#!/usr/bin/env bash

topspeedUser="topspeed"
topspeedHome="/var/lib/topspeed"
topspeedInstallDir="${topspeedHome}/server"
topspeedRuntimeDir="${topspeedInstallDir}/topspeed"
topspeedServiceFile="/etc/systemd/system/topspeed.service"
topspeedServiceScript="${topspeedInstallDir}/topspeed-service.sh"
topspeedStopScript="${topspeedInstallDir}/topspeed-stop.sh"
topspeedBinaryPath="${topspeedRuntimeDir}/TopSpeed.Server"
topspeedSessionName="topspeed"
topspeedRepoApi="https://api.github.com/repos/diamondStar35/top_speed/releases"
topspeedAssetPattern='^TopSpeed\.Server-linux-arm64-Release-v-.*\.zip$'
topspeedServerPort="28630"
topspeedDiscoveryPort="28631"

package_installed() {
    local packageName="$1"
    pacman -Q "$packageName" &> /dev/null
}

ufw_installed() {
    pacman -Q ufw &> /dev/null
}

ensure_topspeed_dependencies() {
    local packagesToInstall=()
    local packageName=""

    for packageName in curl jq tmux unzip; do
        if ! package_installed "$packageName"; then
            packagesToInstall+=("$packageName")
        fi
    done

    if [[ "${#packagesToInstall[@]}" -gt 0 ]]; then
        if ! install_package "${packagesToInstall[@]}"; then
            msgbox "Failed to install the required Top Speed dependencies."
            return 1
        fi
    fi

    return 0
}

fetch_topspeed_asset() {
    local tempDir=""
    local metadataFile=""
    local assetName=""
    local assetUrl=""

    tempDir="$(mktemp -d)"
    metadataFile="${tempDir}/topspeed-release.json"

    if ! curl -fsSL -H "Accept: application/vnd.github+json" "$topspeedRepoApi" -o "$metadataFile"; then
        rm -rf "$tempDir"
        msgbox "Failed to fetch Top Speed release metadata from GitHub."
        return 1
    fi

    assetName="$(jq -r --arg assetPattern "$topspeedAssetPattern" '
        ([.[] | .assets[] | select(.name | test($assetPattern))] | .[0].name) // empty
    ' "$metadataFile")"
    assetUrl="$(jq -r --arg assetPattern "$topspeedAssetPattern" '
        ([.[] | .assets[] | select(.name | test($assetPattern))] | .[0].browser_download_url) // empty
    ' "$metadataFile")"

    if [[ -z "$assetName" || -z "$assetUrl" || "$assetName" == "null" || "$assetUrl" == "null" ]]; then
        rm -rf "$tempDir"
        msgbox "Unable to find the latest Top Speed arm64 server download in GitHub release metadata."
        return 1
    fi

    if ! curl -fL --retry 5 -o "${tempDir}/${assetName}" "$assetUrl"; then
        rm -rf "$tempDir"
        msgbox "Failed to download the Top Speed server archive."
        return 1
    fi

    printf '%s\n' "${tempDir}/${assetName}"
}

ensure_topspeed_user() {
    if id -u "$topspeedUser" &> /dev/null; then
        return 0
    fi

    # `sudoFlags` is initialized by the main launcher before sourcing this file.
    # shellcheck disable=SC2154
    if ! sudo "${sudoFlags[@]}" useradd \
        --system \
        --home-dir "$topspeedHome" \
        --create-home \
        --shell /usr/bin/nologin \
        "$topspeedUser"; then
        msgbox "Failed to create the topspeed service user."
        return 1
    fi

    return 0
}

stop_topspeed_service_if_present() {
    # `sudoFlags` is initialized by the main launcher before sourcing this file.
    # shellcheck disable=SC2154
    if sudo "${sudoFlags[@]}" systemctl cat topspeed.service &> /dev/null; then
        # shellcheck disable=SC2154
        sudo "${sudoFlags[@]}" systemctl stop topspeed.service &> /dev/null || true
    fi
}

install_topspeed_server() {
    local archivePath=""
    local archiveDir=""

    archivePath="$(fetch_topspeed_asset)" || return 1
    archiveDir="$(dirname "$archivePath")"

    stop_topspeed_service_if_present
    # `sudoFlags` is initialized by the main launcher before sourcing this file.
    # shellcheck disable=SC2154
    if ! sudo "${sudoFlags[@]}" install -d -o "$topspeedUser" -g "$topspeedUser" -m 755 "$topspeedRuntimeDir"; then
        rm -rf "$archiveDir"
        msgbox "Failed to create the Top Speed install directory."
        return 1
    fi

    # shellcheck disable=SC2154
    if ! sudo "${sudoFlags[@]}" unzip -o -d "$topspeedRuntimeDir" "$archivePath"; then
        rm -rf "$archiveDir"
        msgbox "Failed to extract the Top Speed server archive."
        return 1
    fi

    # shellcheck disable=SC2154
    if ! sudo "${sudoFlags[@]}" chown -R "${topspeedUser}:${topspeedUser}" "$topspeedHome"; then
        rm -rf "$archiveDir"
        msgbox "Failed to set ownership on the Top Speed files."
        return 1
    fi

    # shellcheck disable=SC2154
    if ! sudo "${sudoFlags[@]}" test -f "$topspeedBinaryPath"; then
        rm -rf "$archiveDir"
        msgbox "The Top Speed server archive did not contain ${topspeedBinaryPath}."
        return 1
    fi

    # shellcheck disable=SC2154
    if ! sudo "${sudoFlags[@]}" chmod 755 "$topspeedBinaryPath"; then
        rm -rf "$archiveDir"
        msgbox "Failed to make ${topspeedBinaryPath} executable."
        return 1
    fi

    rm -rf "$archiveDir"
    return 0
}

write_topspeed_runtime_scripts() {
    local tempServiceScript=""
    local tempStopScript=""

    tempServiceScript="$(mktemp)"
    tempStopScript="$(mktemp)"

cat > "$tempServiceScript" <<EOF
#!/usr/bin/env bash

sessionName="${topspeedSessionName}"
runtimeDir="${topspeedRuntimeDir}"
binaryPath="${topspeedBinaryPath}"

cd "\$runtimeDir" || exit 1
if tmux has-session -t "\$sessionName" &> /dev/null; then
    tmux kill-session -t "\$sessionName"
fi

if [[ ! -x "\$binaryPath" ]]; then
    exit 1
fi

tmux new-session -d -s "\$sessionName" /bin/bash -lc 'exec ./TopSpeed.Server' || exit 1

while tmux has-session -t "\$sessionName" &> /dev/null; do
    sleep 5
done

exit 1
EOF

    cat > "$tempStopScript" <<EOF
#!/usr/bin/env bash

sessionName="${topspeedSessionName}"
if tmux has-session -t "\$sessionName" &> /dev/null; then
    tmux send-keys -t "\$sessionName" C-c
    sleep 2
    if tmux has-session -t "\$sessionName" &> /dev/null; then
        tmux kill-session -t "\$sessionName"
    fi
fi
EOF

    # `sudoFlags` is initialized by the main launcher before sourcing this file.
    # shellcheck disable=SC2154
    if ! sudo "${sudoFlags[@]}" install -o "$topspeedUser" -g "$topspeedUser" -m 755 "$tempServiceScript" "$topspeedServiceScript"; then
        rm -f "$tempServiceScript" "$tempStopScript"
        msgbox "Failed to install the Top Speed runtime script."
        return 1
    fi

    # shellcheck disable=SC2154
    if ! sudo "${sudoFlags[@]}" install -o "$topspeedUser" -g "$topspeedUser" -m 755 "$tempStopScript" "$topspeedStopScript"; then
        rm -f "$tempServiceScript" "$tempStopScript"
        msgbox "Failed to install the Top Speed stop script."
        return 1
    fi

    rm -f "$tempServiceScript" "$tempStopScript"
    return 0
}

write_topspeed_service() {
    local tempServiceFile=""

    tempServiceFile="$(mktemp)"
    cat > "$tempServiceFile" <<EOF
[Unit]
Description=Top Speed Server
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
User=${topspeedUser}
Group=${topspeedUser}
WorkingDirectory=${topspeedRuntimeDir}
ExecStart=${topspeedServiceScript}
ExecStop=${topspeedStopScript}
Restart=on-failure
RestartSec=5
TimeoutStopSec=15

[Install]
WantedBy=multi-user.target
EOF

    # `sudoFlags` is initialized by the main launcher before sourcing this file.
    # shellcheck disable=SC2154
    if ! sudo "${sudoFlags[@]}" install -m 644 "$tempServiceFile" "$topspeedServiceFile"; then
        rm -f "$tempServiceFile"
        msgbox "Failed to write the Top Speed systemd service file."
        return 1
    fi

    rm -f "$tempServiceFile"
    # shellcheck disable=SC2154
    if ! sudo "${sudoFlags[@]}" systemctl daemon-reload; then
        msgbox "Failed to reload systemd after writing the Top Speed service."
        return 1
    fi

    return 0
}

configure_topspeed_firewall() {
    if ! ufw_installed; then
        return 0
    fi

    if [[ "$(yesno "ufw is installed. Open the default Top Speed ports ${topspeedServerPort} and ${topspeedDiscoveryPort} now?")" != "Yes" ]]; then
        return 0
    fi

    # `sudoFlags` is initialized by the main launcher before sourcing this file.
    # shellcheck disable=SC2154
    if ! sudo "${sudoFlags[@]}" ufw allow "${topspeedServerPort}/tcp"; then
        msgbox "Failed to allow the Top Speed server port ${topspeedServerPort}/tcp."
        return 1
    fi

    # shellcheck disable=SC2154
    if ! sudo "${sudoFlags[@]}" ufw allow "${topspeedServerPort}/udp"; then
        msgbox "Failed to allow the Top Speed server port ${topspeedServerPort}/udp."
        return 1
    fi

    # shellcheck disable=SC2154
    if ! sudo "${sudoFlags[@]}" ufw allow "${topspeedDiscoveryPort}/udp"; then
        msgbox "Failed to allow the Top Speed discovery port ${topspeedDiscoveryPort}/udp."
        return 1
    fi

    msgbox "The default Top Speed firewall rules were added."
    return 0
}

enable_topspeed_service() {
    # `sudoFlags` is initialized by the main launcher before sourcing this file.
    # shellcheck disable=SC2154
    if ! sudo "${sudoFlags[@]}" systemctl enable --now topspeed.service; then
        msgbox "Top Speed was installed, but the service failed to enable or start."
        return 1
    fi

    return 0
}

install_topspeed_flow() {
    ensure_topspeed_dependencies || return 1
    ensure_topspeed_user || return 1
    install_topspeed_server || return 1
    write_topspeed_runtime_scripts || return 1
    write_topspeed_service || return 1
    enable_topspeed_service || return 1
    configure_topspeed_firewall || return 1

    msgbox "Top Speed Server is installed. The service is enabled and started, and the console is available through the Top Speed Console menu entry."
    return 0
}

topspeed_session_running() {
    if ! id -u "$topspeedUser" &> /dev/null; then
        return 1
    fi

    # `sudoFlags` is initialized by the main launcher before sourcing this file.
    # shellcheck disable=SC2154
    sudo "${sudoFlags[@]}" -u "$topspeedUser" tmux has-session -t "$topspeedSessionName" &> /dev/null
}

attach_topspeed_console() {
    local attachStatus=0

    if ! topspeed_session_running; then
        msgbox "Top Speed is not running."
        return 1
    fi

    clear
    echo "Attaching to the Top Speed console."
    echo "To detach from the server and leave it running, press Ctrl+b followed by d."
    # `sudoFlags` is initialized by the main launcher before sourcing this file.
    # shellcheck disable=SC2154
    sudo "${sudoFlags[@]}" -u "$topspeedUser" tmux attach-session -t "$topspeedSessionName"
    attachStatus=$?
    reset
    return "$attachStatus"
}

case "${1:-install}" in
    install)
        install_topspeed_flow
        ;;
    console)
        attach_topspeed_console
        ;;
    *)
        msgbox "Unknown Top Speed action: ${1}"
        return 1
        ;;
esac