function reprocessFile()

in common.js [842:914]
53 lines of code
7 McCabe index (conditional complexity)

function reprocessFile(dynamoDB, s3, region, file, callback) {
    // get the file so we know what the current batch ID is
    var fileItem = {
        Key: {
            loadFile: {
                S: file
            }
        },
        TableName: filesTable
    };
    dynamoDB.getItem(fileItem, function (err, data) {
        if (err) {
            if (callback) {
                callback(err);
            }
        } else {
            if (data.Item.batchId && data.Item.batchId.S) {
                var updateExpr = "remove #batchId ";

                if (data.Item.previousBatches) {
                    // add to the end of the list
                    updateExpr = updateExpr + "set previousBatches = list_append(previousBatches,:oldBatch)"
                } else {
                    // create a new list
                    updateExpr = updateExpr + "set previousBatches = :oldBatch";
                }

                // rotate the current batch information onto a tracking list
                var update = {
                    Key: {
                        loadFile: {
                            S: file
                        }
                    },
                    TableName: filesTable,
                    ExpressionAttributeNames: {
                        "#batchId": "batchId"
                    },
                    ExpressionAttributeValues: {
                        ":oldBatch": {
                            L: [
                                {S: "" + data.Item.batchId.S}
                            ]
                        }
                    },
                    UpdateExpression: updateExpr,
                    ReturnValues: "ALL_NEW"
                };

                dynamoDB.updateItem(update, function (err, data) {
                    if (err) {
                        callback(err);
                    } else {
                        // now the file needs an in-place copy with new metadata
                        // to cause a reprocess
                        inPlaceCopyFile(s3, undefined, file, function (err, data) {
                            if (callback) {
                                callback(err);
                            }
                        });
                    }
                });
            } else {
                // not currently assigned to a batch, so just do an s3 update
                inPlaceCopyFile(s3, undefined, file, function (err, data) {
                    if (callback) {
                        callback(err);
                    }
                });
            }
        }
    });
}