#!/usr/bin/env bash
# campus-login: detect a captive portal and open it in your browser,
# reporting every step through the notification daemon.
#
# Usage: campus-login [-n|--no-wait] [-h|--help]
#   -n, --no-wait   don't wait around to confirm you're online afterwards
#
# Env overrides:
#   PROBE_URL     plain-HTTP URL that returns 204 when there is no portal
#   WAIT_TIMEOUT  seconds to wait for connectivity after opening the portal

set -u

PROBE_URL=${PROBE_URL:-http://connectivitycheck.gstatic.com/generate_204}
WAIT_TIMEOUT=${WAIT_TIMEOUT:-180}
WAIT=1

case "${1:-}" in
    -n|--no-wait) WAIT=0 ;;
    -h|--help)    sed -n '2,12p' "$0" | sed 's/^# \{0,1\}//'; exit 0 ;;
esac

# --- notifications ----------------------------------------------------------
# Every notification shares one "synchronous" tag so they replace each other
# instead of stacking (works with dunst, mako, swaync).
notify() { # notify <urgency> <icon> <title> <body>
    local urgency=$1 icon=$2 title=$3 body=$4
    echo "$title: $body"
    command -v notify-send >/dev/null 2>&1 || return 0
    notify-send -a campus-login -u "$urgency" -i "$icon" \
        -h string:x-canonical-private-synchronous:campus-login \
        -h string:x-dunst-stack-tag:campus-login \
        "$title" "$body"
}

# --- probe ------------------------------------------------------------------
# Prints "<http_code> <redirect_url>". curl resolves relative redirects for us,
# so no more grepping/sed-ing the Location header.
probe() {
    curl -s -o /dev/null --max-time 5 \
        -w '%{http_code} %{redirect_url}' "$PROBE_URL" 2>/dev/null
}

read -r CODE URL < <(probe)
CODE=${CODE:-000}

case "$CODE" in
    000)
        notify critical network-error "No connection" \
            "Couldn't reach the network. Are you connected to the Wi-Fi?"
        exit 2
        ;;
    204)
        notify low network-wireless "Already online" \
            "No captive portal detected."
        exit 0
        ;;
esac

if [[ -n "${URL:-}" ]]; then
    notify normal network-wireless-acquiring "Captive portal detected" "$URL"
else
    # Some portals hijack the request and answer 200 without redirecting.
    # Opening a plain-HTTP page lets the portal intercept it in the browser.
    URL=$PROBE_URL
    notify normal network-wireless-acquiring "Captive portal likely" \
        "Got HTTP $CODE with no redirect. Opening a test page to trigger it."
fi

# --- pick a browser ---------------------------------------------------------
# $BROWSER is often unset when launched from a menu (aurora-run, rofi), so fall back.
launch=()
if [[ -n "${BROWSER:-}" ]]; then
    read -ra launch <<< "$BROWSER"
fi
if ! (( ${#launch[@]} )) || ! command -v "${launch[0]}" >/dev/null 2>&1; then
    launch=()
    for b in xdg-open firefox chromium google-chrome-stable brave; do
        if command -v "$b" >/dev/null 2>&1; then launch=("$b"); break; fi
    done
fi

if ! (( ${#launch[@]} )); then
    notify critical dialog-error "No browser found" \
        "Set \$BROWSER or install one. Portal URL: $URL"
    exit 3
fi

# Detach so the browser outlives this script (and the launcher).
setsid -f "${launch[@]}" "$URL" >/dev/null 2>&1
notify normal web-browser "Opened portal" "${launch[0]} -> $URL"

# --- wait for confirmation --------------------------------------------------
(( WAIT )) || exit 0

end=$((SECONDS + WAIT_TIMEOUT))
while (( SECONDS < end )); do
    sleep 3
    read -r CODE _ < <(probe)
    if [[ "${CODE:-000}" == 204 ]]; then
        notify normal network-wireless "Connected" "You're online."
        exit 0
    fi
done

notify normal network-wireless-offline "Still not online" \
    "No connectivity after ${WAIT_TIMEOUT}s. The login may not have completed."
exit 4