#!/usr/bin/env bash
# Install or update the Sessions server on this computer:
#   curl -fsSL https://sessions.olibuijr.com/install.sh | bash
#
# What it does, all inside your home directory and without sudo:
#   ~/.local/lib/agent-sessions/        the server and the `ses` command (Python, standard library only)
#   ~/.local/bin/ses                    session manager: `ses`, `ses new claude`, `ses pair`
#   ~/.config/agent-sessions/token      random access token, created on the first run, never sent anywhere
#   ~/.config/systemd/user/agent-sessions.service   starts the server (port 8170) at login
# Options (environment): SESSIONS_WRAP=1 also makes plain `claude`, `codex` and `pi` in new bash
# shells start inside tmux so they show up in the app; SESSIONS_BASE=URL installs from another mirror.
# Uninstall: systemctl --user disable --now agent-sessions; rm -rf ~/.local/lib/agent-sessions
#   ~/.local/bin/ses ~/.config/agent-sessions ~/.config/systemd/user/agent-sessions.service
set -euo pipefail

main() {
    local base=${SESSIONS_BASE:-https://sessions.olibuijr.com}
    local lib=$HOME/.local/lib/agent-sessions conf=$HOME/.config/agent-sessions units=$HOME/.config/systemd/user

    [[ $(uname -s) == Linux ]] || die "this installer supports Linux (systemd). See $base/setup"
    need python3 "install Python 3.9 or newer"
    need tmux "install tmux (apt install tmux, dnf install tmux, pacman -S tmux)"
    need curl "install curl"
    need tar "install tar"
    python3 -c 'import sys; sys.exit(sys.version_info < (3, 9))' || die "Python 3.9 or newer is needed"
    systemctl --user show-environment >/dev/null 2>&1 || die "no systemd user session (systemctl --user). See $base/setup to run the server by hand"

    local tmp
    tmp=$(mktemp -d)
    trap "rm -rf '$tmp'" EXIT
    echo "Downloading the Sessions server…"
    curl -fsSL "$base/agent-sessions-server.tar.gz" -o "$tmp/server.tar.gz"
    tar -xzf "$tmp/server.tar.gz" -C "$tmp"
    [[ -f $tmp/server/sessions_server.py && -f $tmp/deploy/agent-sessions.service ]] || die "the download is incomplete"
    python3 -m py_compile "$tmp"/server/*.py || die "the download is damaged"

    mkdir -p "$lib" "$conf" "$units" "$HOME/.local/bin"
    install -m 644 "$tmp"/server/*.py "$lib/"
    chmod 755 "$lib/ses.py"
    ln -sf "$lib/ses.py" "$HOME/.local/bin/ses"
    install -m 644 "$tmp/deploy/agent-sessions.service" "$units/"
    install -m 644 "$tmp/deploy/shell.bash" "$conf/"
    if [[ ! -s $conf/token ]]; then
        (umask 077; python3 -c 'import secrets; print(secrets.token_urlsafe(32))' > "$conf/token")
    fi
    chmod 600 "$conf/token"

    if [[ ${SESSIONS_WRAP:-} == 1 ]]; then
        local line='[ -f ~/.config/agent-sessions/shell.bash ] && . ~/.config/agent-sessions/shell.bash'
        grep -qxF "$line" "$HOME/.bashrc" 2>/dev/null || printf '\n# Sessions: claude, codex and pi start inside tmux\n%s\n' "$line" >> "$HOME/.bashrc"
    fi

    systemctl --user daemon-reload
    systemctl --user enable agent-sessions.service >/dev/null 2>&1
    systemctl --user restart agent-sessions.service
    # Keep the server running after you log out (best effort; needs no sudo on most systems).
    loginctl enable-linger "$USER" >/dev/null 2>&1 || true

    local i ok=
    for i in $(seq 30); do
        if curl -fsS -m 2 -H "Authorization: Bearer $(cat "$conf/token")" http://127.0.0.1:8170/api/health >/dev/null 2>&1; then
            ok=1
            break
        fi
        sleep 0.5
    done
    [[ -n $ok ]] || die "the server did not start. Look at: journalctl --user -u agent-sessions -n 30"

    echo
    echo "Sessions server $(cat "$tmp/VERSION" 2>/dev/null) is running on port 8170."
    case ":$PATH:" in *":$HOME/.local/bin:"*) ;; *) echo "Note: add ~/.local/bin to your PATH to use the ses command." ;; esac
    if command -v ufw >/dev/null 2>&1 || command -v firewall-cmd >/dev/null 2>&1; then
        echo "If a firewall is on, allow TCP port 8170 from your phone's network."
    fi
    command -v qrencode >/dev/null 2>&1 || echo "Tip: install qrencode to get a QR code from ses pair."
    echo
    echo "Next: pair your iPhone with"
    echo "    ~/.local/bin/ses pair"
    echo "Start an agent the app can see with: ses new claude   (or codex, pi, shell)"
}

need() { command -v "$1" >/dev/null 2>&1 || die "$1 is missing: $2"; }
die() { echo "install: $*" >&2; exit 1; }

# The whole script is read before anything runs, so a cut-off download does nothing.
main "$@"