#!/usr/bin/env bash
# Copyright (C) 2023  Umorpha Systems
# SPDX-License-Identifier: AGPL-3.0-or-later

set -euE -o pipefail

usage() {
	cat <<EOF
Usage: ${0##*/} --name=HOSTNAME --plan=PLAN_ID --region=REGION_ID
   or: ${0##*/} --help
Create/wipe a Vultr instance and install an image onto it.

For selecting the appropriate plan ID, determine which type you want
from the following table, then list the plans of that type with
\`vultr-cli plans list --type=TYPE\`

    | type  | WebUI label                                 | ID format                                   |
    |-------+---------------------------------------------+---------------------------------------------|
    | vc2   | Cloud Compute : Regular Performance         | vc2-${nproc}c-${ram}gb[-sc1]                |
    | vhf   | Cloud Compute : High Frequency              | vhf-${nproc}c-${ram}gb[-sc1]                |
    | vhp   | Cloud Compute : High Performance            | vhp-${nproc}c-${ram}gb-{amd,intel}[-sc1]    |
    | voc-g | Optimized Cloud Compute : General Purpose   | voc-g-${nproc}c-${ram}gb-${disk}s-amd[-sc1] |
    | voc-c | Optimized Cloud Compute : CPU Optimized     | voc-c-${nproc}c-${ram}gb-${disk}s-amd[-sc1] |
    | voc-m | Optimized Cloud Compute : Memory Optimized  | voc-m-${nproc}c-${ram}gb-${disk}s-amd[-sc1] |
    | voc-s | Optimized Cloud Compute : Storage Optimized | voc-s-${nproc}c-${ram}gb-${disk}s-amd[-sc1] |
    | vcg   | Cloud GPU                                   | vcg-${gpu}-{nproc}c-${ram}g-${vram}vram     |

    (The "-sc1" prefix for the "sao" region (São Paulo, Brazil), which have
    separate plan types because it's more expensive there.)

For selecting the appropriate region ID, here lis a list of the
regions in the US:

    | ID  | Location       | HDD | NVMe |
    |-----+----------------+-----+------|
    | atl | Atlanta        | yes |      |
    | dfw | Dallas         | yes |      |
    | ewr | New Jersey     | yes | yes  |
    | hnl | Honolulu       | yes |      |
    | lax | Los Angeles    | yes | yes  |
    | mia | Miami          | yes |      |
    | ord | Chicago        | yes |      |
    | sea | Seattle        | yes |      |
    | sjc | Silicon Valley | yes |      |
EOF
}				

run() {
	local arg_name arg_plan arg_region
	arg_name=$1
	arg_plan=$2
	arg_region=$3

	export VULTR_API_KEY=$(cat secrets/vultr-api-key.txt)

	# Upload ISO
	printf >&2 ':: Uploading bootstrap ISO to Vultr S3...\n'
	local iso_file iso_label iso_url
	iso_file="images/${arg_name%%.*}.bootstrap.iso"
	iso_label=$(xorriso -indev "$iso_file" |& sed -En "s/^Volume id *: *'(.*)'$/\1/p")
	iso_url=$(bin/vultr-upload "$iso_file" "s3://umorpha-images/${iso_label}.iso")

	# Set ISO as an ISO
	printf >&2 ':: Converting from Vultr S3 to Vultr ISO...\n'
	local iso_id
	iso_id=$(bin/vultr-iso-id "$iso_url")

	# Set up instance

	local instance_id
	instance_id=$(bin/vultr-api "instances?label=${arg_name}" | jq -r '.instances[]|.id')

	local user_data
	user_data="#!/bin/bash
vultr-api() {
	curl \\
		--no-progress-meter \\
		--fail-with-body \\
		-H 'Authorization: Bearer ${VULTR_API_KEY}' \\
		-H 'Content-Type: application/json' \\
		\"https://api.vultr.com/v2/\$@\"
}
set -ex
instance_id=\$(curl --fail-with-body --no-progress-meter http://169.254.169.254/v1/instance-v2-id)
vultr-api instances/\${instance_id} -XPATCH --data '{\"user_data\":\"\"}'
vultr-api instances/\${instance_id}/iso/detach -XPOST
"

	if [[ -z "$instance_id" ]]; then
		printf >&2 ':: Creating instance...\n'
		vultr-cli instance create \
			  --host="$arg_name" \
			  --label="$arg_name" \
			  \
			  --plan="$arg_plan" \
			  --region="$arg_region" \
			  --ipv6=true \
			  --auto-backup=true \
			  \
			  --iso="$iso_id" \
			  \
			  --userdata="$user_data"
	else
		printf >&2 ':: Updating instance %s...\n' "$instance_id"
		# Determine what we need to patch.
		instance_data="$(bin/vultr-api instances/$instance_id)"
		declare -A patch
		patch[user_data]="$(base64 --wrap=0 <<<"$user_data")"
		if [[ "$(jq -r .instance.region <<<"$instance_data")" != "$arg_region" ]]; then
			patch[region]="$arg_region"
		fi
		if [[ "$(jq -r .instance.plan <<<"$instance_data")" != "$arg_plan" ]]; then
			patch[plan]="$arg_plan"
		fi

		# Format that patch as JSON.
		data='{'
		for k in "${!patch[@]}"; do
			data+="\"$k\":\"${patch[$k]}\","
		done
		data="${data%,}}"

		# Apply.

		printf >&2 ' -> Halting instance...\n'
		bin/vultr-api instances/$instance_id/halt -XPOST

		printf >&2 ' -> Updating instance...\n'
		bin/vultr-api instances/$instance_id -XPATCH --data "$data" | jq

		printf >&2 ' -> Attaching ISO...\n'
		resp=$(bin/vultr-api instances/$instance_id/iso/attach -XPOST --data "{\"iso_id\":\"${iso_id}\"}")
		resp_state=$(jq -r .iso_status.state <<<"$resp")
		resp_id=$(jq -r .iso_status.iso_id <<<"$resp")
		while ! [[ "$resp_state" == isomounted && "$resp_id" == "$iso_id" ]]; do
			printf >&2 '    instance iso: state=%q id=%q\n' "$resp_state" "$resp_id"
			sleep 1
			resp=$(bin/vultr-api instances/$instance_id/iso)
			resp_state=$(jq -r .iso_status.state <<<"$resp")
			resp_id=$(jq -r .iso_status.iso_id <<<"$resp")
		done
		printf >&2 '    instance iso: state=%q id=%q\n' "$resp_state" "$resp_id"

		printf >&2 ' -> Starting instance...\n'
		bin/vultr-api instances/$instance_id/start -XPOST
	fi
}

main() {
	local arg_name=
	local arg_plan=
	local arg_region=
	local arg_mode=run

	local args
	if ! args="$(getopt -n "${0##*/}" -o '' -l 'help,name:,plan:,region:' -- "$@")"; then
		arg_mode=error
	else
		eval "set -- $args"
		while true; do
			case "$1" in
				--help) shift; arg_mode=help;;
				--name) shift; arg_name=$1; shift;;
				--plan) shift; arg_plan=$1; shift;;
				--region) shift; arg_region=$1; shift;;
				--) shift; break;;
			esac
		done
		if [[ $@ -gt 0 ]]; then
			printf >&2 '%s: error: unexpected positional arguments: %s' "${*@Q}"
			arg_mode=error
		fi
		if [[ -z "$arg_name" ]]; then
			printf >&2 '%s: error: --name=HOSTNAME is required\n' "${0##*/}"
			arg_mode=error
		fi
		if [[ -z "$arg_plan" ]]; then
			printf >&2 '%s: error: --plan=PLAN_ID is required\n' "${0##*/}"
			arg_mode=error
		fi
		if [[ -z "$arg_region" ]]; then
			printf >&2 '%s: error: --region=REGION_ID is required\n' "${0##*/}"
			arg_mode=error
		fi
		case "$arg_mode" in
			error) printf >&2 "Try '%q --help' for more information\n" "${0##*/}"; exit 2;;
			help)  show_help;;
			run)   run "$arg_name" "$arg_plan" "$arg_region";;
		esac
	fi
}

main "$@"