/*
 * Copyright 2010-2017 JetBrains s.r.o.
 *
 * 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 org.jetbrains.kotlin.native.interop.gen

import org.jetbrains.kotlin.native.interop.indexer.*

/**
 * Returns the expression which could be used for this type in C code.
 * Note: the resulting string doesn't exactly represent this type, but it is enough for current purposes.
 *
 * TODO: use libclang to implement?
 */
fun Type.getStringRepresentation(): String = when (this) {
    VoidType -> "void"
    CharType -> "char"
    CBoolType -> "_Bool"
    CPPBoolType -> "bool"
    ObjCBoolType -> "BOOL"
    is IntegerType -> this.spelling
    is FloatingType -> this.spelling

    is VectorType -> this.spelling
    is PointerType -> getPointerTypeStringRepresentation(this.pointeeType)
    is ArrayType -> getPointerTypeStringRepresentation(this.elemType)

    is RecordType -> this.decl.spelling

    is EnumType -> if (this.def.isAnonymous) {
        this.def.baseType.getStringRepresentation()
    } else {
        this.def.spelling
    }

    is Typedef -> this.def.aliased.getStringRepresentation()

    is ObjCPointer -> when (this) {
        is ObjCIdType -> "id$protocolQualifier"
        is ObjCClassPointer -> "Class$protocolQualifier"
        is ObjCObjectPointer -> "${def.name}$protocolQualifier*"
        is ObjCInstanceType -> TODO(this.toString()) // Must have already been handled.
        is ObjCBlockPointer -> "id"
    }

    else -> throw NotImplementedError()
}

fun getPointerTypeStringRepresentation(pointee: Type): String =
        (getStringRepresentationOfPointee(pointee) ?: "void") + "*"

private fun getStringRepresentationOfPointee(type: Type): String? {
    val unwrapped = type.unwrapTypedefs()

    return when (unwrapped) {
        is PrimitiveType -> unwrapped.getStringRepresentation()
        is PointerType -> getStringRepresentationOfPointee(unwrapped.pointeeType)?.plus("*")
        is RecordType -> if (unwrapped.decl.isAnonymous || unwrapped.decl.spelling == "struct __va_list_tag") {
            null
        } else {
            unwrapped.decl.spelling
        }
        is EnumType -> if (unwrapped.def.isAnonymous) {
            unwrapped.def.baseType.getStringRepresentation()
        } else {
            unwrapped.def.spelling
        }
        else -> null
    }
}

private val ObjCQualifiedPointer.protocolQualifier: String
    get() = if (this.protocols.isEmpty()) "" else " <${protocols.joinToString { it.name }}>"

fun blockTypeStringRepresentation(type: ObjCBlockPointer): String {
    return buildString {
        append(type.returnType.getStringRepresentation())
        append("(^)")
        append("(")
        val blockParameters = if (type.parameterTypes.isEmpty()) {
            "void"
        } else {
            type.parameterTypes.joinToString { it.getStringRepresentation() }
        }
        append(blockParameters)
        append(")")
    }
}
