import pygame  # Importing the pygame library for game development
import sys  # Importing the sys module to access system-specific parameters and functions

# Initialize Pygame
pygame.init()

# Create a display surface with dimensions 400x300 pixels
display = pygame.display.set_mode((400, 300))

# Define a class for text input fields, inheriting from pygame.sprite.Sprite
class TextInput(pygame.sprite.Sprite):
    def __init__(self, x, y, width=100, height=50, color=(0, 0, 0),
                 bgcolor=(0, 255, 0), selectedColor=(0, 0, 255)):
        super().__init__()
        # Initialize text input properties
        self.text_value = ""  # Initial text value
        self.isSelected = False  # Indicates whether the text input is currently selected
        self.color = color  # Text color
        self.bgcolor = bgcolor  # Background color
        self.selectedColor = selectedColor  # Color when selected

        # Create a font object for rendering text
        self.font = pygame.font.SysFont("Verdana", 20)
        # Render the initial text value
        self.text = self.font.render(self.text_value, True, self.color)
        # Define the background rectangle for the text input field
        self.bg = pygame.Rect(x, y, width, height)

    # Method to handle mouse click events on the text input field
    def clicked(self, mousePos):
        # Check if the mouse click occurred within the text input field
        if self.bg.collidepoint(mousePos):
            # Toggle the selection status
            self.isSelected = not(self.isSelected)
            return True  # Return True to indicate that the click event was handled
        return False  # Return False if the click event was not handled

    # Method to update the text input field (placeholder, not implemented)
    def update(self, mousePos):
        pass

    # Method to update the text value of the text input field
    def update_text(self, new_text):
        # Render the new text value
        temp = self.font.render(new_text, True, self.color)
        # Check if the width of the rendered text exceeds the width of the background rectangle
        if temp.get_rect().width >= (self.bg.width - 20):
            return  # Return if the text exceeds the width of the background rectangle
        self.text_value = new_text  # Update the text value
        self.text = temp  # Update the rendered text

    # Method to render the text input field on the display surface
    def render(self, display):
        # Calculate the position for rendering the text
        self.pos = self.text.get_rect(center=(self.bg.x + self.bg.width / 2,
                                               self.bg.y + self.bg.height / 2))
        # Draw the background rectangle
        if self.isSelected:
            pygame.draw.rect(display, self.selectedColor, self.bg)
        else:
            pygame.draw.rect(display, self.bgcolor, self.bg)
        # Render the text on the display surface
        display.blit(self.text, self.pos)

# Define a custom group class for managing text input fields
class CustomGroup(pygame.sprite.Group):
    def __init__(self):
        super().__init__()
        self.current = None  # Initialize the current text input field to None

    def current(self):
        return self.current  # Return the current text input field
 
# Create a CustomGroup instance to manage text input fields
TextInputGroup = CustomGroup()

# Add text input fields to the group with specified positions and widths
TextInputGroup.add(TextInput(x=100, y=100, width=200))
TextInputGroup.add(TextInput(x=100, y=200, width=200))

# Define the ibeam cursor for text input mode
ibeam = pygame.cursors.Cursor(pygame.SYSTEM_CURSOR_IBEAM)

# Main game loop
while True:
    # Get the current mouse position
    mouse_pos = pygame.mouse.get_pos()
    
    # Handle events
    for event in pygame.event.get():
        # Check if the user wants to quit the game
        if event.type == pygame.QUIT:
            pygame.quit()  # Quit Pygame
            sys.exit()  # Exit the program
        
        # Handle mouse button click events
        if event.type == pygame.MOUSEBUTTONDOWN:
            # Iterate over text input fields
            for textinput in TextInputGroup:
                # Check if a text input field was clicked
                if textinput.clicked(mouse_pos): 
                    if TextInputGroup.current:
                        TextInputGroup.current.isSelected = False
                    textinput.isSelected = True
                    TextInputGroup.current = textinput
                    break
        
        # Handle keyboard events
        if event.type == pygame.KEYDOWN:
            # Handle backspace key press
            if event.key == pygame.K_BACKSPACE:
                # Update the text value of the current text input field by removing the last character
                TextInputGroup.current.update_text(TextInputGroup.current.text_value[:-1])
                
            # Handle return key press
            if event.key == pygame.K_RETURN:
                if TextInputGroup.current:
                    print(TextInputGroup.current.text_value)
        
        # Handle text input events
        if event.type == pygame.TEXTINPUT:
            # Update the text value of the current text input field by adding the entered text
            TextInputGroup.current.update_text(TextInputGroup.current.text_value + event.text)
     
    # Update and render text input fields
    for textinput in TextInputGroup:
        textinput.update(mouse_pos)
        textinput.render(display)
    
    # Change cursor to ibeam if it's over a text input field
    if TextInputGroup.current and TextInputGroup.current.bg.collidepoint(mouse_pos):
        pygame.mouse.set_cursor(ibeam)
    else:
        pygame.mouse.set_cursor(pygame.cursors.Cursor())
         
    # Update the display
    pygame.display.update()