#!/usr/bin/env bash
#===============================================================================
#
# created: 2015-09-09
# updated: 2026-07-21
# usage: tm [session_name]
# desc: Interactive and declarative tmux session manager.
# notes:
# author: chawley
#
#===============================================================================

set -euo pipefail

readonly TMUX_CONF="${HOME}/.tmux.conf.aamon"

# Ensure we are not nesting tmux sessions
if [[ -n "${TMUX:-}" ]]; then
    echo "Error: Already inside a tmux session. Nesting is disabled." >&2
    exit 1
fi

# Define session layouts as data maps: "window_index:window_name:command"
# Field separator is ';' to safely allow command chains (&&, ;, etc.) inside field 3.
# Index 1 is reserved for the initial session window.
declare -A SESSIONS

SESSIONS[mine]="
1;local(phansible@aamon);
2;phansible@overlook;exec ssh phansible@overlook.tailc38dc9.ts.net
3;weechat;ssh -t overlook-ts 'docker start -ai weechat'
4;chawley@overlook;exec ssh overlook-ts
5;chawley@shawshank;exec ssh shawshank-ts
6;root@derry;exec ssh derry-ts
"

list_active_sessions() {
    echo "----------------------------------"
    echo "Active Tmux Sessions"
    echo "----------------------------------"
    if tmux has-session 2>/dev/null; then
        tmux list-sessions
    else
        echo "No active tmux sessions."
    fi
}

# Resolve target session (argument or fuzzy picker via fzf if available)
session="${1:-}"

if [[ -z "${session}" ]]; then
    if command -v fzf &>/dev/null; then
        session=$(printf '\%s\n' "${!SESSIONS[@]}" | fzf --prompt="Select Tmux Session > " --height=10 --reverse || true)
    fi
fi

if [[ -z "${session}" ]]; then
    echo "Usage: $(basename "$0") <session_name>"
    echo ""
    list_active_sessions
    exit 1
fi

if [[ -z "${SESSIONS[$session]:-}" ]]; then
    echo "Error: Unknown session layout '${session}'" >&2
    echo ""
    list_active_sessions
    exit 1
fi

# Attach if session exists; otherwise construct and attach
if tmux has-session -t "=${session}" 2>/dev/null; then
    echo "Attaching to existing session: ${session}"
    exec tmux -f "${TMUX_CONF}" attach-session -t "=${session}"
fi

echo "Building session: ${session}"

# Process layout line by line using semicolon delimiter
first_window=true
while IFS=';' read -r idx name cmd; do
    [[ -z "${idx}" ]] && continue

    if [[ "${first_window}" == true ]]; then
        tmux -f "${TMUX_CONF}" new-session -d -s "${session}" -n "${name}"
        if [[ -n "${cmd}" ]]; then
            tmux send-keys -t "=${session}:1" "${cmd}" C-m
        fi
        first_window=false
    else
        if [[ -n "${cmd}" ]]; then
            tmux -f "${TMUX_CONF}" new-window -t "=${session}:${idx}" -n "${name}" "${cmd}"
        else
            tmux -f "${TMUX_CONF}" new-window -t "=${session}:${idx}" -n "${name}"
        fi
    fi
done <<< "${SESSIONS[$session]}"

exec tmux -f "${TMUX_CONF}" attach-session -t "=${session}"