set -euo pipefail
trap 'echo "Interrupted or failed. Repo may be mid-rebase/cherry-pick." ; exit 1' INT ERR

if [[ $# -eq 0 ]]; then
  echo "Usage: ngcp [mode] [options]"
  echo "Run 'ngcp --help' for more information."
  exit 1
fi

# waits for an internet connection. It pings both Google DNS  and Cloudfare dns in case one of them is down
pings=0
until ping -c1 -W1 1.1.1.1 >/dev/null 2>&1 || \
  ping -c1 -W1 8.8.8.8 >/dev/null 2>&1
  do
  sleep 1
  ((pings++))
  if (( pings > 2 )); then
    echo "No internet connection. Retrying in 1 second..."
  fi
done

CONFIG="$HOME/.config/nix-git-cherry-picker/config.json"

if [[ ! -f "$CONFIG" ]]; then
  echo "Error: Config file not found at $CONFIG"
  echo "Please create it with the necessary settings."
  exit 1
fi

localBranch=$(jq -r '.localBranch' "$CONFIG")
remoteBranch=$(jq -r '.remoteBranch' "$CONFIG")
nixConfigPath=$(jq -r '.nixConfigPath' "$CONFIG")

automatic=0

# if there is the flag --automatic it will fail when merge conflict and tell you to do it manually.
# if there is the flag --no-rebuild it won't rebuild your system to test the new commits
# if there is the flag --continue-with-rebuild it will rebuild if --no-rebuild was set
for flag in "$@"; do
  if [[ "$flag" == "--automatic" ]]; then
    automatic=1
  elif [[ "$flag" == "--help" ]]; then
    echo "Usage: ngcp [mode] [options]"
    echo "Mode:"
    echo " pick <commit 1> <commit2> <...>    Cherry-pick commits for the remote branch."
    echo " pick -i [n]                        Interactively select from the last 10 (or n) commits."
    echo " pick --interactive [n]             Interactively select from the last 10 (or n) commits."
    echo " last <int n>                       Cherry-pick the last n commits."
    echo " pull                               Pulls the changes to the local branch."
    echo "Options:"
    echo "  --automatic                       Exit with no changes if merge conflict and instructs the user to pull manually. Use this option for automation."
    exit
  fi
done
# checks if connection


if [[ "$1" == "pick" || "$1" == "last" ]]; then
  interactive=0
  interactive_count=10

  if [[ "$1" == "pick" && "${2:-}" == "-i" || "$1" == "pick" && "${2:-}" == "--interactive" ]]; then
    interactive=1

    if [[ -n "${3:-}" ]]; then
      if ! [[ "$3" =~ ^[1-9][0-9]*$ ]]; then
        echo "Invalid interactive commit count: $3"
        exit 1
      fi
      interactive_count="$3"
    fi
  fi

  if (( interactive )); then
    if ! command -v fzf >/dev/null 2>&1; then
      echo "Error: fzf is required for interactive mode."
      echo "Please install fzf and try again."
      exit 1
    fi

    mapfile -t commits < <(
      git -C "$nixConfigPath" log \
        --format='%H%x09%h%x09%s' \
        -n "$interactive_count" \
        HEAD |
      fzf \
        --multi \
        --reverse \
        --header="TAB select/deselect • ENTER confirm" \
        --preview="git -C '$nixConfigPath' show --stat --oneline {1}" |
      cut -f1
    )

    if [[ "${#commits[@]}" -eq 0 ]]; then
      echo "No commits selected."
      exit 0
    fi

    # fzf displays newest -> oldest, but cherry-picking should happen
    # oldest -> newest.
    mapfile -t commits < <(printf '%s\n' "${commits[@]}" | tac)

  elif [[ "$1" == "last" ]]; then
    if [[ "$#" -lt 2 ]] || ! [[ "$2" =~ ^[1-9][0-9]*$ ]]; then
      echo "Invalid arguments. Usage: ngcp last <number>"
      exit 1
    fi
  
    mapfile -t commits < <(
      git -C "$nixConfigPath" log --format='%H' --reverse -n "$2" HEAD
    )
  
    echo "Cherry-picking the last ${#commits[@]} commits:"
    printf '  %s\n' "${commits[@]}"
  
  else
    commits=("${@:2}")
  fi
  
  #if doesnt exist, just get the branch from the remote
  if ! git -C "$nixConfigPath" checkout "$remoteBranch"; then
    git -C "$nixConfigPath" checkout -b "$remoteBranch" "origin/$remoteBranch"
  fi
  echo "Pulling latest commits before cherry-picking..."
  if git -C "$nixConfigPath" pull --rebase ; then
    echo "Pull successful."
  elif (( automatic )); then
    echo "Merge conflict detected during pull. Please run ngcp pull manually"
    notify-send "Merge conflict detected during ngcp pull." "Please run ngcp pull manually"
    git -C "$nixConfigPath" rebase --abort
    exit 1
  else
    echo "Merge conflict detected during pull."
    echo "Resolve conflicts and run:"
    echo "  git rebase --continue"
    echo "Type 'y' when done."
    
    while git -C "$nixConfigPath" rev-parse --verify REBASE_HEAD >/dev/null 2>&1; do
      read -r answer
      [[ "$answer" == "y" ]] || continue
    done
    echo "Pull successful"
  fi
  for commit in "${commits[@]}"; do
    if git -C "$nixConfigPath" cherry-pick "$commit"; then
      echo "Applied $commit successfully"
    else
      echo "Cherry-pick of $commit failed."
      echo "Resolve conflicts and run:"
      echo "  git cherry-pick --continue"
      echo
      echo "Type 'y' when done."
  
      while git -C "$nixConfigPath" rev-parse --verify CHERRY_PICK_HEAD >/dev/null 2>&1; do
        read -r answer
        [[ "$answer" == "y" ]] || continue
      done
  
      echo "Cherry-pick for $commit resolved."
    fi
  done
  git -C "$nixConfigPath" push --force origin "$remoteBranch"
  git -C "$nixConfigPath" checkout "$localBranch"
elif [[ "$1" == "pull" ]]; then
  gitStatus=$(git -C "$nixConfigPath" status --porcelain)
  if [[ -n "$gitStatus" ]]; then
    echo "Git directory is dirty. Please clean it up before running ngcp pull"
    echo "$gitStatus"
    notify-send "Git directory is dirty." "Please clean it up before running ngcp pull\n $gitStatus"
    exit 1
  fi
  if git -C "$nixConfigPath" pull --rebase ; then
    echo "Pull successful"
  else
    if (( automatic )); then
      git -C "$nixConfigPath" rebase --abort || true
      echo "git pull failed. Please run ngcp pull manually"
      notify-send "Git pull failed." "Please run ngcp pull manually"
      exit 1
    else
      echo "Merge conflict detected during pull."
      echo "Resolve conflicts and run:"
      echo "  git rebase --continue"
      echo "Type 'y' when done."
      
      while git -C "$nixConfigPath" rev-parse --verify REBASE_HEAD >/dev/null 2>&1; do
        read -r answer
        [[ "$answer" == "y" ]] || continue
      done
      echo "Pull successful"
    fi
  fi
    git -C "$nixConfigPath" push --force origin "$localBranch"
else
  echo "Invalid argument. Please run ngcp --help"
  exit
fi