#!/usr/bin/env python3
"""Batch render scenes from different datasets: generate GLB files and render top/diagonal views.

Supports: scannet, arkitscenes, matterport3d, 3rscan

Usage:
    # Step 1: Generate all GLB files (use internscenes environment)
    conda activate internscenes
    python batch_render_scenes.py --dataset arkitscenes --mode compose --workers 4

    # Step 2: Render all views (use blender environment)  
    conda activate blender
    python batch_render_scenes.py --dataset arkitscenes --mode render --workers 8

    # Process all datasets
    python batch_render_scenes.py --dataset all --mode render --workers 8
"""

from __future__ import annotations

import argparse
import os
import subprocess
import sys
from pathlib import Path
from concurrent.futures import ProcessPoolExecutor, as_completed
from multiprocessing import cpu_count

try:
    from tqdm import tqdm
except ImportError:
    def tqdm(iterable, desc=None, total=None, **kwargs):
        if desc:
            print(f"{desc}...")
        for i, item in enumerate(iterable):
            yield item
    tqdm.write = print

# Paths
LAYOUT_INFO_DIR = "/home/v-meiszhang/backup/datas/InternScenes/Layout_info"
ASSET_LIBRARY_DIR = "/home/v-meiszhang/backup/datas/InternScenes/asset_library"
SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
BLENDER_RENDERER = os.path.join(SCRIPT_DIR, "blender_renderer.py")

# Set environment variables for compose_scenes.py
os.environ['PTH_ASSET_LIBRARY'] = ASSET_LIBRARY_DIR
os.environ['STRUCTURE_MESH_DIRS'] = LAYOUT_INFO_DIR

# Supported datasets
DATASETS = ["scannet", "arkitscenes", "matterport3d", "3rscan"]


def get_dataset_dir(dataset: str) -> str:
    """Get the directory for a dataset."""
    return os.path.join(LAYOUT_INFO_DIR, dataset)


def get_all_scenes(dataset: str) -> list[tuple[str, str]]:
    """Get all scene names and their full paths for a dataset.
    
    Returns list of (scene_name, scene_dir) tuples.
    For arkitscenes, handles the Training/Validation subdirectory structure.
    """
    dataset_dir = get_dataset_dir(dataset)
    scenes = []
    
    if not os.path.isdir(dataset_dir):
        print(f"Warning: Dataset directory not found: {dataset_dir}")
        return scenes
    
    if dataset == "arkitscenes":
        # arkitscenes has Training/Validation subdirectories
        for split in ["Training", "Validation"]:
            split_dir = os.path.join(dataset_dir, split)
            if os.path.isdir(split_dir):
                for scene_name in sorted(os.listdir(split_dir)):
                    scene_path = os.path.join(split_dir, scene_name)
                    layout_json = os.path.join(scene_path, "layout.json")
                    if os.path.isdir(scene_path) and os.path.exists(layout_json):
                        full_scene_name = f"{dataset}/{split}/{scene_name}"
                        scenes.append((full_scene_name, scene_path))
    elif dataset == "matterport3d":
        # matterport3d has building/region structure
        for building in sorted(os.listdir(dataset_dir)):
            building_dir = os.path.join(dataset_dir, building)
            if os.path.isdir(building_dir):
                for region in sorted(os.listdir(building_dir)):
                    region_path = os.path.join(building_dir, region)
                    layout_json = os.path.join(region_path, "layout.json")
                    if os.path.isdir(region_path) and os.path.exists(layout_json):
                        full_scene_name = f"{dataset}/{building}/{region}"
                        scenes.append((full_scene_name, region_path))
    else:
        # scannet, 3rscan have flat structure
        for scene_name in sorted(os.listdir(dataset_dir)):
            scene_path = os.path.join(dataset_dir, scene_name)
            layout_json = os.path.join(scene_path, "layout.json")
            if os.path.isdir(scene_path) and os.path.exists(layout_json):
                full_scene_name = f"{dataset}/{scene_name}"
                scenes.append((full_scene_name, scene_path))
    
    return scenes


def compose_one_scene(args: tuple[str, str, bool]) -> tuple[str, bool, str]:
    """Compose GLB for a single scene. Returns (scene_name, success, message)."""
    full_scene_name, scene_dir, skip_existing = args
    
    # Check if GLB already exists and skip if requested
    glb_path = os.path.join(scene_dir, "glb_scene.glb")
    if skip_existing and os.path.exists(glb_path) and os.path.getsize(glb_path) > 0:
        return full_scene_name, True, "SKIPPED (already exists)"
    
    try:
        # Import here to avoid issues when running in blender environment
        from compose_scenes import SceneComposer
        
        composer = SceneComposer()
        # Override both scene_files_dir and scene_info_dir to use Layout_info directory
        composer.scene_files_dir = LAYOUT_INFO_DIR
        composer.scene_info_dir = LAYOUT_INFO_DIR
        
        composer.compose_one_scene(
            full_scene_name, 
            use_texture=True, 
            add_floor=True, 
            add_wall=False, 
            add_ceiling=False
        )
        return full_scene_name, True, "OK"
    except Exception as e:
        return full_scene_name, False, str(e)


def compose_all_scenes(scenes: list[tuple[str, str]], max_workers: int = 4, skip_existing: bool = False) -> None:
    """Compose GLB files for all scenes using multiprocessing."""
    print(f"Composing {len(scenes)} scenes with {max_workers} workers...")
    if skip_existing:
        print("  (skipping scenes with existing GLB files)")
    
    success_count = 0
    skip_count = 0
    fail_count = 0
    
    # Add skip_existing flag to each scene tuple
    scenes_with_flag = [(name, path, skip_existing) for name, path in scenes]
    
    with ProcessPoolExecutor(max_workers=max_workers) as executor:
        futures = {executor.submit(compose_one_scene, scene): scene[0] for scene in scenes_with_flag}
        
        with tqdm(total=len(futures), desc="Composing GLB") as pbar:
            for future in as_completed(futures):
                scene_name, success, msg = future.result()
                if success:
                    if "SKIPPED" in msg:
                        skip_count += 1
                    else:
                        success_count += 1
                else:
                    fail_count += 1
                    tqdm.write(f"  Failed: {scene_name} - {msg}")
                pbar.update(1)
    
    print(f"\nCompose complete: {success_count} success, {skip_count} skipped, {fail_count} failed")


def render_one_scene(args: tuple[str, str, bool]) -> tuple[str, bool, str]:
    """Render top and diagonal views for a single scene."""
    full_scene_name, scene_dir, skip_existing = args
    try:
        glb_path = os.path.join(scene_dir, "glb_scene.glb")
        
        # Output paths (same directory as layout.json)
        topdown_output = os.path.join(scene_dir, "render_topdown.png")
        diagonal_output = os.path.join(scene_dir, "render_diagonal.png")
        
        # Skip if both renders already exist
        if skip_existing:
            topdown_exists = os.path.exists(topdown_output) and os.path.getsize(topdown_output) > 0
            diagonal_exists = os.path.exists(diagonal_output) and os.path.getsize(diagonal_output) > 0
            if topdown_exists and diagonal_exists:
                return full_scene_name, True, "SKIPPED"
        
        # Common render arguments - use conda run -n blender to ensure bpy is available
        base_args = [
            "conda", "run", "-n", "blender", "python", BLENDER_RENDERER,
            "--input", glb_path,
            "--scene-y-up",
            "--engine", "BLENDER_EEVEE",
            "--samples", "128",
            "--auto-crop",
            "--crop-padding", "20",
        ]
        
        # Render top-down view
        topdown_args = base_args + [
            "--output", topdown_output,
            "--view-mode", "topdown",
            "--topdown-height", "1.5",
            "--topdown-scale", "1.2",
        ]
        result = subprocess.run(topdown_args, capture_output=True, text=True, timeout=120)
        if result.returncode != 0:
            return full_scene_name, False, f"Topdown render failed: {result.stderr[:200]}"
        
        # Render diagonal view
        diagonal_args = base_args + [
            "--output", diagonal_output,
            "--view-mode", "diagonal",
            "--diagonal-distance", "1.2",
            "--diagonal-height-offset", "0.1",
        ]
        result = subprocess.run(diagonal_args, capture_output=True, text=True, timeout=120)
        if result.returncode != 0:
            return full_scene_name, False, f"Diagonal render failed: {result.stderr[:200]}"
        
        return full_scene_name, True, "OK"
    except subprocess.TimeoutExpired:
        return full_scene_name, False, "Timeout"
    except Exception as e:
        return full_scene_name, False, str(e)


def render_all_scenes(scenes: list[tuple[str, str]], max_workers: int = 4, skip_existing: bool = False) -> None:
    """Render all scenes that have GLB files using multiprocessing."""
    print(f"Checking {len(scenes)} scenes for rendering...")
    
    # Find scenes with existing valid GLB files (non-empty)
    scenes_to_render = []
    skipped_empty = 0
    skipped_missing = 0
    skipped_existing = 0
    
    for full_scene_name, scene_dir in scenes:
        glb_path = os.path.join(scene_dir, "glb_scene.glb")
        if os.path.exists(glb_path):
            if os.path.getsize(glb_path) > 0:
                # Check if renders already exist when skip_existing is enabled
                if skip_existing:
                    topdown_output = os.path.join(scene_dir, "render_topdown.png")
                    diagonal_output = os.path.join(scene_dir, "render_diagonal.png")
                    if os.path.exists(topdown_output) and os.path.exists(diagonal_output):
                        skipped_existing += 1
                        continue
                scenes_to_render.append((full_scene_name, scene_dir))
            else:
                skipped_empty += 1
        else:
            skipped_missing += 1
    
    print(f"Found {len(scenes_to_render)} scenes to render")
    if skipped_existing > 0:
        print(f"  Skipped {skipped_existing} already rendered scenes")
    if skipped_empty > 0:
        print(f"  Skipped {skipped_empty} empty/corrupted GLB files")
    if skipped_missing > 0:
        print(f"  Skipped {skipped_missing} missing GLB files")
    print(f"Using {max_workers} workers")
    
    if not scenes_to_render:
        print("No scenes to render!")
        return
    
    success_count = 0
    fail_count = 0
    
    with ProcessPoolExecutor(max_workers=max_workers) as executor:
        futures = {
            executor.submit(render_one_scene, (scene[0], scene[1], skip_existing)): scene[0] 
            for scene in scenes_to_render
        }
        
        with tqdm(total=len(futures), desc="Rendering") as pbar:
            for future in as_completed(futures):
                scene_name, success, msg = future.result()
                if success:
                    success_count += 1
                else:
                    fail_count += 1
                    tqdm.write(f"  Failed: {scene_name} - {msg}")
                pbar.update(1)
    
    print(f"\nRender complete: {success_count} success, {fail_count} failed")


def main():
    parser = argparse.ArgumentParser(description="Batch process scenes from different datasets")
    parser.add_argument(
        "--dataset", 
        choices=DATASETS + ["all"], 
        default="matterport3d",
        help="Dataset to process (default: scannet)"
    )
    parser.add_argument(
        "--mode", 
        choices=["compose", "render", "all"], 
        default="all",
        help="compose: generate GLB files, render: render views, all: both"
    )
    parser.add_argument(
        "--workers",
        type=int,
        default=20,
        help=f"Number of parallel workers (default: {max(1, cpu_count() // 2)})"
    )
    parser.add_argument(
        "--limit",
        type=int,
        default=None,
        help="Limit number of scenes to process (for testing)"
    )
    parser.add_argument(
        "--start",
        type=int,
        default=0,
        help="Start index for scenes (for resuming)"
    )
    parser.add_argument(
        "--skip-existing",
        action="store_true",
        default=False,
        help="Skip scenes that already have GLB/render files (for resuming)"
    )
    args = parser.parse_args()
    
    # Get datasets to process
    if args.dataset == "all":
        datasets_to_process = DATASETS
    else:
        datasets_to_process = [args.dataset]
    
    for dataset in datasets_to_process:
        print(f"\n{'='*60}")
        print(f"Processing dataset: {dataset}")
        print(f"{'='*60}")
        
        # Get all scenes
        all_scenes = get_all_scenes(dataset)
        print(f"Found {len(all_scenes)} scenes in {dataset}")
        
        if not all_scenes:
            print(f"No scenes found for {dataset}, skipping...")
            continue
        
        # Apply limits
        scenes = all_scenes[args.start:]
        if args.limit:
            scenes = scenes[:args.limit]
        
        if args.start > 0 or args.limit:
            print(f"Processing scenes {args.start} to {args.start + len(scenes)}")
        
        if args.mode in ["compose", "all"]:
            print("\n=== Step 1: Composing GLB files ===")
            compose_all_scenes(scenes, max_workers=args.workers, skip_existing=args.skip_existing)
        
        if args.mode in ["render", "all"]:
            print("\n=== Step 2: Rendering views ===")
            render_all_scenes(scenes, max_workers=args.workers, skip_existing=args.skip_existing)
    
    print("\nAll done!")


if __name__ == "__main__":
    main()