import gradio as gr
import os
import shutil
import pandas as pd
from datetime import datetime

# --- Configuration ---
UPLOAD_DIR = "shared_files"
MAX_STORAGE_GB = 1 
MAX_STORAGE_BYTES = MAX_STORAGE_GB * 1024 * 1024 * 1024
OWNER_PASSWORD = os.environ.get("OWNER_PASSWORD")
USER_PASSWORD = os.environ.get("USER_PASSWORD")

os.makedirs(UPLOAD_DIR, exist_ok=True)

def get_dir_size(path):
    total_size = 0
    for dirpath, _, filenames in os.walk(path):
        for f in filenames:
            total_size += os.path.getsize(os.path.join(dirpath, f))
    return total_size

def get_file_info():
    file_data = []
    file_list_for_dropdown = []
    for f in os.listdir(UPLOAD_DIR):
        path = os.path.join(UPLOAD_DIR, f)
        if os.path.isfile(path):
            stats = os.stat(path)
            dt_object = datetime.fromtimestamp(stats.st_mtime)
            
            # --- PARSING LOGIC ---
            # Format: Timestamp_UserName_OriginalName.ext
            parts = f.split("_", 2)
            if len(parts) == 3:
                user_name = parts[1]
                display_name = parts[2]
            else:
                user_name = "Anonymous"
                display_name = parts[1] if len(parts) > 1 else f
            
            file_data.append({
                "Filename": display_name,
                "Uploaded By": user_name,
                "Date": dt_object.strftime("%Y-%m-%d"),
                "Time": dt_object.strftime("%H:%M:%S"),
                "Size (MB)": round(stats.st_size / (1024 * 1024), 2),
                "mtime": stats.st_mtime
            })
            file_list_for_dropdown.append(f)
    
    df = pd.DataFrame(file_data)
    current_bytes = get_dir_size(UPLOAD_DIR)
    usage_pct = (current_bytes / MAX_STORAGE_BYTES) * 100
    status_msg = f"📊 Storage Usage: {round(current_bytes/(1024**3), 3)}GB / {MAX_STORAGE_GB}GB ({round(usage_pct, 1)}%)"
    
    if df.empty:
        return pd.DataFrame(columns=["Filename", "Uploaded By", "Date", "Time", "Size (MB)"]), status_msg, []
    
    sorted_df = df.sort_values(by="mtime", ascending=False).drop(columns=['mtime'])
    return sorted_df, status_msg, file_list_for_dropdown

def upload_and_refresh(uploaded_files, user_name):
    if not user_name or user_name.strip() == "":
        user_name = "Anonymous"
    
    # Clean user name to prevent filename errors
    user_name = "".join(x for x in user_name if x.isalnum())

    if uploaded_files:
        if not isinstance(uploaded_files, list):
            uploaded_files = [uploaded_files]
        for file in uploaded_files:
            file_size = os.stat(file.name).st_size
            
            # Janitor to maintain 1GB limit
            while get_dir_size(UPLOAD_DIR) + file_size > MAX_STORAGE_BYTES:
                oldest_files = sorted([os.path.join(UPLOAD_DIR, f) for f in os.listdir(UPLOAD_DIR)], key=os.path.getmtime)
                if not oldest_files: break
                os.remove(oldest_files[0])

            timestamp = datetime.now().strftime("%H%M%S")
            # New format: Time_User_Filename
            safe_filename = f"{timestamp}_{user_name}_{os.path.basename(file.name)}"
            shutil.copy(file.name, os.path.join(UPLOAD_DIR, safe_filename))
    
    df, status, files = get_file_info()
    # Returns None for file_input and empty string for name_input to clear them
    return None, "", df, status, gr.update(choices=files)

def delete_selected_files(password, files_to_delete):
    if password != OWNER_PASSWORD:
        return "❌ Incorrect Password."
    if not files_to_delete:
        return "⚠️ No files selected."
    for f in files_to_delete:
        path = os.path.join(UPLOAD_DIR, f)
        if os.path.exists(path):
            os.remove(path)
    return f"✅ Deleted {len(files_to_delete)} file(s)."

with gr.Blocks(title="File Exchange") as demo:
    gr.Markdown("# 🚀 File Exchange")
    storage_label = gr.Markdown("📊 Storage Usage: Calculating...")
    
    with gr.Row():
        with gr.Column(scale=1):
            name_input = gr.Textbox(label="Your Name (Optional)")
            file_input = gr.File(label="Select Files", file_count="multiple", type="filepath")
            upload_btn = gr.Button("Upload & Share", variant="primary")
            
            with gr.Accordion("Owner Controls", open=False):
                pass_input = gr.Textbox(label="Owner Password", type="password")
                delete_dropdown = gr.Dropdown(label="Select Files to Delete", choices=[], multiselect=True)
                delete_btn = gr.Button("🗑 Delete Selected", variant="stop")
                admin_status = gr.Markdown("")
            
        with gr.Column(scale=2):
            file_table = gr.Dataframe(label="Current Files", interactive=False)
            download_manager = gr.File(label="Download List", file_count="multiple", interactive=False)
            refresh_btn = gr.Button("🔄 Refresh List")

    def full_refresh():
        df, status, files = get_file_info()
        paths = [os.path.join(UPLOAD_DIR, f) for f in files]
        return df, status, gr.update(choices=files), paths

    demo.load(fn=full_refresh, outputs=[file_table, storage_label, delete_dropdown, download_manager])

    upload_btn.click(
        fn=upload_and_refresh, 
        inputs=[file_input, name_input], 
        outputs=[file_input, name_input, file_table, storage_label, delete_dropdown]
    ).then(fn=lambda: [os.path.join(UPLOAD_DIR, f) for f in os.listdir(UPLOAD_DIR)], outputs=download_manager)
    
    delete_btn.click(
        fn=delete_selected_files, 
        inputs=[pass_input, delete_dropdown], 
        outputs=admin_status
    ).then(fn=full_refresh, outputs=[file_table, storage_label, delete_dropdown, download_manager])

    refresh_btn.click(fn=full_refresh, outputs=[file_table, storage_label, delete_dropdown, download_manager])

demo.launch(auth=(USER_PASSWORD,USER_PASSWORD))