/*
 * Minecraft Development for IntelliJ
 *
 * https://mcdev.io/
 *
 * Copyright (C) 2026 minecraft-dev
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, version 3.0 only.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 
package com.demonwav.mcdev.platform.mixin.inspection.injector
 
import com.demonwav.mcdev.platform.mixin.inspection.MixinInspection
import com.demonwav.mcdev.platform.mixin.util.LocalInfo
import com.demonwav.mcdev.platform.mixin.util.MixinConstants.Annotations.MODIFY_VARIABLE
import com.demonwav.mcdev.platform.mixin.util.hasMissingLVT
import com.demonwav.mcdev.platform.mixin.util.mixinTargets
import com.demonwav.mcdev.util.findAnnotation
import com.demonwav.mcdev.util.findContainingClass
import com.intellij.codeInspection.ProblemsHolder
import com.intellij.psi.JavaElementVisitor
import com.intellij.psi.PsiAnnotation
import com.intellij.psi.PsiElement
import com.intellij.psi.PsiMethod
import com.intellij.util.ThreeState
 
class ModifyVariableNameWithoutLVTInspection : MixinInspection() {
    override fun buildVisitor(holder: ProblemsHolder) = object : JavaElementVisitor() {
        override fun visitMethod(method: PsiMethod) {
            val modifyVariable = method.findAnnotation(MODIFY_VARIABLE) ?: return
            val localType = method.parameterList.getParameter(0)?.type ?: return
            val localInfo = LocalInfo.fromAnnotation(localType, modifyVariable)
 
            val problemElement = Util.getProblemElement(localInfo, modifyVariable, modifyVariable) ?: return
            holder.registerProblem(
                problemElement,
                "@ModifyVariable uses a variable name, but the target class has no local variable names at runtime",
            )
        }
    }
 
    object Util {
        private val GENERATED_NAME_REGEX = Regex("(?:arg|var)\\d+")
 
        fun getProblemElement(
            localInfo: LocalInfo,
            localAnnotation: PsiAnnotation,
            injectorAnnotation: PsiAnnotation,
        ): PsiElement? {
            // names generated by Mixin don't depend on the local variable table
            if (localInfo.names.all { GENERATED_NAME_REGEX.matches(it) }) {
                return null
            }
 
            val mixinTargets = injectorAnnotation.findContainingClass()?.mixinTargets ?: return null
            val isMissingLVT = mixinTargets.any {
                injectorAnnotation.hasMissingLVT(it.name.replace('/', '.')) == ThreeState.YES
            }
            if (!isMissingLVT) {
                return null
            }
 
            return localAnnotation.findDeclaredAttributeValue("name") ?: localAnnotation.nameReferenceElement
        }
    }
}