"""Command-line interface for the LiDAR archaeological pipeline.

Handles argument parsing, logging configuration, and entry point.
"""

import argparse
import logging
import signal
import sys

from .pipeline import resolve_workers
from .pipeline import LidarArchaeoPipeline
from .gpu import log_gpu_status

logger = logging.getLogger("lidar")

# pkill pattern for the PDAL processes of THIS run (set in main) — see
# _kill_orphan_pdal: scoped to our output to spare other runs.
_pdal_kill_pattern = None


def setup_logging(verbose=False, debug=False):
    """Configure the 'lidar' logger.

    Args:
        verbose: If True, include timestamps and level names.
        debug:    If True, set level to DEBUG and add file:line info.
    """
    # Ensure UTF-8 output for non-ASCII characters in messages (✓, ✗, →, ≠, etc.)
    if hasattr(sys.stdout, 'reconfigure'):
        sys.stdout.reconfigure(encoding='utf-8', errors='replace')
    if hasattr(sys.stderr, 'reconfigure'):
        sys.stderr.reconfigure(encoding='utf-8', errors='replace')

    if debug:
        level = logging.DEBUG
        fmt = "%(asctime)s.%(msecs)03d %(levelname)-5s [%(filename)s:%(lineno)d] %(message)s"
    elif verbose:
        level = logging.INFO
        fmt = "%(asctime)s %(levelname)-5s %(message)s"
    else:
        level = logging.INFO
        fmt = "%(message)s"

    handler = logging.StreamHandler(sys.stdout)
    handler.setFormatter(logging.Formatter(fmt, datefmt="%H:%M:%S"))
    logger.setLevel(level)
    logger.handlers.clear()
    logger.addHandler(handler)
    logger.propagate = False  # Prevent double logging via root logger

    # Also configure the root logger so worker processes log properly
    root_logger = logging.getLogger()
    root_logger.setLevel(level)
    if not root_logger.handlers:
        root_handler = logging.StreamHandler(sys.stdout)
        root_handler.setFormatter(logging.Formatter(fmt, datefmt="%H:%M:%S"))
        root_logger.addHandler(root_handler)

    return logger


def main():
    """Entry point for the LiDAR archaeological pipeline."""
    parser = argparse.ArgumentParser(
        description="LiDAR pipeline for archaeological detection",
        formatter_class=argparse.RawDescriptionHelpFormatter,
       epilog="""\
 Examples:
   Standard processing (0.2 m/px):
     python -m lidar_pipeline /data/input -o /data/output

   Coarser 0.5 m/px resolution:
     python -m lidar_pipeline /data/input -o /data/output -r 0.5

   Select a specific GPU (index 0):
     python -m lidar_pipeline /data/input -o /data/output -g 0

   Select several GPUs (indices 0 and 2):
     python -m lidar_pipeline /data/input -o /data/output -g 0,2

   Use all available GPUs:
     python -m lidar_pipeline /data/input -o /data/output -g all

   Verbose mode (timestamps):
     python -m lidar_pipeline /data/input -o /data/output -v

   Debug mode (internal details):
     python -m lidar_pipeline /data/input -o /data/output --debug

   Force regeneration of all files:
     python -m lidar_pipeline /data/input -o /data/output --force

   Process a single file (for testing):
     python -m lidar_pipeline /data/input -o /data/output --file LHD_FXX_1000_6881_PTS_LAMB93_IGN69.copc

   Parallel processing (4 workers):
     python -m lidar_pipeline /data/input -o /data/output -w 4
"""
    )
    parser.add_argument(
        "input",
        nargs="?",
        default="/data/input",
        help="Directory containing the LAZ/LAS files (default: /data/input; "
             "optional with --rebuild-index)"
    )
    parser.add_argument(
        "-o", "--output",
        default="/data/output",
        help="Output directory (default: /data/output)"
    )
    parser.add_argument(
        "-r", "--resolution",
        type=str,
        default="0.2",
        help="Resolution in m/px, or several comma-separated values (default: 0.2)"
    )
    parser.add_argument(
        "-w", "--workers",
        type=str,
        default="auto",
        help="Number of workers for parallel processing, or \"auto\" = "
             "cores - 2 clamped to [2, 16], evaluated when the run starts "
             "(default: auto)"
    )
    parser.add_argument(
        "-g", "--gpu",
        nargs="?",
        const="all",
        default=None,
        metavar="LIST",
        help="Select the GPU(s) to use: an index (e.g. -g 0), "
             "a list (e.g. -g 0,2), or 'all' for all of them. "
             "Without -g: all available GPUs; workers are spread across them "
             "within the free VRAM, the excess runs on CPU."
    )
    parser.add_argument(
        "-f", "--force",
        action="store_true",
        help="Regenerate all files even if the output images (AVIF/WebP) already exist"
    )
    parser.add_argument(
        "--force-classification",
        action="store_true",
        help="Reclassify the ground even if the method is unchanged (also regenerates the "
             "DTM and the images). Without this flag, changing --ground-classification is "
             "enough: the recorded method is compared and a change triggers reclassification."
    )
    parser.add_argument(
        "--openness-downsample",
        type=int,
        default=None,
        metavar="FACTOR",
        help="Downsampling factor for the openness computation (ray tracing): "
             "block-decimated grid, then resampling. Default: 2 (cost divided by "
             "factor³, ~13x faster measured, near-identical rendering); 1 = full resolution"
    )
    parser.add_argument(
        "--edge-buffer",
        type=float,
        default=100.0,
        metavar="METERS",
        help="Edge stitching: extend the DTM by an N-meter band filled with the "
             "ground points of the 8 neighboring LAZ tiles, so that large-kernel "
             "renders (openness, SVF, LRM) are continuous from one tile to the next. "
             "100 m covers all radii; final images are cropped to the exact 1 km "
             "tile. Default: 100 (always applied in production); 0 = disabled. "
             "Changing the value regenerates the affected DTMs."
    )
    parser.add_argument(
        "--no-strip-align",
        action="store_true",
        help="Disable vertical alignment of flight strips. By default, vertical offsets "
             "≥ 0.5 cm between the flight strips (PointSourceId) of a tile are measured on "
             "the ground points and corrected before DTM rasterization, then each scan line "
             "is adjusted jointly (offset and roll) against the other strips, with a "
             "per-strip scan-angle calibration profile (GPS-time window jitter correction "
             "when scan_angle is missing); corrections are recorded in "
             "DTM/*_stripalign.json"
    )
    parser.add_argument(
        "--keep-tif",
        action="store_true",
        help="Keep the TIFF files (DTM + visualizations) so the output images can be regenerated without recomputing"
    )
    parser.add_argument(
        "--ground-classification",
        choices=["auto", "ign", "smrf", "csf"],
        default="ign",
        help="Ground classification method: auto (prefers the IGN pre-classification when "
             "present — fast path — otherwise SMRF/CSF detection), ign, smrf, csf. "
             "With ign, the DTM is rasterized from the chosen classes (--ign-classes); "
             "with smrf/csf, ground is classified by PDAL first. In every case small gaps "
             "are filled within the point envelope. "
             "(default: ign, enforced in production)"
    )
    parser.add_argument(
        "--ign-classes",
        default="sol",
        help="LAS classes extracted for the DTM with the IGN classification (ign/auto "
             "method): comma-separated list of names or codes — "
             "sol(2, ground), unclassified(1), eau(9, water), virtuel(66, virtual), "
             "pont(17, bridge), sursol(64, above-ground). "
             "E.g. --ign-classes sol,unclassified. Changing the list reclassifies the "
             "affected tiles. (default: sol)"
    )
    parser.add_argument(
        "--quality",
        type=int,
        default=60,
        help="Image quality (1-100, default: 60). 100 requests lossless (honored in WebP; "
             "Pillow ignores it in AVIF)."
    )
    parser.add_argument(
        "--lossless",
        action="store_true",
        help="Force lossless compression (same as --quality 100)"
    )
    parser.add_argument(
        "--format",
        choices=["webp", "avif"],
        default="avif",
        help="Output format: avif (default, better quality) or webp"
    )
    parser.add_argument(
        "--only",
        nargs="+",
        type=str,
        default=None,
        help="Generate only these visualizations (e.g. --only hillshade svf mslrm)"
    )
    parser.add_argument(
        "--skip",
        nargs="+",
        type=str,
        default=None,
        help="Exclude these visualizations (e.g. --skip ortho topo)"
    )
    parser.add_argument(
        "--file",
        nargs="+",
        type=str,
        default=None,
        help="Process one or more LAZ/LAS files (full name without extension, e.g. LHD_FXX_1000_6882_PTS_LAMB93_IGN69.copc)"
    )
    parser.add_argument(
        "--fetch-tiles",
        nargs="+",
        default=None,
        metavar="COL,ROW",
        help="Download these LiDAR HD tiles from IGN before processing "
             "(tiles not generated yet, e.g. --fetch-tiles 1055,6882 1056,6883)"
    )
    parser.add_argument(
        "-v", "--verbose",
        action="store_true",
        help="Verbose mode: show timestamps and levels"
    )
    parser.add_argument(
        "--debug",
        action="store_true",
        help="Debug mode: show internal details (file:line)"
    )
    parser.add_argument(
        "--rebuild-index",
        action="store_true",
        help="Only rebuild the catalog of processed tiles (thumbnails, subtiles, inventory — no reprocessing)"
    )
    parser.add_argument(
        "--no-index",
        action="store_true",
        help="Do not build the catalog (thumbnails + inventory), neither after each tile nor at the end of processing"
    )
    parser.add_argument(
        "--incremental-index",
        action="store_true",
        help="Kept for compatibility: the catalog is now rebuilt after every "
             "finished tile by default (unless --no-index)"
    )
    parser.add_argument(
        "--quality-backfill",
        action="store_true",
        help="Only compute the quality sidecars (ground density, flight dates) "
             "of the input LAZ files that lack one, then rebuild the inventory "
             "(no DTM or visualization, ~5 s per tile)"
    )

    args = parser.parse_args()

    # Configure logging before any other output
    setup_logging(verbose=args.verbose, debug=args.debug)

    # Add file prefix filter for parallel processing
    from .pipeline import _file_filter
    logger.addFilter(_file_filter)

    logger.info("=" * 60)
    logger.info("LiDAR Archaeological Pipeline")
    logger.info("=" * 60)

    # Parse --gpu into a list of GPU IDs
    gpu_ids = None
    gpu_arg = args.gpu
    if gpu_arg is not None:
        if gpu_arg == 'all':
            gpu_ids = None  # Don't restrict — use all GPUs
        else:
            try:
                gpu_ids = [int(g.strip()) for g in gpu_arg.split(',')]
            except ValueError:
                parser.error(f"Invalid GPU: {gpu_arg!r}. Use an index, a list (0,2) or 'all'.")
        if gpu_ids is not None:
            from .gpu import restrict_gpus
            restrict_gpus(gpu_ids)

    # Kill orphan PDAL processes on interrupt or termination. The pattern is
    # scoped to OUR temp directory (pdal pipeline <output>/temp/...): a global
    # pkill would slaughter the PDAL processes of other runs on the machine
    # (e.g. a concurrent generation job). No atexit hook: a normal exit has no
    # reason to kill anything.
    global _pdal_kill_pattern
    _pdal_kill_pattern = f"pdal pipeline {args.output}/temp/"
    signal.signal(signal.SIGINT, _kill_orphan_pdal)
    signal.signal(signal.SIGTERM, _kill_orphan_pdal)

    log_gpu_status()

    try:
        # --rebuild-index mode: only rebuild the catalog, no reprocessing
        if args.rebuild_index:
            from .index import build_index
            index_path = build_index(args.output, args.format)
            if index_path:
                logger.info(f"Catalog built: {index_path}")
            else:
                logger.warning("No processed tile found — catalog not built")
            return

        if args.quality_backfill:
            from .dtm import parse_ign_classes
            from .index import build_index
            from .quality import backfill_quality
            n = backfill_quality(args.input, args.output,
                                 codes=tuple(parse_ign_classes(args.ign_classes)))
            logger.info(f"{n} quality sidecar(s) written")
            build_index(args.output, args.format)
            return

        # New run: reset the event log (generation queue). Done here, before
        # downloading — download events survive the start of processing
        # (process_all no longer truncates the log).
        from .progress import reset_events
        reset_events(args.output)

        quality = 100 if args.lossless else args.quality
        # Parse --only and --skip: accept comma-separated values
        only_viz = None
        if args.only:
            only_viz = [v.strip() for item in args.only for v in item.split(',')]
        skip_viz = None
        if args.skip:
            skip_viz = [v.strip() for item in args.skip for v in item.split(',')]
        resolutions = [float(r.strip()) for r in args.resolution.split(',') if r.strip()]

        # Download missing IGN tiles before processing.
        # only_viz/resolutions: a tile is skipped only if it already has all
        # the requested visualizations — an incomplete tile is
        # (re)downloaded to generate its missing visualizations.
        if args.fetch_tiles:
            from .fetch_ign import fetch_tiles, parse_tile_specs
            try:
                specs = parse_tile_specs(args.fetch_tiles)
            except ValueError as e:
                logger.error(str(e))
                return
            logger.info(f"Downloading {len(specs)} LiDAR HD tile(s) from IGN...")
            fetched = fetch_tiles(args.input, specs, args.output,
                                  only_viz=only_viz, resolutions=resolutions,
                                  force=args.force or args.force_classification)
            if fetched:
                logger.info(f"{len(fetched)} tile(s) downloaded — processing...")
            else:
                logger.warning("No tile downloaded (already present or not found)")
        pipeline = LidarArchaeoPipeline(
            input_dir=args.input,
            output_dir=args.output,
            resolution=args.resolution,
            workers=resolve_workers(args.workers),
            force=args.force,
            ground_method=args.ground_classification,
            ign_classes=args.ign_classes,
            force_classify=args.force_classification,
            keep_tif=args.keep_tif,
            strip_align=not args.no_strip_align,
            openness_downsample=args.openness_downsample,
            edge_buffer=args.edge_buffer,
            quality=quality,
            only_viz=only_viz,
            skip_viz=skip_viz,
            output_format=args.format,
            gpu_ids=gpu_ids,
            no_index=args.no_index,
            incremental_index=args.incremental_index,
        )

        # If --file is specified, process only matching files
        if args.file:
            from pathlib import Path
            input_dir = Path(args.input)
            # Each pattern is the full filename without extension (e.g. LHD_FXX_1000_6882_PTS_LAMB93_IGN69.copc)
            # Also supports bare name without .copc (e.g. LHD_FXX_1000_6882_PTS_LAMB93_IGN69)
            selected_files = []
            for pattern in args.file:
                # Try exact filename first (e.g. LHD_FXX_...copc.laz)
                exact_match = input_dir / pattern
                if exact_match.exists() and exact_match.is_file():
                    matches = [exact_match]
                else:
                    # Try with added extensions (e.g. pattern=LHD_FXX_...IGN69)
                    matches = (list(input_dir.glob(f"{pattern}.laz"))
                              + list(input_dir.glob(f"{pattern}.las"))
                              + list(input_dir.glob(f"{pattern}.copc.laz"))
                              + list(input_dir.glob(f"{pattern}.copc.las")))
                # Remove duplicates
                matches = list(dict.fromkeys(matches))
                if not matches:
                    logger.warning(f"No file found for: {pattern}")
                    continue
                selected_files.extend(matches)
            # Remove duplicates across patterns
            seen = set()
            unique_files = []
            for f in selected_files:
                if f not in seen:
                    seen.add(f)
                    unique_files.append(f)
            if not unique_files:
                logger.error("No file found for the given patterns")
                sys.exit(1)
            logger.info(f"Processing {len(unique_files)} selected file(s)")
            for laz_file in unique_files:
                logger.info(f"  → {laz_file.name}")
            # Reuse process_all: parallel workers, summary, index, cleanup
            pipeline.process_all(files=unique_files)
        else:
            pipeline.process_all()
    except Exception as e:
        logger.error(f"Fatal error: {e}", exc_info=True)
        sys.exit(1)


def _kill_orphan_pdal(signum=None, frame=None):
    """Kill orphan PDAL processes of THIS run on interrupt or termination."""
    import subprocess
    # Belt-and-suspenders: os.killpg below is the primary mechanism.
    # This handles the edge case where a child escapes the process group.
    # Pattern scoped to our output (see main) so the PDAL processes of other
    # runs on the machine are not killed.
    if _pdal_kill_pattern:
        try:
            import re
            subprocess.run(["pkill", "-9", "-f", re.escape(_pdal_kill_pattern)],
                           capture_output=True, timeout=3)
        except Exception:
            pass
    if signum is not None:
        logger.info("Interrupted — cleaning up processes")
        # Force-kill all child processes immediately
        try:
            import os
            os.killpg(os.getpgrp(), signal.SIGKILL)
        except Exception:
            pass
        sys.exit(130)