Gemini Based Doc Generator

.zshrc

# ==============================================
# === Start of Gemini Diff-Based Docs Generator ===
# ==============================================

# ---- Documentation Generation Prompt ----
__gemini_docs_prompt=$(
  cat <<'EOF'
You are generating technical documentation from code changes.
Produce clear, maintainable, developer-friendly documentation.

Requirements:
- Summarize purpose & behavior of the changed code.
- Explain new APIs, functions, parameters, return values.
- Highlight architecture interactions & dependencies.
- Provide examples or usage notes.
- If the change affects existing docs, state what should be updated.

Do NOT rewrite code. Do NOT propose speculative features.
EOF
)

# ---- State Tracking for Git ----
LAST_GIT_CMD=""
LAST_GIT_EXIT_CODE=""

git() {
  if [[ "$1" == "commit" ]]; then
    LAST_GIT_CMD="commit"
  else
    LAST_GIT_CMD=""
  fi
  command git "$@"
  LAST_GIT_EXIT_CODE=$?
  return $LAST_GIT_EXIT_CODE
}

# ======================================================
# === Modular file/folder finder for documentation ===
# ======================================================

# allowed search patterns (modular; easy to extend)
DOC_TARGETS=(
  "README.md"
  "docs"
  "wiki"
)

# check if a doc target exists in the repo root
find_existing_doc_target() {
  for target in "${DOC_TARGETS[@]}"; do
    if [[ -e "$target" ]]; then
      echo "$target"
      return 0
    fi
  done
  return 1
}

# prompt user for a manual doc target path
prompt_for_doc_target() {
  echo "No documentation folder/file found."
  read -r "?Enter a file or folder path where documentation should be written: " user_path
  echo "$user_path"
}

# generate documentation target path
resolve_doc_target() {
  local existing
  existing=$(find_existing_doc_target)
  if [[ $? -eq 0 ]]; then
    echo "$existing"
  else
    prompt_for_doc_target
  fi
}

# ==============================================
# === pre-cmd hook for auto docs-generation ===
# ==============================================
precmd() {
  if [[ "${LAST_GIT_CMD:-}" == "commit" ]] && [[ "${LAST_GIT_EXIT_CODE:-1}" -eq 0 ]]; then
    LAST_GIT_CMD=""
    LAST_GIT_EXIT_CODE=""

    echo
    read -r "REPLY?Generate documentation for the committed changes? [y/n] "
    if [[ ! "$REPLY" =~ ^[Yy]$ ]]; then
      return
    fi

    echo "Locating documentation target..."

    DOC_TARGET=$(resolve_doc_target)
    echo "Documentation will be generated into: $DOC_TARGET"
    echo

    # get changed files
    if git rev-parse --verify HEAD~1 >/dev/null 2>&1; then
      files=$(git diff --name-only HEAD~1 HEAD)
    else
      files=$(git show --name-only --pretty="" HEAD)
    fi

    if [[ -z "${files//[[:space:]]/}" ]]; then
      echo "No files changed in the last commit."
      return
    fi

    for file in $files; do
      if [[ -f "$file" ]]; then
        echo "Analyzing changes in: $file"
        git diff HEAD~1 HEAD -- "$file" | \
          gemini -p "$__gemini_docs_prompt" | \
          tee -a "$DOC_TARGET/GENERATED_DOCS.md" >/dev/null
      fi
    done

    echo "Documentation appended to: $DOC_TARGET/GENERATED_DOCS.md"
  fi
}

# ==============================================
# === End of Gemini Diff-Based Docs Generator ===
# ==============================================