Merge pull request #8 from ajschofield/refining-phase

mostly minor changes (fixing things up)

7 files changed, 161 insertions, 154 deletions

diff --git a/obfuscator/csv_reader.py b/obfuscator/csv_reader.py
deleted file mode 100644
index 8f4ebea..0000000
--- a/obfuscator/csv_reader.py
+++ /dev/null
@@ -1,97 +0,0 @@
-import csv
-import io
-import boto3
-import os
-from typing import List, Dict
-from obfuscator.logger import get_logger
-from obfuscator.utils import get_s3_path
-
-# Create the logger
-logger = get_logger("CSVReader")
-
-# Putting the CSV reading components into a class may seem like overkill
-# for a simple script, but it allows for better organization and scalability.
-# @staticmethod is used to define the method without an instance of the class
-# being required. The methods could be defined just as functions, and this
-# may still be changed.
-
-
-class CSVReader:
-    """
-    A class to read CSV data from a local file, S3 object, or string. Near
-    the project completion, support for JSON/Parquet files will be added.
-    """
-
-    @staticmethod
-    def read_local(path) -> List[Dict[str, str]]:
-        """
-        A method to read a local CSV file and return the data as a list of
-        dictionaries.
-        """
-        # Log the path of the file being read for debugging
-        logger.debug(f"Reading local CSV from: {path}")
-
-        # Attempt to read the file and return the data as a list of dictionaries
-        # However, if the file isn't found or there is a generic exception, log
-        # the error and raise an exception
-        try:
-            with open(path, mode="r", encoding="utf-8") as f:
-                reader = csv.DictReader(f)
-                return [dict(row) for row in reader]
-        except FileNotFoundError:
-            logger.error(f"File not found: {path}")
-            raise
-        except Exception as e:
-            logger.error(f"Error reading file: {e}")
-
-    @staticmethod
-    def read_s3(path) -> List[Dict[str, str]]:
-        """
-        A method to read an S3 object containing CSV data
-        and return the data as a list of dictionaries.
-        """
-        bucket, key = get_s3_path(path)
-        logger.debug(f"Reading S3 CSV from: {bucket}/{key}")
-
-        # If DEBUG=TRUE, use the localstack endpoint for testing
-        if os.getenv("DEBUG", "FALSE").upper() == "TRUE":
-            localstack_endpoint = "http://localhost.localstack.cloud:4566"
-            logger.debug("Using LocalStack endpoint for S3")
-            client = boto3.client(
-                "s3",
-                endpoint_url=localstack_endpoint,
-                aws_access_key_id="dummy",
-                aws_secret_access_key="dummy",
-            )
-            logger.debug(f"endpoint_url: {localstack_endpoint}")
-        else:
-            client = boto3.client("s3")
-
-        try:
-            # Attempt to read the S3 object and return the data as a list of dictionaries
-            response = client.get_object(Bucket=bucket, Key=key)
-            logger.info("S3 object read successfully")
-            # Read and decode the content
-            content = response["Body"].read().decode("utf-8")
-            # Even though the read_string method was only created for testing,
-            # it can be reused here to read and return the CSV data
-            return CSVReader.read_string(content)
-        # TODO: Add more specific exceptions to catch
-        except Exception as e:
-            logger.error(f"Error reading S3 object: {e}")
-            raise
-
-    @staticmethod
-    def read_string(content: str) -> List[Dict[str, str]]:
-        """
-        A method to read CSV data from a string and return the data as a list
-        of dictionaries.
-        """
-        # If the content is empty, return an empty list
-        if not content.strip():
-            return []
-
-        # Treat the string as a file-like object and return as list of dictionaries
-        f = io.StringIO(content)
-        reader = csv.DictReader(f)
-        return [dict(row) for row in reader]
diff --git a/obfuscator/csv_writer.py b/obfuscator/csv_writer.py
deleted file mode 100644
index aa5ac3f..0000000
--- a/obfuscator/csv_writer.py
+++ /dev/null
@@ -1,26 +0,0 @@
-import csv
-import io
-from typing import List, Dict
-from obfuscator.logger import get_logger
-
-# Create the logger
-logger = get_logger("CSVWriter")
-
-
-def create_byte_stream(data: List[Dict[str, str]]) -> bytes:
-    if not data:
-        logger.info("No valid data was provided to write")
-        return b""
-
-    output = io.StringIO()
-
-    headers = list(data[0].keys())
-
-    writer = csv.DictWriter(output, fieldnames=headers)
-    writer.writeheader()
-    writer.writerows(data)
-
-    csv_string = output.getvalue()
-    logger.debug(f"CSV data: {csv_string}")
-
-    return csv_string.encode("utf-8")
diff --git a/obfuscator/logger.py b/obfuscator/logger.py
index ca41e95..140fa8f 100644
--- a/obfuscator/logger.py
+++ b/obfuscator/logger.py
@@ -1,24 +1,36 @@
 import logging
 import os
+from enum import Enum
 
 
-def get_logger(name: str) -> logging.Logger:
-    logger = logging.getLogger(name)
+class LogLevel(Enum):
+    DEBUG = logging.DEBUG
+    INFO = logging.INFO
+    WARNING = logging.WARNING
+    ERROR = logging.ERROR
+    CRITICAL = logging.CRITICAL
+
 
-    if not logger.hasHandlers():
-        if os.getenv("DEBUG", "FALSE").upper() == "TRUE":
-            log_level = logging.DEBUG
-        else:
-            log_level = logging.INFO
+def get_logger(name: str, level: LogLevel = LogLevel.INFO) -> logging.Logger:
+    if isinstance(level, str):
+        try:
+            level = LogLevel[level.upper()]
+        except KeyError:
+            raise ValueError(
+                f"Invalid log level '{level}'. Choose from: {', '.join(l.name for l in LogLevel)}"
+            )
 
-        logger.setLevel(log_level)
+    logger = logging.getLogger(name)
 
-        handler = logging.StreamHandler()
-        formatting = logging.Formatter(
-            "%(asctime)s - %(levelname)s - %(name)s - %(message)s"
-        )
-        handler.setFormatter(formatting)
+    if logger.hasHandlers():
+        logger.handlers.clear()
 
-        logger.addHandler(handler)
+    handler = logging.StreamHandler()
+    logger.setLevel(level.value)
+    formatting = logging.Formatter(
+        "[%(asctime)s] - %(levelname)s::%(name)s - %(message)s"
+    )
+    handler.setFormatter(formatting)
+    logger.addHandler(handler)
 
     return logger
diff --git a/obfuscator/obfuscate.py b/obfuscator/obfuscate.py
index 3f589cb..cd12b6d 100644
--- a/obfuscator/obfuscate.py
+++ b/obfuscator/obfuscate.py
@@ -1,8 +1,7 @@
 from typing import List, Dict
 from obfuscator.logger import get_logger
 
-# Create the logger
-logger = get_logger("Obfuscator")
+logger = get_logger("OBFUSCATE")
 
 
 def obfuscate(
@@ -12,14 +11,15 @@ def obfuscate(
     A function to obfuscate PII fields in a list of dictionaries, replacing
     sensitive values with a string of asterisks.
     """
-    # If no data is provided, log a message and return an empty list
     if not data:
-        logger.info("No valid data was provided to obfuscate")
+        logger.error(
+            "Invalid or empty data was provided to obfuscate. Returning empty list."
+        )
         return []
+    if not pii_fields:
+        logger.error("No PII fields provided to obfuscate. Returning data unchanged.")
+        return data
 
-    # Obfuscate the PII fields in each record using a list/dict comprehension
-    # This code is good but makes debugging a bit tricky. I may consider
-    # breaking it down into a for loop.
     return [
         {k: ("***" if k in pii_fields else v) for k, v in record.items()}
         for record in data
diff --git a/obfuscator/read.py b/obfuscator/read.py
new file mode 100644
index 0000000..b704643
--- /dev/null
+++ b/obfuscator/read.py
@@ -0,0 +1,89 @@
+import csv
+import io
+import boto3
+import os
+from typing import List, Dict
+from obfuscator.logger import get_logger
+from obfuscator.utils import Utilities
+
+
+class DataReader:
+    """
+    A class to read CSV data from a local file, S3 object, or string. Near
+    the project completion, support for JSON/Parquet files will be added.
+    """
+
+    def __init__(self, log_level=None):
+        self.log_level = log_level
+        self.logger = get_logger("CSVREADER", log_level)
+
+    def read_local(self, path) -> List[Dict[str, str]]:
+        """
+        A method to read a local CSV file and return the data as a list of
+        dictionaries.
+        """
+        self.logger.debug(f"Reading local CSV from: {path}")
+
+        try:
+            with open(path, mode="r", encoding="utf-8") as f:
+                reader = csv.DictReader(f)
+                return [dict(row) for row in reader]
+        except FileNotFoundError:
+            self.logger.error(f"File not found: {path}")
+            raise
+        except Exception as e:
+            self.logger.error(f"Error reading file: {e}")
+
+    def read_s3(self, path) -> List[Dict[str, str]]:
+        """
+        A method to read an S3 object containing CSV data
+        and return the data as a list of dictionaries.
+        """
+        utils = Utilities(self.log_level)
+        bucket, key = utils.get_s3_path(path)
+        self.logger.debug(f"Reading S3 CSV from: {bucket}/{key}")
+
+        if os.getenv("LOCALSTACK", "FALSE").upper() == "TRUE":
+            localstack_endpoint = "http://localhost.localstack.cloud:4566"
+            self.logger.debug(
+                "Using LocalStack endpoint for S3 - ensure LocalStack is running"
+            )
+            client = boto3.client(
+                "s3",
+                endpoint_url=localstack_endpoint,
+                aws_access_key_id="dummy",
+                aws_secret_access_key="dummy",
+            )
+            self.logger.debug(f"endpoint_url: {localstack_endpoint}")
+        else:
+            client = boto3.client("s3")
+
+        try:
+            response = client.get_object(Bucket=bucket, Key=key)
+            self.logger.info("S3 object read successfully")
+            content = response["Body"].read().decode("utf-8")
+            return self.read_string(content)
+        except client.exceptions.NoSuchKey:
+            self.logger.error(f"Object not found: {bucket}/{key}")
+            raise
+        except client.exceptions.ClientError as e:
+            self.logger.error(f"Error reading S3 object: {e}")
+            raise
+        except UnicodeDecodeError as e:
+            self.logger.error(f"Error decoding S3 object: {e}")
+            raise
+        except Exception as e:
+            self.logger.error(f"Error reading S3 object: {e}")
+            raise
+
+    def read_string(self, content: str) -> List[Dict[str, str]]:
+        """
+        A method to read CSV data from a string and return the data as a list
+        of dictionaries.
+        """
+        if not content.strip():
+            return []
+
+        f = io.StringIO(content)
+        reader = csv.DictReader(f)
+        return [dict(row) for row in reader]
diff --git a/obfuscator/utils.py b/obfuscator/utils.py
index 2e4211f..77ca1cf 100644
--- a/obfuscator/utils.py
+++ b/obfuscator/utils.py
@@ -1,15 +1,16 @@
 # Utility functions
 from obfuscator.logger import get_logger
 
-# Create the logger
-logger = get_logger("CLI")
 
+class Utilities:
+    def __init__(self, logger=None):
+        self.logger = get_logger("UTILITIES", logger)
 
-def get_s3_path(uri):
-    parts = uri.replace("s3://", "").split("/")
-    logger.debug(f"Parts: {parts}")
-    bucket = parts.pop(0)
-    logger.debug(f"Bucket: {bucket}")
-    key = "/".join(parts)
-    logger.debug(f"Key: {key}")
-    return bucket, key
+    def get_s3_path(self, uri):
+        parts = uri.replace("s3://", "").split("/")
+        self.logger.debug(f"Parts: {parts}")
+        bucket = parts.pop(0)
+        self.logger.debug(f"Bucket: {bucket}")
+        key = "/".join(parts)
+        self.logger.debug(f"Key: {key}")
+        return bucket, key
diff --git a/obfuscator/write.py b/obfuscator/write.py
new file mode 100644
index 0000000..451b073
--- /dev/null
+++ b/obfuscator/write.py
@@ -0,0 +1,28 @@
+import csv
+import io
+from typing import List, Dict
+from obfuscator.logger import get_logger
+
+logger = get_logger("CSVWRITER")
+
+
+class DataWriter:
+    def __init__(self):
+        pass
+
+    def create_byte_stream(self, data: List[Dict[str, str]]) -> bytes:
+        if not data:
+            logger.error("Invalid or empty data was provided to write")
+            return b""
+
+        output = io.StringIO()
+
+        headers = list(data[0].keys())
+
+        writer = csv.DictWriter(output, fieldnames=headers)
+        writer.writeheader()
+        writer.writerows(data)
+
+        csv_string = output.getvalue()
+
+        return csv_string.encode("utf-8")