#!/usr/bin/env bash
# pdf-fzf — interactive PDF text search via fzf + bat
# Deps: pdftotext (poppler-utils), fzf, bat

set -euo pipefail

DIR="${1:-.}"
CACHE=$(mktemp -d /tmp/pdf-fzf.XXXXXX)
trap 'rm -rf "$CACHE"' EXIT

MAPFILE="$CACHE/map.tsv"
INDEX="$CACHE/index.tsv"

echo "Indexing PDFs in '$DIR'..." >&2

find "$DIR" -type f -iname "*.pdf" | sort | while read -r pdf; do
    hash=$(printf '%s' "$pdf" | md5sum | cut -c1-8)
    txtfile="$CACHE/${hash}.txt"
    pdftotext "$pdf" - 2>/dev/null > "$txtfile" || continue
    [[ ! -s "$txtfile" ]] && continue
    printf '%s\t%s\t%s\n' "$hash" "$pdf" "$txtfile" >> "$MAPFILE"
    awk -v src="$pdf" -F'\t' \
        'NF { printf "%s\t%d\t%s\n", src, NR, $0 }' "$txtfile"
done > "$INDEX"

PDF_COUNT=$(wc -l < "${MAPFILE:-/dev/null}" 2>/dev/null || echo 0)
LINE_COUNT=$(wc -l < "$INDEX")
echo "Indexed $LINE_COUNT lines from $PDF_COUNT PDFs." >&2

# Preview script — receives the raw fzf line, shows bat at matched line
PREVIEW_SH="$CACHE/preview.sh"
cat > "$PREVIEW_SH" <<PREVIEW
#!/usr/bin/env bash
IFS=\$'\\t' read -r pdf linenum _ <<< "\$1"
txtfile=\$(awk -F'\\t' -v p="\$pdf" '\$2==p{print \$3; exit}' "$MAPFILE")
[[ -f "\$txtfile" ]] || { echo "No preview for: \$pdf"; exit 1; }
echo -e "\\033[1;34m\$pdf\\033[0m" 
batcat --style=numbers,grid \\
    --highlight-line="\$linenum" \\
    --language=txt \\
    --pager=never \\
    "\$txtfile"
PREVIEW
chmod +x "$PREVIEW_SH"

fzf \
    --delimiter=$'\t' \
    --with-nth='1,3' \
    --preview="$PREVIEW_SH {}" \
    --preview-window='right:65%:wrap' \
    --prompt='PDF › ' \
    --header="$LINE_COUNT lines · $PDF_COUNT PDFs · $DIR  [Enter: open PDF]" \
    --color='header:italic,prompt:bold' \
    --bind "enter:execute(xdg-open {1} 2>/dev/null &)" \
    < "$INDEX"