feat: add caching feature (#7)

A basic caching feature has been added. It stores newly searched words
in a file named .cambd-cache.json in $HOME. And for every new word
lookup, it checks the cache file if the definition for that specific word
already exists. If yes then return immediately else fetch the new
definition and add it to the cache file for future reference.

fixes #6

Makefile

@@ -1,12 +1,12 @@
-dest_dir := /usr/local/src/cambd-cli
-bin_file := /usr/bin/cambd
+DIST = /usr/local/src/cambd-cli
+BIN = /usr/bin/cambd
 
 install:
-	cp -f cambd-cli/cambd.sh $(bin_file)
-	chmod +x $(bin_file)
-	mkdir -m 777 -p $(dest_dir)
-	cp -f cambd-cli/cambd.py $(dest_dir)/cambd.py
-	@echo "\nInstall successful ✅"
+	cp -f cambd-cli/cambd.sh $(BIN)
+	chmod +x $(BIN)
+	mkdir -m 777 -p $(DIST)
+	cp -f cambd-cli/cambd.py $(DIST)
+	@echo "Install successful."
 
 uninstall:
 	rm -rf $(bin_file)

README.md

@@ -42,22 +42,23 @@ cambd neccesseery
 
 > The above word spelling is incorrect. So cambd will suggest related words.
 
-## Uninstall
-
-To uninstall you can run the below command from the `cambd-cli` directory
-
-```sh
-sudo make uninstall
-```
-
 ## TODO:
 
 - [x] Add loading animation
 - [x] Handle error for getting definition of words with spaces
 - [x] Show only 2 examples per definition by default
-- [ ] Implement a basic local caching mechanism
+- [x] Implement a basic local caching mechanism
 - [ ] Add flag to show all definitions. Default is 1
 
+## Caching
+
+This is how the basic caching feature is implemented
+
+- Search definition for given word in the CLI.
+- Check if the word was already looked up before in the cache file in `$HOME`.
+- If yes then return it from the cache file immediently.
+- If not fetch the new definition and add it to the cache file for future usecase.
+
 ## LICENSE
 
 [MIT](./LICENSE) License © [Rocktim Saikia](https://rocktimsaikia.com) 2022

cambd-cli/cambd.py

@@ -1,18 +1,22 @@
 #!/bin/env python3
 
+import os
+import re
 import sys
+import yaml
+import json
 import requests
 from bs4 import BeautifulSoup
 from simple_term_menu import TerminalMenu
 from halo import Halo
-import yaml
-import re
 
 spinner = Halo(text="Loading", spinner="dots")
 
+# Don't touch this. Unless you want to deal with permission issues in other places
+cached_dictionary = os.path.expanduser("~") + "/.cambd-cache.json"
+
 spellcheck_url = "https://dictionary.cambridge.org/spellcheck/english/?q="
 definition_url = "https://dictionary.cambridge.org/dictionary/english/"
-# This is needed to not get detected as a bot
 headers = {"User-Agent": "Mozilla/5.0"}
 
 
@@ -31,11 +35,36 @@ def get_suggestions(word: str) -> list[str]:
     return suggested_words
 
 
+def is_cached(word: str):
+    # File exists and has content
+    if os.path.exists(cached_dictionary) and os.path.getsize(cached_dictionary) > 0:
+        with open(cached_dictionary, "r") as file:
+            file_data = json.load(file)
+            if word in file_data:
+                return file_data[word]
+
+
+def cache_it(word, definitions):
+    # File does not exists or file is empty;
+    if not os.path.exists(cached_dictionary) or os.path.getsize(cached_dictionary) == 0:
+        with open(cached_dictionary, "w") as ofile:
+            json.dump({word: definitions}, ofile)
+            return
+
+    # Content already exists, append
+    with open(cached_dictionary, "r+") as ofile:
+        file_data = json.load(ofile)
+        file_data[word] = definitions
+        ofile.seek(0)
+        json.dump(file_data, ofile)
+
+
 @spinner
 def get_definitions(word: str) -> list[str]:
-    # In browser, getting definition for word with spaces inbetween automatically formats dashes (-) replacing the spaces
-    # Replicating the same behaviour here too for consistency
-    word = word.strip().replace(" ", "-")
+    # Return cahced version if available
+    cached_word = is_cached(word)
+    if cached_word is not None:
+        return cached_word
 
     response = requests.get(definition_url + word, headers=headers)
 
@@ -76,7 +105,8 @@ def get_definitions(word: str) -> list[str]:
 
 def main():
     arg = sys.argv[1:][0]
-    definitions = get_definitions(arg)
+    word = arg.strip().replace(" ", "-").lower()
+    definitions = get_definitions(word)
 
     if len(definitions) == 0:
         suggestions = get_suggestions(arg)
@@ -86,12 +116,13 @@ def main():
         menu_entry_index = terminal_menu.show()
 
         if type(menu_entry_index) is int:
-            arg = suggestions[menu_entry_index]
-            definitions = get_definitions(arg)
+            suggested_word = suggestions[menu_entry_index]
+            definitions = get_definitions(suggested_word)
 
     spinner.succeed(f"Showing definition for: \033[1m{arg}\033[0m")
 
     print("\n" + yaml.dump(definitions[0], indent=3, sort_keys=False))
+    cache_it(word, definitions)
 
 
 if __name__ == "__main__":