#!/usr/bin/env bash
# Ingest a paper source into a --work tree. Never compiles e-print TeX.
set -euo pipefail

WORK=""
KIND=""
SRC=""
while [[ $# -gt 0 ]]; do
  case "$1" in
    --work|--out) WORK="$2"; shift 2 ;;
    --arxiv)   KIND=arxiv;   SRC="$2"; shift 2 ;;
    --pdf)     KIND=pdf;     SRC="$2"; shift 2 ;;
    --tex)     KIND=tex;     SRC="$2"; shift 2 ;;
    --excerpt|--markdown) KIND=excerpt; SRC="$2"; shift 2 ;;
    *) echo "usage: ingest.sh --work DIR (--arxiv ID|--pdf FILE|--tex FILE|--excerpt FILE)" >&2; exit 2 ;;
  esac
done
[[ -n "$WORK" && -n "$KIND" ]] || { echo "need --work and a source" >&2; exit 2; }

ARXIV_RE='^(ar[Xx]iv:)?([0-9]{4}\.[0-9]{4,5}(v[0-9]+)?|[a-z-]+/[0-9]{7})$'

mkdir -p "$WORK/source/pages" "$WORK/notes/sections" "$WORK/out"
meta="$WORK/source/meta.yaml"

sha_of() { sha256sum "$1" | awk '{print $1}'; }

write_meta() {
  local extra="$1"
  cat > "$meta" <<EOF
kind: $KIND
$extra
EOF
}

case "$KIND" in
  excerpt)
    cp -- "$SRC" "$WORK/source/excerpt.md"
    write_meta "excerpt: source/excerpt.md"
    ;;
  tex)
    mkdir -p "$WORK/source/tex"
    if [[ -d "$SRC" ]]; then
      cp -R -- "$SRC/." "$WORK/source/tex/"
    else
      cp -- "$SRC" "$WORK/source/tex/"
    fi
    write_meta "tex: source/tex"
    ;;
  pdf)
    cp -- "$SRC" "$WORK/source/paper.pdf"
    pdftotext -layout "$WORK/source/paper.pdf" "$WORK/source/paper.txt" || true
    pdftoppm -png -r 120 "$WORK/source/paper.pdf" "$WORK/source/pages/pg"
    python3 - <<'PY' "$WORK/source/pages"
from pathlib import Path
import sys, re
d = Path(sys.argv[1])
files = sorted(d.glob("pg*.png"))
for i, p in enumerate(files, 1):
    dest = d / f"pg-{i:03d}.png"
    if p.resolve() != dest.resolve():
        p.rename(dest)
PY
    pages=$(find "$WORK/source/pages" -name 'pg-*.png' | wc -l)
    write_meta "local_pdf: source/paper.pdf
sha256: $(sha_of "$WORK/source/paper.pdf")
pages: $pages"
    ;;
  arxiv)
    id="$SRC"
    [[ "$id" =~ $ARXIV_RE ]] || { echo "bad arxiv id: $id" >&2; exit 2; }
    id="${id#arxiv:}"; id="${id#arXiv:}"
    mkdir -p "$WORK/source"
    pdf="$WORK/source/paper.pdf"
    if [[ ! -f "$pdf" ]]; then
      curl -fsSL "https://arxiv.org/pdf/${id}.pdf" -o "$pdf" \
        || curl -fsSL "https://export.arxiv.org/pdf/${id}.pdf" -o "$pdf"
    fi
    pdftotext -layout "$pdf" "$WORK/source/paper.txt" || true
    pdftoppm -png -r 120 "$pdf" "$WORK/source/pages/pg"
    python3 - <<'PY' "$WORK/source/pages"
from pathlib import Path
import sys
d = Path(sys.argv[1])
files = sorted(d.glob("pg*.png"))
for i, p in enumerate(files, 1):
    dest = d / f"pg-{i:03d}.png"
    if p.resolve() != dest.resolve():
        p.rename(dest)
PY
    # best-effort e-print; never compile
    if [[ ! -d "$WORK/source/eprint" ]]; then
      tmp=$(mktemp)
      if curl -fsSL "https://arxiv.org/e-print/${id}" -o "$tmp"; then
        mkdir -p "$WORK/source/eprint"
        tar -xf "$tmp" -C "$WORK/source/eprint" --max-size=50M 2>/dev/null \
          || tar -xf "$tmp" -C "$WORK/source/eprint" || true
      fi
      rm -f "$tmp"
    fi
    pages=$(find "$WORK/source/pages" -name 'pg-*.png' | wc -l)
    write_meta "arxiv: $id
local_pdf: source/paper.pdf
sha256: $(sha_of "$pdf")
pages: $pages"
    ;;
esac

echo "ingested $KIND -> $WORK"