app.py

# app.py
import streamlit as st
import streamlit.components.v1 as components
import os
import json
import pandas as pd
import uuid
from PIL import Image, ImageDraw # For minimap (using buttons instead now)
from streamlit_js_eval import streamlit_js_eval, sync # For JS communication

# --- Constants ---
SAVE_DIR = "saved_worlds"
PLOT_WIDTH = 50.0 # Width of each plot in 3D space (adjust as needed)
CSV_COLUMNS = ['obj_id', 'type', 'pos_x', 'pos_y', 'pos_z', 'rot_x', 'rot_y', 'rot_z', 'rot_order']

# --- Ensure Save Directory Exists ---
os.makedirs(SAVE_DIR, exist_ok=True)

# --- Helper Functions ---

@st.cache_data(ttl=3600) # Cache plot list for an hour, or clear manually
def load_plot_metadata():
    """Scans save dir, sorts plots, calculates metadata."""
    plots = []
    plot_files = sorted([f for f in os.listdir(SAVE_DIR) if f.endswith(".csv")])

    current_x_offset = 0.0
    for i, filename in enumerate(plot_files):
        # Extract name - assumes format like 'plot_001_MyName.csv' or just 'plot_001.csv'
        parts = filename[:-4].split('_') # Remove .csv and split by underscore
        plot_id = parts[0] # Assume first part is ID/order
        plot_name = " ".join(parts[1:]) if len(parts) > 1 else f"Plot {i+1}"

        plots.append({
            'id': plot_id,
            'name': plot_name,
            'filename': filename,
            'x_offset': current_x_offset
        })
        current_x_offset += PLOT_WIDTH
    return plots, current_x_offset # Return plots and the next available offset

def load_plot_objects(filename, x_offset):
    """Loads objects from a CSV, applying the plot's x_offset."""
    file_path = os.path.join(SAVE_DIR, filename)
    objects = []
    try:
        df = pd.read_csv(file_path)
        if not all(col in df.columns for col in CSV_COLUMNS):
             st.warning(f"CSV '{filename}' missing expected columns. Skipping.")
             return []

        for _, row in df.iterrows():
            obj_data = row.to_dict()
            # Apply world offset
            obj_data['pos_x'] += x_offset
            objects.append(obj_data)
        return objects
    except FileNotFoundError:
        st.error(f"File not found during object load: {filename}")
        return []
    except pd.errors.EmptyDataError:
         st.info(f"Plot file '{filename}' is empty.")
         return [] # Empty file is valid
    except Exception as e:
        st.error(f"Error loading objects from {filename}: {e}")
        return []


def save_plot_data(filename, objects_data_list, plot_x_offset):
    """Saves object data list to a new CSV file, making positions relative."""
    file_path = os.path.join(SAVE_DIR, filename)
    relative_objects = []
    for obj in objects_data_list:
        # Ensure required fields exist before proceeding
        if not all(k in obj for k in ['position', 'rotation', 'type', 'obj_id']):
            print(f"Skipping malformed object during save: {obj}")
            continue

        relative_obj = {
            'obj_id': obj.get('obj_id', str(uuid.uuid4())), # Generate ID if missing
            'type': obj.get('type', 'Unknown'),
            'pos_x': obj['position'].get('x', 0.0) - plot_x_offset, # Make relative
            'pos_y': obj['position'].get('y', 0.0),
            'pos_z': obj['position'].get('z', 0.0),
            'rot_x': obj['rotation'].get('_x', 0.0),
            'rot_y': obj['rotation'].get('_y', 0.0),
            'rot_z': obj['rotation'].get('_z', 0.0),
            'rot_order': obj['rotation'].get('_order', 'XYZ')
        }
        relative_objects.append(relative_obj)

    try:
        df = pd.DataFrame(relative_objects, columns=CSV_COLUMNS)
        df.to_csv(file_path, index=False)
        st.success(f"Saved plot data to {filename}")
        return True
    except Exception as e:
        st.error(f"Failed to save plot data to {filename}: {e}")
        return False

# --- Page Config ---
st.set_page_config(
    page_title="Shared World Builder",
    layout="wide"
)

# --- Initialize Session State ---
if 'selected_object' not in st.session_state:
    st.session_state.selected_object = 'None'
if 'new_plot_name' not in st.session_state:
    st.session_state.new_plot_name = ""
if 'save_request_data' not in st.session_state: # To store data back from JS
    st.session_state.save_request_data = None

# --- Load Plot Metadata ---
# Cached function returns list of plots and the next starting x_offset
plots_metadata, next_plot_x_offset = load_plot_metadata()

# --- Load ALL Objects for Rendering ---
# This could be slow with many plots! Consider optimization later.
all_initial_objects = []
for plot in plots_metadata:
    all_initial_objects.extend(load_plot_objects(plot['filename'], plot['x_offset']))

# --- Sidebar ---
with st.sidebar:
    st.title("🏗️ World Controls")

    st.header("Navigation (Plots)")
    st.caption("Click to teleport player to the start of a plot.")

    # Use columns for a horizontal button layout if desired
    cols = st.columns(3)
    col_idx = 0
    for plot in plots_metadata:
        # Use an emoji + name for the button
        button_label = f"➡️ {plot.get('name', plot['id'])}"
        if cols[col_idx].button(button_label, key=f"nav_{plot['id']}"):
            # Send command to JS to move the player
            target_x = plot['x_offset']
            streamlit_js_eval(js_code=f"teleportPlayer({target_x});")
            # No rerun needed here, JS handles the move

        col_idx = (col_idx + 1) % 3 # Cycle through columns

    st.markdown("---")

    # --- Object Placement ---
    st.header("Place Objects")
    object_types = ["None", "Simple House", "Tree", "Rock", "Fence Post"]
    current_object_index = 0
    try:
        current_object_index = object_types.index(st.session_state.selected_object)
    except ValueError:
        st.session_state.selected_object = "None" # Reset if invalid

    selected_object_type_widget = st.selectbox(
        "Select Object:",
        options=object_types,
        index=current_object_index,
        key="selected_object_widget"
    )
    if selected_object_type_widget != st.session_state.selected_object:
         st.session_state.selected_object = selected_object_type_widget
         # No rerun needed just for selection, JS will read state on next placement


    st.markdown("---")

    # --- Saving ---
    st.header("Save New Plot")
    st.session_state.new_plot_name = st.text_input(
        "Name for New Plot:",
        value=st.session_state.new_plot_name,
        placeholder="My Awesome Creation"
    )

    if st.button("💾 Save Current Work as New Plot"):
        # 1. Trigger JS function to get data
        # This function `getSaveData` should be defined in index.html
        # It should collect data for objects considered "new"
        # and return them as a JSON string.
        # The positions should be WORLD positions.
        js_get_data_code = "getSaveData();"
        # Use streamlit_js_eval to run JS and get data back into session_state
        st.session_state.save_request_data = streamlit_js_eval(
             js_code=js_get_data_code,
             key="get_save_data" # Unique key for this eval call
             # Removed want_output=True, value goes to key if specified
        )
        # Need to trigger a rerun to process the data AFTER it arrives
        # Using sync() might help ensure the value is available immediately after? Let's try without first.
        st.rerun() # Rerun to process the returned data below


# --- Process Save Data (if received from JS via key) ---
# This runs AFTER the rerun triggered by the save button
save_data_from_js = st.session_state.get("save_request_data", None)

if save_data_from_js:
    st.info("Received save data from client...")
    try:
        objects_to_save = json.loads(save_data_from_js) # Parse JSON string from JS

        if isinstance(objects_to_save, list) and len(objects_to_save) > 0:
            # Determine filename for the new plot
            new_plot_index = len(plots_metadata) + 1
            plot_name_sanitized = "".join(c for c in st.session_state.new_plot_name if c.isalnum() or c in (' ', '_')).rstrip() or f"Plot_{new_plot_index}"
            new_filename = f"plot_{new_plot_index:03d}_{plot_name_sanitized.replace(' ','_')}.csv"

            # Save the data, converting world coords to relative coords inside the func
            save_ok = save_plot_data(new_filename, objects_to_save, next_plot_x_offset)

            if save_ok:
                # IMPORTANT: Clear the plot metadata cache so it reloads with the new file
                load_plot_metadata.clear()
                # Clear the JS data request state
                st.session_state.save_request_data = None
                # Reset the new plot name field
                st.session_state.new_plot_name = ""
                # Reset newly placed objects in JS? Needs another call.
                try:
                     streamlit_js_eval(js_code="resetNewlyPlacedObjects();", key="reset_js_state")
                except Exception as js_e:
                     st.warning(f"Could not reset JS state after save: {js_e}")

                st.success(f"New plot '{plot_name_sanitized}' saved!")
                # Rerun AGAIN to reload plots list, redraw minimap, and update JS injection
                st.rerun()
            else:
                st.error("Failed to save plot data to file.")
                # Clear the request data even if save failed to prevent retry loop
                st.session_state.save_request_data = None

        elif isinstance(objects_to_save, list) and len(objects_to_save) == 0:
            st.warning("Nothing new to save.")
            st.session_state.save_request_data = None # Clear request
        else:
             st.error(f"Received invalid save data format from client: {type(objects_to_save)}")
             st.session_state.save_request_data = None # Clear request


    except json.JSONDecodeError:
        st.error("Failed to decode save data from client. Data might be corrupted or empty.")
        print("Received raw data:", save_data_from_js) # Log for debugging
        st.session_state.save_request_data = None # Clear request
    except Exception as e:
        st.error(f"Error processing save: {e}")
        st.exception(e)
        st.session_state.save_request_data = None # Clear request


# --- Main Area ---
st.header("Shared 3D World")
st.caption("Build side-by-side with others. Changes load on refresh/save.")

# --- Load and Prepare HTML ---
html_file_path = 'index.html'
html_content_with_state = None # Initialize

try:
    with open(html_file_path, 'r', encoding='utf-8') as f:
        html_template = f.read()

    # --- Inject Python state into JavaScript ---
    js_injection_script = f"""
<script>
    // Set global variables BEFORE the main script runs
    window.ALL_INITIAL_OBJECTS = {json.dumps(all_initial_objects)}; // All objects from all plots
    window.SELECTED_OBJECT_TYPE = {json.dumps(st.session_state.selected_object)};
    window.PLOT_WIDTH = {json.dumps(PLOT_WIDTH)};
    window.NEXT_PLOT_X_OFFSET = {json.dumps(next_plot_x_offset)}; // Needed for save calculation
    console.log("Streamlit State Injected:", {{
        selectedObject: window.SELECTED_OBJECT_TYPE,
        initialObjectsCount: window.ALL_INITIAL_OBJECTS ? window.ALL_INITIAL_OBJECTS.length : 0,
        plotWidth: window.PLOT_WIDTH,
        nextPlotX: window.NEXT_PLOT_X_OFFSET
    }});
</script>
"""
    html_content_with_state = html_template.replace('</head>', js_injection_script + '\n</head>', 1)

    # --- Embed HTML Component ---
    components.html(
        html_content_with_state,
        height=750,
        scrolling=False
    )

except FileNotFoundError:
    st.error(f"CRITICAL ERROR: Could not find the file '{html_file_path}'.")
    st.warning(f"Make sure `{html_file_path}` is in the same directory as `app.py` and `{SAVE_DIR}` exists.")
except Exception as e:
    st.error(f"An critical error occurred during HTML preparation or component rendering: {e}")
    st.exception(e)