app.py

import gradio as gr
import pandas as pd
import os
import random
from datetime import datetime
from apscheduler.schedulers.background import BackgroundScheduler
from PIL import Image
from filelock import FileLock # Added for file locking

import config
import utils

# --- Global Variables & Initial Setup ---
# Attempt to log in to Hugging Face Hub at startup
utils.login_hugging_face()

print(f"Attempting to load preferences from Hugging Face Hub, ensuring local {config.RESULTS_CSV_FILE} is synchronized.")
# We assume utils.load_preferences_from_hf_hub:
# 1. Downloads from Hub, overwrites local config.RESULTS_CSV_FILE.
# 2. If Hub file doesn't exist, local config.RESULTS_CSV_FILE becomes empty (or reflects this).
# 3. Returns the DataFrame loaded from the (now synchronized) local file.
# 4. Returns None on major failure (e.g. network, file not found on Hub).
preferences_df = utils.load_preferences_from_hf_hub(config.HF_DATASET_REPO_ID, config.RESULTS_CSV_FILE)

if preferences_df is None:
    print(f"Failed to load from Hub or Hub is empty/file not found. Initializing/loading from {config.RESULTS_CSV_FILE} as a fallback.")
    if os.path.exists(config.RESULTS_CSV_FILE):
        try:
            preferences_df = pd.read_csv(config.RESULTS_CSV_FILE)
            if not preferences_df.empty and list(preferences_df.columns) != config.CSV_HEADERS:
                print(f"Warning: Local CSV {config.RESULTS_CSV_FILE} columns ({list(preferences_df.columns)}) do not match expected headers ({config.CSV_HEADERS}). Re-initializing file and DataFrame.")
                preferences_df = pd.DataFrame(columns=config.CSV_HEADERS)
                preferences_df.to_csv(config.RESULTS_CSV_FILE, index=False)
            elif preferences_df.empty: # Loaded an empty DataFrame
                # Check if the file itself had incorrect headers or was truly empty
                current_headers = []
                if os.path.getsize(config.RESULTS_CSV_FILE) > 0:
                    try:
                        current_headers = list(pd.read_csv(config.RESULTS_CSV_FILE, nrows=0).columns)
                    except Exception: # Handle cases where reading headers might fail
                        pass # Will be caught by re-initialization if headers are bad
                if current_headers != config.CSV_HEADERS:
                    print(f"Local CSV {config.RESULTS_CSV_FILE} is empty or has incorrect headers. Re-initializing file and DataFrame with correct headers.")
                    preferences_df = pd.DataFrame(columns=config.CSV_HEADERS)
                    preferences_df.to_csv(config.RESULTS_CSV_FILE, index=False)
                else: # Empty dataframe, but headers in file are correct
                    preferences_df = pd.DataFrame(columns=config.CSV_HEADERS) # Ensure in-memory df also has columns

        except pd.errors.EmptyDataError:
            print(f"Local CSV {config.RESULTS_CSV_FILE} is empty. Initializing file and DataFrame with headers.")
            preferences_df = pd.DataFrame(columns=config.CSV_HEADERS)
            preferences_df.to_csv(config.RESULTS_CSV_FILE, index=False)
        except Exception as e:
            print(f"Error loading local {config.RESULTS_CSV_FILE}: {e}. Initializing file and DataFrame.")
            preferences_df = pd.DataFrame(columns=config.CSV_HEADERS)
            preferences_df.to_csv(config.RESULTS_CSV_FILE, index=False)
    else:
        print(f"Local CSV {config.RESULTS_CSV_FILE} not found. Initializing file and DataFrame.")
        preferences_df = pd.DataFrame(columns=config.CSV_HEADERS)
        preferences_df.to_csv(config.RESULTS_CSV_FILE, index=False)
else:
    # Successfully loaded from Hub; local file config.RESULTS_CSV_FILE should be synchronized.
    print(f"Successfully loaded preferences from Hugging Face Hub. Local copy at {config.RESULTS_CSV_FILE} should be up-to-date.")
    if not preferences_df.empty and list(preferences_df.columns) != config.CSV_HEADERS:
        print(f"CRITICAL: Data from Hub has incorrect columns {list(preferences_df.columns)}. Expected {config.CSV_HEADERS}. Re-initializing local file and DataFrame to empty to prevent corruption.")
        preferences_df = pd.DataFrame(columns=config.CSV_HEADERS)
        preferences_df.to_csv(config.RESULTS_CSV_FILE, index=False)
    elif preferences_df.empty:
        # Hub data is empty. Ensure DataFrame in memory has correct columns.
        # And ensure the local CSV (which should have been written by load_preferences_from_hf_hub) has correct headers.
        if list(preferences_df.columns) != config.CSV_HEADERS:
             preferences_df = pd.DataFrame(columns=config.CSV_HEADERS) # Correct columns in memory
        
        # Ensure the local file has correct headers if it's empty or its headers are wrong
        needs_header_rewrite = True
        if os.path.exists(config.RESULTS_CSV_FILE):
            if os.path.getsize(config.RESULTS_CSV_FILE) == 0: # File is completely empty
                 needs_header_rewrite = True
            else:
                try:
                    local_headers = list(pd.read_csv(config.RESULTS_CSV_FILE, nrows=0).columns)
                    if local_headers == config.CSV_HEADERS:
                        needs_header_rewrite = False
                except Exception: # Error reading headers, assume rewrite is needed
                    pass
        if needs_header_rewrite:
            print(f"Local file {config.RESULTS_CSV_FILE} (after Hub sync resulted in empty data) is empty or has incorrect headers. Writing/Re-writing headers.")
            pd.DataFrame(columns=config.CSV_HEADERS).to_csv(config.RESULTS_CSV_FILE, index=False)


# Final safety net: ensure preferences_df is a DataFrame with correct columns.
if not isinstance(preferences_df, pd.DataFrame) or list(preferences_df.columns) != config.CSV_HEADERS:
    print("Critical: preferences_df is not a valid DataFrame with correct headers after initialization. Resetting to empty with correct headers.")
    preferences_df = pd.DataFrame(columns=config.CSV_HEADERS)
    # Ensure the CSV file reflects this state
    preferences_df.to_csv(config.RESULTS_CSV_FILE, index=False)


# Scan for available data
ALL_SAMPLES_BY_DOMAIN = utils.scan_data_directory(config.DATA_FOLDER)
if not ALL_SAMPLES_BY_DOMAIN:
    print(f"CRITICAL: No data found in {config.DATA_FOLDER}. The app might not function correctly.")
    # Potentially raise an error or display a message in the UI if no data

# --- Scheduler for Periodic Uploads ---
def scheduled_upload_job():
    global preferences_df
    print(f"Running scheduled job: Preparing to upload preferences from {config.RESULTS_CSV_FILE} at {datetime.now()}")
    
    lock_path = config.RESULTS_CSV_FILE + ".lock"
    with FileLock(lock_path):
        print(f"Acquired lock for scheduled upload: {lock_path}")
        if os.path.exists(config.RESULTS_CSV_FILE):
            try:
                # Read the current state of the CSV file for upload
                df_to_upload = pd.read_csv(config.RESULTS_CSV_FILE)
                if not df_to_upload.empty:
                    utils.save_preferences_to_hf_hub(
                        df_to_upload, # df_to_upload is passed for the empty check inside save_preferences_to_hf_hub
                        config.HF_DATASET_REPO_ID,
                        config.RESULTS_CSV_FILE, # This is the target filename on the Hub
                        commit_message="Periodic background update"
                    )
                    print(f"Scheduled job: Attempted upload of data from {config.RESULTS_CSV_FILE}.")
                else:
                    print(f"Scheduled job: Local preferences file {config.RESULTS_CSV_FILE} is empty. Nothing to upload.")
            except pd.errors.EmptyDataError:
                print(f"Scheduled job: Local preferences file {config.RESULTS_CSV_FILE} is empty (read as EmptyDataError). Nothing to upload.")
            except Exception as e:
                print(f"Scheduled job: Error reading or uploading {config.RESULTS_CSV_FILE}: {e}")
        else:
            print(f"Scheduled job: Local preferences file {config.RESULTS_CSV_FILE} does not exist. Nothing to upload.")
        print(f"Released lock for scheduled upload: {lock_path}")

scheduler = BackgroundScheduler()
scheduler.add_job(scheduled_upload_job, 'interval', hours=config.PUSH_INTERVAL_HOURS)
scheduler.start()
print(f"Scheduler started. Will attempt to upload preferences every {config.PUSH_INTERVAL_HOURS} hour(s).")


# --- Core Gradio App Functions ---
def start_new_session():
    """Initializes a new user session."""
    session_id = utils.generate_session_id()
    sample_queue = utils.prepare_session_samples(ALL_SAMPLES_BY_DOMAIN, config.SAMPLES_PER_DOMAIN)
    current_sample_index = 0
    if not sample_queue:
        no_samples_msg = f"# 😥 No Samples Available!\n\n### Please check the data folder configuration or try again later."
        return session_id, sample_queue, current_sample_index, no_samples_msg, None, None, None, [], [], True
    
    print(f"New session started: {session_id}, with {len(sample_queue)} samples.")
    domain_prompt_md, bg, fg, s_data, out_imgs, disp_info, end_flag = load_and_display_sample(sample_queue, current_sample_index)
    return session_id, sample_queue, current_sample_index, domain_prompt_md, bg, fg, s_data, out_imgs, disp_info, end_flag


def load_and_display_sample(sample_queue, current_sample_index):
    """Loads and prepares a single sample for display."""
    if not sample_queue or current_sample_index >= len(sample_queue):
        end_session_msg = f"# 🎉 All Rated! 🎉\n\n### All samples for this session have been rated. Thank you!"
        return end_session_msg, None, None, None, [], [], True # End of session

    domain, sample_id = sample_queue[current_sample_index]
    sample_data = utils.load_sample_data(domain, sample_id)

    if sample_data is None:
        print(f"Error loading sample {domain}/{sample_id}. Skipping.")
        error_msg = f"## ⚠️ Error Loading Sample\n\nCould not load data for {domain}/{sample_id}. Skipping to the next one."
        return error_msg, None, None, None, [], [], False

    prompt_text = sample_data["prompt"]
    bg_img_path = sample_data["background_img_path"]
    fg_img_path = sample_data["foreground_img_path"]
    
    # Load input bg/fg images without forcing them to be square
    # The gr.Image component will handle scaling to the specified height while preserving aspect ratio.
    bg_image_to_display = Image.open(bg_img_path)
    fg_image_to_display = Image.open(fg_img_path)
    
    output_model_keys = list(sample_data["output_image_paths"].keys())
    random.shuffle(output_model_keys)
    
    displayed_models_info = []
    output_images_for_display = []
    
    # square_size is still used for output option images
    square_size = (config.IMAGE_DISPLAY_SIZE[0], config.IMAGE_DISPLAY_SIZE[0])

    for model_key in output_model_keys:
        img_path = sample_data["output_image_paths"][model_key]
        try:
            img = Image.open(img_path).resize(square_size) # Output images remain square
            output_images_for_display.append(img)
            displayed_models_info.append((model_key, img_path)) 
        except FileNotFoundError:
            print(f"Image not found: {img_path} for model {model_key}. Skipping this option.")
        except Exception as e:
            print(f"Error loading or resizing image {img_path}: {e}. Skipping this option.")

    blank_image = Image.new('RGB', square_size, (200, 200, 200))
    while len(output_images_for_display) < 4:
        output_images_for_display.append(blank_image)
        displayed_models_info.append(("BLANK_SLOT", "N/A"))

    domain_prompt_markdown = f"""
    <div style="padding:15px 20px 20px 20px;border-left:3px black;background-color:#4B5966;border-radius: 10px;color:black;">
    
    ### Domain: {domain}

    </div>
    <br>
    <div style="padding:15px 20px 20px 20px;border-left:3px black;background-color:#4B5966;border-radius: 10px;color:black;">
    
    ## Prompt        
        
    ### _"{prompt_text}"_
    
    </div>
    """
    
    return (
        domain_prompt_markdown,
        bg_image_to_display, # Pass the PIL image directly
        fg_image_to_display, # Pass the PIL image directly
        sample_data,
        output_images_for_display[:4],
        displayed_models_info[:4],
        False
    )

def process_vote(choice_index, session_id, sample_queue, current_sample_index, current_sample_data, displayed_models_info_for_sample):
    global preferences_df
    
    if current_sample_data is None or not displayed_models_info_for_sample or choice_index >= len(displayed_models_info_for_sample):
        print("Error: Invalid data for processing vote. Skipping.")
        current_sample_index += 1
        if current_sample_index >= len(sample_queue):
            error_end_msg = f"# ⚠️ Error Processing Vote ⚠️\n\n### An issue occurred. The session has ended."
            return preferences_df, current_sample_index, error_end_msg, None, None, None, [], [], True
        else:
            next_prompt_md, next_bg, next_fg, next_s_data, next_out_imgs, next_disp_info, next_hide = load_and_display_sample(sample_queue, current_sample_index)
            return preferences_df, current_sample_index, next_prompt_md, next_bg, next_fg, next_s_data, next_out_imgs, next_disp_info, next_hide

    domain, sample_id = sample_queue[current_sample_index]
    preferred_model_key, _ = displayed_models_info_for_sample[choice_index]

    if preferred_model_key == "BLANK_SLOT":
        print("User clicked on a blank slot. Vote not recorded. Please select a valid image.")
        _prompt_md, _bg, _fg, _s_data, _out_imgs, _disp_info, _hide = load_and_display_sample(sample_queue, current_sample_index)
        return preferences_df, current_sample_index, _prompt_md, _bg, _fg, _s_data, _out_imgs, _disp_info, _hide

    print(f"Session {session_id}: Voted for model '{config.MODEL_DISPLAY_NAMES.get(preferred_model_key, preferred_model_key)}' (key: {preferred_model_key}) for sample {domain}/{sample_id}")

    preferences_df = utils.record_preference(
        df=preferences_df,
        session_id=session_id,
        domain=domain,
        sample_id=sample_id,
        prompt=current_sample_data["prompt"],
        bg_path=current_sample_data["background_img_path"],
        fg_path=current_sample_data["foreground_img_path"],
        displayed_models_info=displayed_models_info_for_sample,
        preferred_model_key=preferred_model_key
    )
    
    # Append the new preference to the CSV file
    if not preferences_df.empty:
        new_preference_df = preferences_df.iloc[-1:] # Get the last row as a new DataFrame
        
        lock_path = config.RESULTS_CSV_FILE + ".lock"
        with FileLock(lock_path):
            print(f"Acquired lock for vote processing: {lock_path}")
            try:
                file_exists_and_has_content = os.path.exists(config.RESULTS_CSV_FILE) and os.path.getsize(config.RESULTS_CSV_FILE) > 0
                new_preference_df.to_csv(
                    config.RESULTS_CSV_FILE,
                    mode='a',
                    header=not file_exists_and_has_content, # Write header if file is new or empty
                    index=False
                )
                print(f"Appended new preference to {config.RESULTS_CSV_FILE}")
            except Exception as e:
                print(f"Error appending preference to local CSV {config.RESULTS_CSV_FILE}: {e}")
            finally:
                print(f"Released lock for vote processing: {lock_path}")
    else:
        print("Warning: preferences_df is empty after utils.record_preference. Cannot append to CSV.")

    # Removed full CSV overwrite:
    # try:
    #     preferences_df.to_csv(config.RESULTS_CSV_FILE, index=False)
    #     print(f"Preferences saved locally to {config.RESULTS_CSV_FILE}")
    # except Exception as e:
    #     print(f"Error saving preferences locally: {e}")

    current_sample_index += 1
    if current_sample_index >= len(sample_queue):
        # Removed session end upload:
        # utils.save_preferences_to_hf_hub(preferences_df, config.HF_DATASET_REPO_ID, config.RESULTS_CSV_FILE, commit_message="Session end update")
        final_msg = f"# 🎉 Session Complete! 🎉\n\n### All samples have been rated. Thank you for your participation!"
        return preferences_df, current_sample_index, final_msg, None, None, None, [], [], True
    
    next_prompt_md, next_bg, next_fg, next_s_data, next_out_imgs, next_disp_info, next_hide = load_and_display_sample(sample_queue, current_sample_index)
    return preferences_df, current_sample_index, next_prompt_md, next_bg, next_fg, next_s_data, next_out_imgs, next_disp_info, next_hide


# --- Gradio UI Definition ---
custom_css = """
.custom-vote-button {
    background-color: #FFA500 !important; /* Light Orange for normal state */
    border-color: #FFA500 !important; /* Light Orange for normal state */
    color: white !important;
}
.custom-vote-button:hover {
    background-color: #FF8C00 !important; /* Dark Orange for hover state */
    border-color: #FF8C00 !important; /* Dark Orange for hover state */
    color: white !important;
}
"""

with gr.Blocks(title=config.APP_TITLE, theme=gr.themes.Soft(primary_hue=gr.themes.colors.blue), css=custom_css) as demo:
    session_id_state = gr.State()
    sample_queue_state = gr.State([])
    current_sample_index_state = gr.State(0)
    current_sample_data_state = gr.State() 
    displayed_models_info_state = gr.State([]) 
    preferences_df_state = gr.State(value=preferences_df)

    gr.Markdown(f"# {config.APP_TITLE}")
    gr.Markdown(config.APP_DESCRIPTION)

    with gr.Row():
        start_button = gr.Button("Start New Session / Load First Sample", variant="primary")
    
    with gr.Row(equal_height=False):
        with gr.Column(scale=1):
            domain_prompt_info_display = gr.Markdown(value="### Click 'Start New Session' to begin.")
        
        with gr.Column(scale=2):
            with gr.Row():
                input_bg_image_display = gr.Image(label="Input Background", type="pil", height=config.IMAGE_DISPLAY_SIZE[0], interactive=False)
                input_fg_image_display = gr.Image(label="Input Foreground", type="pil", height=config.IMAGE_DISPLAY_SIZE[0], interactive=False)

    gr.Markdown("---")
    gr.Markdown("## Choose your preferred composed image:")

    output_image_displays = []
    vote_buttons = []
    with gr.Row():
        for i in range(4):
            with gr.Column():
                img_display = gr.Image(label=f"Option {i+1}", type="pil", height=config.IMAGE_DISPLAY_SIZE[0], interactive=False)
                output_image_displays.append(img_display)
                vote_btn = gr.Button(f"Select Option {i+1}", elem_id=f"vote_btn_{i}", elem_classes=["custom-vote-button"])
                vote_buttons.append(vote_btn)
    
    end_of_session_msg_display = gr.Markdown("", visible=True)

    def handle_start_session():
        s_id, s_queue, s_idx, domain_prompt_or_end_msg, bg, fg, s_data, out_imgs, disp_info, end = start_new_session()
        
        while len(out_imgs) < 4: out_imgs.append(None)
        while len(disp_info) < 4: disp_info.append(("BLANK_SLOT", "N/A"))
        
        updates = {
            session_id_state: s_id,
            sample_queue_state: s_queue,
            current_sample_index_state: s_idx,
            domain_prompt_info_display: domain_prompt_or_end_msg if not end else "",
            input_bg_image_display: bg,
            input_fg_image_display: fg,
            current_sample_data_state: s_data,
            displayed_models_info_state: disp_info,
            end_of_session_msg_display: domain_prompt_or_end_msg if end else ""
        }
        for i in range(4):
            updates[output_image_displays[i]] = out_imgs[i] if i < len(out_imgs) else None
            num_actual_outputs = 0
            if s_data and "output_image_paths" in s_data and s_data["output_image_paths"]:
                 num_actual_outputs = sum(1 for m_key, _ in disp_info if m_key != "BLANK_SLOT" and m_key is not None)
            updates[vote_buttons[i]] = gr.Button(interactive=not end and i < num_actual_outputs)
        return updates

    start_button.click(
        fn=handle_start_session,
        inputs=[],
        outputs=[
            session_id_state, sample_queue_state, current_sample_index_state,
            domain_prompt_info_display,
            input_bg_image_display, input_fg_image_display,
            current_sample_data_state, displayed_models_info_state, end_of_session_msg_display,
            *output_image_displays, *vote_buttons
        ]
    )

    def make_vote_fn(choice_idx):
        def vote_action(s_id, s_queue, s_idx, current_s_data, disp_info_for_sample, prefs_df_val):
            global preferences_df
            preferences_df = prefs_df_val

            new_prefs_df, new_s_idx, domain_prompt_or_end_msg, bg, fg, new_s_data, out_imgs, new_disp_info, end = process_vote(
                choice_idx, s_id, s_queue, s_idx, current_s_data, disp_info_for_sample
            )
            
            while len(out_imgs) < 4: out_imgs.append(None)
            while len(new_disp_info) < 4: new_disp_info.append(("BLANK_SLOT", "N/A"))

            updates = {
                preferences_df_state: new_prefs_df,
                current_sample_index_state: new_s_idx,
                domain_prompt_info_display: domain_prompt_or_end_msg if not end else "",
                input_bg_image_display: bg,
                input_fg_image_display: fg,
                current_sample_data_state: new_s_data,
                displayed_models_info_state: new_disp_info,
                end_of_session_msg_display: domain_prompt_or_end_msg if end else ""
            }
            for i in range(4):
                updates[output_image_displays[i]] = out_imgs[i] if i < len(out_imgs) else None
                num_actual_outputs = 0
                if new_s_data and "output_image_paths" in new_s_data and new_s_data["output_image_paths"]:
                    num_actual_outputs = sum(1 for m_key, _ in new_disp_info if m_key != "BLANK_SLOT" and m_key is not None)
                updates[vote_buttons[i]] = gr.Button(interactive=not end and i < num_actual_outputs)
            return updates
        return vote_action

    for i, btn in enumerate(vote_buttons):
        btn.click(
            fn=make_vote_fn(i),
            inputs=[
                session_id_state, sample_queue_state, current_sample_index_state,
                current_sample_data_state, displayed_models_info_state, preferences_df_state
            ],
            outputs=[
                preferences_df_state, current_sample_index_state,
                domain_prompt_info_display,
                input_bg_image_display, input_fg_image_display,
                current_sample_data_state, displayed_models_info_state, end_of_session_msg_display,
                *output_image_displays, *vote_buttons
            ]
        )

    gr.Markdown(config.FOOTER_MESSAGE)

if __name__ == "__main__":
    if not os.path.exists(config.DATA_FOLDER):
        print(f"Creating dummy data folder: {config.DATA_FOLDER}")
        os.makedirs(config.DATA_FOLDER, exist_ok=True)
        
        dummy_domains = ["Real-Cartoon", "Real-Painting"]
        dummy_model_keys = list(config.MODEL_OUTPUT_IMAGE_NAMES.keys())

        for domain in dummy_domains:
            domain_path = os.path.join(config.DATA_FOLDER, domain)
            os.makedirs(domain_path, exist_ok=True)
            for i in range(config.SAMPLES_PER_DOMAIN + 2):
                sample_id = f"sample_{i:03d}"
                sample_path = os.path.join(domain_path, sample_id)
                os.makedirs(sample_path, exist_ok=True)

                with open(os.path.join(sample_path, config.PROMPT_FILE_NAME), "w") as f:
                    f.write(f"This is a dummy prompt for {domain} sample {sample_id}.")
                
                colors = [(255,0,0), (0,255,0), (0,0,255), (255,255,0), (0,255,255)]
                try:
                    img_bg = Image.new('RGB', config.IMAGE_DISPLAY_SIZE, color='gray')
                    img_bg.save(os.path.join(sample_path, config.BACKGROUND_IMAGE_NAME))
                    
                    img_fg = Image.new('RGB', config.IMAGE_DISPLAY_SIZE, color='lightgray')
                    img_fg.save(os.path.join(sample_path, config.FOREGROUND_IMAGE_NAME))

                    for idx, model_key in enumerate(dummy_model_keys):
                        model_img_name = config.MODEL_OUTPUT_IMAGE_NAMES[model_key]
                        img_model = Image.new('RGB', config.IMAGE_DISPLAY_SIZE, color=colors[idx % len(colors)])
                        img_model.save(os.path.join(sample_path, model_img_name))
                except Exception as e:
                    print(f"Error creating dummy image: {e}")
        print("Dummy data creation complete.")
        ALL_SAMPLES_BY_DOMAIN = utils.scan_data_directory(config.DATA_FOLDER)

    demo.launch()

import atexit
atexit.register(lambda: scheduler.shutdown() if scheduler.running else None)