#!/usr/bin/env bash

sessions() {
  if [ "$HERDR_ENV" = "1" ]; then
    # herdr workspaces are live/dynamic, unlike tmux's static @SESSIONS list; list the
    # currently open workspaces instead
    herdr workspace list 2> /dev/null | jq -r '.result.workspaces[].label'
    return
  fi
  local list
  list=$(tmux show-options -g -v @SESSIONS 2> /dev/null)
  if [ -z "$list" ] && [ -f ~/.tmux.conf.local ]; then
    # no tmux server (e.g. running inside herdr): read @SESSIONS from the static config instead
    list=$(grep -E '^\s*set-option\s+-g\s+@SESSIONS\s' ~/.tmux.conf.local \
      | sed -E 's/^\s*set-option\s+-g\s+@SESSIONS\s+"([^"]*)".*/\1/')
  fi
  if [ -n "$list" ]; then
    echo "$list" | tr ' ' '\n'
  else
    tmux list-sessions -F '#{session_name}' 2> /dev/null | sort | uniq
  fi
}

servers() {
  if [ "$HERDR_ENV" = "1" ]; then
    # herdr has its own saved-machine catalog for multi-machine access; use it instead of
    # the tmux-only @SERVERS static list
    herdr machine list --json 2> /dev/null | jq -r '.[].target' | awk '{print "@" $1}'
    return
  fi
  local list
  list=$(tmux show-options -g -v @SERVERS 2> /dev/null)
  if [ -z "$list" ] && [ -f ~/.tmux.conf.local ]; then
    list=$(grep -E '^\s*set-option\s+-g\s+@SERVERS\s' ~/.tmux.conf.local \
      | sed -E 's/^\s*set-option\s+-g\s+@SERVERS\s+"([^"]*)".*/\1/')
  fi
  echo "$list" | tr ' ' '\n' | awk '{print "@" $1}'
}

search() {
  grep -v "^$" | nl -w 1 -s ": " | fzf --no-sort --prompt "  " --pointer='➤ ' --marker='➤' | awk '{print $2}'
}

search_sessions() {
  sessions | search
}

search_servers() {
  servers | search
}

search_all() {
  (sessions; servers) | search
}

# find or create a workspace labeled $SESSION (the herdr equivalent of a tmux session),
# then focus it
function herdr_switch_session {
  local workspace_id working_directory
  workspace_id=$(herdr workspace list \
    | jq -r --arg n "$SESSION" '.result.workspaces[] | select(.label == $n) | .workspace_id' | head -1)
  if [ -n "$workspace_id" ]; then
    herdr workspace focus "$workspace_id" > /dev/null
  else
    working_directory="$PROJECTS/$SESSION"
    if [ ! -d "$working_directory" ]; then
      working_directory="$HOME"
    fi
    herdr workspace create --cwd "$working_directory" --label "$SESSION" --focus > /dev/null
  fi
}

# find or create a workspace labeled $SESSION on $SERVER, running the herdr CLI over SSH
# against that machine's own socket (workspace IDs are scoped to a single server, so this
# can't be done from the local socket), then attach to it via herdr's own SSH remote support
function herdr_remote_switch_session {
  local remote_session workspace_id
  remote_session=$(herdr machine list --json 2> /dev/null \
    | jq -r --arg t "$SERVER" '.[] | select(.target == $t) | .session' | head -1)

  workspace_id=$(ssh -o BatchMode=yes -o ConnectTimeout=5 "$SERVER" bash -lc "'herdr workspace list'" 2> /dev/null \
    | jq -r --arg n "$SESSION" '.result.workspaces[] | select(.label == $n) | .workspace_id' | head -1)
  if [ -n "$workspace_id" ]; then
    ssh -o BatchMode=yes "$SERVER" bash -lc "'herdr workspace focus $workspace_id'" > /dev/null 2>&1
  else
    ssh -o BatchMode=yes "$SERVER" bash -lc "'herdr workspace create --label $SESSION --focus'" > /dev/null 2>&1
  fi

  if [ -n "$remote_session" ] && [ "$remote_session" != "default" ]; then
    exec herdr --remote "$SERVER" --session "$remote_session"
  else
    exec herdr --remote "$SERVER"
  fi
}

SESSION="$1"

if [[ -z $SESSION ]]; then
  # herdr unifies "sessions" and "servers" into one workspace picker; tmux keeps them
  # separate (bare tmux-sessions defaults to local sessions only, use "all" for both)
  if [ "$HERDR_ENV" = "1" ]; then
    SESSION=$(search_all)
  else
    tmux_running=$(pgrep tmux)
    if [[ -z $TMUX ]] && [[ -z $tmux_running ]]; then
      tmux new-session -ds main
    fi
    SESSION=$(search_sessions)
  fi
elif [[ "$SESSION" == "sessions" ]]; then
  if [ "$HERDR_ENV" != "1" ]; then
    tmux_running=$(pgrep tmux)
    if [[ -z $TMUX ]] && [[ -z $tmux_running ]]; then
      tmux new-session -ds main
    fi
  fi
  SESSION=$(search_sessions)
elif [[ "$SESSION" == "servers" ]]; then
  if [ "$HERDR_ENV" != "1" ]; then
    tmux_running=$(pgrep tmux)
    if [[ -z $TMUX ]] && [[ -z $tmux_running ]]; then
      tmux new-session -ds main
    fi
  fi
  SESSION=$(search_servers)
elif [[ "$SESSION" == "all" ]]; then
  if [ "$HERDR_ENV" != "1" ]; then
    tmux_running=$(pgrep tmux)
    if [[ -z $TMUX ]] && [[ -z $tmux_running ]]; then
      tmux new-session -ds main
    fi
  fi
  SESSION=$(search_all)
fi

if [[ $SESSION  =~ "@" ]]; then
  SERVER=$(echo $SESSION | cut -d@ -f2)
  SESSION=$(echo $SESSION | cut -d@ -f1)
  if [[ -z $SESSION ]]; then
    SESSION="main"
  fi
  if [ "$HERDR_ENV" = "1" ]; then
    herdr_remote_switch_session
  elif command -v caffeinate &>/dev/null; then
    AUTOSSH_GATETIME=0 exec caffeinate autossh -M0 -t -o ServerAliveCountMax=2 -o ServerAliveInterval=5 -o ConnectTimeout=5 -o BatchMode=yes $SERVER '/bin/bash --login -ic "tmux-sessions '$SESSION'"'
  else
    AUTOSSH_GATETIME=0 exec autossh -M0 -t -o ServerAliveCountMax=2 -o ServerAliveInterval=5 -o ConnectTimeout=5 -o BatchMode=yes $SERVER '/bin/bash --login -ic "tmux-sessions '$SESSION'"'
  fi
elif [[ -n $SESSION ]]; then
  if [ "$HERDR_ENV" = "1" ]; then
    herdr_switch_session
  else
    # new session if session is not available
    tmux_running=$(pgrep tmux)
    if [[ -z $TMUX ]] && [[ -z $tmux_running ]]; then
      tmux new-session -A -D -s $SESSION
    else
      if ! tmux has-session -t $SESSION 2> /dev/null; then
        WORKING_DIRECTORY=$PROJECTS/$SESSION
        INITIAL_FILE="~/.dotfiles/tmux/sessions/$SESSION.tmux.conf"
        if [[ -f "$INITIAL_FILE" ]]; then
          INITIAL_COMMAND="tmux source-file $INTIALL_FILE"
        fi
        if [[ ! -d "$WORKING_DIRECTORY" ]]; then
          WORKING_DIRECTORY="~"
        fi
        tmux new-session -ds $SESSION -c $WORKING_DIRECTORY $INTIAL_COMMAND
      fi
      if [[ -z $TMUX ]]; then
        tmux new-session -A -D -s $SESSION
      else
        tmux switch-client -t $SESSION
      fi
    fi
  fi
fi