Merge pull request #5 from Muawiya-contact/SE-UNDO

Good work. Try to find more room for improvements.

Author: Muawiya-contact

SearchEngine.zip

@@ -1 +1,4 @@
-Python is a powerful programming language. It is widely used in data science, artificial intelligence, and web development. Its simple and readable syntax makes it an excellent choice for beginners. Many open-source libraries are available to extend its functionality.
+Python is a powerful programming language. 
+It is widely used in data science, artificial intelligence, and web development. 
+Its simple and readable syntax makes it an excellent choice for beginners. 
+Many open-source libraries are available to extend its functionality.

SearchEngine/__pycache__/search.cpython-312.pyc

@@ -1,4 +1,4 @@
-Data structures are a fundamental concept in computer science.
+Data structures are a fundamental concept in computer science or CS.
 They are used to organize and store data efficiently.
 Examples include arrays, linked lists, stacks, and queues. 
 Understanding these structures is key to writing effective algorithms.

SearchEngine/documents/doc1.txt

@@ -1 +1,3 @@
-An algorithm is a step-by-step procedure or formula for solving a problem. Algorithms are crucial in computer programming and are independent of the programming language. Searching and sorting are classic examples of problems solved with various algorithms.
+An algorithm is a step-by-step procedure or formula for solving a problem. 
+Algorithms are crucial in computer programming and are independent of the programming language. 
+Searching and sorting are classic examples of problems solved with various algorithms.

SearchEngine/documents/doc2.txt

@@ -1 +1,3 @@
-A stack is a linear data structure that follows the Last-In, First-Out (LIFO) principle. Think of it like a stack of plates. The last plate you put on top is the first one you take off. Operations on a stack include push (to add an item) and pop (to remove an item).
+A stack is a linear data structure that follows the Last-In, First-Out (LIFO) principle. 
+Think of it like a stack of plates. The last plate you put on top is the first one you take off. 
+Operations on a stack include push (to add an item) and pop (to remove an item).

SearchEngine/documents/doc3.txt

@@ -1 +1,3 @@
-The field of artificial intelligence, or AI, involves the development of computer systems that can perform tasks that would normally require human intelligence. This includes things like visual perception, speech recognition, decision-making, and language translation. Machine learning is a subfield of AI.
+The field of artificial intelligence, or AI, involves the development of computer systems that can perform tasks that would normally require human intelligence. 
+This includes things like visual perception, speech recognition, decision-making, and language translation. 
+Machine learning is a subfield of AI.

SearchEngine/documents/doc4.txt

@@ -4,14 +4,15 @@
 from index import InvertedIndex
 
 # Path to the folder that has all text files
-PATH = "./documents" # First we go to base dir
+PATH = "./documents" #  to base dir
 
 class SearchSim:
     """A simple search engine simulation."""
 
     def __init__(self, path=PATH):
         self.index = InvertedIndex()   # for word search
         self.history = Stack()         # to store search history
+        self.redo = Stack()            # to redo
         self.path = path               # folder path
         self.results = []              # last search results
         self._load()                   # load documents into index
@@ -35,13 +36,15 @@ def _load(self):
     def run(self):
         """Main loop for user interaction."""
         while True:
-            user_input = input("\nEnter search query, 'back', 'show', or 'quit': ").strip().lower()
+            user_input = input("\nEnter search query, 'back', 'next', 'show', or 'quit': ").strip().lower()
 
             if user_input == "quit":
                 print("Goodbye!")
                 break
             elif user_input == "back":
                 self._back()
+            elif user_input == "next":
+                self._next()
             elif user_input == "show":
                 self.history.show()
             elif user_input:   # if user typed something
@@ -66,8 +69,8 @@ def _search(self, query):
     def _open_doc(self):
         """Open and show the contents of a selected document."""
         while True:
-            choice = input("\nEnter document number to open, or 'next': ").strip().lower()
-            if choice == "next":
+            choice = input("\nEnter document number to open, or 'continue': ").strip().lower()
+            if choice == "continue":
                 break
             try:
                 num = int(choice)
@@ -78,7 +81,7 @@ def _open_doc(self):
                 else:
                     print("Invalid number.")
             except ValueError:
-                print("Please enter a valid number or 'next'.")
+                print("Please enter a valid number or 'continue'.")
             except FileNotFoundError:
                 print("File not found.")
 
@@ -88,8 +91,9 @@ def _back(self):
             print("No previous search available.")
             return
 
-        self.history.pop()   # remove current search
-        prev_query = self.history.peek()  # last one left
+        current = self.history.pop()     # remove current
+        self.redo.push(current)          # store it for redo
+        prev_query = self.history.peek() # now last one left
         print(f"\nBack to: '{prev_query}'")
 
         self.results = self.index.search(prev_query)
@@ -99,3 +103,21 @@ def _back(self):
             for i, r in enumerate(self.results, start=1):
                 print(f"{i}. {r['doc']}.txt | Score: {r['score']}")
             self._open_doc()
+
+    def _next(self):
+        """Redo the last undone search query."""
+        if self.redo.empty():
+            print("Nothing to Redo!")
+            return
+
+        redo_query = self.redo.pop()     # get last undone query
+        self.history.push(redo_query)    # put it back into history
+        print(f"\nRedo: '{redo_query}'")
+
+        self.results = self.index.search(redo_query)
+        if not self.results:
+            print("No matches found.")
+        else:
+            for i, r in enumerate(self.results, start=1):
+                print(f"{i}. {r['doc']}.txt | Score: {r['score']}")
+            self._open_doc()