#!/usr/bin/env bash
# Copyright 2026 Umbra Tools (umbratools.com)
# SPDX-License-Identifier: Apache-2.0

#
# commit_check.sh — warn when the working tree has been dirty too long.
#
# UmbraAudio convention (AGENTS.md -> "Commit Cadence"): commit at least once a
# week, on Sunday. On 2026-09-20 a single `git checkout --` wiped a month of
# uncommitted edits to umbraaudio/web/routes.py; it survived only because the
# editor kept a snapshot. Uncommitted work has no such guarantee.
#
# The script measures how long the tree has been dirty (the oldest edit among
# uncommitted files) and exits non-zero once it exceeds the threshold. Run it
# by hand, or wire it to launchd/cron for a weekly reminder.
#
# Usage:
#   scripts/commit_check.sh [--days N] [--any] [--quiet]
#
# Exit codes:
#   0  clean, or uncommitted work is within the threshold
#   1  uncommitted work is overdue — commit now
#   2  not a git repository / bad usage
set -u

DAYS=7
QUIET=0
ANY=0

usage() {
  cat <<'USAGE'
commit_check.sh — warn when uncommitted work is older than the threshold.

Usage:
  scripts/commit_check.sh [--days N] [--any] [--quiet]

Options:
  --days N        Threshold in days (default: 7).
  --any           Warn on ANY uncommitted change, ignoring the age threshold
                  (used by the weekly Sunday reminder job).
  --quiet, -q     Print nothing when the tree is clean.
  -h, --help      Show this help.

Exit codes:
  0  clean, or uncommitted work is within the threshold
  1  uncommitted work is overdue — commit now
  2  not a git repository / bad usage

Policy: commit at least once a week, on Sunday (AGENTS.md -> "Commit Cadence").
USAGE
}

while [ "$#" -gt 0 ]; do
  case "$1" in
    --days)
      DAYS="${2:-}"
      if [ "$#" -ge 2 ]; then shift 2; else shift; fi
      ;;
    --days=*)   DAYS="${1#*=}"; shift ;;
    --any)      ANY=1; shift ;;
    --quiet|-q) QUIET=1; shift ;;
    -h|--help)  usage; exit 0 ;;
    *) echo "commit_check.sh: unknown argument: $1" >&2; usage >&2; exit 2 ;;
  esac
done

case "$DAYS" in
  ''|*[!0-9]*) echo "commit_check.sh: --days must be a non-negative integer" >&2; exit 2 ;;
esac

if ! REPO_ROOT="$(git rev-parse --show-toplevel 2>/dev/null)"; then
  echo "commit_check.sh: not inside a git repository" >&2
  exit 2
fi
cd "$REPO_ROOT" || exit 2

# Submodule working-tree dirt is a separate repo; --ignore-submodules=dirty hides
# it while still surfacing a moved submodule pointer (which IS ours to commit).
DIRTY="$(git status --porcelain --ignore-submodules=dirty)"
if [ -z "$DIRTY" ]; then
  [ "$QUIET" -eq 0 ] && echo "commit_check: working tree clean ($REPO_ROOT)."
  exit 0
fi
CHANGED="$(printf '%s\n' "$DIRTY" | grep -c .)"

NOW="$(date +%s)"
stat_mtime() { stat -f %m "$1" 2>/dev/null || stat -c %Y "$1" 2>/dev/null || echo 0; }

# Union of staged, unstaged and untracked paths (deletions are skipped below).
FILES="$(
  { git diff --ignore-submodules=dirty --name-only
    git diff --cached --ignore-submodules=dirty --name-only
    git ls-files -o --exclude-standard
  } | sort -u
)"

# Oldest uncommitted edit ~ how long the tree has been dirty; newest = last touch.
oldest=0
newest=0
while IFS= read -r path; do
  [ -n "$path" ] || continue
  [ -e "$path" ] || continue
  m="$(stat_mtime "$path")"
  case "$m" in ''|*[!0-9]*) continue ;; esac
  [ "$m" -gt 0 ] || continue
  if [ "$oldest" -eq 0 ] || [ "$m" -lt "$oldest" ]; then oldest="$m"; fi
  if [ "$m" -gt "$newest" ]; then newest="$m"; fi
done <<EOF
$FILES
EOF

LAST_EPOCH="$(git log -1 --format=%ct 2>/dev/null || echo 0)"
case "$LAST_EPOCH" in ''|*[!0-9]*) LAST_EPOCH=0 ;; esac
if [ "$LAST_EPOCH" -gt 0 ]; then
  LAST_DAYS="$(( (NOW - LAST_EPOCH) / 86400 ))"
else
  LAST_DAYS=""
fi

if [ "$oldest" -gt 0 ]; then
  AGE_DAYS="$(( (NOW - oldest) / 86400 ))"
  AGE_SOURCE="oldest uncommitted edit"
elif [ "$LAST_EPOCH" -gt 0 ]; then
  AGE_DAYS="$LAST_DAYS"
  AGE_SOURCE="last commit (no file mtimes available)"
else
  AGE_DAYS=999999
  AGE_SOURCE="repository has no commits"
fi
if [ "$newest" -gt 0 ]; then
  NEWEST_DAYS="$(( (NOW - newest) / 86400 ))"
else
  NEWEST_DAYS=""
fi

if [ "$ANY" -eq 0 ] && [ "$AGE_DAYS" -le "$DAYS" ]; then
  if [ "$QUIET" -eq 0 ]; then
    echo "commit_check: $CHANGED uncommitted path(s); dirty ${AGE_DAYS}d (threshold ${DAYS}d) - OK."
  fi
  exit 0
fi

{
  echo "commit_check: COMMIT REMINDER"
  echo "  Working tree:  $CHANGED uncommitted path(s)"
  if [ "$ANY" -eq 1 ]; then
    echo "  Trigger:       any uncommitted change (--any)"
  fi
  echo "  Dirty for:     ${AGE_DAYS} day(s)  ($AGE_SOURCE)"
  if [ -n "$NEWEST_DAYS" ]; then
    echo "  Last edit:     ${NEWEST_DAYS} day(s) ago"
  fi
  if [ -n "$LAST_DAYS" ]; then
    echo "  Last commit:   ${LAST_DAYS} day(s) ago"
  fi
  echo
  echo "  Policy: commit at least once a week, on Sunday (AGENTS.md)."
  echo "  Uncommitted work has no backup - a single 'git checkout' on 2026-09-20"
  echo "  wiped a month of edits to umbraaudio/web/routes.py."
  echo
  echo "  Next:  git status && git add -A && git commit"
  echo "         (book data, tmp_out/, logs and static/samples/ are gitignored)"
} >&2
exit 1