#!/usr/bin/env bash
# Groups commits since the last tag (or full history if no tag exists) into
# Keep-a-Changelog sections by Conventional Commit type. Prints Markdown to
# stdout for review before pasting into CHANGELOG.md under [Unreleased].
#
# Usage: scripts/generate-changelog.sh [range]
#   range   git revision range, e.g. "v0.1.0..HEAD". Defaults to
#           "<last-tag>..HEAD", or full history if no tag exists yet.
#
# Optional: set GITEA_TOKEN to also list merged PRs since the last tag
# (requires curl + jq; silently skipped if either is unavailable).

set -euo pipefail

REPO_OWNER="devil"
REPO_NAME="youtube-studio-flow"
GITEA_HOST="https://git.devils.zone"

RANGE="${1:-}"
if [ -z "$RANGE" ]; then
  LAST_TAG=$(git describe --tags --abbrev=0 2>/dev/null || true)
  if [ -n "$LAST_TAG" ]; then
    RANGE="${LAST_TAG}..HEAD"
  else
    RANGE="HEAD"
  fi
fi

section_for_type() {
  case "$1" in
    feat) echo "Added" ;;
    fix) echo "Fixed" ;;
    refactor|perf|style) echo "Changed" ;;
    docs) echo "Docs" ;;
    chore|build|ci) echo "Chore" ;;
    revert) echo "Removed" ;;
    *) echo "Other" ;;
  esac
}

TMP_DIR=$(mktemp -d)
trap 'rm -rf "$TMP_DIR"' EXIT

while IFS='|' read -r hash subject; do
  [ -z "$hash" ] && continue
  type=$(echo "$subject" | sed -nE 's/^([a-z]+)(\([^)]*\))?!?:.*/\1/p')
  [ -z "$type" ] && type="other"
  breaking=""
  if echo "$subject" | grep -qE '^[a-z]+(\([^)]*\))?!:'; then
    breaking=" **BREAKING**"
  fi
  section=$(section_for_type "$type")
  echo "- ${subject}${breaking} (${hash})" >> "$TMP_DIR/$section"
done < <(git log "$RANGE" --pretty=format:'%h|%s' --no-merges; echo)

for section in Added Changed Fixed Removed Docs Chore Other; do
  if [ -f "$TMP_DIR/$section" ]; then
    echo "### $section"
    cat "$TMP_DIR/$section"
    echo ""
  fi
done

if [ -n "${GITEA_TOKEN:-}" ] && command -v curl >/dev/null && command -v jq >/dev/null; then
  SINCE_DATE=$(git log -1 --format=%aI $(echo "$RANGE" | sed 's/\.\.HEAD//') 2>/dev/null || echo "1970-01-01T00:00:00Z")
  PRS=$(curl -s -H "Authorization: token ${GITEA_TOKEN}" \
    "${GITEA_HOST}/api/v1/repos/${REPO_OWNER}/${REPO_NAME}/pulls?state=closed&limit=50" \
    | jq -r --arg since "$SINCE_DATE" '[.[] | select(.merged == true and .merged_at > $since)] | .[] | "- #\(.number) \(.title)"')
  if [ -n "$PRS" ]; then
    echo "### Pull Requests"
    echo "$PRS"
    echo ""
  fi
fi