Copy operations calculate required storage before conflict resolution dialog #474

private fun startCopyMove(...) {
    val availableSpace = destinationPath.getAvailableStorageB()
    val sumToCopy = files.sumByLong { it.getProperSize(applicationContext, copyHidden) }

    // ❌ Space check happens BEFORE checkConflicts
    if (availableSpace == -1L || sumToCopy < availableSpace) {
        checkConflicts(files, destinationPath, 0, LinkedHashMap()) { conflictResolutions ->
            // ...
        }
    } else {
        val text = String.format(getString(R.string.no_space), ...)
        toast(text, Toast.LENGTH_LONG)
    }
}

private fun startCopyMove(...) {
    // Step 1: Always resolve conflicts first
    checkConflicts(files, destinationPath, 0, LinkedHashMap()) { conflictResolutions ->
        
        // Step 2: Calculate effective transfer size based on conflict resolutions
        var effectiveSize = 0L
        for (file in files) {
            val newPath = "$destinationPath/${file.name}"
            val resolution = getConflictResolution(conflictResolutions, newPath)
            val fileExists = getDoesFilePathExist(newPath)
            
            when {
                fileExists && resolution == CONFLICT_SKIP -> { /* exclude skipped files */ }
                fileExists && resolution == CONFLICT_OVERWRITE -> { /* exclude overwritten bytes */ }
                else -> effectiveSize += file.getProperSize(applicationContext, copyHidden)
            }
        }
        
        val availableSpace = destinationPath.getAvailableStorageB()
        
        // Step 3: Check space using the effective size
        if (availableSpace != -1L && effectiveSize >= availableSpace) {
            val text = String.format(
                getString(R.string.no_space),
                effectiveSize.formatSize(),
                availableSpace.formatSize()
            )
            toast(text, Toast.LENGTH_LONG)
            return@checkConflicts
        }
        
        // Step 4: Proceed with operation
        toast(if (isCopyOperation) R.string.copying else R.string.moving)
        val pair = Pair(files, destinationPath)
        CopyMoveTask(
            activity = this,
            isCopyOperation = isCopyOperation,
            copyPhotoVideoOnly = copyPhotoVideoOnly,
            conflictResolutions = conflictResolutions,
            listener = copyMoveListener,
            copyHidden = copyHidden
        ).execute(pair)
    }
}