#!/bin/sh
# Timer target: rebuild the garden only when the vault or repo changed.
# Successor to the Quartz update_quartz_docker.sh change-detection loop.
# Usage: auto-build.sh [--force]   (--force skips change detection — used
# by the manual rebuild hook)
set -eu

REPO=$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)
VAULT="${VAULT:-/home/nox/docker/obsidian/vaults/weeslahw_coppermind}"
STATE="$REPO/.build_state"
FORCE=0
[ "${1:-}" = "--force" ] && FORCE=1

cd "$REPO"

# serialize builds: the 5-min timer and the manual hook must never run
# docker/npm into the same checkout concurrently
exec 9>"$REPO/.build.lock"
flock 9

# a dirty tree can make pull fail; still rebuild whatever is checked out
git pull -q || echo "git pull failed (dirty tree?) — building local state"

# signature covers committed HEAD, any uncommitted repo edits, vault mtimes,
# and the notebook exports (gitignored, so git status/diff can't see them —
# they land here on their own timer via deploy/export-notebooks.py)
sig=$({
    git rev-parse HEAD
    git status --porcelain=v1
    git diff
    find "$VAULT" -name .obsidian -prune -o -type f -printf '%T@ %p\n' | sort
    find "$REPO/notebooks-export" -type f -printf '%T@ %p\n' 2>/dev/null | sort
    # the ACannons export: gitignored like the notebooks, written by a Gitea
    # Action on cannons_reloaded rather than a timer here. Its own clause for
    # the reason spelled out below -- with `-o` the -printf binds only to the
    # LAST clause, so folding this into an OR-chain would silently print the
    # other matches in a different format and stop the signature being stable.
    find "$REPO/cannons-export" -type f -printf '%T@ %p\n' 2>/dev/null | sort
    # same deal for every reading map payload: gitignored, written by library-rag-export.service
    # on its own timer, so git status/diff above cannot see them change. One glob rather than a
    # list — with `-o` the `-printf` binds only to the LAST clause, so an OR-chain silently
    # prints the earlier matches in a different format and the signature stops being stable.
    # It also means a future payload is watched without editing this line.
    find "$REPO/public" -maxdepth 1 -name 'reading_*.json' -printf '%T@ %p\n' 2>/dev/null | sort
} | sha256sum | cut -d' ' -f1)

if [ "$FORCE" -eq 0 ] && [ -f "$STATE" ] && [ "$(cat "$STATE")" = "$sig" ]; then
    exit 0
fi

sh "$REPO/deploy/build.sh"
printf %s "$sig" >"$STATE"
echo "garden rebuilt $(date -Is)"