#!/bin/bash

# Internal Initialization

source "${DIP_FUNCTIONS}"

if [[ -r "${DIP_BASE_DIR}/conf.d/${DIP_AGENT_NAME}.conf" ]]; then
    source "${DIP_BASE_DIR}/conf.d/${DIP_AGENT_NAME}.conf"
fi

if [[ -r "${DIP_BASE_DIR}/conf.d/${DIP_AGENT_EXEC}.conf" ]]; then
    source "${DIP_BASE_DIR}/conf.d/${DIP_AGENT_EXEC}.conf"
fi

if [[ -z "$agent_update_dns_linode_v4_token" ]]; then
    logerr "ERROR: Need 'agent_update_dns_linode_v4_token' to be defined to your Linode API Access Token"
    exit 99
fi

if [[ -z "$DIP_CUR_IP" ]] || [[ -z "$DIP_OLD_IP" ]] || [[ -z "$DIP_RECORD" ]] || [[ -z "$DIP_DOMAIN" ]]; then
    logerr "ERROR: Agent expects currentip, existingip, record and domain."
    exit 98
else
    DIP_RECORD="${DIP_RECORD%%."$DIP_DOMAIN"}"
fi

# Get Domain ID

_update_dns_linode_v4_get_domain_id() {
    local domain=$1
    local domain_id
    local response
    local page
    local total_pages
    local i=2
    local p=1

    while read -r response
    do
        if [[ -n "$(echo "$response" | jq 'select(.errors != null)')" ]]
        then
            return 1
        fi

        page=$(echo "$response" | jq ".page")
        total_pages=$(echo "$response" | jq ".pages")

        # FIXME
        domain_id="$(sed -e 's/^"//' -e 's/"$//' <<<"$(echo "$response" | jq --arg domain "$domain" '.data[] | select(.domain==$domain).id')")"

        if [[ -n "$domain_id" ]]
        then
            DIP_DOMAIN_ID=$domain_id
            return 0
        fi

        if [[ $page -ge $total_pages ]]
        then
            return 1
        fi
    done <<< "$(curl --silent -X GET -H "Content-Type: application/json" -H "Authorization: Bearer $agent_update_dns_linode_v4_token" "https://api.linode.com/v4/domains/")"
    return 1
}

# Get Record ID

_update_dns_linode_v4_get_record_id() {
    local domain=$1
    local dtype=$2
    local subdomain=$3
    local response
    local record_id

    response=$(curl \
        --silent \
        -X GET \
        -H "Content-Type: application/json" \
        -H "Authorization: Bearer $agent_update_dns_linode_v4_token" \
        "https://api.linode.com/v4/domains/$domain/records")

    record_id="$(echo "$response" | jq --arg subdomain "$subdomain" --arg dtype "$dtype" '.data[] | select(.name==$subdomain and .type==$dtype).id')"

    if [[ -z "$record_id" ]]
    then
        return 1
    else
        DIP_RECORD_ID=$record_id
        return 0
    fi
}

if _update_dns_linode_v4_get_domain_id "$DIP_DOMAIN"; then
    if valid_ipv4 "$DIP_CUR_IP"; then
        log "Updating Linode DNS IPv4 Record: ${DIP_RECORD}.${DIP_DOMAIN} to ${DIP_CUR_IP}"

        if _update_dns_linode_v4_get_record_id "${DIP_DOMAIN_ID}" "A" "${DIP_RECORD}"
        then
            curl --silent \
                -X PUT \
                -H "Content-Type: application/json" \
                -H "Authorization: Bearer $agent_update_dns_linode_v4_token" \
                -d '{"target":"'$DIP_CUR_IP'"}' \
                "https://api.linode.com/v4/domains/${DIP_DOMAIN_ID}/records/${DIP_RECORD_ID}" > /dev/null;
        else
            logerr "WARN: No A record exists for $DIP_RECORD"
        fi
    fi

    if valid_ipv6 "$DIP_CUR_IP"; then
        log "Updating Linux DNS IPv6 Record: ${DIP_RECORD}.${DIP_DOMAIN} to ${DIP_CUR_IP}"

        if _update_dns_linode_v4_get_record_id "${DIP_DOMAIN_ID}" "AAAA" "${DIP_RECORD}"
        then
            curl --silent \
                -X PUT \
                -H "Content-Type: application/json" \
                -H "Authorization: Bearer $agent_update_dns_linode_v4_token" \
                -d '{"target":"'$DIP_CUR_IP'"}' \
                "https://api.linode.com/v4/domains/${DIP_DOMAIN_ID}/records/${DIP_RECORD_ID}" > /dev/null;
        else
            logerr "WARN: No AAAA record exists for $DIP_RECORD"
        fi
    fi
    unset DIP_DOMAIN_ID
    unset DIP_RECORD_ID
else
    logerr "ERROR: Cannot find domain in Linode DNS API"
    exit 99
fi