#!/usr/bin/env python3
"""
05-crop-bboxes.py — Eager crop generation from bounding boxes

For each page.md, read `images_detected[]`, `tables_detected[]`, and
`signatures_observed[]` (the elements whose visual content is worth showing
inline in chat replies). For each element with a bbox, crop the corresponding
region from the page PNG using Pillow and save to:

  processing/crops/<doc-id>/<crop-id>.png

Where <crop-id> follows the convention:
  IMG-<DOC>-p<NNN>-<NN>   for images_detected
  TBL-<DOC>-p<NNN>-<NN>   for tables_detected
  SIG-<DOC>-p<NNN>-<NN>   for signatures_observed

Padding: 1% of page dimensions around each bbox to avoid tight clipping.

Idempotent: skips crops whose output PNG already exists with non-zero size
(unless --force).

Usage:
  ./05-crop-bboxes.py                  # all docs
  ./05-crop-bboxes.py --doc-id <id>    # single doc
  ./05-crop-bboxes.py --force          # overwrite existing crops
"""
from __future__ import annotations

import argparse
import re
import sys
from datetime import datetime, timezone
from pathlib import Path

try:
    import yaml
except ImportError:
    sys.stderr.write("Missing pyyaml. Run: pip3 install pyyaml\n")
    sys.exit(1)

try:
    from PIL import Image
except ImportError:
    sys.stderr.write("Missing pillow. Run: pip3 install pillow\n")
    sys.exit(1)


UFO_ROOT = Path("/Users/guto/ufo")
PAGES_BASE = UFO_ROOT / "wiki" / "pages"
PNG_BASE = UFO_ROOT / "processing" / "png"
CROPS_BASE = UFO_ROOT / "processing" / "crops"
LOG_PATH = UFO_ROOT / "wiki" / "log.md"

PADDING_FRACTION = 0.01  # 1% padding around bbox


def utc_now_iso() -> str:
    return datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ")


def read_frontmatter(path: Path) -> dict:
    c = path.read_text(encoding="utf-8")
    if not c.startswith("---"):
        return {}
    end = c.find("---", 4)
    if end == -1:
        return {}
    try:
        return yaml.safe_load(c[3:end].strip()) or {}
    except yaml.YAMLError:
        return {}


def doc_id_short(doc_id: str) -> str:
    """Compact uppercase tag for use inside crop ids.
    'dow-uap-d54-mission-report-mediterranean-sea-na' → 'DOWD54'
    'doc-65-hs1-...' → 'D65HS1' (drop common prefixes, keep first signal)
    """
    s = doc_id.upper()
    # Remove common prefixes / fillers
    for prefix in ("DOW-UAP-", "DOS-UAP-", "NASA-UAP-", "FBI-PHOTO-", "DOC-"):
        if s.startswith(prefix):
            s = s[len(prefix):]
            break
    # Take first ~6 alphanumeric chars
    s = re.sub(r"[^A-Z0-9]", "", s)[:8]
    return s or "X"


def make_crop_id(prefix: str, doc_id: str, page_num: int, idx: int) -> str:
    return f"{prefix}-{doc_id_short(doc_id)}-p{page_num:03d}-{idx:02d}"


def crop_bbox(
    *,
    src_png: Path,
    dest_png: Path,
    bbox: dict,
    padding: float,
    force: bool,
) -> tuple[bool, str | None]:
    """Crop src_png by bbox and save to dest_png.
    Returns (created, reason_skipped_or_error).
    """
    if not force and dest_png.exists() and dest_png.stat().st_size > 0:
        return (False, "exists")
    try:
        with Image.open(src_png) as im:
            W, H = im.size
            x = float(bbox.get("x", 0))
            y = float(bbox.get("y", 0))
            w = float(bbox.get("w", 0))
            h = float(bbox.get("h", 0))
            if w <= 0 or h <= 0:
                return (False, "zero-size-bbox")
            # Apply padding
            x_pad = max(0.0, x - padding)
            y_pad = max(0.0, y - padding)
            w_pad = min(1.0 - x_pad, w + 2 * padding)
            h_pad = min(1.0 - y_pad, h + 2 * padding)
            # Pixel coords
            px = int(round(x_pad * W))
            py = int(round(y_pad * H))
            pw = max(1, int(round(w_pad * W)))
            ph = max(1, int(round(h_pad * H)))
            crop = im.crop((px, py, px + pw, py + ph))
            dest_png.parent.mkdir(parents=True, exist_ok=True)
            crop.save(dest_png, "PNG", optimize=True)
        return (True, None)
    except Exception as e:
        return (False, f"error: {e}")


def process_page(page_md: Path, force: bool) -> dict:
    """Returns counts {created, skipped, error} for this page."""
    fm = read_frontmatter(page_md)
    if not fm or fm.get("type") != "page":
        return {"created": 0, "skipped": 0, "error": 0}

    doc_id = fm.get("doc_id", "")
    page_id = fm.get("page_id", "")
    png_rel = fm.get("png_path", "")
    if not doc_id or not page_id or not png_rel:
        return {"created": 0, "skipped": 0, "error": 0}

    src_png = (page_md.parent / png_rel).resolve()
    if not src_png.exists():
        sys.stderr.write(f"  ✗ source PNG missing: {src_png}\n")
        return {"created": 0, "skipped": 0, "error": 1}

    page_num = int(fm.get("page_number", 0))
    counts = {"created": 0, "skipped": 0, "error": 0}

    # 1. Images detected
    for idx, item in enumerate(fm.get("images_detected") or [], start=1):
        bbox = item.get("bbox")
        if not bbox:
            continue
        crop_id = make_crop_id("IMG", doc_id, page_num, idx)
        dest = CROPS_BASE / doc_id / f"{crop_id}.png"
        created, reason = crop_bbox(
            src_png=src_png, dest_png=dest, bbox=bbox,
            padding=PADDING_FRACTION, force=force,
        )
        if created:
            counts["created"] += 1
        elif reason == "exists":
            counts["skipped"] += 1
        else:
            counts["error"] += 1

    # 2. Tables detected
    for idx, item in enumerate(fm.get("tables_detected") or [], start=1):
        bbox = item.get("bbox")
        if not bbox:
            continue
        crop_id = make_crop_id("TBL", doc_id, page_num, idx)
        dest = CROPS_BASE / doc_id / f"{crop_id}.png"
        created, reason = crop_bbox(
            src_png=src_png, dest_png=dest, bbox=bbox,
            padding=PADDING_FRACTION * 2, force=force,
        )
        if created:
            counts["created"] += 1
        elif reason == "exists":
            counts["skipped"] += 1
        else:
            counts["error"] += 1

    # 3. Signatures observed
    for idx, item in enumerate(fm.get("signatures_observed") or [], start=1):
        bbox = item.get("bbox")
        if not bbox:
            continue
        crop_id = make_crop_id("SIG", doc_id, page_num, idx)
        dest = CROPS_BASE / doc_id / f"{crop_id}.png"
        created, reason = crop_bbox(
            src_png=src_png, dest_png=dest, bbox=bbox,
            padding=PADDING_FRACTION, force=force,
        )
        if created:
            counts["created"] += 1
        elif reason == "exists":
            counts["skipped"] += 1
        else:
            counts["error"] += 1

    return counts


def main():
    ap = argparse.ArgumentParser(description="Eager-crop bounding boxes from page PNGs.")
    g = ap.add_mutually_exclusive_group()
    g.add_argument("--doc-id", help="restrict to a single doc_id")
    g.add_argument("--all", action="store_true", help="process all pages (default)")
    ap.add_argument("--force", action="store_true", help="overwrite existing crops")
    args = ap.parse_args()

    if args.doc_id:
        glob = PAGES_BASE / args.doc_id / "*.md"
        pages = sorted(Path(str(glob).rsplit("/", 1)[0]).glob("*.md"))
    else:
        pages = sorted(PAGES_BASE.rglob("*.md"))

    totals = {"created": 0, "skipped": 0, "error": 0}
    doc_summary: dict[str, dict] = {}

    print(f"Cropping bboxes from {len(pages)} page(s)...", flush=True)
    for page_md in pages:
        c = process_page(page_md, args.force)
        doc_id = page_md.parent.name
        doc_summary.setdefault(doc_id, {"created": 0, "skipped": 0, "error": 0})
        for k in c:
            totals[k] += c[k]
            doc_summary[doc_id][k] += c[k]

    for doc_id, c in sorted(doc_summary.items()):
        if c["created"] or c["error"]:
            print(f"  {doc_id}: created={c['created']} skipped={c['skipped']} error={c['error']}", flush=True)

    print(f"\nTotal: created={totals['created']}, skipped={totals['skipped']}, error={totals['error']}", flush=True)

    if totals["created"] > 0 or totals["error"] > 0:
        with open(LOG_PATH, "a", encoding="utf-8") as fh:
            fh.write(f"\n## {utc_now_iso()} — CROP BBOXES (Phase 5.5)\n")
            fh.write(f"- operator: archivist\n- script: scripts/05-crop-bboxes.py\n")
            fh.write(f"- target: {args.doc_id or '(all)'}\n")
            fh.write(f"- created: {totals['created']}\n- skipped: {totals['skipped']}\n- error: {totals['error']}\n")


if __name__ == "__main__":
    main()