room/compiler/src/main/kotlin/androidx/room/processor/DaoProcessor.kt

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * 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
 *
 *      http://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 androidx.room.processor

import androidx.room.Delete
import androidx.room.Insert
import androidx.room.Query
import androidx.room.RawQuery
import androidx.room.SkipQueryVerification
import androidx.room.Transaction
import androidx.room.Update
import androidx.room.processing.XConstructorElement
import androidx.room.processing.XDeclaredType
import androidx.room.processing.XTypeElement
import androidx.room.verifier.DatabaseVerifier
import androidx.room.vo.Dao
import androidx.room.vo.KotlinDefaultMethodDelegate

class DaoProcessor(
    baseContext: Context,
    val element: XTypeElement,
    val dbType: XDeclaredType,
    val dbVerifier: DatabaseVerifier?
) {
    val context = baseContext.fork(element)

    companion object {
        val PROCESSED_ANNOTATIONS = listOf(Insert::class, Delete::class, Query::class,
                Update::class, RawQuery::class)
    }

    fun process(): Dao {
        context.checker.hasAnnotation(element, androidx.room.Dao::class,
                ProcessorErrors.DAO_MUST_BE_ANNOTATED_WITH_DAO)
        context.checker.check(element.isAbstract() || element.isInterface(),
                element, ProcessorErrors.DAO_MUST_BE_AN_ABSTRACT_CLASS_OR_AN_INTERFACE)

        val declaredType = element.asDeclaredType()
        val allMethods = element.getAllMethods()
        val methods = allMethods
            .filter {
                it.isAbstract() &&
                        it.findKotlinDefaultImpl() == null
            }.groupBy { method ->
                context.checker.check(
                        PROCESSED_ANNOTATIONS.count { method.hasAnnotation(it) } == 1, method,
                        ProcessorErrors.INVALID_ANNOTATION_COUNT_IN_DAO_METHOD
                )
                if (method.hasAnnotation(Query::class)) {
                    Query::class
                } else if (method.hasAnnotation(Insert::class)) {
                    Insert::class
                } else if (method.hasAnnotation(Delete::class)) {
                    Delete::class
                } else if (method.hasAnnotation(Update::class)) {
                    Update::class
                } else if (method.hasAnnotation(RawQuery::class)) {
                    RawQuery::class
                } else {
                    Any::class
                }
            }
        val processorVerifier = if (element.hasAnnotation(SkipQueryVerification::class) ||
                element.hasAnnotation(RawQuery::class)) {
            null
        } else {
            dbVerifier
        }

        val queryMethods = methods[Query::class]?.map {
            QueryMethodProcessor(
                    baseContext = context,
                    containing = declaredType,
                    executableElement = it,
                    dbVerifier = processorVerifier).process()
        } ?: emptyList()

        val rawQueryMethods = methods[RawQuery::class]?.map {
            RawQueryMethodProcessor(
                    baseContext = context,
                    containing = declaredType,
                    executableElement = it
            ).process()
        } ?: emptyList()

        val insertionMethods = methods[Insert::class]?.map {
            InsertionMethodProcessor(
                    baseContext = context,
                    containing = declaredType,
                    executableElement = it).process()
        } ?: emptyList()

        val deletionMethods = methods[Delete::class]?.map {
            DeletionMethodProcessor(
                    baseContext = context,
                    containing = declaredType,
                    executableElement = it).process()
        } ?: emptyList()

        val updateMethods = methods[Update::class]?.map {
            UpdateMethodProcessor(
                    baseContext = context,
                    containing = declaredType,
                    executableElement = it).process()
        } ?: emptyList()

        val transactionMethods = allMethods.filter { member ->
            member.hasAnnotation(Transaction::class) &&
                    PROCESSED_ANNOTATIONS.none { member.hasAnnotation(it) }
        }.map {
            TransactionMethodProcessor(
                    baseContext = context,
                    containing = declaredType,
                    executableElement = it).process()
        }

        val kotlinDefaultMethodDelegates = if (element.isInterface()) {
            val allProcessedMethods =
                methods.values.flatten() + transactionMethods.map { it.element }
            allMethods.filterNot {
                allProcessedMethods.contains(it)
            }.mapNotNull { method ->
                method.findKotlinDefaultImpl()?.let { delegate ->
                    KotlinDefaultMethodDelegate(
                        element = method,
                        delegateElement = delegate
                    )
                }
            }
        } else {
            emptyList()
        }

        val constructors = element.getConstructors()
        val goodConstructor = constructors.firstOrNull {
            it.parameters.size == 1 &&
                    it.parameters[0].type.isAssignableFrom(dbType)
        }
        val constructorParamType = if (goodConstructor != null) {
            goodConstructor.parameters[0].type.typeName
        } else {
            validateEmptyConstructor(constructors)
            null
        }

        context.checker.check(methods[Any::class] == null, element,
                ProcessorErrors.ABSTRACT_METHOD_IN_DAO_MISSING_ANY_ANNOTATION)

        val type = declaredType.typeName
        context.checker.notUnbound(type, element,
                ProcessorErrors.CANNOT_USE_UNBOUND_GENERICS_IN_DAO_CLASSES)

        return Dao(element = element,
                type = declaredType,
                queryMethods = queryMethods,
                rawQueryMethods = rawQueryMethods,
                insertionMethods = insertionMethods,
                deletionMethods = deletionMethods,
                updateMethods = updateMethods,
                transactionMethods = transactionMethods,
                kotlinDefaultMethodDelegates = kotlinDefaultMethodDelegates,
                constructorParamType = constructorParamType)
    }

    private fun validateEmptyConstructor(constructors: List<XConstructorElement>) {
        if (constructors.isNotEmpty() && constructors.all { it.parameters.isNotEmpty() }) {
            context.logger.e(element, ProcessorErrors.daoMustHaveMatchingConstructor(
                    element.toString(), dbType.toString()))
        }
    }
}