#!/usr/bin/env bash
# push-split.sh — push a subdirectory of the monorepo working-copy to its
# matching split repo on Hephaestus, preserving history via git-subtree-split.
#
# Since silentmode/silentmode was deleted and each project lives in its own
# repo on the forge (silentmode/theseus, silentmode/ariadne, silentmode/hephaestus,
# silentmode/sirius, …), cross-cutting commits made in this working copy need to
# be routed to whichever remote corresponds to the touched project.
#
# Usage:
#   scripts/push-split.sh <project-dir> [remote-name]
#
# Examples:
#   scripts/push-split.sh Hephaestus                 # → git remote 'hephaestus'
#   scripts/push-split.sh TheseusNavigator           # → git remote 'theseus'   (Navigator suffix stripped)
#   scripts/push-split.sh AriadneResolver            # → git remote 'ariadne'   (Resolver suffix stripped)
#   scripts/push-split.sh site-sirius-x sirius       # → remote 'sirius' (explicit override)
#
# List of configured remotes: `git remote -v`
#
# Notes:
# - Only ONE prefix per invocation. Cross-cutting changes that touched multiple
#   projects need to be run once per touched directory.
# - Uses --branch <ephemeral>, pushes, then deletes it. Nothing sticks around.
# - Push target is always <remote>:master. Passing --branch was intentional
#   over --squash: split history is preserved so file blame on the split repo
#   still points at the real commits.
set -euo pipefail

prefix="${1:?usage: push-split.sh <project-dir> [remote-name]}"

# Derive a remote name from the directory if not passed.
# Heuristic: lowercase, strip Navigator/Resolver suffix. Otherwise pass explicitly.
default_remote=$(echo "$prefix" | tr '[:upper:]' '[:lower:]' | sed 's/navigator$//; s/resolver$//')
remote="${2:-$default_remote}"

[ -d "$prefix" ] || { echo "error: no such directory: $prefix" >&2; exit 1; }
git remote get-url "$remote" >/dev/null 2>&1 || {
  echo "error: no git remote named '$remote'." >&2
  echo "available remotes: $(git remote | paste -sd ' ' -)" >&2
  echo "pass an explicit remote name as the 2nd arg." >&2
  exit 1
}

# Uncommitted changes get carried into the split — usually not what you want.
# Warn (but don't block; sometimes you know what you're doing).
if ! git diff --quiet HEAD -- "$prefix" 2>/dev/null; then
  echo "warning: $prefix has uncommitted changes — those will NOT be included in the split." >&2
fi

branch="_push_${remote}_$$"
trap 'git branch -D "$branch" >/dev/null 2>&1 || true' EXIT

echo "→ splitting $prefix/ into ephemeral branch $branch …"
git subtree split --prefix="$prefix" HEAD -b "$branch" >/dev/null

# Silent Mode public repos do not carry AI-tool attribution in commit metadata
# (see CLAUDE.md at the repo root). Strip any "Co-Authored-By: Claude ..." /
# "Co-authored-by: Claude ..." trailers from the ephemeral branch before push.
# Local monorepo history is untouched — only what lands on the forge is filtered.
echo "→ scrubbing Co-Authored-By: Claude trailers from $branch …"
# filter-branch refuses to run from a dirty working tree ("You have unstaged
# changes"), and with set -e that silently aborted the push whenever another
# session had uncommitted edits. Run it from a throwaway worktree of the
# ephemeral branch instead — refs are shared, the main tree is never touched.
scrubwt=$(mktemp -d "${TMPDIR:-/tmp}/push-split-XXXXXX")
git worktree add --detach --quiet "$scrubwt" "$branch"
if ! (cd "$scrubwt" && FILTER_BRANCH_SQUELCH_WARNING=1 git filter-branch --force --msg-filter '
  sed -e "/^Co-[Aa]uthored-[Bb]y: Claude.*/d"
' "$branch" >/dev/null 2>&1); then
  git worktree remove --force "$scrubwt" >/dev/null 2>&1 || true
  echo "error: trailer scrub failed — not pushing." >&2
  exit 1
fi
git worktree remove --force "$scrubwt" >/dev/null 2>&1 || true
# filter-branch leaves refs/original/refs/heads/$branch as a backup — delete it
# so it can not be pushed by accident (--mirror isn't used here, but be safe).
git update-ref -d "refs/original/refs/heads/$branch" 2>/dev/null || true

echo "→ pushing $branch → $remote:master …"
git push --force "$remote" "$branch:master"

echo "✓ done — see https://code.silentmode.st/silentmode/$remote"