📝 To-Do List App

A simple, efficient command-line to-do list manager built with Go. Manage your tasks directly from the terminal with an intuitive interface. This project was based on the following YouTube tutorial: "How to Build A CLI Todo App in Go" by Coding with Patrik. Link: https://www.youtube.com/watch?v=g16Zf0KQEWI It is intended for learning purposes.

✨ Features

• ✅ Add tasks - Quickly add new to-do items with priority levels
• 🗑️ Delete tasks - Remove completed or unwanted tasks
• ✏️ Edit tasks - Update task titles anytime
• ✔️ Toggle completion - Mark tasks as done/undone with timestamps
• 🎯 Priority levels - Categorize tasks as Low, Medium, or High priority
• 🏷️ Tags/Categories - Organize tasks with custom tags
• 📅 Due dates - Set deadlines for your tasks with reminders
• 🔍 Search functionality - Find tasks by title
• 🏷️ Filter by tags - View tasks by category
• 📊 Statistics - See task completion progress and priority breakdown
• 🔄 Sorting - Sort tasks by priority or creation date
• 💾 Persistent storage - All tasks saved to JSON file
• 📊 Beautiful CLI table - View all tasks in a colored, formatted table
• 🎨 Color-coded output - Priorities and completion status shown with colors

🚀 Getting Started

Prerequisites

• Go 1.18 or higher installed on your machine

Installation

1. Clone the repository:

git clone https://github.com/ybrodsky-rh/ToDoListApp.git
cd ToDoListApp

2. Install dependencies:

go mod download

3. Build the application:

go build

📖 Usage

Add a Task (Basic)

./ToDoListApp -add "Buy groceries"
./ToDoListApp -add "Finish project report"

Add a Task (With Priority, Tags & Due Date)

./ToDoListApp -add "Learn Go" -priority "High" -tags "learning,golang" -due "2026-01-20"
./ToDoListApp -add "Buy groceries" -priority "Low" -tags "shopping,home"
./ToDoListApp -add "Project deadline" -priority "High" -tags "work" -due "2026-01-25"

List All Tasks

./ToDoListApp -list

Shows all tasks in a colored table with priorities, due dates, and task statistics.

Search Tasks by Title

./ToDoListApp -search "Go"

Finds all tasks containing the search term (case-insensitive).

Filter Tasks by Tag

./ToDoListApp -tag "work"
./ToDoListApp -tag "home"

View Statistics

./ToDoListApp -stats

Displays: Total tasks, Completed, Pending, and High Priority count.

Sort Tasks

./ToDoListApp -sort "priority"  # Sort by priority (High → Medium → Low)
./ToDoListApp -sort "date"      # Sort by creation date (oldest first)

Toggle Task Completion

./ToDoListApp -toggle 0

Delete a Task

./ToDoListApp -del 0

Edit a Task

./ToDoListApp -edit "0:Updated task title"

📂 Project Structure

ToDoListApp/
├── main.go          # Entry point of the application
├── todo.go          # Todo struct and operations (add, delete, toggle, etc.)
├── command.go       # Command-line flag parsing
├── storage.go       # JSON file I/O operations
├── go.mod           # Go module definition
├── go.sum           # Dependency checksums
├── todos.json       # Persistent storage file (auto-generated)
└── README.md        # This file

🔧 How It Works

1. Load - Reads existing todos from todos.json
2. Parse - Parses command-line flags (-add, -del, -toggle, -edit, -list, -search, -tag, -sort, -stats, etc.)
3. Execute - Performs the requested operation
4. Save - Persists changes back to todos.json

📋 Available CLI Flags

Flag	Description	Example
-add	Add a new task	-add "Buy milk"
-priority	Set priority level	-priority "High" (Low, Medium, High)
-tags	Add tags (comma-separated)	-tags "work,urgent,learning"
-due	Set due date	-due "2026-01-20" (YYYY-MM-DD)
-list	List all tasks	-list
-search	Search by title	-search "golang"
-tag	Filter by tag	-tag "work"
-sort	Sort tasks	-sort "priority" or -sort "date"
-stats	Show statistics	-stats
-toggle	Mark as complete/incomplete	-toggle 0
-edit	Edit task title	-edit "0:New title"
-del	Delete a task	-del 0

💡 Key Go Concepts Used

• Pointers (*) - Modify original data in methods
• Methods - Functions attached to types using receivers
• Generics ([T any]) - Flexible Storage type for any data
• Error Handling - Proper error returns and validation
• JSON marshaling - Serialize/deserialize data
• Slices - Dynamic arrays for managing todos
• Type constants - Custom Priority type and color constants
• Sorting - Using sort.Slice() for custom sorting logic
• String manipulation - Parsing dates, tags, and search queries

📦 Dependencies

• github.com/aquasecurity/table - Beautiful CLI table formatting

🛠️ Development

Running Tests (if applicable)

go test ./...

Modifying Dependencies

go mod tidy

📝 Example Workflow

# Add some tasks with different priorities
./ToDoListApp -add "Learn Go basics" -priority "High" -tags "learning,golang" -due "2026-01-20"
./ToDoListApp -add "Build a CLI project" -priority "High" -tags "work,golang"
./ToDoListApp -add "Buy groceries" -priority "Low" -tags "shopping,home"
./ToDoListApp -add "Code review" -priority "Medium" -tags "work"

# View all tasks with colors and statistics
./ToDoListApp -list

# Search for specific tasks
./ToDoListApp -search "Go"

# Filter tasks by tag
./ToDoListApp -tag "work"
./ToDoListApp -tag "shopping"

# Sort tasks by priority
./ToDoListApp -sort "priority"

# View quick statistics
./ToDoListApp -stats

# Mark first task as done
./ToDoListApp -toggle 0

# Edit a task
./ToDoListApp -edit "1:Completed my first project"

# Delete a task
./ToDoListApp -del 2

# View updated list
./ToDoListApp -list

Output Example

When you run -list, you'll see:

┌───┬─────────────────────────┬──────────┬───────────┬────────────┬────────────┐
│ # │        Title            │ Priority │ Completed │ Created At │  Due Date  │
├───┼─────────────────────────┼──────────┼───────────┼────────────┼────────────┤
│ 0 │ Learn Go basics          │ High     │ ✅        │ 2026-01-11 │ 2026-01-20 │
│ 1 │ Build a CLI project      │ High     │ ❌        │ 2026-01-11 │            │
│ 2 │ Buy groceries            │ Low      │ ❌        │ 2026-01-11 │            │
│ 3 │ Code review              │ Medium   │ ❌        │ 2026-01-11 │            │
└───┴─────────────────────────┴──────────┴───────────┴────────────┴────────────┘

📊 Task Statistics:
   Total: 4 | Completed: 1 | Pending: 3 | High Priority: 2

⏰ Due Today:
   Nothing due today! 🎉

🎓 Learning Resource

This project is great for learning:

• Go fundamentals (structs, methods, receivers)
• Command-line argument parsing with the flag package
• File I/O and JSON handling (marshaling/unmarshaling)
• Generic types (Go 1.18+)
• Error handling patterns
• Custom type definitions and constants
• Sorting and searching algorithms
• Working with time/date handling
• Building practical CLI applications

📄 License

This project is open source and available under the MIT License.

🤝 Contributing

Feel free to fork this repository and submit pull requests for any improvements!

📧 Contact

For questions or suggestions, please open an issue on GitHub.

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Happy task managing! 🚀