#!/bin/bash
set -e
update=yes
if [[ "$update" = "yes" ]]; then
  repo="https://github.com/alexbelgium/BirdNET-Pi.git"
  # repo="https://github.com/Nachtzuster/BirdNET-Pi.git"
  branch="main"
  echo "Update with $branch of $repo"

  temp_dir="$(mktemp -d)"
  target_dir="/home/${USER}/BirdNET-Pi"

  # Parse owner/repo from the URL
  _url_no_git="${repo%.git}"
  _path="${_url_no_git#https://github.com/}"
  owner="${_path%%/*}"
  reponame="${_path#*/}"

  # --- helper: list open PRs via GitHub API (unauthenticated) ----------------
  list_open_prs() {
    # prints PR numbers, one per line; returns non-zero if none or curl missing
    command -v curl >/dev/null 2>&1 || return 1
    local page=1 per_page=100 out
    local -a all=() chunk=()
    while :; do
      out="$(curl -fsSL "https://api.github.com/repos/${owner}/${reponame}/pulls?state=open&per_page=${per_page}&page=${page}")" || break
      [[ -z "$out" || "$out" == "[]" ]] && break
      if command -v jq >/dev/null 2>&1; then
        mapfile -t chunk < <(printf '%s' "$out" | jq -r '.[] | select(.draft == false) | .number')
      else
        # Fallback JSON scraping if jq is unavailable
        mapfile -t chunk < <(printf '%s' "$out" | grep -o '"number":[[:space:]]*[0-9]\+' | grep -o '[0-9]\+')
      fi
      ((${#chunk[@]}==0)) && break
      all+=("${chunk[@]}")
      ((${#chunk[@]} < per_page)) && break
      ((page++))
    done
    ((${#all[@]}==0)) && return 1
    printf '%s\n' "${all[@]}"
  }

  # --- clone base ------------------------------------------------------------
  git clone --quiet --branch "$branch" "$repo" "$temp_dir"
  pushd "$temp_dir" >/dev/null
  git fetch --quiet origin
  git config user.name "Local PR Aggregator"
  git config user.email "local@example.invalid"
  git checkout -B with-open-prs "origin/${branch}"

  # --- fetch & merge only OPEN PRs -------------------------------------------
  mapfile -t prs < <(list_open_prs || true)
  if ((${#prs[@]})); then
    # Sort numerically (oldest first)
    IFS=$'\n' prs=($(sort -n <<<"${prs[*]}")); unset IFS
    echo "Open PR(s): ${prs[*]}"

    for pr in "${prs[@]}"; do
      echo "Fetching PR #${pr}…"
      if git fetch --quiet origin "pull/${pr}/head:pr-${pr}"; then
        echo "Merging PR #${pr} into with-open-prs…"
        if git merge --no-ff -X theirs --no-edit "pr-${pr}"; then
          echo "✓ merged PR #${pr}"
        else
          echo "! Conflict merging PR #${pr}; aborting and skipping."
          git merge --abort || true
          git reset --hard
          git checkout with-open-prs
        fi
      else
        echo "! Could not fetch refs for PR #${pr}; skipping."
      fi
    done
  else
    echo "No open PRs detected (API unavailable or none open)."
  fi

  popd >/dev/null
  rm -rf "$target_dir"
  mv "$temp_dir" "$target_dir"
fi