/*
 * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
 * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
 */

package org.jetbrains.kotlin.fir.analysis.checkers.declaration

import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
import org.jetbrains.kotlin.diagnostics.reportOn
import org.jetbrains.kotlin.fir.analysis.checkers.MppCheckerKind
import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
import org.jetbrains.kotlin.fir.declarations.DirectDeclarationsAccess
import org.jetbrains.kotlin.fir.declarations.FirRegularClass
import org.jetbrains.kotlin.fir.declarations.utils.isCompanion

object FirManyCompanionObjectsChecker : FirRegularClassChecker(MppCheckerKind.Common) {
    context(context: CheckerContext, reporter: DiagnosticReporter)
    override fun check(declaration: FirRegularClass) {
        var hasCompanion = false

        @OptIn(DirectDeclarationsAccess::class)
        for (it in declaration.declarations) {
            if (it is FirRegularClass && it.isCompanion) {
                if (hasCompanion) {
                    reporter.reportOn(it.source, FirErrors.MANY_COMPANION_OBJECTS)
                }
                hasCompanion = true
            }
        }
    }
}
