#!/usr/bin/env sh
set -eu

role="${DOSH_ROLE:-both}"
repo="${DOSH_REPO:-}"
server="${DOSH_SERVER:-}"
dosh_host="${DOSH_HOST:-${DOSH_DOSH_HOST:-}}"
port="${DOSH_PORT:-50000}"
prefix="${PREFIX:-$HOME/.local}"
from_current=0
start_server=1
force_config=0
update_cache="${DOSH_UPDATE_CACHE:-$HOME/.cache/dosh/source}"

usage() {
  cat <<'EOF'
Usage:
  install.sh [server|client|both] [options]

Options:
  --repo URL        Git repository to clone when not run from a checkout
  --server HOST     Default SSH target for client config, for example user@host
  --dosh-host HOST  UDP host for Dosh packets when different from SSH target
  --port PORT       Dosh UDP port; default 50000
  --prefix DIR      Install prefix; default ~/.local
  --update-cache DIR
                  Persistent source checkout for incremental updates
  --no-start        Install server but do not start it
  --force-config    Rewrite existing ~/.config/dosh/*.toml files

Environment alternatives:
  DOSH_REPO, DOSH_ROLE, DOSH_SERVER, DOSH_HOST, DOSH_PORT, PREFIX,
  DOSH_UPDATE_CACHE
EOF
}

while [ "$#" -gt 0 ]; do
  case "$1" in
    server|client|both)
      role="$1"
      ;;
    --repo)
      repo="$2"
      shift
      ;;
    --server)
      server="$2"
      shift
      ;;
    --dosh-host)
      dosh_host="$2"
      shift
      ;;
    --port)
      port="$2"
      shift
      ;;
    --prefix)
      prefix="$2"
      shift
      ;;
    --update-cache)
      update_cache="$2"
      shift
      ;;
    --from-current)
      from_current=1
      ;;
    --no-start)
      start_server=0
      ;;
    --force-config)
      force_config=1
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      echo "unknown argument: $1" >&2
      usage >&2
      exit 2
      ;;
  esac
  shift
done

case "$role" in
  server|client|both) ;;
  *)
    echo "role must be server, client, or both" >&2
    exit 2
    ;;
esac

need() {
  if ! command -v "$1" >/dev/null 2>&1; then
    echo "missing required command: $1" >&2
    exit 1
  fi
}

ensure_cargo() {
  if command -v cargo >/dev/null 2>&1; then
    return
  fi
  need curl
  echo "cargo not found; installing Rust toolchain with rustup" >&2
  curl --proto '=https' --tlsv1.2 -fsSL https://sh.rustup.rs | sh -s -- -y
  # shellcheck disable=SC1091
  . "$HOME/.cargo/env"
}

ensure_cargo

cleanup() {
  if [ -n "${tmpdir:-}" ]; then
    rm -rf "$tmpdir"
  fi
}
trap cleanup EXIT INT TERM

if [ "$from_current" -eq 1 ] || [ -f Cargo.toml ]; then
  src_dir="$(pwd)"
else
  if [ -z "$repo" ]; then
    echo "DOSH_REPO or --repo is required when running the installer from curl" >&2
    exit 2
  fi
  case "$update_cache" in
    ""|"/"|"$HOME"|"$HOME/"|"$HOME/.cache")
      echo "refusing unsafe update cache path: $update_cache" >&2
      exit 2
      ;;
  esac
  need git
  mkdir -p "$(dirname "$update_cache")"
  if [ -d "$update_cache/.git" ]; then
    git -C "$update_cache" remote set-url origin "$repo"
    git -C "$update_cache" fetch --depth 1 origin main
    git -C "$update_cache" checkout -q -B main FETCH_HEAD
  else
    rm -rf "$update_cache"
    git clone --depth 1 --branch main "$repo" "$update_cache" >/dev/null
  fi
  src_dir="$update_cache"
fi

cd "$src_dir"
if [ "$role" = "client" ]; then
  cargo build --release --bin dosh-client
else
  cargo build --release
fi

bindir="$prefix/bin"
config_dir="$HOME/.config/dosh"
data_dir="$HOME/.local/share/dosh"
systemd_user_dir="$HOME/.config/systemd/user"

mkdir -p "$bindir" "$config_dir" "$data_dir"

install -m 0755 target/release/dosh-client "$bindir/dosh-client"
ln -sf dosh-client "$bindir/dosh"
if [ "$role" = "server" ] || [ "$role" = "both" ]; then
  install -m 0755 target/release/dosh-server "$bindir/dosh-server"
  install -m 0755 target/release/dosh-auth "$bindir/dosh-auth"
fi
if [ -f target/release/dosh-bench ]; then
  install -m 0755 target/release/dosh-bench "$bindir/dosh-bench"
fi

if [ "$role" = "server" ] || [ "$role" = "both" ]; then
  server_config="$config_dir/server.toml"
  if [ "$force_config" -eq 1 ] || [ ! -f "$server_config" ]; then
    login_shell="$(
      if command -v getent >/dev/null 2>&1; then
        getent passwd "$(id -un)" | awk -F: '{print $7}'
      fi
    )"
    login_shell="${login_shell:-${SHELL:-/bin/sh}}"
    cat >"$server_config" <<EOF
port = $port
bind = "0.0.0.0"
scrollback = 5000
auth_ttl_secs = 30
attach_ticket_ttl_secs = 3600
allow_attach_tickets = true
client_timeout_secs = 30
retransmit_window = 256
default_input_mode = "read-write"
prewarm_sessions = ["default"]
create_on_attach = true
shell = "$login_shell"
sessions_dir = "~/.local/share/dosh/sessions"
secret_path = "~/.config/dosh/secret"
EOF
  fi

  if command -v systemctl >/dev/null 2>&1; then
    mkdir -p "$systemd_user_dir"
    sed "s#ExecStart=%h/.local/bin/dosh-server serve#ExecStart=$bindir/dosh-server serve#" \
      packaging/systemd/dosh-server.service >"$systemd_user_dir/dosh-server.service"
    if [ "$start_server" -eq 1 ] && systemctl --user daemon-reload >/dev/null 2>&1; then
      systemctl --user enable --now dosh-server.service
    fi
  elif [ "$start_server" -eq 1 ]; then
    nohup "$bindir/dosh-server" serve >"$data_dir/dosh-server.log" 2>&1 &
  fi
fi

if [ "$role" = "client" ] || [ "$role" = "both" ]; then
  case ":$PATH:" in
    *":$bindir:"*) ;;
    *)
      if [ "$(uname -s)" = "Darwin" ] || [ "$(basename "${SHELL:-}")" = "zsh" ]; then
        shell_rc="$HOME/.zshrc"
      else
        shell_rc="$HOME/.profile"
      fi
      mkdir -p "$(dirname "$shell_rc")"
      if [ ! -f "$shell_rc" ] || ! grep -F "$bindir" "$shell_rc" >/dev/null 2>&1; then
        printf '\nexport PATH="%s:$PATH"\n' "$bindir" >>"$shell_rc"
      fi
      ;;
  esac

  client_config="$config_dir/client.toml"
  if [ "$force_config" -eq 1 ] || [ ! -f "$client_config" ]; then
    default_server="${server:-user@example.com}"
    update_repo="${repo:-https://git.palav.dev/Palav/dosh.git}"
    if [ -n "$dosh_host" ]; then
      dosh_host_line="dosh_host = \"$dosh_host\""
    else
      dosh_host_line="# dosh_host = \"public.example.com\""
    fi
    cat >"$client_config" <<EOF
update_repo = "$update_repo"
update_port = $port
server = "$default_server"
$dosh_host_line
ssh_auth_command = "~/.local/bin/dosh-auth"
# ssh_port = 22
dosh_port = $port
default_session = "new"
reconnect_timeout_secs = 5
view_only = false
cache_attach_tickets = true
credential_cache = "~/.local/share/dosh/credentials"
EOF
  fi
fi

cat <<EOF
Installed Dosh to $bindir
Configured UDP port $port
EOF

if [ "$role" = "client" ] || [ "$role" = "both" ]; then
  cat <<EOF

Client command:
  $bindir/dosh ${server:-user@host}
EOF
fi

if [ "$role" = "server" ] || [ "$role" = "both" ]; then
  cat <<EOF

Server command:
  $bindir/dosh-server serve
EOF
fi