#!/usr/bin/env bash
set -e
set -o pipefail

DEBUG=0
declare -a COMMANDS

error() {
  local message
  printf -v message "\e[31mERROR:\e[0m %s\n" "$1"
  >&2 printf "%b" "${message}"
}

debug() {
  local message
  if [[ $DEBUG -eq 1 ]]; then
    printf -v message "\e[3;34mDEBUG:\e[0m %s\n" "$*"
    >&2 printf "%b" "$message"
  fi
}

process_args() {
  until [[ -z $1 ]]; do
    case $1 in
    -s | --session-name | --session)
      SESSION="$2"
      shift
      ;;
    -p | --project-name | --window)
      PROJECT="$2"
      shift
      ;;
    -d | --debug)
      DEBUG=1
      ;;
    *)
      COMMANDS+=("$1")
      ;;
    esac
    shift
  done
}

has_session() {
  local session_name="${1}"
  tmux has-session -t "${session_name}" 2>/dev/null
}

get_project_path() {
  local identifier="${1}"
  debug "get project path with identifier '$identifier'"
  if [[ -z "$identifier" ]]; then
    CURRENT_PATH=$(ghq list -p | fzf)
  else
    CURRENT_PATH=$(ghq list -p -e "$identifier")
  fi
}

is_running_in_tmux() {
  debug "check if running in tmux"
  if [[ -z $TMUX ]]; then
    error "This script should run in a running instance of Tmux"
    exit 10
  fi
}

check_script_inputs() {
  debug "check script inputs"
  if [[ -z "$SESSION" ]]; then
    error "You must provide a session name"
    exit 5
  fi
}

process_commands() {
  local input="$1"
  debug "Process command '$input'"
  local cmd arg
  if [[ "$input" =~ ^.*:.*$ ]]; then
    debug "command and parameter found"
    arg=${input##*:}
    cmd=${input%%:*}
  else
    debug "command found without parameter"
    cmd="$input"
  fi
  if ! "tmux_${cmd}" "${arg}"; then
    error "Command \`$cmd\` not exist"
  fi
}

tmux_vsplit() {
  local size="${1:-20}"
  debug "execute vsplit with size '${size}'"
  tmux split-window -t "$SESSION" -c "$CURRENT_PATH" -v -p "$size"
}

tmux_hsplit() {
  local size="${1:-20}"
  debug "execute hsplit with size '${size}'"
  tmux split-window -t "$SESSION" -c "$CURRENT_PATH" -h -p "$size"
}

tmux_neww() {
  local name="$1"
  debug "execute neww with name '${name}'"
  local command=(tmux new-window -t "${SESSION}:$" -c "$CURRENT_PATH" -a)
  if [[ -n "$name" ]]; then
    command+=(-n "$name")
  fi
  "${command[@]}"
}

tmux_run() {
  local shell_command="$1"
  debug "execute run with command '${shell_command}'"
  if [[ -z "$shell_command" ]]; then
    error "tmux-run need a command"
  else
    tmux send-keys -t "$SESSION" "$shell_command" "C-m"
  fi
}

project() {
  local arg="$1"
  debug "execute project with arg '${arg}'"
  get_project_path "$arg"
}

main() {
  process_args "$@"
  is_running_in_tmux
  check_script_inputs
  if ! has_session "$SESSION"; then
    get_project_path "${PROJECT:-$SESSION}"
    tmux new-session -ds "${SESSION}" -c "${CURRENT_PATH}" -n "${PROJECT}"

    # Process commands passed with command line
    for command in "${COMMANDS[@]}"; do
      process_commands "$command"
    done
  fi

  tmux switch-client -t "${SESSION}"
}

main "${@}"