add generic json reader

beancount_reds_importers/libreader/jsonreader.py

@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+
+"""JSON reader for beancount-reds-importers.
+
+JSON files have widely varying specifications, and thus, this is a very generic reader, and most of
+the logic will have to be the institution specific readers.
+
+"""
+
+import json
+
+from beancount.ingest import importer
+from beancount_reds_importers.libreader import reader
+
+class Importer(reader.Reader, importer.ImporterProtocol):
+    FILE_EXTS = ["json"]
+
+    def initialize_reader(self, file):
+        if getattr(self, "file", None) != file:
+            self.file = file
+            self.reader_ready = False
+            with open(file.name, 'r') as f:
+                self.json_data = json.load(f)
+            self.reader_ready = self.deep_identify(file)
+        if self.reader_ready:
+            self.set_currency()
+
+    def deep_identify(self, file):
+        """For overriding by institution specific importer which can check if an account name
+        matches, and other such things."""
+        # default value to False, else jsonreader.initialize_reader fail to execute because missing attribut "config"
+        return False
+
+    def file_date(self, file):
+        """Get the ending date of the statement."""
+        if not getattr(self, "json_data", None):
+            self.initialize(file)
+        # TODO:
+        return None
+
+    def read_file(self, file):
+        with open(file.name, 'r') as f:
+            self.json_data = json.load(f)
+
+    def get_json_elements(self, json_path, json_interpreter=lambda x: x):
+        """Extract a list of elements in the JSON file at the given JSON path. Typically,
+        transactions are stored in a JSON path, and this extracts them."""
+        elements = self.json_data
+        for key in json_path.split('.'):
+            if key in elements:
+                elements = elements[key]
+            else:
+                return []
+        for elem in elements:
+            yield json_interpreter(elem)
+
+    def get_transactions(self):
+        """/Transactions/Transaction is a dummy default path for transactions that needs to be
+        overriden in the institution specific importer."""
+        yield from self.get_json_elements("Transactions.Transaction")