main.sh

#!/bin/bash

# create a users.json file if it does not exist
if [ ! -f users.json ]; then
    echo "[]" > users.json
fi

# create a notes directory if it does not exist
if [ ! -d notes ]; then
    mkdir notes
fi

# function to show the main menu
main_menu() {
    echo -e "\n📝 Welcome to the Note Taking App 📝"
    echo -e "1. 📝 Create a Note"
    echo -e "2. 📖 View Notes"
    echo -e "3. 📝 Update a Note"
    echo -e "4. 🗑️ Delete a Note"
    echo -e "5. ❌ Exit"
    read -p "Choose an option: " option
    case $option in
        1)
            create_note
            ;;
        2)
            view_notes
            ;;
        3)
            update_note
            ;;
        4)
            delete_note
            ;;
        5)
            exit 0
            ;;
        *)
            echo -e "\e[31m❌ Invalid option\e[0m"
            main_menu
            ;;
    esac
}

# function to create a note
create_note() {
    read -p "Enter the title of the note: " title
    read -p "Enter the body of the note: " body
    echo "{\"title\": \"$title\", \"body\": \"$body\"}" > notes/$title.json
    echo -e "\e[32m📝 Note created successfully\e[0m"
    main_menu
}

# function to view notes
view_notes() {
    echo -e "1. 📖 View all notes"
    echo -e "2. 📖 View a specific note"
    read -p "Choose an option: " option
    case $option in
        1)
            for note in notes/*.json; do
                title=$(jq -r '.title' $note)
                body=$(jq -r '.body' $note)
                echo -e "\n\e[34mTitle: $title\e[0m"
                echo -e "\e[34mBody: $body\e[0m"
            done
            ;;
        2)
            read -p "Enter the title of the note: " title
            if [ -f notes/$title.json ]; then
                body=$(jq -r '.body' notes/$title.json)
                echo -e "\n\e[34mTitle: $title\e[0m"
                echo -e "\e[34mBody: $body\e[0m"
            else
                echo -e "\e[31m❌ Note does not exist\e[0m"
            fi
            ;;
        *)
            echo -e "\e[31m❌ Invalid option\e[0m"
            view_notes
            ;;
    esac
    main_menu
}

# function to update a note
update_note() {
    read -p "Enter the title of the note: " title
    if [ -f notes/$title.json ]; then
        read -p "Enter the new body of the note: " body
        echo "{\"title\": \"$title\", \"body\": \"$body\"}" > notes/$title.json
        echo -e "\e[32m📝 Note updated successfully\e[0m"
    else
        echo -e "\e[31m❌ Note does not exist\e[0m"
    fi
    main_menu
}

# function to delete a note
delete_note() {
    read -p "Enter the title of the note: " title
    if [ -f notes/$title.json ]; then
        rm notes/$title.json
        echo -e "\e[32m📝 Note deleted successfully\e[0m"
    else
        echo -e "\e[31m❌ Note does not exist\e[0m"
    fi
    main_menu
}

# function to register a user
register() {
    read -p "Enter your username: " username
    read -s -p "Enter your password: " password
    echo
    hash=$(echo -n $password | sha256sum | awk '{print $1}')
    # echo "Registering user: $username with hash: $hash"  # Debug statement
    if ! grep -q "\"username\": \"$username\"" users.json; then
        jq ". += [{\"username\": \"$username\", \"password\": \"$hash\"}]" users.json > temp.json
        mv temp.json users.json
        echo -e "\n\e[32m🎉 User registered successfully\e[0m"
        main_menu
    else
        echo -e "\n\e[31m❌ Username already exists\e[0m"
        register
    fi
}

# function to login a user
login() {
    read -p "Enter your username: " username
    read -s -p "Enter your password: " password
    echo
    hash=$(echo -n $password | sha256sum | awk '{print $1}')
    # echo "Logging in user: $username with hash: $hash"  # Debug statement
    stored_hash=$(jq -r --arg username "$username" '.[] | select(.username == $username) | .password' users.json)
    if [ "$hash" == "$stored_hash" ]; then
        echo -e "\n\e[32m✅ Login successful\e[0m"
        main_menu
    else
        echo -e "\n\e[31m❌ Invalid username or password\e[0m"
        login
    fi
}

# check if the user is registered or not
if [ $(jq '. | length' users.json) -eq 0 ]; then
    echo -e "📝 Welcome to the Note Taking App 📝"
    register
else
    echo -e "📝 Welcome to the Note Taking App 📝"
    echo -e "1. 📝 Login"
    echo -e "2. 📝 Register"
    read -p "Choose an option: " option
    case $option in
        1)
            login
            ;;
        2)
            register
            ;;
        *)
            echo -e "\e[31m❌ Invalid option\e[0m"
            ;;
    esac
fi

main_menu


# Tools and libraries used in the project
# jq: https://stedolan.github.io/jq/