Incremental Compilation Support

/**
 * Main interface for incremental compilation functionality
 * Provides tracking components for optimization and change detection
 */
interface IncrementalCompilationComponents {
    /** Symbol lookup tracker for dependency analysis */
    val lookupTracker: LookupTracker
    
    /** Multiplatform expect/actual tracker */
    val expectActualTracker: ExpectActualTracker
    
    /** Inline constant usage tracker */
    val inlineConstTracker: InlineConstTracker
    
    /** Enum when exhaustiveness tracker */
    val enumWhenTracker: EnumWhenTracker
    
    /** Import statement tracker */
    val importTracker: ImportTracker
    
    companion object {
        /** Create default incremental compilation components */
        fun create(): IncrementalCompilationComponents
        
        /** Create with custom configuration */
        fun create(configuration: IncrementalCompilationConfiguration): IncrementalCompilationComponents
    }
}

// Setup incremental compilation
val incrementalComponents = IncrementalCompilationComponents.create()

val configuration = CompilerConfiguration().apply {
    put(JVMConfigurationKeys.INCREMENTAL_COMPILATION_COMPONENTS, incrementalComponents)
}

val compiler = K2JVMCompiler()
val arguments = K2JVMCompilerArguments().apply {
    destination = "build/classes"
    // Other configuration...
}

// Compile with incremental support
val exitCode = compiler.exec(messageCollector, Services.EMPTY, arguments)

// Access tracking information
val lookupTracker = incrementalComponents.lookupTracker
val usedSymbols = lookupTracker.getUsedSymbols()
println("Used ${usedSymbols.size} symbols during compilation")

/**
 * Tracks symbol lookups during compilation
 * Essential for determining compilation dependencies and change impact
 */
interface LookupTracker {
    /** Record a symbol lookup at specific location */
    fun record(
        filePath: String,
        position: Int,
        scopeFqName: String,
        name: String
    ): Unit
    
    /** Record lookup with additional context */
    fun record(
        filePath: String,
        position: Int,
        scopeFqName: String,
        scopeKind: ScopeKind,
        name: String
    ): Unit
    
    /** Get all recorded lookups */
    fun getUsedSymbols(): Set<LookupSymbol>
    
    /** Get lookups for specific file */
    fun getLookups(filePath: String): Collection<LookupSymbol>
    
    /** Clear all recorded lookups */
    fun clear(): Unit
    
    /** Check if lookup tracking is enabled */
    val requiresPosition: Boolean
}

/**
 * Represents a symbol lookup for incremental compilation
 */
data class LookupSymbol(
    /** Fully qualified name of the scope */
    val scope: String,
    
    /** Name of the looked up symbol */
    val name: String,
    
    /** Kind of scope (package, class, etc.) */
    val scopeKind: ScopeKind
)

/**
 * Types of scopes for symbol lookups
 */
enum class ScopeKind {
    PACKAGE, CLASSIFIER, OBJECT
}

// Custom lookup tracker implementation
class DetailedLookupTracker : LookupTracker {
    private val lookups = mutableMapOf<String, MutableSet<LookupSymbol>>()
    
    override fun record(
        filePath: String,
        position: Int,
        scopeFqName: String,
        name: String
    ) {
        val symbol = LookupSymbol(scopeFqName, name, ScopeKind.CLASSIFIER)
        lookups.getOrPut(filePath) { mutableSetOf() }.add(symbol)
        
        // Log for debugging
        println("Lookup: $filePath:$position -> $scopeFqName.$name")
    }
    
    override fun record(
        filePath: String,
        position: Int,
        scopeFqName: String,
        scopeKind: ScopeKind,
        name: String
    ) {
        val symbol = LookupSymbol(scopeFqName, name, scopeKind)
        lookups.getOrPut(filePath) { mutableSetOf() }.add(symbol)
    }
    
    override fun getUsedSymbols(): Set<LookupSymbol> {
        return lookups.values.flatten().toSet()
    }
    
    override fun getLookups(filePath: String): Collection<LookupSymbol> {
        return lookups[filePath] ?: emptySet()
    }
    
    override fun clear() {
        lookups.clear()
    }
    
    override val requiresPosition: Boolean = true
    
    // Additional functionality
    fun getDependentFiles(changedSymbol: LookupSymbol): Set<String> {
        return lookups.filterValues { symbols ->
            changedSymbol in symbols
        }.keys
    }
}

/**
 * Tracks expect/actual declarations in multiplatform projects
 * Ensures proper incremental compilation across platforms
 */
interface ExpectActualTracker {
    /** Report expect declaration */
    fun reportExpectDeclaration(
        filePath: String,
        fqName: String,
        position: Int
    ): Unit
    
    /** Report actual declaration */
    fun reportActualDeclaration(
        filePath: String,
        fqName: String,
        position: Int
    ): Unit
    
    /** Get all expect declarations */
    fun getExpectDeclarations(): Collection<ExpectActualDeclaration>
    
    /** Get all actual declarations */
    fun getActualDeclarations(): Collection<ExpectActualDeclaration>
    
    /** Find actual declarations for expect */
    fun findActuals(expectFqName: String): Collection<ExpectActualDeclaration>
    
    /** Find expect declaration for actual */
    fun findExpect(actualFqName: String): ExpectActualDeclaration?
}

/**
 * Represents an expect or actual declaration
 */
data class ExpectActualDeclaration(
    val filePath: String,
    val fqName: String,
    val position: Int,
    val isExpect: Boolean
)

/**
 * Tracks usage of inline constants
 * Critical for incremental compilation when constant values change
 */
interface InlineConstTracker {
    /** Report usage of inline constant */
    fun report(
        filePath: String,
        position: Int,
        owner: String,
        name: String,
        constType: ConstType
    ): Unit
    
    /** Get all tracked inline constant usages */
    fun getUsedInlineConsts(): Collection<InlineConstUsage>
    
    /** Get inline constant usages for specific file */
    fun getUsages(filePath: String): Collection<InlineConstUsage>
    
    /** Check if constant change affects file */
    fun isAffectedBy(filePath: String, changedConst: InlineConstUsage): Boolean
}

/**
 * Represents usage of an inline constant
 */
data class InlineConstUsage(
    val filePath: String,
    val position: Int,
    val owner: String,
    val name: String,
    val constType: ConstType
)

/**
 * Types of inline constants
 */
enum class ConstType {
    PROPERTY, ENUM_ENTRY, COMPANION_OBJECT_PROPERTY
}

/**
 * Tracks enum when expressions
 * Ensures recompilation when enum entries are added/removed
 */
interface EnumWhenTracker {
    /** Report enum when expression */
    fun report(
        filePath: String,
        position: Int,
        enumClassFqName: String,
        whenExpression: WhenExpressionInfo
    ): Unit
    
    /** Get all tracked when expressions */
    fun getWhenExpressions(): Collection<EnumWhenUsage>
    
    /** Check if enum change affects when expressions */
    fun isAffectedByEnumChange(
        enumFqName: String,
        addedEntries: Set<String>,
        removedEntries: Set<String>
    ): Collection<EnumWhenUsage>
}

/**
 * Information about when expression on enum
 */
data class WhenExpressionInfo(
    val isExhaustive: Boolean,
    val matchedEntries: Set<String>
)

/**
 * Usage of enum in when expression
 */
data class EnumWhenUsage(
    val filePath: String,
    val position: Int,
    val enumClassFqName: String,
    val whenInfo: WhenExpressionInfo
)

/**
 * Tracks import statements and their usage
 * Helps optimize incremental compilation by tracking import dependencies
 */
interface ImportTracker {
    /** Report import statement */
    fun report(filePath: String, importedFqName: String): Unit
    
    /** Report star import */
    fun reportStarImport(filePath: String, packageFqName: String): Unit
    
    /** Get all imports for file */
    fun getImports(filePath: String): Collection<ImportInfo>
    
    /** Get files that import from package */
    fun getFilesImportingFrom(packageFqName: String): Collection<String>
    
    /** Check if symbol change affects imports */
    fun isAffectedBySymbolChange(symbolFqName: String): Collection<String>
}

/**
 * Information about an import
 */
data class ImportInfo(
    val importedFqName: String,
    val isStarImport: Boolean
)

/**
 * Analyzes classpath changes for incremental compilation
 */
interface ClasspathChangesComputer {
    /** Compute changes between classpaths */
    fun compute(
        previousClasspath: List<File>,
        currentClasspath: List<File>
    ): ClasspathChanges
    
    /** Create snapshot of current classpath */
    fun createSnapshot(classpath: List<File>): ClasspathSnapshot
    
    /** Compare snapshots for changes */
    fun compareSnapshots(
        previous: ClasspathSnapshot,
        current: ClasspathSnapshot
    ): ClasspathChanges
}

/**
 * Represents changes in classpath between compilations
 */
data class ClasspathChanges(
    /** Files added to classpath */
    val added: Set<File>,
    
    /** Files removed from classpath */
    val removed: Set<File>,
    
    /** Files modified in classpath */
    val modified: Set<File>,
    
    /** Unchanged files */
    val unchanged: Set<File>
) {
    /** Check if any changes occurred */
    val hasChanges: Boolean get() = added.isNotEmpty() || removed.isNotEmpty() || modified.isNotEmpty()
    
    /** Get all changed files */
    val changedFiles: Set<File> get() = added + removed + modified
}

/**
 * Snapshot of classpath state
 */
interface ClasspathSnapshot {
    /** Classpath entries in this snapshot */
    val entries: List<ClasspathEntrySnapshot>
    
    /** Timestamp when snapshot was created */
    val timestamp: Long
    
    /** Hash of the complete classpath */
    val hash: String
}

/**
 * Snapshot of individual classpath entry
 */
interface ClasspathEntrySnapshot {
    /** File path */
    val file: File
    
    /** Content hash */
    val hash: String
    
    /** Last modified timestamp */
    val lastModified: Long
    
    /** File size */
    val size: Long
    
    /** ABI hash for incremental compilation */
    val abiHash: String?
}

// Complete incremental compilation setup
class IncrementalCompilationManager {
    private val lookupTracker = DetailedLookupTracker()
    private val classpathComputer = ClasspathChangesComputer.create()
    private var previousSnapshot: ClasspathSnapshot? = null
    
    fun compile(
        sources: List<File>,
        classpath: List<File>,
        outputDir: File
    ): CompilationResult {
        
        // Check classpath changes
        val currentSnapshot = classpathComputer.createSnapshot(classpath)
        val classpathChanges = previousSnapshot?.let {
            classpathComputer.compareSnapshots(it, currentSnapshot)
        }
        
        // Determine which sources need recompilation
        val sourcesToCompile = if (classpathChanges?.hasChanges == true) {
            // Significant classpath changes - recompile all
            sources
        } else {
            // Check individual source changes
            determineChangedSources(sources)
        }
        
        // Setup incremental compilation components
        val incrementalComponents = IncrementalCompilationComponents.create().apply {
            // Use our custom lookup tracker
            (this as MutableIncrementalCompilationComponents).lookupTracker = this@IncrementalCompilationManager.lookupTracker
        }
        
        val configuration = CompilerConfiguration().apply {
            put(JVMConfigurationKeys.INCREMENTAL_COMPILATION_COMPONENTS, incrementalComponents)
            put(JVMConfigurationKeys.OUTPUT_DIRECTORY, outputDir)
        }
        
        // Perform compilation
        val compiler = K2JVMCompiler()
        val arguments = K2JVMCompilerArguments().apply {
            destination = outputDir.absolutePath
            classpath = classpath.joinToString(File.pathSeparator) { it.absolutePath }
            freeArgs = sourcesToCompile.map { it.absolutePath }
        }
        
        val messageCollector = PrintingMessageCollector(System.err, MessageRenderer.PLAIN, false)
        val exitCode = compiler.exec(messageCollector, Services.EMPTY, arguments)
        
        // Update snapshot for next compilation
        previousSnapshot = currentSnapshot
        
        return CompilationResult(
            exitCode = exitCode,
            compiledFiles = sourcesToCompile.size,
            incrementalInfo = IncrementalInfo(
                classpathChanges = classpathChanges,
                recompiledSources = sourcesToCompile,
                symbolLookups = lookupTracker.getUsedSymbols()
            )
        )
    }
    
    private fun determineChangedSources(sources: List<File>): List<File> {
        // Implementation would check source file modifications
        // and use lookup tracker to determine dependent files
        return sources.filter { it.lastModified() > getLastCompilationTime() }
    }
    
    fun getImpactAnalysis(changedSymbol: String): Set<String> {
        return lookupTracker.getDependentFiles(
            LookupSymbol(changedSymbol, "", ScopeKind.CLASSIFIER)
        )
    }
}

// Result with incremental compilation information
data class IncrementalInfo(
    val classpathChanges: ClasspathChanges?,
    val recompiledSources: List<File>,
    val symbolLookups: Set<LookupSymbol>
)

// Incremental compilation configuration
data class IncrementalCompilationConfiguration(
    /** Enable lookup tracking */
    val enableLookupTracking: Boolean = true,
    
    /** Enable expect/actual tracking */
    val enableExpectActualTracking: Boolean = true,
    
    /** Enable inline constant tracking */
    val enableInlineConstTracking: Boolean = true,
    
    /** Enable enum when tracking */
    val enableEnumWhenTracking: Boolean = true,
    
    /** Enable import tracking */
    val enableImportTracking: Boolean = true,
    
    /** Maximum cache size for tracking data */
    val maxCacheSize: Int = 10000,
    
    /** Whether to persist tracking data between sessions */
    val persistTrackingData: Boolean = true,
    
    /** Directory for storing incremental data */
    val incrementalDataDir: File? = null
)