()
        if (READ_ONLY_TYPE.equals(annotationNode.classNode)) {
            methodBody.addStatement(
                assignS(propX(transactionAttributeVar, 'readOnly'), ConstantExpression.TRUE)
            )
        }

        members.each { String name, Expression expr ->
            if (name == 'rollbackFor' || name == 'rollbackForClassName' || name == 'noRollbackFor' || name == 'noRollbackForClassName') {
                final targetClassNode = (name == 'rollbackFor' || name == 'rollbackForClassName') ? rollbackRuleAttributeClassNode : noRollbackRuleAttributeClassNode
                name = 'rollbackRules'
                if (expr instanceof ListExpression) {
                    for (exprItem in ((ListExpression) expr).expressions) {
                        appendRuleElement(methodBody, transactionAttributeVar, name, ctorX(targetClassNode, exprItem))
                    }
                } else {
                    appendRuleElement(methodBody, transactionAttributeVar, name, ctorX(targetClassNode, expr))
                }
            } else {
                if (name == 'isolation') {
                    name = 'isolationLevel'
                    expr = callX(expr, 'value', ZERO_ARGUMENTS)
                } else if (name == 'propagation') {
                    name = 'propagationBehavior'
                    expr = callX(expr, 'value', ZERO_ARGUMENTS)
                }

                if (name != 'value') {
                    methodBody.addStatement(
                        assignS(propX(transactionAttributeVar, name), expr)
                    )
                }
            }
        }

        final transactionName = classNode.name + '.' + methodNode.name
        methodBody.addStatement(
            assignS(propX(transactionAttributeVar, 'name'), new ConstantExpression(transactionName))
        )
    }

    private void appendRuleElement(BlockStatement methodBody, VariableExpression transactionAttributeVar, String name, Expression expr) {
        final rollbackRuleAttributeClassNode = make(RollbackRuleAttribute)
        ClassNode rollbackRulesListClassNode = nonGeneric(make(List), rollbackRuleAttributeClassNode)
        def getRollbackRules = castX(rollbackRulesListClassNode, buildGetPropertyExpression(transactionAttributeVar, name, transactionAttributeVar.getType()))
        methodBody.addStatement(
            stmt(
                callX(getRollbackRules, 'add', expr)
            )
        )
    }

    @Override
    protected boolean hasExcludedAnnotation(MethodNode md) {
        return super.hasExcludedAnnotation(md) || hasExcludedAnnotation(md, ANNOTATION_NAME_EXCLUDES)
    }

    /**
     * Whether the given method has a transactional annotation
     *
     * @param md The method node
     * @return
     */
    static boolean hasTransactionalAnnotation(AnnotatedNode md) {
        for (AnnotationNode annotation : md.getAnnotations()) {
            if (ANNOTATION_NAME_EXCLUDES.any() { String n -> n == annotation.classNode.name }) {
                return true
            }
        }
        return false
    }

    @Override
    protected String getRenamedMethodPrefix() {
        return RENAMED_METHOD_PREFIX
    }

    @Override
    int priority() {
        GroovyTransformOrder.TRANSACTIONAL_ORDER
    }
}
