feat: Add FileInfoQuery (#181)

* feat: add FileInfo class

Signed-off-by: dosi <[email protected]>

* test: add FileInfo unit tests

Signed-off-by: dosi <[email protected]>

* feat: add FileInfoQuery

Signed-off-by: dosi <[email protected]>

* test: add FileInfoQuery unit tests

Signed-off-by: dosi <[email protected]>

* test: add integration tests for FileInfoQuery

Signed-off-by: dosi <[email protected]>

* docs: update examples README

Signed-off-by: dosi <[email protected]>

* docs: add file info query example

Signed-off-by: dosi <[email protected]>

* chore: add FileInfoQuery to __init__.py

Signed-off-by: dosi <[email protected]>

* chore: add Optional in set_file_id()

Signed-off-by: dosi <[email protected]>

* chore: add FileInfo to __init__.py

Signed-off-by: dosi <[email protected]>

* chore: add traceback.print_exec() to address PR feedback

Signed-off-by: dosi <[email protected]>

* chore: remove trailing

Signed-off-by: dosi <[email protected]>

* docs: update example to address PR feedback

Signed-off-by: dosi <[email protected]>

* test: update integration tests

Signed-off-by: dosi <[email protected]>

* test: add integration test for invalid file id

Signed-off-by: dosi <[email protected]>

* style: update linting and type hinting in file info query

Signed-off-by: dosi <[email protected]>

* style: update linting and type hinting in file info unit test

Signed-off-by: dosi <[email protected]>

---------

Signed-off-by: dosi <[email protected]>

Author: Dosik13

examples/README.md

@@ -48,6 +48,7 @@ You can choose either syntax or even mix both styles in your projects.
   - [Querying Topic Message](#querying-topic-message)
 - [File Transactions](#file-transactions)
   - [Creating a File](#creating-a-file)
+  - [Querying File Info](#querying-file-info)
 - [Miscellaneous Queries](#miscellaneous-queries)
   - [Querying Transaction Record](#querying-transaction-record)
 
@@ -939,6 +940,28 @@ transaction.execute(client)
 
     transaction.execute(client)
 
+```
+
+### Querying File Info
+
+#### Pythonic Syntax:
+```
+file_info_query = FileInfoQuery(file_id=file_id)
+file_info = file_info_query.execute(client)
+print(file_info)
+```
+
+#### Method Chaining:
+```
+file_info = (
+    FileInfoQuery()
+    .set_file_id(file_id)
+    .execute(client)
+)
+print(file_info)
+
+```
+
 ## Miscellaneous Queries
 
 ### Querying Transaction Record

examples/query_file_info.py

@@ -0,0 +1,81 @@
+"""
+This example demonstrates how to query file info using the Python SDK.
+"""
+
+import os
+import sys
+
+from dotenv import load_dotenv
+
+from hiero_sdk_python import AccountId, Client, Network, PrivateKey
+from hiero_sdk_python.file.file_create_transaction import FileCreateTransaction
+from hiero_sdk_python.file.file_info_query import FileInfoQuery
+from hiero_sdk_python.response_code import ResponseCode
+
+load_dotenv()
+
+
+def setup_client():
+    """Initialize and set up the client with operator account"""
+    network = Network(network="testnet")
+    client = Client(network)
+
+    operator_id = AccountId.from_string(os.getenv("OPERATOR_ID"))
+    operator_key = PrivateKey.from_string(os.getenv("OPERATOR_KEY"))
+    client.set_operator(operator_id, operator_key)
+
+    return client
+
+
+def create_file(client: Client):
+    """Create a test file"""
+    file_private_key = PrivateKey.generate_ed25519()
+
+    receipt = (
+        FileCreateTransaction()
+        .set_keys([file_private_key.public_key(), client.operator_private_key.public_key()])
+        .set_contents(b"Hello, this is a test file for querying!")
+        .set_file_memo("Test file for query")
+        .freeze_with(client)
+        .sign(file_private_key)
+        .execute(client)
+    )
+
+    if receipt.status != ResponseCode.SUCCESS:
+        print(f"File creation failed with status: {ResponseCode(receipt.status).name}")
+        sys.exit(1)
+
+    file_id = receipt.file_id
+    print(f"\nFile created with ID: {file_id}")
+
+    return file_id
+
+
+def query_file_info():
+    """
+    Demonstrates querying file info by:
+    1. Setting up client with operator account
+    2. Creating a test file
+    3. Querying the file info
+    """
+    client = setup_client()
+
+    # Create a test file first
+    file_id = create_file(client)
+
+    info = FileInfoQuery().set_file_id(file_id).execute(client)
+
+    print("\nFile Info:")
+    print(f"File ID: {info.file_id}")
+    print(f"Size: {info.size} bytes")
+    print(f"Memo: {info.file_memo}")
+    print(f"Expiration Time: {info.expiration_time}")
+    print(f"Deleted: {info.is_deleted}")
+    print(f"Total key(s): {len(info.keys)}")
+    for i, key in enumerate(info.keys, 1):
+        print(f"Key {i}: {key.to_string()}")
+
+
+if __name__ == "__main__":
+    query_file_info()
+

src/hiero_sdk_python/__init__.py

@@ -81,6 +81,8 @@
 
 # File
 from .file.file_create_transaction import FileCreateTransaction
+from .file.file_info_query import FileInfoQuery
+from .file.file_info import FileInfo
 
 __all__ = [
     # Client
@@ -162,4 +164,6 @@
 
     # File
     "FileCreateTransaction",
+    "FileInfoQuery",
+    "FileInfo",
 ]

src/hiero_sdk_python/file/file_info.py

@@ -0,0 +1,113 @@
+from dataclasses import dataclass, field
+import datetime
+from typing import Optional
+from hiero_sdk_python.crypto.public_key import PublicKey
+from hiero_sdk_python.file.file_id import FileId
+from hiero_sdk_python.timestamp import Timestamp
+from hiero_sdk_python.hapi.services.file_get_info_pb2 import FileGetInfoResponse
+from hiero_sdk_python.hapi.services.basic_types_pb2 import KeyList as KeyListProto
+
+@dataclass
+class FileInfo:
+    """
+    Information about a file stored on the Hedera network.
+    
+    Attributes:
+        file_id (Optional[FileId]): The ID of the file
+        size (Optional[int]): The size of the file in bytes
+        expiration_time (Optional[Timestamp]): When the file will expire
+        is_deleted (Optional[bool]): Whether the file has been deleted
+        keys (list[PublicKey]): The keys that can modify this file
+        file_memo (Optional[str]): The memo associated with the file
+        ledger_id (Optional[bytes]): The ID of the ledger this file exists in
+    """
+    file_id: Optional[FileId] = None
+    size: Optional[int] = None
+    expiration_time: Optional[Timestamp] = None
+    is_deleted: Optional[bool] = None
+    keys: list[PublicKey] = field(default_factory=list)
+    file_memo: Optional[str] = None
+    ledger_id: Optional[bytes] = None
+
+    @classmethod
+    def _from_proto(cls, proto: FileGetInfoResponse.FileInfo) -> 'FileInfo':
+        """
+        Creates a FileInfo instance from its protobuf representation.
+
+        Args:
+            proto (FileGetInfoResponse.FileInfo): The protobuf to convert from.
+
+        Returns:
+            FileInfo: A new FileInfo instance.
+        """
+        if proto is None:
+            raise ValueError("File info proto is None")
+        
+        return cls(
+            file_id=FileId._from_proto(proto.fileID),
+            size=proto.size,
+            expiration_time=Timestamp._from_protobuf(proto.expirationTime),
+            is_deleted=proto.deleted,
+            keys=[PublicKey._from_proto(key) for key in proto.keys.keys],
+            file_memo=proto.memo,
+            ledger_id=proto.ledger_id
+        )
+
+    def _to_proto(self) -> FileGetInfoResponse.FileInfo:
+        """
+        Converts this FileInfo instance to its protobuf representation.
+
+        Returns:
+            FileGetInfoResponse.FileInfo: The protobuf representation of this FileInfo.
+        """
+        return FileGetInfoResponse.FileInfo(
+            fileID=self.file_id._to_proto() if self.file_id else None,
+            size=self.size,
+            expirationTime=self.expiration_time._to_protobuf() if self.expiration_time else None,
+            deleted=self.is_deleted,
+            keys=KeyListProto(keys=[key._to_proto() for key in self.keys or []]),
+            memo=self.file_memo,
+            ledger_id=self.ledger_id
+        )
+        
+    def __repr__(self) -> str:
+        """
+        Returns a string representation of the FileInfo object.
+
+        Returns:
+            str: A string representation of the FileInfo object.
+        """
+        return self.__str__()
+
+    def __str__(self) -> str:
+        """
+        Pretty-print the FileInfo.
+        """
+        # Format expiration time as datetime if available
+        exp_dt = (
+            datetime.datetime.fromtimestamp(self.expiration_time.seconds)
+            if self.expiration_time and hasattr(self.expiration_time, "seconds")
+            else self.expiration_time
+        )
+
+        # Format keys as readable strings
+        keys_str = [key.to_string() for key in self.keys] if self.keys else []
+
+        # Format ledger_id as hex if it's bytes
+        ledger_id_display = (
+            f"0x{self.ledger_id.hex()}"
+            if isinstance(self.ledger_id, (bytes, bytearray))
+            else self.ledger_id
+        )
+
+        return (
+            "FileInfo(\n"
+            f"  file_id={self.file_id},\n"
+            f"  size={self.size},\n"
+            f"  expiration_time={exp_dt},\n"
+            f"  is_deleted={self.is_deleted},\n"
+            f"  keys={keys_str},\n"
+            f"  file_memo='{self.file_memo}',\n"
+            f"  ledger_id={ledger_id_display}\n"
+            ")"
+        )

src/hiero_sdk_python/file/file_info_query.py

@@ -0,0 +1,139 @@
+"""
+Query to get information about a file on the network.
+"""
+
+import traceback
+from typing import Optional
+
+from hiero_sdk_python.channels import _Channel
+from hiero_sdk_python.client.client import Client
+from hiero_sdk_python.executable import _Method
+from hiero_sdk_python.file.file_id import FileId
+from hiero_sdk_python.file.file_info import FileInfo
+from hiero_sdk_python.hapi.services import file_get_info_pb2, query_pb2, response_pb2
+from hiero_sdk_python.hapi.services.file_get_info_pb2 import FileGetInfoResponse
+from hiero_sdk_python.query.query import Query
+
+
+class FileInfoQuery(Query):
+    """
+    A query to retrieve information about a specific File.
+
+    This class constructs and executes a query to retrieve information
+    about a file on the network, including the file's properties and settings.
+
+    """
+
+    def __init__(self, file_id: Optional[FileId] = None) -> None:
+        """
+        Initializes a new FileInfoQuery instance with an optional file_id.
+
+        Args:
+            file_id (Optional[FileId], optional): The ID of the file to query.
+        """
+        super().__init__()
+        self.file_id: Optional[FileId] = file_id
+
+    def set_file_id(self, file_id: Optional[FileId]) -> "FileInfoQuery":
+        """
+        Sets the ID of the file to query.
+
+        Args:
+            file_id (Optional[FileId]): The ID of the file.
+
+        Returns:
+            FileInfoQuery: Returns self for method chaining.
+        """
+        self.file_id = file_id
+        return self
+
+    def _make_request(self) -> query_pb2.Query:
+        """
+        Constructs the protobuf request for the query.
+
+        Builds a FileGetInfoQuery protobuf message with the
+        appropriate header and file ID.
+
+        Returns:
+            Query: The protobuf query message.
+
+        Raises:
+            ValueError: If the file ID is not set.
+            Exception: If any other error occurs during request construction.
+        """
+        try:
+            if not self.file_id:
+                raise ValueError("File ID must be set before making the request.")
+
+            query_header = self._make_request_header()
+
+            file_info_query = file_get_info_pb2.FileGetInfoQuery()
+            file_info_query.header.CopyFrom(query_header)
+            file_info_query.fileID.CopyFrom(self.file_id._to_proto())
+
+            query = query_pb2.Query()
+            query.fileGetInfo.CopyFrom(file_info_query)
+
+            return query
+        except Exception as e:
+            print(f"Exception in _make_request: {e}")
+            traceback.print_exc()
+            raise
+
+    def _get_method(self, channel: _Channel) -> _Method:
+        """
+        Returns the appropriate gRPC method for the file info query.
+
+        Implements the abstract method from Query to provide the specific
+        gRPC method for getting file information.
+
+        Args:
+            channel (_Channel): The channel containing service stubs
+
+        Returns:
+            _Method: The method wrapper containing the query function
+        """
+        return _Method(transaction_func=None, query_func=channel.file.getFileInfo)
+
+    def execute(self, client: Client) -> FileInfo:
+        """
+        Executes the file info query.
+
+        Sends the query to the Hedera network and processes the response
+        to return a FileInfo object.
+
+        This function delegates the core logic to `_execute()`, and may propagate
+        exceptions raised by it.
+
+        Args:
+            client (Client): The client instance to use for execution
+
+        Returns:
+            FileInfo: The file info from the network
+
+        Raises:
+            PrecheckError: If the query fails with a non-retryable error
+            MaxAttemptsError: If the query fails after the maximum number of attempts
+            ReceiptStatusError: If the query fails with a receipt status error
+        """
+        self._before_execute(client)
+        response = self._execute(client)
+
+        return FileInfo._from_proto(response.fileGetInfo.fileInfo)
+
+    def _get_query_response(
+        self, response: response_pb2.Response
+    ) -> FileGetInfoResponse.FileInfo:
+        """
+        Extracts the file info response from the full response.
+
+        Implements the abstract method from Query to extract the
+        specific file info response object.
+
+        Args:
+            response: The full response from the network
+
+        Returns:
+            The file get info response object
+        """
+        return response.fileGetInfo