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:
    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
    # Optional: Clear old media files
    # if os.path.exists(st.session_state.visual_engine.output_dir):
    #     for f_name in os.listdir(st.session_state.visual_engine.output_dir):
    #         try:
    #             os.remove(os.path.join(st.session_state.visual_engine.output_dir, f_name))
    #         except OSError: # File might be in use by video player, handle gracefully
    #             print(f"Could not remove {f_name}, it might be in use.")


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.
    """
    scene_num_for_log = scene_data.get('scene_number', scene_index + 1)
    st.info(f"Processing visual concept for Scene {scene_num_for_log} (v{version_count})...")
    
    textual_image_prompt = ""
    if is_regeneration and scene_index < len(st.session_state.scene_image_prompts):
        textual_image_prompt = st.session_state.scene_image_prompts[scene_index]
        st.caption(f"Using (potentially refined) prompt for Scene {scene_num_for_log}.")
    else:
        textual_image_prompt = create_image_prompt_from_scene_data(
            scene_data,
            st.session_state.character_definitions,
            st.session_state.style_reference_description
        )
        st.caption(f"Generated initial prompt for Scene {scene_num_for_log}.")

    if not textual_image_prompt:
        st.error(f"Failed to create/retrieve textual image prompt for Scene {scene_num_for_log}.")
        return False

    # Update session state for the textual prompt if it's new or changed
    if scene_index >= len(st.session_state.scene_image_prompts):
        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

    image_filename = f"scene_{scene_num_for_log}_visual_v{version_count}.png"
    
    generated_image_path = st.session_state.visual_engine.generate_image_visual(
        textual_image_prompt,
        image_filename
    )

    # Ensure generated_images_paths is long enough
    while len(st.session_state.generated_images_paths) <= scene_index:
        st.session_state.generated_images_paths.append(None)

    if generated_image_path and os.path.exists(generated_image_path):
        st.success(f"Visual concept for Scene {scene_num_for_log} (v{version_count}) available: {os.path.basename(generated_image_path)}")
        st.session_state.generated_images_paths[scene_index] = generated_image_path
        return True
    else:
        st.error(f"Visual generation failed for Scene {scene_num_for_log} (v{version_count}). Path: {generated_image_path}")
        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")

    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="✅")

                    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_loop, scene_data_loop_var in enumerate(st.session_state.story_scenes):
                        if generate_visual_for_scene_wrapper(i_loop, 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")
    with st.expander("Character Consistency", expanded=False):
        char_name_input = st.text_input("Character Name (e.g., Eva)", key="char_name_adv_input") # Unique key
        char_desc_input = st.text_area("Character Description (for visual consistency)", key="char_desc_adv_input", height=80) # Unique key
        if st.button("Add/Update Character", key="add_char_adv_btn"): # Unique key
            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.caption("Defined Characters:")
            for char, desc in st.session_state.character_definitions.items():
                st.markdown(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_adv_input", height=80) # Unique key
        if st.button("Apply Textual Style", key="apply_style_adv_btn"): # Unique key
            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)
        # Create a more robust unique part for keys, sanitizing special characters
        action_summary = scene_data_display.get('key_action', f"scene{i}")
        key_part_raw = ''.join(e for e in action_summary if e.isalnum() or e.isspace())
        unique_key_part = key_part_raw.replace(" ", "_")[:20] # Take first 20 alphanumeric/space chars

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

        col1, col2 = st.columns([2, 3]) # Ratio for text vs image

        with col1: 
            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')}")
                
                current_textual_prompt = st.session_state.scene_image_prompts[i] if i < len(st.session_state.scene_image_prompts) else None
                if current_textual_prompt:
                     with st.popover("View Image Prompt Text"): 
                        st.markdown(f"**Textual Prompt for Image Generation:**")
                        st.code(current_textual_prompt, language='text')

        with col2: 
            current_image_path = st.session_state.generated_images_paths[i] if i < len(st.session_state.generated_images_paths) else None
            if current_image_path and os.path.exists(current_image_path):
                st.image(current_image_path, caption=f"Visual Concept for Scene {scene_num_display}")
            else:
                if st.session_state.story_scenes: 
                    st.info("Visual concept for this scene is pending or failed.")

            # Removed 'key' argument from st.popover calls
            with st.popover(f"✏️ Edit Scene {scene_num_display} Script"): 
                feedback_script = st.text_area("Describe changes to script details:",
                    key=f"script_feedback_{unique_key_part}_{i}", height=100) 
                if st.button(f"🔄 Regenerate Scene {scene_num_display} Script", key=f"regen_script_btn_{unique_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="✍️")
                                
                                version = 1
                                if current_image_path:
                                    try: 
                                        base, _ = os.path.splitext(os.path.basename(current_image_path))
                                        if '_v' in base: version = int(base.split('_v')[-1]) + 1
                                    except (ValueError, AttributeError, TypeError): pass
                                
                                generate_visual_for_scene_wrapper(i, updated_scene_data, is_regeneration=True, version_count=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"): 
                prompt_for_edit_visuals = st.session_state.scene_image_prompts[i] if i < len(st.session_state.scene_image_prompts) else "No prompt text available."
                st.caption("Current Image Prompt Text:")
                st.code(prompt_for_edit_visuals, language='text')
                
                feedback_visual = st.text_area("Describe visual changes to apply to the prompt:",
                    key=f"visual_feedback_{unique_key_part}_{i}", height=100) 
                if st.button(f"🔄 Regenerate Scene {scene_num_display} Visuals", key=f"regen_visual_btn_{unique_key_part}_{i}"): 
                    if feedback_visual:
                        with st.spinner(f"Refining image prompt for Scene {scene_num_display}..."):
                            prompt_refinement_request = create_visual_regeneration_prompt(
                                prompt_for_edit_visuals, feedback_visual, scene_data_display 
                            )
                            try:
                                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="💡")

                                version = 1
                                if current_image_path:
                                    try:
                                        base, _ = os.path.splitext(os.path.basename(current_image_path))
                                        if '_v' in base: version = int(base.split('_v')[-1]) + 1
                                    except (ValueError, AttributeError, TypeError): pass
                                
                                generate_visual_for_scene_wrapper(i, scene_data_display, is_regeneration=True, version_count=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 if p is not None):
        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 application logs for details from VisualEngine.")
                else:
                    st.error("No valid images found to assemble video. Please ensure visuals were generated successfully.")
    elif st.session_state.story_scenes:
         st.info("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_obj:
                video_bytes_content = video_file_obj.read()
            st.video(video_bytes_content)
            # Download button
            with open(st.session_state.video_path, "rb") as fp_download_video:
                st.download_button(
                    label="Download Animatic Video",
                    data=fp_download_video,
                    file_name=os.path.basename(st.session_state.video_path), # e.g., "cinegen_pro_animatic.mp4"
                    mime="video/mp4"
                )
        except Exception as e:
            st.error(f"Error displaying or preparing video for download: {e}")

# --- Footer ---
st.sidebar.markdown("---")
st.sidebar.caption("CineGen AI Pro | Powered by Gemini & Streamlit")