#!/usr/bin/env python3
"""
Tool to download a specified format using yt-dlp as a Python library.
"""

import argparse
import contextlib
import copy
import io
import json
import logging
import os
import re
import shlex
import sys
import time
from datetime import datetime

try:
    import yt_dlp
    from yt_dlp.utils import match_filter_func
except ImportError:
    print("yt-dlp is not installed. Please install it with: pip install yt-dlp", file=sys.stderr)
    sys.exit(1)

logger = logging.getLogger('download_native_py_tool')

# A custom logger for yt-dlp to capture output and key events
class YTDLPLogger:
    def __init__(self):
        self.final_filename = None
        self.is_403 = False
        self.is_timeout = False
        self.has_errors = False

    def debug(self, msg):
        # yt-dlp logs the destination file path at the debug level.
        if msg.startswith('[download] Destination:'):
            self.final_filename = msg.split(':', 1)[1].strip()
        elif msg.startswith('[Merger] Merging formats into "'):
            # This captures the final filename after merging.
            self.final_filename = msg.split('"')[1]
        elif msg.startswith('[download]') and 'has already been downloaded' in msg:
            match = re.search(r'\[download\]\s+(.*)\s+has already been downloaded', msg)
            if match:
                self.final_filename = match.group(1).strip()
        logger.debug(msg)

    def info(self, msg):
        logger.info(msg)

    def warning(self, msg):
        logger.warning(msg)

    def error(self, msg):
        if "HTTP Error 403" in msg:
            self.is_403 = True
        if "Read timed out" in msg:
            self.is_timeout = True
        self.has_errors = True
        logger.error(msg)

def ytdlp_progress_hook(d, ytdlp_logger):
    """Progress hook to capture the final filename."""
    if d['status'] == 'finished':
        ytdlp_logger.final_filename = d.get('filename')
        logger.info(f"Download finished. Final file: {ytdlp_logger.final_filename}")

def add_download_native_py_parser(subparsers):
    """Add the parser for the 'download py' command."""
    parser = subparsers.add_parser(
        'py',
        description='Download using yt-dlp as a Python library (recommended). This method calls yt-dlp functions directly.',
        formatter_class=argparse.RawTextHelpFormatter,
        help='Download using a direct Python call to yt-dlp (recommended).'
    )
    parser.add_argument('--load-info-json', type=argparse.FileType('r', encoding='utf-8'), help="Path to the info.json file. If not provided, reads from stdin.")
    parser.add_argument('-f', '--format', required=True, help='The format selection string to download (e.g., "18", "299/137", "bestvideo+bestaudio").')
    parser.add_argument('--output-dir', default='.', help='Directory to save the downloaded file. Defaults to current directory.')
    parser.add_argument('--save-info-json-dir', help='If specified, save the info.json received from stdin to this directory with an auto-generated name.')
    parser.add_argument('--proxy', help='Proxy to use for the download, e.g., "socks5://127.0.0.1:1080".')
    parser.add_argument('--proxy-rename', help='Apply sed-style regex substitution to the proxy URL. Format: s/pattern/replacement/')
    parser.add_argument('--temp-path', help='Directory for temporary files (e.g., fragments). Use a RAM disk for best performance.')
    parser.add_argument('--pause', type=int, default=0, help='Seconds to wait before starting the download.')
    parser.add_argument('--download-continue', action='store_true', help='Enable download continuation (--no-overwrites and --continue flags for yt-dlp).')
    parser.add_argument('--verbose', action='store_true', help='Enable verbose output for this script and yt-dlp.')
    parser.add_argument('--config', default=None, help='Path to a yt-dlp JSON configuration file (e.g., ytdlp.json). If not provided, searches for ytdlp.json.')
    parser.add_argument('--downloader', help='Name of the external downloader backend for yt-dlp to use (e.g., "aria2c", "native").')
    parser.add_argument('--downloader-args', help='Arguments to pass to the external downloader backend (e.g., "aria2c:-x 8").')
    parser.add_argument('--extra-ytdlp-args', help='A string of extra command-line arguments to pass to yt-dlp.')
    parser.add_argument('--output-buffer', action='store_true', help='Download to an in-memory buffer and print raw bytes to stdout. Final filename is printed to stderr.')
    parser.add_argument('--cleanup', action='store_true', help='After download, rename the file to include a timestamp and truncate it to 0 bytes.')
    parser.add_argument('--merge-output-format', help='Container format to merge to (e.g., "mp4", "mkv"). Overrides config file.')
    parser.add_argument('--retries', type=int, help='Number of retries for the entire download (default: 10).')
    parser.add_argument('--fragment-retries', type=int, help='Number of retries for each fragment (default: 10).')
    parser.add_argument('--socket-timeout', type=int, help='Timeout for socket operations in seconds (default: 20).')
    parser.add_argument('--add-header', action='append', help='Add a custom HTTP header for the download. Format: "Key: Value". Can be used multiple times.')
    parser.add_argument('--concurrent-fragments', type=int, help='Number of fragments to download concurrently for each media.')
    # Arguments to pass through to yt-dlp
    parser.add_argument('--download-sections', help='yt-dlp --download-sections argument (e.g., "*0-10240").')
    parser.add_argument('--test', action='store_true', help='yt-dlp --test argument (download small part).')
    return parser


def _download_single_format(format_id, info_data, base_ydl_opts, args):
    """
    Download a single format ID from the given info_data.
    This function filters info_data to only contain the requested format,
    preventing yt-dlp from auto-merging with other streams.
    
    Returns a tuple: (success: bool, ytdlp_logger: YTDLPLogger)
    """
    # Deep copy info_data so we can modify it without affecting other downloads
    local_info_data = copy.deepcopy(info_data)
    
    available_formats = local_info_data.get('formats', [])
    
    # Find the exact format
    target_format = next((f for f in available_formats if f.get('format_id') == format_id), None)
    
    if not target_format:
        logger.error(f"Format '{format_id}' not found in info.json")
        ytdlp_logger = YTDLPLogger()
        ytdlp_logger.has_errors = True
        return False, ytdlp_logger
    
    # Filter to only this format - this is the key to preventing auto-merge
    local_info_data['formats'] = [target_format]
    
    # Clear any pre-selected format fields that might trigger merging
    local_info_data.pop('requested_formats', None)
    local_info_data.pop('format', None)
    local_info_data.pop('format_id', None)
    
    logger.info(f"Filtered info_data to only contain format '{format_id}' (removed {len(available_formats) - 1} other formats)")
    
    # Create a fresh logger for this download
    ytdlp_logger = YTDLPLogger()
    
    # Copy base options and update with this format's specifics
    ydl_opts = dict(base_ydl_opts)
    ydl_opts['format'] = format_id
    ydl_opts['logger'] = ytdlp_logger
    ydl_opts['progress_hooks'] = [lambda d, yl=ytdlp_logger: ytdlp_progress_hook(d, yl)]
    
    try:
        download_buffer = None
        if args.output_buffer:
            download_buffer = io.BytesIO()
            ctx_mgr = contextlib.redirect_stdout(download_buffer)
        else:
            ctx_mgr = contextlib.nullcontext()

        with ctx_mgr, yt_dlp.YoutubeDL(ydl_opts) as ydl:
            ydl.process_ie_result(local_info_data)

        if ytdlp_logger.has_errors:
            logger.error(f"Download of format '{format_id}' failed: yt-dlp reported an error during execution.")
            return False, ytdlp_logger

        logger.info(f"Download of format '{format_id}' completed successfully.")
        
        if args.output_buffer and download_buffer:
            sys.stdout.buffer.write(download_buffer.getvalue())
            sys.stdout.buffer.flush()
        
        return True, ytdlp_logger

    except yt_dlp.utils.DownloadError as e:
        logger.error(f"yt-dlp DownloadError for format '{format_id}': {e}")
        ytdlp_logger.has_errors = True
        return False, ytdlp_logger
    except Exception as e:
        logger.exception(f"Unexpected error downloading format '{format_id}': {e}")
        ytdlp_logger.has_errors = True
        return False, ytdlp_logger


def main_download_native_py(args):
    """Main logic for the 'download-native-py' command."""
    # All logging should go to stderr to keep stdout clean for the final filename, or for binary data with --output-buffer.
    log_stream = sys.stderr
    log_level = logging.DEBUG if args.verbose else logging.INFO
    # Reconfigure root logger
    for handler in logging.root.handlers[:]:
        logging.root.removeHandler(handler)
    logging.basicConfig(level=log_level, stream=log_stream, format='%(asctime)s - %(name)s - %(levelname)s - %(message)s')

    if args.pause > 0:
        logger.info(f"Pausing for {args.pause} seconds...")
        time.sleep(args.pause)

    info_json_content = ""
    input_source_name = ""
    if args.load_info_json:
        info_json_content = args.load_info_json.read()
        input_source_name = args.load_info_json.name
    else:
        info_json_content = sys.stdin.read()
        input_source_name = "stdin"

    if not info_json_content.strip():
        logger.error(f"Failed to read info.json from {input_source_name}. Input is empty.")
        return 1

    try:
        info_data = json.loads(info_json_content)
        logger.info(f"Successfully loaded info.json from {input_source_name}.")
    except json.JSONDecodeError:
        logger.error(f"Failed to parse info.json from {input_source_name}. Is the input valid JSON?")
        return 1

    if args.save_info_json_dir:
        try:
            video_id = info_data.get('id', 'unknown_video_id')
            timestamp = datetime.now().strftime('%Y%m%d_%H%M%S')
            filename = f"{timestamp}-{video_id}-info.json"
            output_path = os.path.join(args.save_info_json_dir, filename)
            os.makedirs(args.save_info_json_dir, exist_ok=True)
            with open(output_path, 'w', encoding='utf-8') as f:
                json.dump(info_data, f, indent=2)
            logger.info(f"Saved info.json to {output_path}")
        except Exception as e:
            logger.error(f"Failed to save info.json: {e}")

    # Handle proxy and proxy rename
    proxy_url = args.proxy
    if not proxy_url:
        proxy_url = info_data.get('_proxy_url')
        if proxy_url:
            logger.info(f"Using proxy from info.json: {proxy_url}")

    if proxy_url and args.proxy_rename:
        rename_rule = args.proxy_rename.strip("'\"")
        if rename_rule.startswith('s/') and rename_rule.count('/') >= 2:
            try:
                parts = rename_rule.split('/')
                pattern, replacement = parts[1], parts[2]
                original_proxy = proxy_url
                proxy_url = re.sub(pattern, replacement, proxy_url)
                logger.info(f"Renamed proxy URL from '{original_proxy}' to '{proxy_url}' using rule '{rename_rule}'")
            except re.error as e:
                logger.error(f"Invalid regex in --proxy-rename: {e}")
                return 1
        else:
            logger.error("Invalid --proxy-rename format. Expected: s/pattern/replacement/")
            return 1

    # For library usage, ensure proxy URL has a scheme. Default to http if missing.
    if proxy_url and '://' not in proxy_url:
        original_proxy = proxy_url
        proxy_url = 'http://' + proxy_url
        logger.info(f"Proxy URL '{original_proxy}' has no scheme. Defaulting to '{proxy_url}'.")

    # Build the yt-dlp options dictionary
    logger.info("--- Configuring yt-dlp options ---")

    param_sources = {}
    ydl_opts = {}

    def _parse_ytdlp_args(args_list, source_name, opts_dict, sources_dict):
        """Helper to parse a list of yt-dlp CLI-style args into an options dict."""
        i = 0
        while i < len(args_list):
            arg = args_list[i]
            if not arg.startswith('--'):
                logger.warning(f"Skipping non-option argument from {source_name}: {arg}")
                i += 1
                continue

            key_cli = arg.lstrip('-')
            key_py = key_cli.replace('-', '_')
            
            is_flag = i + 1 >= len(args_list) or args_list[i + 1].startswith('--')
            
            if is_flag:
                if key_py.startswith('no_'):
                    real_key = key_py[3:]
                    # Handle special cases where the Python option name is different
                    if real_key == 'resize_buffer': real_key = 'noresizebuffer'
                    opts_dict[real_key] = False
                    sources_dict[real_key] = source_name
                else:
                    # Handle special cases
                    if key_py == 'resize_buffer':
                        opts_dict['noresizebuffer'] = False
                        sources_dict['noresizebuffer'] = source_name
                    else:
                        opts_dict[key_py] = True
                        sources_dict[key_py] = source_name
                i += 1
            else: # Has a value
                value = args_list[i + 1]
                # Special key name conversions
                if key_py == 'limit_rate': key_py = 'ratelimit'
                elif key_py == 'buffer_size': key_py = 'buffersize'
            
                # Special value conversion for match_filter
                if key_py == 'match_filter':
                    try:
                        value = match_filter_func(value)
                    except Exception as e:
                        logger.error(f"Failed to compile --match-filter '{value}': {e}")
                        # Skip this option
                        i += 2
                        continue
                else:
                    # Try to convert values to numbers, which yt-dlp expects
                    try:
                        value = int(value)
                    except (ValueError, TypeError):
                        try:
                            value = float(value)
                        except (ValueError, TypeError):
                            pass # Keep as string
            
                opts_dict[key_py] = value
                sources_dict[key_py] = source_name
                i += 2

    # 1. Load from JSON config file
    config_path = args.config
    log_msg = ""
    if config_path:
        log_msg = f"1. [Source: Config File] Loading from: {config_path}"
    else:
        if os.path.exists('ytdlp.json'):
            config_path = 'ytdlp.json'
            log_msg = f"1. [Source: Config File] No --config provided. Found and loading local '{config_path}'."

    if config_path and os.path.exists(config_path):
        if log_msg:
            logger.info(log_msg)
        try:
            with open(config_path, 'r', encoding='utf-8') as f:
                config_data = json.load(f)

            # All yt-dlp options are expected under the 'ytdlp_params' key.
            config_opts = config_data.get('ytdlp_params', {})

            if config_opts:
                logger.info(f"Parameters from config file ('{config_path}'):")
                config_str = json.dumps(config_opts, indent=2)
                for line in config_str.splitlines():
                    logger.info(f"  {line}")

            # Special handling for match_filter before updating ydl_opts
            if 'match_filter' in config_opts and isinstance(config_opts['match_filter'], str):
                logger.info(f"   Compiling 'match_filter' string from config file...")
                try:
                    config_opts['match_filter'] = match_filter_func(config_opts['match_filter'])
                except Exception as e:
                    logger.error(f"Failed to compile match_filter from config: {e}")
                    del config_opts['match_filter']

            ydl_opts.update(config_opts)
            for key in config_opts:
                param_sources[key] = "Config File"
        except (json.JSONDecodeError, IOError) as e:
            logger.error(f"Failed to read or parse JSON config file {config_path}: {e}")
            return 1
    elif args.config:
        logger.warning(f"Config file '{args.config}' not found. Ignoring.")
    
    # 2. Load from extra command-line args
    if args.extra_ytdlp_args:
        logger.info(f"2. [Source: CLI Extra Args] Loading extra arguments...")
        extra_args_list = shlex.split(args.extra_ytdlp_args)
        _parse_ytdlp_args(extra_args_list, "CLI Extra Args", ydl_opts, param_sources)

    # 3. Apply internal defaults if not already set
    if 'noresizebuffer' not in ydl_opts:
        ydl_opts['noresizebuffer'] = True
        param_sources['noresizebuffer'] = "Internal Default"
    if 'buffersize' not in ydl_opts:
        ydl_opts['buffersize'] = '4M'
        param_sources['buffersize'] = "Internal Default"
    if 'force_progress' not in ydl_opts:
        ydl_opts['force_progress'] = True
        param_sources['force_progress'] = "Internal Default"

    # 4. Apply explicit arguments from this script's CLI (highest priority)
    logger.info("3. [Source: CLI Explicit Args] Applying explicit overrides:")
    
    os.makedirs(args.output_dir, exist_ok=True)

    ydl_opts['verbose'] = args.verbose
    param_sources['verbose'] = "CLI Explicit"

    # Handle output template ('outtmpl')
    if args.output_buffer:
        ydl_opts['outtmpl'] = '-'
        param_sources['outtmpl'] = "CLI Explicit (Buffer)"
    elif 'outtmpl' in ydl_opts:
        # Respect outtmpl from config, but prepend the output directory
        outtmpl_val = ydl_opts['outtmpl']
        if isinstance(outtmpl_val, dict):
            # Prepend dir to each template in the dict
            ydl_opts['outtmpl'] = {k: os.path.join(args.output_dir, v) for k, v in outtmpl_val.items()}
        else:
            # Prepend dir to the single template string
            ydl_opts['outtmpl'] = os.path.join(args.output_dir, str(outtmpl_val))
        param_sources['outtmpl'] = "Config File (Path Applied)"
        logger.info(f"   Using 'outtmpl' from config, with output directory '{args.output_dir}' prepended.")
    else:
        # Use a default template if not specified in config
        output_template = os.path.join(args.output_dir, '%(title)s [%(id)s].f%(format_id)s.%(ext)s')
        ydl_opts['outtmpl'] = output_template
        param_sources['outtmpl'] = "Internal Default"
        logger.info(f"   Using default 'outtmpl': {output_template}")
    
    if args.temp_path:
        ydl_opts['paths'] = {'temp': args.temp_path}
        param_sources['paths'] = "CLI Explicit"
        logger.info(f"   Temporary path: {args.temp_path}")

    if args.add_header:
        if 'http_headers' not in ydl_opts:
            ydl_opts['http_headers'] = {}
        elif not isinstance(ydl_opts['http_headers'], dict):
            logger.warning(f"Overwriting non-dictionary http_headers with headers from command line.")
            ydl_opts['http_headers'] = {}
        for header in args.add_header:
            if ':' in header:
                key, value = header.split(':', 1)
                ydl_opts['http_headers'][key.strip()] = value.strip()
            else:
                logger.error(f"Invalid header format: '{header}'. Expected 'Key: Value'.")
        param_sources['http_headers'] = "CLI Explicit (Merged)"

    if args.download_continue:
        ydl_opts['continuedl'] = True
        ydl_opts['nooverwrites'] = True
        param_sources['continuedl'] = "CLI Explicit"
        param_sources['nooverwrites'] = "CLI Explicit"

    if proxy_url:
        ydl_opts['proxy'] = proxy_url
        param_sources['proxy'] = "CLI Explicit"

    if args.downloader:
        ydl_opts['downloader'] = {args.downloader: None}
        param_sources['downloader'] = "CLI Explicit"
    if args.downloader_args:
        try:
            downloader_name, args_str = args.downloader_args.split(':', 1)
            ydl_opts.setdefault('downloader_args', {})[downloader_name] = shlex.split(args_str)
            param_sources['downloader_args'] = "CLI Explicit"
        except ValueError:
            logger.error(f"Invalid --downloader-args format. Expected 'downloader:args'.")
            return 1

    if args.merge_output_format:
        ydl_opts['merge_output_format'] = args.merge_output_format
        param_sources['merge_output_format'] = "CLI Explicit"
    if args.download_sections:
        ydl_opts['download_sections'] = args.download_sections
        param_sources['download_sections'] = "CLI Explicit"
    if args.test:
        ydl_opts['test'] = True
        param_sources['test'] = "CLI Explicit"
    if args.retries is not None:
        ydl_opts['retries'] = args.retries
        param_sources['retries'] = "CLI Explicit"
    if args.fragment_retries is not None:
        ydl_opts['fragment_retries'] = args.fragment_retries
        param_sources['fragment_retries'] = "CLI Explicit"
    if args.socket_timeout is not None:
        ydl_opts['socket_timeout'] = args.socket_timeout
        param_sources['socket_timeout'] = "CLI Explicit"
    if args.concurrent_fragments is not None:
        ydl_opts['concurrent_fragments'] = args.concurrent_fragments
        param_sources['concurrent_fragments'] = "CLI Explicit"

    # To prevent timeouts on slow connections, ensure progress reporting is not disabled.
    # The CLI wrapper enables this by default, so we match its behavior for robustness.
    if ydl_opts.get('noprogress'):
        logger.info("Overriding 'noprogress' option. Progress reporting is enabled to prevent network timeouts.")
        ydl_opts['noprogress'] = False
        param_sources['noprogress'] = "Internal Override"

    # Ensure byte-size options are integers for library use
    try:
        from yt_dlp.utils import parse_bytes
        if 'buffersize' in ydl_opts and isinstance(ydl_opts['buffersize'], str):
            ydl_opts['buffersize'] = parse_bytes(ydl_opts['buffersize'])
            param_sources['buffersize'] = param_sources.get('buffersize', 'Unknown') + ' (Parsed)'
    except (ImportError, Exception) as e:
        logger.warning(f"Could not parse 'buffersize' option: {e}")

    # Force skip_download to False, as this script's purpose is to download.
    if ydl_opts.get('skip_download'):
        logger.info("Overriding 'skip_download: true' from config. This tool is for downloading.")
        ydl_opts['skip_download'] = False
        param_sources['skip_download'] = "Internal Override"

    # Log final effective options with sources
    logger.info("=== Final Effective yt-dlp Options (base) ===")
    for k in sorted(ydl_opts.keys()):
        v = ydl_opts[k]
        src = param_sources.get(k, "Unknown")
        if k in ['logger', 'progress_hooks']: continue
        logger.info(f"  {k}: {v} [Source: {src}]")

    # --- Parse and process the format string ---
    requested_format = args.format
    available_formats = [str(f['format_id']) for f in info_data.get('formats', []) if 'format_id' in f]
    
    # Determine what kind of format string we have
    # Keywords that yt-dlp treats as special selectors
    selector_keywords = ('best', 'worst', 'bestvideo', 'bestaudio')
    
    # Split by comma to get individual format requests
    # Each item could be a simple format ID or a fallback chain (with /)
    format_items = [f.strip() for f in requested_format.split(',') if f.strip()]
    
    logger.info(f"Format string '{requested_format}' parsed into {len(format_items)} item(s): {format_items}")
    
    # Process each format item
    all_success = True
    final_filename = None
    
    for format_item in format_items:
        logger.info(f"--- Processing format item: '{format_item}' ---")
        
        # Check if this specific item is a simple format ID or a complex selector
        item_has_complex_syntax = any(c in format_item for c in '/+[]()') or format_item.startswith(selector_keywords)
        
        if item_has_complex_syntax:
            # This is a complex selector like "299/298/137" or "bestvideo+bestaudio"
            # We need to handle fallback chains specially
            
            if '/' in format_item and '+' not in format_item:
                # This is a fallback chain like "299/298/137"
                # Try each format in order until one succeeds
                fallback_formats = [f.strip() for f in format_item.split('/') if f.strip()]
                logger.info(f"Detected fallback chain with {len(fallback_formats)} options: {fallback_formats}")
                
                item_success = False
                for fallback_fmt in fallback_formats:
                    # Check if this fallback is a simple format ID that exists
                    if fallback_fmt in available_formats:
                        logger.info(f"Trying fallback format '{fallback_fmt}'...")
                        success, ytdlp_logger = _download_single_format(fallback_fmt, info_data, ydl_opts, args)
                        if success:
                            item_success = True
                            if ytdlp_logger.final_filename:
                                final_filename = ytdlp_logger.final_filename
                            break
                        else:
                            logger.warning(f"Fallback format '{fallback_fmt}' failed, trying next...")
                    else:
                        # Try to find a matching format with a suffix (e.g., "140" matches "140-0")
                        prefix_match_re = re.compile(rf'^{re.escape(fallback_fmt)}-\d+$')
                        first_match = next((af for af in available_formats if prefix_match_re.match(af)), None)
                        
                        if first_match:
                            logger.info(f"Fallback format '{fallback_fmt}' not found exactly. Using match: '{first_match}'...")
                            success, ytdlp_logger = _download_single_format(first_match, info_data, ydl_opts, args)
                            if success:
                                item_success = True
                                if ytdlp_logger.final_filename:
                                    final_filename = ytdlp_logger.final_filename
                                break
                            else:
                                logger.warning(f"Fallback format '{first_match}' failed, trying next...")
                        else:
                            logger.warning(f"Fallback format '{fallback_fmt}' not available, trying next...")
                
                if not item_success:
                    logger.error(f"All fallback formats in '{format_item}' failed or were unavailable.")
                    all_success = False
            else:
                # This is a merge request or other complex selector
                # We can't safely filter for these, so we pass through to yt-dlp
                # but warn the user
                logger.warning(f"Complex format selector '{format_item}' detected. Cannot prevent auto-merge for this type.")
                logger.warning("If you experience merge errors, try specifying simple format IDs separated by commas.")
                
                # Use the original yt-dlp behavior for complex selectors
                ytdlp_logger = YTDLPLogger()
                local_ydl_opts = dict(ydl_opts)
                local_ydl_opts['format'] = format_item
                local_ydl_opts['logger'] = ytdlp_logger
                local_ydl_opts['progress_hooks'] = [lambda d, yl=ytdlp_logger: ytdlp_progress_hook(d, yl)]
                
                try:
                    download_buffer = None
                    if args.output_buffer:
                        download_buffer = io.BytesIO()
                        ctx_mgr = contextlib.redirect_stdout(download_buffer)
                    else:
                        ctx_mgr = contextlib.nullcontext()

                    with ctx_mgr, yt_dlp.YoutubeDL(local_ydl_opts) as ydl:
                        ydl.process_ie_result(copy.deepcopy(info_data))

                    if ytdlp_logger.has_errors:
                        logger.error(f"Download of '{format_item}' failed.")
                        all_success = False
                    else:
                        if ytdlp_logger.final_filename:
                            final_filename = ytdlp_logger.final_filename
                        if args.output_buffer and download_buffer:
                            sys.stdout.buffer.write(download_buffer.getvalue())
                            sys.stdout.buffer.flush()

                except yt_dlp.utils.DownloadError as e:
                    logger.error(f"yt-dlp DownloadError for '{format_item}': {e}")
                    all_success = False
                except Exception as e:
                    logger.exception(f"Unexpected error downloading '{format_item}': {e}")
                    all_success = False
        else:
            # This is a simple format ID like "299-dashy" or "140"
            # Check if it exists in available formats
            if format_item in available_formats:
                success, ytdlp_logger = _download_single_format(format_item, info_data, ydl_opts, args)
                if success:
                    if ytdlp_logger.final_filename:
                        final_filename = ytdlp_logger.final_filename
                else:
                    all_success = False
            else:
                # Try to find a matching format with a suffix (e.g., "140" matches "140-0")
                prefix_match_re = re.compile(rf'^{re.escape(format_item)}-\d+$')
                first_match = next((af for af in available_formats if prefix_match_re.match(af)), None)
                
                if first_match:
                    logger.info(f"Requested format '{format_item}' not found. Using first available match: '{first_match}'.")
                    success, ytdlp_logger = _download_single_format(first_match, info_data, ydl_opts, args)
                    if success:
                        if ytdlp_logger.final_filename:
                            final_filename = ytdlp_logger.final_filename
                    else:
                        all_success = False
                else:
                    logger.error(f"Requested format '{format_item}' not found in available formats: {available_formats}")
                    all_success = False

    # Final output
    if all_success:
        logger.info("All format downloads completed successfully.")
        if final_filename:
            print(final_filename, file=sys.stdout)
        
        if args.cleanup and final_filename and os.path.exists(final_filename):
            try:
                logger.info(f"Cleanup: Renaming and truncating '{final_filename}'")
                timestamp = datetime.now().strftime('%Y%m%d_%H%M%S')
                directory, original_filename = os.path.split(final_filename)
                filename_base, filename_ext = os.path.splitext(original_filename)
                new_filename = f"{filename_base}_{timestamp}{filename_ext}.empty"
                new_filepath = os.path.join(directory, new_filename)
                os.rename(final_filename, new_filepath)
                logger.info(f"Renamed to '{new_filepath}'")
                with open(new_filepath, 'w') as f:
                    pass
                logger.info(f"Truncated '{new_filepath}' to 0 bytes.")
            except Exception as e:
                logger.error(f"Cleanup failed: {e}")
                return 1
        
        return 0
    else:
        logger.error("One or more format downloads failed.")
        return 1