app.py

# app.py
import streamlit as st
from core.gemini_handler import GeminiHandler
from core.visual_engine import VisualEngine # Your updated VisualEngine
from core.prompt_engineering import (
    create_story_breakdown_prompt,
    create_image_prompt_from_scene_data, # Generates the TEXT prompt for AI/placeholder
    create_scene_regeneration_prompt,
    create_visual_regeneration_prompt   # Regenerates the TEXT prompt
)
import os
# import json # Only if you need to st.json for debugging, not essential for core logic

# --- Configuration & Initialization ---
st.set_page_config(page_title="CineGen AI Pro", layout="wide", initial_sidebar_state="expanded")

# --- Global State Variables (Using session state for persistence) ---
if 'GEMINI_API_KEY' not in st.session_state:
    try:
        st.session_state.GEMINI_API_KEY = st.secrets["GEMINI_API_KEY"]
    except KeyError: # For local dev if secrets aren't set yet
        if "GEMINI_API_KEY" in os.environ:
             st.session_state.GEMINI_API_KEY = os.environ["GEMINI_API_KEY"]
        else:
            st.error("GEMINI_API_KEY not found in secrets or environment variables. Please add it.")
            st.stop()
    except Exception as e: # Catch any other secrets-related errors
        st.error(f"Error loading secrets: {e}")
        st.stop()


if 'gemini_handler' not in st.session_state:
    st.session_state.gemini_handler = GeminiHandler(api_key=st.session_state.GEMINI_API_KEY)
if 'visual_engine' not in st.session_state:
    # Ensure VisualEngine is initialized (it will print font loading status)
    st.session_state.visual_engine = VisualEngine(output_dir="temp_cinegen_media")

# Story and generated content
if 'story_scenes' not in st.session_state: # List of scene dicts
    st.session_state.story_scenes = []
if 'scene_image_prompts' not in st.session_state: # List of textual image prompts
    st.session_state.scene_image_prompts = []
if 'generated_images_paths' not in st.session_state: # List of file paths for generated visuals
    st.session_state.generated_images_paths = []
if 'video_path' not in st.session_state:
    st.session_state.video_path = None

# For Character Consistency (placeholders)
if 'character_definitions' not in st.session_state:
    st.session_state.character_definitions = {} 

# For Style Transfer (placeholders)
if 'style_reference_description' not in st.session_state:
    st.session_state.style_reference_description = None

# --- Helper Functions ---
def initialize_new_story():
    st.session_state.story_scenes = []
    st.session_state.scene_image_prompts = []
    st.session_state.generated_images_paths = []
    st.session_state.video_path = None
    # Clear old media files if any (optional, good for space management on persistent storage)
    # For Hugging Face Spaces, temp files are usually cleared on restart/rebuild anyway.
    # if os.path.exists(st.session_state.visual_engine.output_dir):
    #     for f in os.listdir(st.session_state.visual_engine.output_dir):
    #         os.remove(os.path.join(st.session_state.visual_engine.output_dir, f))


def generate_visual_for_scene_wrapper(scene_index, scene_data, is_regeneration=False, version_count=1):
    """
    Wrapper to generate the textual image prompt and then the actual visual.
    Updates session state for prompts and image paths.
    """
    st.info(f"Generating visual concept for Scene {scene_data.get('scene_number', scene_index + 1)}...")
    
    # 1. Get/Regenerate the detailed image prompt TEXT
    if is_regeneration and scene_index < len(st.session_state.scene_image_prompts):
        # For regeneration, we assume the prompt text is already updated in session state
        # (e.g., by a call to create_visual_regeneration_prompt and Gemini)
        textual_image_prompt = st.session_state.scene_image_prompts[scene_index]
    else:
        textual_image_prompt = create_image_prompt_from_scene_data(
            scene_data,
            st.session_state.character_definitions,
            st.session_state.style_reference_description
        )
        # Optional: Call Gemini here to refine this initial prompt if desired
        # textual_image_prompt = st.session_state.gemini_handler.generate_image_prompt(textual_image_prompt)

    if not textual_image_prompt:
        st.error(f"Failed to create textual image prompt for Scene {scene_data.get('scene_number', scene_index + 1)}.")
        return False

    # Update session state for the textual prompt
    if scene_index < len(st.session_state.scene_image_prompts):
        st.session_state.scene_image_prompts[scene_index] = textual_image_prompt
    else:
        # Ensure list is long enough before appending (shouldn't happen if initialized correctly)
        while len(st.session_state.scene_image_prompts) <= scene_index:
             st.session_state.scene_image_prompts.append("")
        st.session_state.scene_image_prompts[scene_index] = textual_image_prompt


    # 2. Generate the actual visual (AI or placeholder) using the textual prompt
    image_filename = f"scene_{scene_data.get('scene_number', scene_index + 1)}_visual_v{version_count}.png"
    
    generated_image_path = st.session_state.visual_engine.generate_image_visual(
        textual_image_prompt,
        image_filename
    )

    if generated_image_path and os.path.exists(generated_image_path):
        st.success(f"Visual concept for Scene {scene_data.get('scene_number', scene_index + 1)} generated: {os.path.basename(generated_image_path)}")
        if scene_index < len(st.session_state.generated_images_paths):
            st.session_state.generated_images_paths[scene_index] = generated_image_path
        else:
            while len(st.session_state.generated_images_paths) <= scene_index:
                st.session_state.generated_images_paths.append(None)
            st.session_state.generated_images_paths[scene_index] = generated_image_path
        return True
    else:
        st.error(f"Visual generation failed for Scene {scene_data.get('scene_number', scene_index + 1)} (path: {generated_image_path}).")
        if scene_index < len(st.session_state.generated_images_paths):
            st.session_state.generated_images_paths[scene_index] = None
        else:
            while len(st.session_state.generated_images_paths) <= scene_index:
                st.session_state.generated_images_paths.append(None)
            st.session_state.generated_images_paths[scene_index] = None
        return False

# --- UI Sidebar ---
with st.sidebar:
    st.title("🎬 CineGen AI Pro")
    st.markdown("### Creative Controls")
    user_idea = st.text_area("Enter your core story idea:", "A detective in a cyberpunk city investigates a rogue AI that believes it's the next step in evolution.", height=100, key="user_idea_input")
    genre = st.selectbox("Genre:", ["Sci-Fi", "Fantasy", "Noir", "Thriller", "Drama", "Horror"], index=2, key="genre_select")
    mood = st.selectbox("Mood:", ["Suspenseful", "Mysterious", "Gritty", "Epic", "Dark", "Hopeful"], index=2, key="mood_select")
    num_scenes_val = st.slider("Number of Scenes:", 1, 5, 3, key="num_scenes_slider") # Max 5 for now

    if st.button("✨ Generate Full Story Concept", type="primary", key="generate_full_story_btn"):
        initialize_new_story()
        if not user_idea.strip():
            st.warning("Please enter a story idea.")
        else:
            with st.spinner("Phase 1: Gemini is drafting the script & scene breakdown... 📜"):
                story_prompt_text = create_story_breakdown_prompt(user_idea, genre, mood, num_scenes_val)
                try:
                    st.session_state.story_scenes = st.session_state.gemini_handler.generate_story_breakdown(story_prompt_text)
                    st.toast("Script breakdown complete!", icon="✅")

                    # Initialize placeholders for prompts and images based on number of scenes
                    num_actual_scenes = len(st.session_state.story_scenes)
                    st.session_state.scene_image_prompts = [""] * num_actual_scenes
                    st.session_state.generated_images_paths = [None] * num_actual_scenes

                except Exception as e:
                    st.error(f"Failed to generate story breakdown: {e}")
                    st.session_state.story_scenes = []

            if st.session_state.story_scenes:
                with st.spinner("Phase 2: Generating initial visual concepts... 🖼️"):
                    success_count = 0
                    for i, scene_data_loop_var in enumerate(st.session_state.story_scenes):
                        if generate_visual_for_scene_wrapper(i, scene_data_loop_var, version_count=1):
                            success_count +=1
                    if success_count == len(st.session_state.story_scenes):
                        st.toast("Initial visual concepts generated!", icon="🖼️")
                    else:
                        st.warning(f"{success_count}/{len(st.session_state.story_scenes)} visual concepts generated. Some may have failed.")


    st.markdown("---")
    st.markdown("### Advanced Options (Conceptual)")
    with st.expander("Character Consistency", expanded=False):
        char_name_input = st.text_input("Character Name (e.g., Eva)", key="char_name")
        char_desc_input = st.text_area("Character Description (for visual consistency)", key="char_desc", height=80)
        if st.button("Add/Update Character", key="add_char_btn"):
            if char_name_input and char_desc_input:
                st.session_state.character_definitions[char_name_input] = char_desc_input
                st.success(f"Character '{char_name_input}' defined.")
            else:
                st.warning("Please provide both name and description.")
        if st.session_state.character_definitions:
            st.write("Defined Characters:")
            for char, desc in st.session_state.character_definitions.items():
                st.caption(f"**{char}:** {desc}")

    with st.expander("Style Transfer", expanded=False):
        style_ref_text = st.text_area("Describe Style (e.g., 'Van Gogh inspired, swirling brushstrokes')", key="style_text_input", height=80)
        if st.button("Apply Textual Style", key="apply_style_btn"):
            st.session_state.style_reference_description = style_ref_text
            st.success("Style reference applied. Re-generate visuals or full story to see changes.")

# --- Main Content Area ---
st.header("📝 Cinematic Storyboard")

if not st.session_state.story_scenes:
    st.info("Enter your idea in the sidebar and click 'Generate Full Story Concept' to begin.")
else:
    for i, scene_data_display in enumerate(st.session_state.story_scenes):
        scene_num_display = scene_data_display.get('scene_number', i + 1)
        # Use a unique key part for expanders if scene numbers can repeat or change
        expander_key_part = scene_data_display.get('key_action', f"scene{i}")[:20].replace(" ", "")

        st.subheader(f"Scene {scene_num_display}: {scene_data_display.get('emotional_beat', 'Untitled Scene')}")

        col1, col2 = st.columns([2, 3])

        with col1: # Scene Details
            with st.expander("Scene Details", expanded=True):
                st.markdown(f"**Setting:** {scene_data_display.get('setting_description', 'N/A')}")
                st.markdown(f"**Characters:** {', '.join(scene_data_display.get('characters_involved', []))}")
                st.markdown(f"**Key Action:** {scene_data_display.get('key_action', 'N/A')}")
                st.markdown(f"**Dialogue Snippet:** `\"{scene_data_display.get('dialogue_snippet', '...')}\"`")
                st.markdown(f"**Visual Style:** {scene_data_display.get('visual_style_suggestion', 'N/A')}")
                st.markdown(f"**Camera:** {scene_data_display.get('camera_angle_suggestion', 'N/A')}")
                
                if i < len(st.session_state.scene_image_prompts) and st.session_state.scene_image_prompts[i]:
                     with st.popover("View Image Prompt Text"):
                        st.markdown(f"**Textual Prompt for Image Generation:**")
                        st.code(st.session_state.scene_image_prompts[i], language='text')

        with col2: # Image and Interactive Editing
            if i < len(st.session_state.generated_images_paths) and \
               st.session_state.generated_images_paths[i] and \
               os.path.exists(st.session_state.generated_images_paths[i]):
                st.image(st.session_state.generated_images_paths[i], caption=f"Visual Concept for Scene {scene_num_display}")
            else:
                if st.session_state.story_scenes: # Only show if story generation was attempted
                    st.warning("Visual concept not generated or path is invalid for this scene.")

            # Interactive Storyboarding UI using unique keys for each scene's widgets
            popover_script_key = f"pop_script_{expander_key_part}_{i}"
            popover_visual_key = f"pop_visual_{expander_key_part}_{i}"
            
            with st.popover(f"✏️ Edit Scene {scene_num_display} Script", key=popover_script_key):
                feedback_script = st.text_area("Describe changes to script details:",
                    key=f"script_feedback_{expander_key_part}_{i}", height=100)
                if st.button(f"🔄 Regenerate Scene {scene_num_display} Script", key=f"regen_script_btn_{expander_key_part}_{i}"):
                    if feedback_script:
                        with st.spinner(f"Gemini is rewriting Scene {scene_num_display}..."):
                            regen_prompt = create_scene_regeneration_prompt(
                                scene_data_display, feedback_script, st.session_state.story_scenes
                            )
                            try:
                                updated_scene_data = st.session_state.gemini_handler.regenerate_scene_script_details(regen_prompt)
                                st.session_state.story_scenes[i] = updated_scene_data
                                st.toast(f"Scene {scene_num_display} script updated!", icon="✍️")
                                # Regenerate visuals for this updated scene with new script details
                                # Increment version for the image filename
                                current_version = 1
                                if st.session_state.generated_images_paths[i]:
                                    try: # Try to extract version from existing filename
                                        base, ext = os.path.splitext(os.path.basename(st.session_state.generated_images_paths[i]))
                                        if '_v' in base:
                                            current_version = int(base.split('_v')[-1]) + 1
                                    except ValueError: pass # Keep current_version as 1 if parsing fails
                                
                                generate_visual_for_scene_wrapper(i, updated_scene_data, is_regeneration=True, version_count=current_version)
                                st.rerun()
                            except Exception as e:
                                st.error(f"Error regenerating scene script: {e}")
                    else:
                        st.warning("Please provide feedback for script regeneration.")

            with st.popover(f"🎨 Edit Scene {scene_num_display} Visuals", key=popover_visual_key):
                current_prompt_for_edit = st.session_state.scene_image_prompts[i] if i < len(st.session_state.scene_image_prompts) else "No prompt yet."
                st.caption("Current Image Prompt Text:")
                st.code(current_prompt_for_edit, language='text')
                
                feedback_visual = st.text_area("Describe visual changes to apply to the prompt:",
                    key=f"visual_feedback_{expander_key_part}_{i}", height=100)
                if st.button(f"🔄 Regenerate Scene {scene_num_display} Visuals", key=f"regen_visual_btn_{expander_key_part}_{i}"):
                    if feedback_visual:
                        with st.spinner(f"Refining image prompt for Scene {scene_num_display}..."):
                            # This creates a prompt FOR GEMINI to refine the image prompt
                            prompt_refinement_request = create_visual_regeneration_prompt(
                                current_prompt_for_edit,
                                feedback_visual,
                                scene_data_display 
                            )
                            try:
                                # Gemini refines the textual image prompt
                                refined_textual_image_prompt = st.session_state.gemini_handler.regenerate_image_prompt_from_feedback(prompt_refinement_request)
                                st.session_state.scene_image_prompts[i] = refined_textual_image_prompt
                                st.toast(f"Image prompt for Scene {scene_num_display} refined!", icon="💡")

                                # Now generate the new visual using the refined prompt
                                current_version = 1
                                if st.session_state.generated_images_paths[i]:
                                    try:
                                        base, ext = os.path.splitext(os.path.basename(st.session_state.generated_images_paths[i]))
                                        if '_v' in base:
                                            current_version = int(base.split('_v')[-1]) + 1
                                    except ValueError: pass
                                
                                generate_visual_for_scene_wrapper(i, scene_data_display, is_regeneration=True, version_count=current_version)
                                st.rerun()
                            except Exception as e:
                                st.error(f"Error refining image prompt or regenerating visual: {e}")
                    else:
                        st.warning("Please provide feedback for visual regeneration.")
        st.markdown("---")

    # Video Generation Button
    if st.session_state.story_scenes and any(p for p in st.session_state.generated_images_paths): # Check if any image exists
        if st.button("🎬 Assemble Animatic Video", key="assemble_video_btn", type="primary"):
            with st.spinner("Assembling video... This might take a moment."):
                valid_image_paths_for_video = [p for p in st.session_state.generated_images_paths if p and os.path.exists(p)]
                if valid_image_paths_for_video:
                    st.session_state.video_path = st.session_state.visual_engine.create_video_from_images(
                        valid_image_paths_for_video,
                        output_filename="cinegen_pro_animatic.mp4",
                        duration_per_image=3
                    )
                    if st.session_state.video_path and os.path.exists(st.session_state.video_path):
                        st.toast("Animatic video assembled!", icon="🎞️")
                        st.balloons()
                    else:
                        st.error("Video assembly failed. Check logs for details.")
                else:
                    st.error("No valid images found to assemble video. Please generate visuals for scenes first.")
    elif st.session_state.story_scenes: # Story exists but no images yet
         st.warning("Generate visuals for scenes before assembling the video.")


    if st.session_state.video_path and os.path.exists(st.session_state.video_path):
        st.header("🎬 Generated Animatic Video")
        try:
            with open(st.session_state.video_path, 'rb') as video_file:
                video_bytes = video_file.read()
            st.video(video_bytes)
            st.markdown(f"Video saved at: `{st.session_state.video_path}` (within the Space's file system)")
            # Provide a download button for the video
            with open(st.session_state.video_path, "rb") as fp_download:
                st.download_button(
                    label="Download Animatic Video",
                    data=fp_download,
                    file_name=os.path.basename(st.session_state.video_path),
                    mime="video/mp4"
                )
        except Exception as e:
            st.error(f"Error displaying or preparing video for download: {e}")


# --- Footer or additional info ---
st.sidebar.markdown("---")
st.sidebar.info("CineGen AI by [Your Name/Company]. Powered by Gemini & Streamlit.")