#!/usr/bin/env bash
# Shared helpers for release and PR title CI scripts.

SOURCE_DIR="python_repositories"

# Returns bump type (major|minor|patch) or empty if no valid prefix.
bump_type_from_title() {
  local title="$1"
  local lower
  lower=$(echo "$title" | tr '[:upper:]' '[:lower:]')

  if echo "$lower" | grep -qE '^\[(major|breaking)\]'; then
    echo "major"
  elif echo "$lower" | grep -qE '^\[(minor|feat)\]'; then
    echo "minor"
  elif echo "$lower" | grep -qE '^\[(patch|fix)\]'; then
    echo "patch"
  fi
}

title_has_bump_prefix() {
  [[ -n "$(bump_type_from_title "$1")" ]]
}

strip_bump_prefix() {
  local title="$1"
  echo "$title" | sed -E 's/^\[(patch|fix|minor|feat|major|breaking)\][[:space:]]*//i'
}

extract_pr_title_from_merge_commit() {
  local msg="$1"
  echo "$msg" | sed -n "s/^Merge pull request '\(.*\)' (#.*/\1/p"
}

changed_source_files() {
  grep -E "^${SOURCE_DIR}/" || true
}

has_source_changes() {
  local files="$1"
  echo "$files" | changed_source_files | grep -q .
}

read_pyproject_version() {
  sed -n 's/^version = "\(.*\)"/\1/p' pyproject.toml | head -1
}

latest_tag_version() {
  local tag
  tag=$(git describe --tags --abbrev=0 2>/dev/null || true)
  if [[ -n "$tag" ]]; then
    echo "${tag#v}"
  else
    read_pyproject_version
  fi
}

set_pyproject_version() {
  local version="$1"
  sed -i.bak -E "s/^version = \".*\"/version = \"${version}\"/" pyproject.toml
  rm -f pyproject.toml.bak
}

# Returns markdown bullet list of commits between two refs (exclusive..inclusive).
# Optional third argument limits entries when from_ref is empty (release notes only).
commits_between() {
  local from_ref="$1"
  local to_ref="${2:-HEAD}"
  local limit="${3:-}"

  if [[ -z "$from_ref" ]]; then
    if [[ -n "$limit" ]]; then
      git log "${to_ref}" --pretty=format:'- %h %s' -"${limit}" 2>/dev/null || true
    else
      git log "${to_ref}" --pretty=format:'- %h %s' 2>/dev/null || true
    fi
  else
    git log "${from_ref}..${to_ref}" --pretty=format:'- %h %s' 2>/dev/null || true
  fi
}

commits_since() {
  commits_between "$1" HEAD
}

changelog_header() {
  cat <<'EOF'
# Changelog

All notable changes to this project will be documented in this file.

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## [Unreleased]

EOF
}

changelog_section() {
  local version="$1"
  local date="$2"
  local summary="$3"
  local commits="$4"

  cat <<EOF
## [${version}] - ${date}

### Summary
${summary}

### Changed
${commits:-- (no commits recorded)}
EOF
}

bump_semver() {
  local current="$1"
  local bump_type="$2"
  local major minor patch

  IFS=. read -r major minor patch <<< "$current"
  case "$bump_type" in
    major)
      major=$((major + 1))
      minor=0
      patch=0
      ;;
    minor)
      minor=$((minor + 1))
      patch=0
      ;;
    patch)
      patch=$((patch + 1))
      ;;
    *)
      echo "Unknown bump type: $bump_type" >&2
      return 1
      ;;
  esac
  echo "${major}.${minor}.${patch}"
}