package elb

import (
	"dagger.io/aws"
)

// Returns a non-taken rule priority (randomized)
#RandomRulePriority: {
	// AWS Config
	config: aws.#Config

	// ListenerArn
	listenerArn: string @dagger(input)

	// Optional vhost for reusing priorities
	vhost?: string @dagger(input)

	// exported priority
	priority: out @dagger(output)

	out: {
		string

		#up: [
			op.#Load & {
				from: aws.#CLI & {
					"config": config
				}
			},

			op.#Exec & {
				args: [
					"/bin/bash",
					"--noprofile",
					"--norc",
					"-eo",
					"pipefail",
					#"""
						if [ -s "$VHOST" ]; then
    				# We passed a vhost as input, try to recycle priority from previously allocated vhost
    				priority=$(aws elbv2 describe-rules \
    					--listener-arn "$LISTENER_ARN" | \
    					jq -r --arg vhost "$VHOST" '.Rules[] | select(.Conditions[].HostHeaderConfig.Values[] == $VHOST) | .Priority')

    				if [ -n "${priority}" ]; then
    					echo -n "${priority}" > /priority
    					exit 0
    				fi
    			fi

    			# Grab a priority random from 1-50k and check if available, retry 10 times if none available
    			priority=0
    			for i in {1..10}
    			do
    				p=$(shuf -i 1-50000 -n 1)
    				# Find the next priority available that we can allocate
    				aws elbv2 describe-rules \
    					--listener-arn "$LISTENER_ARN" \
    					| jq -e "select(.Rules[].Priority == \"${p}\") | true" && continue
    				priority="${p}"
    				break
    			done
    			if [ "${priority}" -lt 1 ]; then
    				echo "Error: cannot determine a Rule priority"
    				exit 1
    			fi
    			echo -n "${priority}" > /priority
						"""#,
				]
				env: {
					LISTENER_ARN: listenerArn
					VHOST:        vhost
				}
			},

			op.#Export & {
				source: "/db_created"
				format: "string"
			},
		]
	}
}