#!/bin/sh

# Validate environment
if ! command -v msgbus > /dev/null; then
    printf "missing msgbus command. Use:  go install git.mills.io/prologic/msgbus/cmd/msgbus@latest"
    exit 1
fi

if ! command -v salty > /dev/null; then
    printf "missing salty command. Use:  go install go.mills.io/salty/cmd/salty@latest"
    exit 1
fi

if ! command -v salty-keygen > /dev/null; then
    printf "missing salty-keygen command. Use:  go install go.mills.io/salty/cmd/salty-keygen@latest"
    exit 1
fi

if [ -z "$SALTY_IDENTITY" ]; then
    export SALTY_IDENTITY="$HOME/.config/salty/$USER.key"
fi

get_user () {
    user=$(grep user: "$SALTY_IDENTITY" | awk '{print $3}')
    if [ -z "$user" ]; then
        user="$USER"
    fi
    echo "$user"
}

stream () {
    if [ -z "$SALTY_IDENTITY" ]; then
        echo "SALTY_IDENTITY not set"
        exit 2
    fi

    jq -r '.payload' | base64 -d | salty -i "$SALTY_IDENTITY" -d
}

lookup () {
    if [ $# -lt 1 ]; then
    printf "Usage: %s nick@domain\n" "$(basename "$0")"
    exit 1
    fi

    user="$1"
    nick="$(echo "$user" | awk -F@ '{ print $1 }')"
    domain="$(echo "$user" | awk -F@ '{ print $2 }')"

    curl -qsSL "https://$domain/.well-known/salty/${nick}.json"
}

readmsgs () {
    topic="$1"

    if [ -z "$topic" ]; then
        topic=$(get_user)
    fi

    export SALTY_IDENTITY="$HOME/.config/salty/$topic.key"
    if [ ! -f "$SALTY_IDENTITY" ]; then
        echo "identity file missing for user $topic" >&2
        exit 1
    fi

    msgbus sub "$topic" "$0"
}

sendmsg () {
    if [ $# -lt 2 ]; then
        printf "Usage: %s nick@domain.tld <message>\n" "$(basename "$0")"
        exit 0
    fi

    if [ -z "$SALTY_IDENTITY" ]; then
        echo "SALTY_IDENTITY not set"
        exit 2
    fi

    user="$1"
    message="$2"

    salty_json="$(mktemp /tmp/salty.XXXXXX)"

    lookup "$user" > "$salty_json"

    endpoint="$(jq -r '.endpoint' < "$salty_json")"
    topic="$(jq -r '.topic' < "$salty_json")"
    key="$(jq -r '.key' < "$salty_json")"

    rm "$salty_json"

    message="[$(date +%FT%TZ)] <$(get_user)> $message"

    echo "$message" \
        | salty -i "$SALTY_IDENTITY" -r "$key" \
        | msgbus -u "$endpoint" pub "$topic"
}

make_user () {
    mkdir -p "$HOME/.config/salty"

    if [ $# -lt 1 ]; then
        user=$USER
    else
        user=$1
    fi

    identity_file="$HOME/.config/salty/$user.key"

    if [ -f "$identity_file" ]; then
        printf "user key exists!"
        exit 1
    fi

    # Check for msgbus env.. probably can make it fallback to looking for a config file?
    if [ -z "$MSGBUS_URI" ]; then
        printf "missing MSGBUS_URI in environment"
        exit 1
    fi


    salty-keygen -o "$identity_file"
    echo "# user: $user" >> "$identity_file"

    pubkey=$(grep key: "$identity_file" | awk '{print $4}')

    cat <<- EOF
Create this file in your webserver well-known folder. https://hostname.tld/.well-known/salty/$user.json

{
  "endpoint": "$MSGBUS_URI",
  "topic": "$user",
  "key": "$pubkey"
}

EOF
}

# check if streaming
if [ ! -t 1 ]; then
    stream
    exit 0
fi

# Show Help
if [ $# -lt 1 ]; then
    printf "Commands: send read lookup"
    exit 0
fi


CMD=$1
shift

case $CMD in
    send)
        sendmsg "$@"
    ;;
    read)
        readmsgs "$@"
    ;;
    lookup)
        lookup "$@"
    ;;
    make-user)
        make_user "$@"
    ;;
esac