app.py

# app.py
import streamlit as st
from core.gemini_handler import GeminiHandler
from core.visual_engine import VisualEngine
from core.prompt_engineering import (
    create_story_breakdown_prompt,
    create_image_prompt_from_scene_data,
    create_scene_regeneration_prompt,
    create_visual_regeneration_prompt
)
import os
import json # For debugging and display

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

# --- 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:
        st.error("GEMINI_API_KEY not found in secrets. Please add it.")
        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 strings
    st.session_state.scene_image_prompts = []
if 'generated_images_paths' not in st.session_state: # List of file paths
    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 = {} # e.g., {"Eva": "Astronaut, red hair..."}

# 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

def generate_visual_for_scene(scene_index, scene_data):
    """Generates image prompt and placeholder image for a specific scene."""
    img_gen_prompt_text = create_image_prompt_from_scene_data(
        scene_data,
        st.session_state.character_definitions,
        st.session_state.style_reference_description
    )
    try:
        actual_image_prompt = st.session_state.gemini_handler.generate_image_prompt(img_gen_prompt_text)
        if actual_image_prompt:
            if scene_index < len(st.session_state.scene_image_prompts):
                st.session_state.scene_image_prompts[scene_index] = actual_image_prompt
            else:
                st.session_state.scene_image_prompts.append(actual_image_prompt)

            img_path = st.session_state.visual_engine.create_placeholder_image(
                f"Scene {scene_data.get('scene_number', scene_index + 1)}: {actual_image_prompt[:100]}...", # Show part of the actual prompt
                f"scene_{scene_data.get('scene_number', scene_index + 1)}_placeholder.png"
            )
            if scene_index < len(st.session_state.generated_images_paths):
                st.session_state.generated_images_paths[scene_index] = img_path
            else:
                st.session_state.generated_images_paths.append(img_path)
            return True
    except Exception as e:
        st.error(f"Error generating visual for Scene {scene_data.get('scene_number', scene_index + 1)}: {e}")
    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.", height=100, key="user_idea_input")
    genre = st.selectbox("Genre:", ["Sci-Fi", "Fantasy", "Noir", "Thriller", "Drama"], index=2, key="genre_select")
    mood = st.selectbox("Mood:", ["Suspenseful", "Mysterious", "Gritty", "Hopeful"], index=2, key="mood_select")
    num_scenes_val = st.slider("Number of Scenes:", 1, 10, 3, key="num_scenes_slider")

    if st.button("✨ Generate Full Story Concept", type="primary", key="generate_full_story_btn"):
        initialize_new_story()
        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
                st.session_state.scene_image_prompts = [""] * len(st.session_state.story_scenes)
                st.session_state.generated_images_paths = [""] * len(st.session_state.story_scenes)

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

        if st.session_state.story_scenes:
            with st.spinner("Phase 2: Generating initial visual concepts... 🖼️"):
                for i, scene_data in enumerate(st.session_state.story_scenes):
                    generate_visual_for_scene(i, scene_data)
                st.toast("Initial visual concepts generated!", icon="🖼️")

    st.markdown("---")
    st.markdown("### Advanced Options (Conceptual)")
    # Character Consistency UI
    st.subheader("Character Consistency")
    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:")
        st.json(st.session_state.character_definitions)

    # Style Transfer UI
    st.subheader("Style Transfer")
    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 to see changes.")
    # conceptual_style_image = st.file_uploader("Or Upload Style Reference Image (Future Feature)", type=['png', 'jpg'])


# --- 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 in enumerate(st.session_state.story_scenes):
        scene_num = scene_data.get('scene_number', i + 1)
        st.subheader(f"Scene {scene_num}: {scene_data.get('emotional_beat', 'N/A')}")

        col1, col2 = st.columns([2,3]) # Left for text, Right for image and edit

        with col1: # Scene Details
            with st.expander("Scene Details", expanded=True):
                st.markdown(f"**Setting:** {scene_data.get('setting_description', 'N/A')}")
                st.markdown(f"**Characters:** {', '.join(scene_data.get('characters_involved', []))}")
                st.markdown(f"**Key Action:** {scene_data.get('key_action', 'N/A')}")
                st.markdown(f"**Dialogue Snippet:** {scene_data.get('dialogue_snippet', 'N/A')}")
                st.markdown(f"**Visual Style:** {scene_data.get('visual_style_suggestion', 'N/A')}")
                st.markdown(f"**Camera:** {scene_data.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"):
                        st.code(st.session_state.scene_image_prompts[i])


        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}")
            else:
                st.info("Visual concept not yet generated or path is invalid.")

            # Interactive Storyboarding UI
            with st.popover(f"✏️ Edit Scene {scene_num} Script"):
                st.markdown("#### Modify Scene Script Details")
                feedback_script = st.text_area(
                    "Describe changes to the scene (e.g., 'Make the action more intense', 'Change dialogue to be more hopeful')",
                    key=f"script_feedback_{i}",
                    height=100
                )
                if st.button(f"🔄 Regenerate Scene {scene_num} Script", key=f"regen_script_btn_{i}"):
                    if feedback_script:
                        with st.spinner(f"Gemini is rewriting Scene {scene_num}..."):
                            regen_prompt = create_scene_regeneration_prompt(
                                scene_data, 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 # Update the specific scene
                                st.toast(f"Scene {scene_num} script updated!", icon="✍️")
                                # Automatically regenerate visuals for this updated scene
                                generate_visual_for_scene(i, updated_scene_data)
                                st.rerun() # Rerun to reflect changes immediately
                            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} Visuals"):
                st.markdown("#### Modify Visual Concept")
                feedback_visual = st.text_area(
                    "Describe visual changes (e.g., 'Make it nighttime', 'Add more fog', 'Use a wider angle')",
                    key=f"visual_feedback_{i}",
                    height=100
                )
                # Advanced Camera Control (Simple Example)
                adv_camera = st.selectbox("Adv. Camera (Conceptual):",
                                          ["Default", "Low Angle", "High Angle", "Dutch Angle", "Close-up"],
                                          key=f"adv_cam_{i}")
                if st.button(f"🔄 Regenerate Scene {scene_num} Visuals", key=f"regen_visual_btn_{i}"):
                    if feedback_visual or adv_camera != "Default":
                        full_visual_feedback = feedback_visual
                        if adv_camera != "Default":
                            full_visual_feedback += f" Emphasize camera: {adv_camera}."

                        with st.spinner(f"Gemini is re-imagining Scene {scene_num} visuals..."):
                            # We need the current image prompt for this scene to refine it
                            current_image_prompt = st.session_state.scene_image_prompts[i] if i < len(st.session_state.scene_image_prompts) else ""
                            if not current_image_prompt: # If no prompt, generate one first
                                img_gen_prompt_text = create_image_prompt_from_scene_data(
                                    scene_data,
                                    st.session_state.character_definitions,
                                    st.session_state.style_reference_description
                                )
                                current_image_prompt = st.session_state.gemini_handler.generate_image_prompt(img_gen_prompt_text)
                                st.session_state.scene_image_prompts[i] = current_image_prompt


                            regen_visual_prompt_text = create_visual_regeneration_prompt(
                                current_image_prompt,
                                full_visual_feedback,
                                scene_data # Pass current scene data for context
                            )
                            try:
                                new_image_prompt = st.session_state.gemini_handler.regenerate_image_prompt_from_feedback(regen_visual_prompt_text)
                                st.session_state.scene_image_prompts[i] = new_image_prompt # Update the prompt

                                # Now generate the new placeholder image with the new prompt
                                img_path = st.session_state.visual_engine.create_placeholder_image(
                                    f"Scene {scene_num}: {new_image_prompt[:100]}...",
                                    f"scene_{scene_num}_placeholder_v{len(st.session_state.generated_images_paths)}.png" # Avoid overwriting, simple versioning
                                )
                                st.session_state.generated_images_paths[i] = img_path
                                st.toast(f"Visuals for Scene {scene_num} updated!", icon="🎨")
                                st.rerun()
                            except Exception as e:
                                st.error(f"Error regenerating visuals: {e}")
                    else:
                        st.warning("Please provide feedback or select an advanced camera angle for visual regeneration.")

        st.markdown("---") # Separator between scenes

    # Video Generation Button (after all scenes are displayed)
    if st.session_state.story_scenes and st.session_state.generated_images_paths and \
       all(p and os.path.exists(p) for p in st.session_state.generated_images_paths):
        if st.button("🎬 Assemble Animatic Video", key="assemble_video_btn"):
            with st.spinner("Assembling video... This might take a moment."):
                valid_image_paths = [p for p in st.session_state.generated_images_paths if p and os.path.exists(p)]
                if valid_image_paths:
                    st.session_state.video_path = st.session_state.visual_engine.create_video_from_images(
                        valid_image_paths,
                        output_filename="cinegen_pro_output.mp4",
                        duration_per_image=3
                    )
                    st.toast("Animatic video assembled!", icon="🎞️")
                    st.balloons()
                else:
                    st.error("No valid images found to assemble video.")
    else:
        if st.session_state.story_scenes:
            st.warning("Some visual concepts are missing. Please ensure all scenes have visuals before assembling video.")


    if st.session_state.video_path and os.path.exists(st.session_state.video_path):
        st.header("🎬 Generated Animatic Video")
        video_file = open(st.session_state.video_path, 'rb')
        video_bytes = video_file.read()
        st.video(video_bytes)
        # For download on Spaces, let user right-click. The path might be tricky for direct download link.
        st.markdown(f"Video saved at: `{st.session_state.video_path}` (within the Space's file system)")