chore: add content branch workflow

Author: YuxiuBai

README.md

@@ -1,2 +1,14 @@
 # EmptyDust.github.io
-Fengling's free website.
+Fengling's free website.
+
+## Content Branch Workflow
+
+This repo can keep written content on a separate `content` branch.
+
+Content paths are defined in `scripts/content-paths.txt`.
+
+- Run `./scripts/export-content-branch.sh` on `master` to refresh the `content` branch from the current branch.
+- Run `./scripts/import-content-branch.sh` on `master` to pull content changes back from the `content` branch.
+- Push the content branch with `git push origin content` when you want it on GitHub.
+
+This avoids merging whole branches and only syncs the content directories you care about.

scripts/content-paths.txt

@@ -0,0 +1,9 @@
+# Paths that belong to the content branch.
+# Keep this list limited to written content and content-specific data.
+source/_posts
+source/about
+source/index
+source/link
+source/fcircle
+source/_data/link.yml
+source/tree.txt

scripts/export-content-branch.sh

@@ -0,0 +1,80 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+repo_root=$(git rev-parse --show-toplevel)
+script_dir=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+paths_file="$script_dir/content-paths.txt"
+content_branch="${1:-content}"
+source_ref="${2:-HEAD}"
+
+cd "$repo_root"
+
+if [[ -n "$(git status --porcelain)" ]]; then
+  echo "Working tree is not clean. Commit or stash changes first." >&2
+  exit 1
+fi
+
+if [[ ! -f "$paths_file" ]]; then
+  echo "Missing content paths file: $paths_file" >&2
+  exit 1
+fi
+
+mapfile -t content_paths < <(grep -Ev '^[[:space:]]*(#|$)' "$paths_file")
+
+if [[ ${#content_paths[@]} -eq 0 ]]; then
+  echo "No content paths configured." >&2
+  exit 1
+fi
+
+mapfile -t content_files < <(git ls-tree -r --name-only "$source_ref" -- "${content_paths[@]}")
+
+tmp_dir=$(mktemp -d "${TMPDIR:-/tmp}/content-branch.XXXXXX")
+
+cleanup() {
+  git worktree remove --force "$tmp_dir" >/dev/null 2>&1 || true
+  rm -rf "$tmp_dir"
+}
+
+trap cleanup EXIT
+
+if git show-ref --verify --quiet "refs/heads/$content_branch"; then
+  git worktree add "$tmp_dir" "$content_branch" >/dev/null
+else
+  git worktree add -b "$content_branch" "$tmp_dir" "$source_ref" >/dev/null
+fi
+
+find "$tmp_dir" -mindepth 1 -maxdepth 1 ! -name .git -exec rm -rf {} +
+
+if [[ ${#content_files[@]} -gt 0 ]]; then
+  git archive "$source_ref" "${content_files[@]}" | tar -x -C "$tmp_dir"
+fi
+
+git show "$source_ref:.gitignore" > "$tmp_dir/.gitignore"
+
+cat > "$tmp_dir/README.md" <<EOF
+# content branch
+
+This branch stores authored content extracted from \`$source_ref\`.
+
+Edit content here if you want to keep Markdown separate from theme and build files.
+Bring the changes back to the main branch with:
+
+\`\`\`bash
+./scripts/import-content-branch.sh $content_branch
+\`\`\`
+EOF
+
+(
+  cd "$tmp_dir"
+  git add --all
+
+  if git diff --cached --quiet; then
+    echo "No content changes to commit on '$content_branch'."
+    exit 0
+  fi
+
+  git commit -m "sync content from $source_ref" >/dev/null
+)
+
+echo "Updated local branch '$content_branch' from '$source_ref'."

scripts/import-content-branch.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+repo_root=$(git rev-parse --show-toplevel)
+script_dir=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+paths_file="$script_dir/content-paths.txt"
+content_branch="${1:-content}"
+
+cd "$repo_root"
+
+if [[ -n "$(git status --porcelain)" ]]; then
+  echo "Working tree is not clean. Commit or stash changes first." >&2
+  exit 1
+fi
+
+if [[ ! -f "$paths_file" ]]; then
+  echo "Missing content paths file: $paths_file" >&2
+  exit 1
+fi
+
+if ! git rev-parse --verify "$content_branch" >/dev/null 2>&1; then
+  echo "Branch '$content_branch' does not exist." >&2
+  exit 1
+fi
+
+mapfile -t content_paths < <(grep -Ev '^[[:space:]]*(#|$)' "$paths_file")
+
+if [[ ${#content_paths[@]} -eq 0 ]]; then
+  echo "No content paths configured." >&2
+  exit 1
+fi
+
+git restore --source "$content_branch" --worktree -- "${content_paths[@]}"
+
+echo "Restored content paths from '$content_branch' into the working tree."