#!/usr/bin/env bash
# Build the Starlight site and force-push an orphan `pages` branch whose
# tree is exactly site/dist/ (index.html at root). Tangled Sites should be
# configured: branch=pages, deploy directory=/.
#
# CI auto-deploy is deferred until a write credential exists in Spindle
# secrets. tools/task.sh finish calls this after every serialized main landing;
# direct/manual landings must call it themselves.
set -euo pipefail

ROOT="$(cd "$(dirname "$0")/.." && pwd)"
SITE="$ROOT/site"
DIST="$SITE/dist"
BRANCH="${PAGES_BRANCH:-pages}"
REMOTE="${PAGES_REMOTE:-origin}"
TMP_REMOTE="pages-remote"
SSH_CMD="$(git -C "$ROOT" config --get core.sshCommand || true)"
HEAD_REVISION="$(git -C "$ROOT" rev-parse --verify 'HEAD^{commit}')"
SOURCE_REVISION="$(git -C "$ROOT" rev-parse --verify "${SITE_SOURCE_REVISION:-HEAD}^{commit}")"
export SITE_SOURCE_REVISION="$SOURCE_REVISION"

if [ "$SOURCE_REVISION" != "$HEAD_REVISION" ]; then
  echo "site-deploy: source revision $SOURCE_REVISION is not checked-out HEAD $HEAD_REVISION" >&2
  exit 1
fi
dirty=$(git -C "$ROOT" status --porcelain)
if [ -n "$dirty" ]; then
  echo "site-deploy: refusing to publish a dirty source tree" >&2
  printf '%s\n' "$dirty" >&2
  exit 1
fi

git_remote() {
  if [ -n "$SSH_CMD" ]; then
    GIT_SSH_COMMAND="$SSH_CMD" git "$@"
  else
    git "$@"
  fi
}

"$ROOT/tools/site-build.sh"

if [ ! -f "$DIST/index.html" ]; then
  echo "site-deploy: missing $DIST/index.html after build" >&2
  exit 1
fi
if ! grep -Fq "<meta name=\"misaligned-source-revision\" content=\"$SOURCE_REVISION\">" "$DIST/index.html"; then
  echo "site-deploy: homepage is missing source revision $SOURCE_REVISION" >&2
  exit 1
fi

TMP="$(mktemp -d "${TMPDIR:-/tmp}/misaligned-pages.XXXXXX")"
cleanup() { rm -rf "$TMP"; }
trap cleanup EXIT

# Orphan commit: only the built site, no history from main.
git -C "$TMP" init -q -b "$BRANCH"
# Copy dist contents (including hidden files like .nojekyll if present).
cp -a "$DIST"/. "$TMP"/
git -C "$TMP" add -A
NEW_TREE="$(git -C "$TMP" write-tree)"

if ! REMOTE_URL="$(git -C "$ROOT" remote get-url "$REMOTE")"; then
  echo "site-deploy: missing remote url for '$REMOTE'" >&2
  exit 1
fi

if ls_remote_output="$(git_remote -C "$ROOT" ls-remote --exit-code --heads "$REMOTE_URL" "$BRANCH" 2>&1)"; then
  git -C "$TMP" remote add "$TMP_REMOTE" "$REMOTE_URL"
  git_remote -C "$TMP" fetch --depth=1 "$TMP_REMOTE" "$BRANCH"
  REMOTE_TREE="$(git -C "$TMP" rev-parse "refs/remotes/$TMP_REMOTE/$BRANCH^{tree}")"

  if [ "$NEW_TREE" = "$REMOTE_TREE" ]; then
    echo "site-deploy: public-site content is current on $REMOTE/$BRANCH"
    echo "site-deploy: nothing to publish"
    exit 0
  fi
else
  ls_remote_status=$?
  if [ "$ls_remote_status" -eq 2 ]; then
    echo "site-deploy: missing remote pages branch $REMOTE/$BRANCH, initial publish"
  else
    printf '%s\n' "$ls_remote_output" >&2
    echo "site-deploy: failed to inspect $REMOTE/$BRANCH" >&2
    exit "$ls_remote_status"
  fi
fi

git -C "$TMP" \
  -c user.name="$(git -C "$ROOT" config user.name || echo misaligned-site)" \
  -c user.email="$(git -C "$ROOT" config user.email || echo site@misaligned.local)" \
  commit -q -m "Publish Starlight wiki site from ${SOURCE_REVISION:0:12}"

# Reuse the repo's SSH command so Tangled auth matches main pushes and reads.
echo "site-deploy: force-pushing orphan $BRANCH → $REMOTE ($REMOTE_URL)"
git_remote -C "$TMP" push --force "$REMOTE_URL" "HEAD:refs/heads/$BRANCH"

echo "site-deploy: OK. Configure Tangled Settings → Sites:"
echo "  branch=$BRANCH  deploy directory=/  (sub-path site)"
echo "  source=$SOURCE_REVISION"