"""Run LiveWorld_comp from a CSV of the four essential fields.

CSV columns (header required; extra columns ignored):

    name,input_image,text,bg_projection,fg_projection

  - name           : optional; output folder name (default: row_{i:04d})
  - input_image    : path to first-frame RGB image
  - text           : inline prompt, OR path to a .txt prompt file
  - bg_projection  : path to bg / scene projection mp4
  - fg_projection  : path to fg projection mp4 (optional; leave empty to skip)

Uses ``condition_source=mp4`` + dummy identity poses (geometry not needed).
Default config ``configs/csv_mp4_81.yaml`` generates a single 81-frame chunk
(final video = first frame + 81 generated = 82 frames).

Example:

    python run_from_csv.py \\
        --csv cases.csv \\
        --output-root outputs_csv \\
        --config configs/csv_mp4_81.yaml

    # subset / resume
    python run_from_csv.py --csv cases.csv --indices 0 1 2 --skip_existing
"""
from __future__ import annotations

import argparse
import csv
import os
import re
import sys
from pathlib import Path
from typing import Dict, List, Optional, Tuple

import torch
from omegaconf import OmegaConf


_HERE = Path(__file__).resolve().parent
_LIVEWORLD_ROOT_CANDIDATES = [
    _HERE.parent / "LiveWorld",
    Path(os.environ.get("LIVEWORLD_ROOT", "")),
]

if str(_HERE) not in sys.path:
    sys.path.insert(0, str(_HERE))

for _root in _LIVEWORLD_ROOT_CANDIDATES:
    if _root and _root.is_dir():
        if str(_root) in sys.path:
            sys.path.remove(str(_root))
        sys.path.insert(0, str(_root))
        break

from core.inputs import load_user_inputs_from_paths  # noqa: E402
from core.model_loader import build_pipeline  # noqa: E402
from core.pipeline import RunOptions, run_iterative_inference_user_pc  # noqa: E402


REQUIRED_COLS = ("input_image", "text", "bg_projection")
OPTIONAL_COLS = ("name", "fg_projection")


def _ensure_ffmpeg_on_path() -> None:
    import shutil
    import tempfile

    if shutil.which("ffmpeg") is not None:
        return
    try:
        import imageio_ffmpeg
        exe = imageio_ffmpeg.get_ffmpeg_exe()
    except Exception as e:  # noqa: BLE001
        print(f"[warn] no system ffmpeg and imageio_ffmpeg unavailable ({e}); "
              f"H.264 video saving will fail.", file=sys.stderr)
        return
    bin_dir = Path(tempfile.gettempdir()) / "lw_comp_ffmpeg_bin"
    bin_dir.mkdir(parents=True, exist_ok=True)
    link = bin_dir / "ffmpeg"
    if not link.exists():
        try:
            link.symlink_to(exe)
        except OSError:
            import shutil as _sh
            _sh.copy(exe, link)
            link.chmod(0o755)
    os.environ["PATH"] = str(bin_dir) + os.pathsep + os.environ.get("PATH", "")
    print(f"[boot] using bundled ffmpeg: {exe} (linked as {link})")


def _slugify(name: str, fallback: str) -> str:
    s = re.sub(r"[^\w.\-]+", "_", str(name).strip())
    s = s.strip("._")
    return s or fallback


def _normalize_header(fieldnames: Optional[List[str]]) -> Dict[str, str]:
    """Map lowercased stripped header -> original header."""
    if not fieldnames:
        raise SystemExit("CSV has no header row")
    mapping: Dict[str, str] = {}
    for h in fieldnames:
        if h is None:
            continue
        key = h.strip().lower()
        mapping[key] = h
    # Aliases
    aliases = {
        "input_image": ("input_image", "image", "first_frame", "first_frame.png"),
        "text": ("text", "prompt", "caption"),
        "bg_projection": ("bg_projection", "bg", "scene_projection", "bg_projection.mp4"),
        "fg_projection": ("fg_projection", "fg", "fg_projection.mp4"),
        "name": ("name", "id", "case", "case_name"),
    }
    resolved: Dict[str, str] = {}
    for canonical, cands in aliases.items():
        for c in cands:
            if c in mapping:
                resolved[canonical] = mapping[c]
                break
    missing = [c for c in REQUIRED_COLS if c not in resolved]
    if missing:
        raise SystemExit(
            f"CSV missing required columns {missing}. "
            f"Need at least: {list(REQUIRED_COLS)}. "
            f"Got headers: {fieldnames}"
        )
    return resolved


def _resolve_path(value: str, base_dir: Path) -> str:
    """Resolve a CSV path: absolute stays as-is; relative is vs ``base_dir``."""
    raw = (value or "").strip()
    if not raw:
        return raw
    p = Path(raw)
    if not p.is_absolute():
        p = (base_dir / p).resolve()
    return str(p)


def _read_csv_rows(csv_path: Path) -> List[Dict[str, str]]:
    base_dir = csv_path.resolve().parent
    path_keys = {"input_image", "bg_projection", "fg_projection"}
    with csv_path.open("r", encoding="utf-8-sig", newline="") as f:
        reader = csv.DictReader(f)
        colmap = _normalize_header(list(reader.fieldnames or []))
        rows: List[Dict[str, str]] = []
        for i, raw in enumerate(reader):
            row = {
                k: (raw.get(src) or "").strip()
                for k, src in colmap.items()
            }
            if not any(row.get(c) for c in REQUIRED_COLS):
                continue  # skip blank lines
            if not row.get("name"):
                row["name"] = f"row_{i:04d}"
            else:
                row["name"] = _slugify(row["name"], f"row_{i:04d}")
            for k in path_keys:
                if row.get(k):
                    row[k] = _resolve_path(row[k], base_dir)
            rows.append(row)
    if not rows:
        raise SystemExit(f"no data rows in {csv_path}")
    return rows


def _parse_args() -> argparse.Namespace:
    p = argparse.ArgumentParser(
        description="LiveWorld_comp inference from a 4-field CSV")
    p.add_argument("--csv", required=True,
                   help="CSV with columns: name,input_image,text,"
                        "bg_projection,fg_projection")
    p.add_argument("--output-root", default=str(_HERE / "outputs_csv"),
                   help="Root for results; each case -> <output-root>/<name>")
    p.add_argument("--config",
                   default=str(_HERE / "configs" / "csv_mp4_81.yaml"),
                   help="System YAML (default: configs/csv_mp4_81.yaml)")
    p.add_argument("--indices", type=int, nargs="*", default=None,
                   help="Only run these 0-based row indices")
    p.add_argument("--limit", type=int, default=None,
                   help="Run only the first N selected rows")
    p.add_argument("--device", default=None, help="Override runtime.device")
    p.add_argument("--skip_existing", action="store_true",
                   help="Skip when <output>/final_video.mp4 already exists")
    p.add_argument("--num_frames", type=int, default=None,
                   help="Override run.num_frames (must be multiple of "
                        "frames_per_iter; default 81 from config)")
    return p.parse_args()


def _options_from_cfg(run_cfg: dict, seed: int) -> RunOptions:
    opts = RunOptions()
    if run_cfg is None:
        run_cfg = {}
    for key, value in run_cfg.items():
        if hasattr(opts, key):
            setattr(opts, key, value)
    opts.seed = seed
    if opts.target_hw is not None:
        opts.target_hw = tuple(int(v) for v in opts.target_hw)
    if opts.denoising_step_list is not None:
        opts.denoising_step_list = [float(v) for v in opts.denoising_step_list]
    return opts


def main() -> None:
    args = _parse_args()
    _ensure_ffmpeg_on_path()

    csv_path = Path(args.csv)
    if not csv_path.exists():
        raise SystemExit(f"csv not found: {csv_path}")

    rows = _read_csv_rows(csv_path)
    if args.indices is not None:
        bad = [i for i in args.indices if i < 0 or i >= len(rows)]
        if bad:
            raise SystemExit(f"--indices out of range {bad} "
                             f"(have {len(rows)} rows)")
        rows = [rows[i] for i in args.indices]
    if args.limit is not None:
        rows = rows[: args.limit]

    cfg = OmegaConf.load(args.config)
    cfg = OmegaConf.to_container(cfg, resolve=True)
    runtime_cfg = cfg.get("runtime", {})
    observer_cfg = cfg.get("observer", {})
    run_cfg = cfg.get("run", {})

    device_str = args.device or runtime_cfg.get("device", "cuda:0")
    device = torch.device(device_str)
    cpu_offload_obs = bool(runtime_cfg.get("cpu_offload", False))
    seed = int(runtime_cfg.get("seed", 71))

    opts = _options_from_cfg(run_cfg, seed)
    opts.cpu_offload = cpu_offload_obs
    if args.num_frames is not None:
        opts.num_frames = int(args.num_frames)

    if opts.condition_source != "mp4":
        print(f"[warn] config condition_source={opts.condition_source!r}; "
              f"CSV path expects 'mp4'. Forcing condition_source='mp4'.")
        opts.condition_source = "mp4"

    output_root = Path(args.output_root)
    cases: List[Tuple[Dict[str, str], Path]] = [
        (row, output_root / row["name"]) for row in rows
    ]

    if args.skip_existing:
        pending = [(r, o) for (r, o) in cases
                   if not (o / "final_video.mp4").exists()]
        skipped = len(cases) - len(pending)
        if skipped:
            print(f"[skip] {skipped}/{len(cases)} case(s) already have "
                  f"final_video.mp4")
        cases = pending
        if not cases:
            print("[done] all selected cases already complete; "
                  "not loading the model.")
            return

    print(f"\n[boot] LiveWorld_comp (CSV four-field)")
    print(f"  csv             : {csv_path}")
    print(f"  device          : {device}")
    print(f"  target_hw       : {opts.target_hw}")
    print(f"  num_frames      : {opts.num_frames} "
          f"(frames_per_iter={opts.frames_per_iter})")
    print(f"  condition_source: {opts.condition_source}")
    print(f"  cases           : {len(cases)}\n")

    pipeline = build_pipeline(
        observer_cfg=observer_cfg,
        device=device,
        cpu_offload=cpu_offload_obs,
    )
    print(f"[boot] pipeline ready (use_fg_proj cfg-level={pipeline.use_fg_proj})")

    n_ok, n_fail = 0, 0
    for row, output_dir in cases:
        print("\n" + "#" * 72)
        print(f"# CASE  {row['name']}")
        print(f"#   image : {row['input_image']}")
        print(f"#   bg    : {row['bg_projection']}")
        print(f"#   fg    : {row.get('fg_projection') or '(none)'}")
        print(f"#   out   : {output_dir}")
        print("#" * 72)
        try:
            inputs = load_user_inputs_from_paths(
                input_image=row["input_image"],
                text=row["text"],
                bg_projection=row["bg_projection"],
                fg_projection=row.get("fg_projection") or None,
                target_hw=opts.target_hw,
                n_poses=opts.num_frames + 1,
            )
            print(f"[input] prompt: {inputs.prompt[:80]!r}"
                  f"{'...' if len(inputs.prompt) > 80 else ''}")
            print(f"[input] poses(dummy): {inputs.poses_c2w.shape},"
                  f"  scene_mp4: {None if inputs.scene_proj_frames is None else inputs.scene_proj_frames.shape},"
                  f"  fg_mp4: {None if inputs.fg_proj_frames is None else inputs.fg_proj_frames.shape}")
            result = run_iterative_inference_user_pc(
                pipeline=pipeline,
                inputs=inputs,
                options=opts,
                output_dir=str(output_dir),
            )
            print(f"[done] {row['name']}: final video {result.final_video.shape}")
            n_ok += 1
        except Exception as e:  # noqa: BLE001
            n_fail += 1
            print(f"[FAIL] {row['name']}: {e}", file=sys.stderr)
            import traceback
            traceback.print_exc()

    print(f"\n[done] ok={n_ok}, fail={n_fail}, total={len(cases)}")


if __name__ == "__main__":
    main()