"""Reorganise the session directory so a file's kind is obvious from where it sits.

Placement is decided by filename rules rather than by hand, so the same layout
can be reproduced for any other session. Dry run by default; --apply to move.

    raw/                 exactly what iTelescope delivered: the zips and jpegs
    calibrated/          the uncompressed calibrated subs
    stacks/masters/      per-filter registered, plate-solved masters
    stacks/original/     the alignment-only baseline stacks
    final/               the four deliverable renderings + the comparison
    renderings/          other finished images (LRGB, HDR, annotated, starless)
    science/figures/     analysis plots
    science/catalogues/  measured tables (CSV)
    science/data/        models, masks and derived quantities
    science/notes/       the analysis write-ups
    intermediates/       caches and scratch that a re-run can regenerate
"""
import os
import shutil
import sys

ROOT = r"C:\Users\lhorrocks-barlow\Downloads\NGC5128\20260721"
STACKED = os.path.join(ROOT, "stacked")
APPLY = "--apply" in sys.argv

DIRS = ["raw", "calibrated", "stacks/masters", "stacks/original", "final",
        "renderings", "science/figures", "science/catalogues", "science/data",
        "science/notes", "intermediates"]


def destination(name, from_stacked):
    """Where a file belongs, decided by its name alone."""
    low = name.lower()
    if not from_stacked:
        if low.endswith(".zip"):
            return "raw"
        if low.startswith("jpeg-") and low.endswith(".jpg"):
            return "raw"
        if low.startswith("calibrated-") and low.endswith((".fit", ".tif")):
            return "calibrated"
        return None

    if name.startswith("_"):
        return "intermediates"
    if name.startswith("master-") and low.endswith(".fit"):
        return "stacks/masters"
    if name.startswith("notes-") and low.endswith(".md"):
        return "science/notes"
    if low.endswith(".csv"):
        return "science/catalogues"
    if name.startswith("sb-") and low.endswith((".fits", ".npy", ".txt")):
        return "science/data"
    if low.endswith(".png") and any(f"-{p}-" in name for p in ("gc", "sb", "mo")):
        return "science/figures"
    if name.startswith(("NGC5128-LRGB", "NGC5128-img-")):
        return "renderings"
    if name == "METHODS.md":
        return "."
    return None


def plan():
    moves = []
    for name in sorted(os.listdir(ROOT)):
        path = os.path.join(ROOT, name)
        if os.path.isfile(path):
            d = destination(name, from_stacked=False)
            if d:
                moves.append((path, os.path.join(ROOT, d, name)))
    for name in sorted(os.listdir(STACKED)):
        path = os.path.join(STACKED, name)
        if name in ("final", "original", "scripts"):
            continue
        if os.path.isdir(path):
            if name.startswith("_"):
                moves.append((path, os.path.join(ROOT, "intermediates", name)))
            continue
        d = destination(name, from_stacked=True)
        if d:
            target = ROOT if d == "." else os.path.join(ROOT, d)
            moves.append((path, os.path.join(target, name)))
    moves.append((os.path.join(STACKED, "final"), os.path.join(ROOT, "final")))
    moves.append((os.path.join(STACKED, "original"),
                  os.path.join(ROOT, "stacks", "original")))
    return moves


if __name__ == "__main__":
    moves = plan()
    counts = {}
    for src, dst in moves:
        rel = os.path.relpath(os.path.dirname(dst), ROOT)
        counts[rel] = counts.get(rel, 0) + 1
    print(f"{len(moves)} moves\n")
    for d in sorted(counts):
        print(f"  {d + '/':24s} {counts[d]:3d}")

    unplaced = []
    for name in sorted(os.listdir(ROOT)):
        if os.path.isfile(os.path.join(ROOT, name)) and \
                not destination(name, False):
            unplaced.append(name)
    for name in sorted(os.listdir(STACKED)):
        p = os.path.join(STACKED, name)
        if os.path.isfile(p) and not destination(name, True):
            unplaced.append("stacked/" + name)
    if unplaced:
        print(f"\nNOT PLACED by any rule ({len(unplaced)}):")
        for n in unplaced:
            print(f"  {n}")

    if not APPLY:
        print("\nDRY RUN - nothing moved. Re-run with --apply")
        sys.exit(0)

    for d in DIRS:
        os.makedirs(os.path.join(ROOT, d), exist_ok=True)
    for src, dst in moves:
        os.makedirs(os.path.dirname(dst), exist_ok=True)
        if os.path.exists(dst):
            print(f"  SKIP (exists): {dst}")
            continue
        shutil.move(src, dst)
    print(f"moved {len(moves)} items")