#!/usr/bin/env bash
set -euC

################################################################################
## Constants

readonly api_url=https://192.168.51.81:8006/api2/json

## FIXME: There seems to be a problem with file upload where the task is
## registered to `node051` no matter what node we are actually uploading to? For
## now, let us just use `node051` everywhere.
readonly node=node051

readonly tmpdir=/tmp/proxmox-provision-$RANDOM
mkdir $tmpdir

################################################################################
## Parse arguments

username=
password=
sockets=1
cores=1
memory=2048
vm_ids=

help () {
  cat <<EOF
Usage: $0 [OPTION...] [ID...]

Authentication options:
  --username STR    Username, with provider (eg. niols@pve)
  --password STR    Password

  If not provided via the command line, username and password will be looked for
  in a '.proxmox' file in the current working directory, the username on the
  first line, and the password on the second.

Other options:
  --sockets INT     Number of sockets (default: $sockets)
  --cores INT       Number of cores (default: $cores)
  --memory INT      Memory (default: $memory)

Others:
  -h|-?|--help      Show this help and exit
EOF
}

die () { printf '\033[31m'; printf "%s" "$@"; printf '\033[0m\n'; exit 2; }
die_with_help () { printf '\033[31m'; printf "%s" "$@"; printf '\033[0m\n'; help; exit 2; }

while [ $# -gt 0 ]; do
  argument=$1
  shift
  case $argument in
    --username) readonly username="$1"; shift ;;
    --password) readonly password="$1"; shift ;;

    --sockets) sockets=$1; shift ;;
    --cores) cores=$1; shift ;;
    --memory) memory=$1; shift ;;

    -h|-\?|--help) help; exit 0 ;;

    -*) die_with_help "Unknown argument: \`\%s\`." "$argument" ;;

    *) vm_ids="$vm_ids $argument" ;;
  esac
done

if [ -z "$username" ] || [ -z "$password" ]; then
  if [ -f .proxmox ]; then
    { read -r username; read -r password; } < .proxmox
  else
    die_with_help "Required: \`--username\` and \`--password\`.\n"
  fi
fi

readonly sockets
readonly cores
readonly memory

## FIXME: When we figure out how to use other nodes than node051.
# if [ -z "$node" ]; then
#   printf 'Picking random node...'
#   proxmox GET $api_url/nodes
#   node=$(from_response .data[].node | sort -R | head -n 1)
#   printf ' done. Picked `%s`.\n' "$node"
# fi
# readonly node

################################################################################
## Getting started

printf 'Authenticating...'
response=$(
    http \
        --verify no \
        POST $api_url/access/ticket \
        "username=$username" \
        "password=$password"
    )
readonly ticket
ticket=$(echo "$response" | jq -r .data.ticket)
readonly csrf_token
csrf_token=$(echo "$response" | jq -r .data.CSRFPreventionToken)
printf ' done.\n'

acquire_lock () {
  until mkdir "$tmpdir/lock-$1" 2>/dev/null; do sleep 1; done
}
release_lock () {
  rmdir "$tmpdir/lock-$1"
}

proxmox () {
  acquire_lock proxmox
  http \
    --form \
    --verify no \
    --ignore-stdin \
    "$@" \
    "Cookie:PVEAuthCookie=$ticket" \
    "CSRFPreventionToken:$csrf_token"
  release_lock proxmox
}

## Synchronous variant for when the `proxmox` function would just respond an
## UPID in the `data` JSON field.
proxmox_sync () (
  response=$(proxmox "$@")
  upid=$(echo "$response" | jq -r .data)

  while :; do
    response=$(proxmox GET "$api_url/nodes/$node/tasks/$upid/status")
    status=$(echo "$response" | jq -r .data.status)

    case $status in
      running) sleep 1 ;;
      stopped) break ;;
      *) die "unexpected status: \`\%s\`" "$status" ;;
    esac
  done
)

################################################################################
## Build ISO

build_iso () {
  acquire_lock build
  printf 'Building ISO for VM %d...\n' "$1"

  nix build \
    ".#isoInstallers.provisioning.fedi$1" \
    --log-format raw --quiet \
    --out-link "$tmpdir/installer-fedi$1"

  ln -sf "$tmpdir/installer-fedi$1/iso/installer.iso" "$tmpdir/installer-fedi$1.iso"

  printf 'done building ISO for VM %d.\n' "$1"
  release_lock build
}

################################################################################
## Upload ISO

upload_iso () {
  acquire_lock upload
  printf 'Uploading ISO for VM %d...\n' "$1"

  proxmox_sync POST"$api_url/nodes/$node/storage/local/upload" \
    "filename@$tmpdir/installer-fedi$1.iso" \
    content==iso

  printf 'done uploading ISO for VM %d.\n' "$1"
  release_lock upload
}

################################################################################
## Remove ISO

remove_iso () {
  printf 'Removing ISO for VM %d...\n' "$1"

  proxmox_sync DELETE "$api_url/nodes/$node/storage/local/content/local:iso/installer-fedi$1.iso"

  printf 'done removing ISO for VM %d.\n' "$1"
}

################################################################################
## Create VM

create_vm () {
  printf 'Creating VM %d...\n' "$1"

  proxmox_sync POST "$api_url/nodes/$node/qemu" \
    \
    vm_id=="$1" \
    name=="fedi$1" \
    pool==Fediversity \
    \
    ide2=="local:iso/installer-fedi$1.iso,media=cdrom" \
    ostype==l26 \
    \
    bios==ovmf \
    efidisk0=='linstor_storage:1,efitype=4m' \
    agent==1 \
    \
    scsihw==virtio-scsi-single \
    scsi0=='linstor_storage:32,discard=on,ssd=on,iothread=on' \
    \
    sockets=="$sockets" \
    cores=="$cores" \
    cpu==x86-64-v2-AES \
    numa==1 \
    \
    memory=="$memory" \
    \
    net0=='virtio,bridge=vnet1306'

  printf 'done creating VM %d.\n' "$1"
}

################################################################################
## Install VM

install_vm () (
  printf 'Installing VM %d...\n' "$1"

  proxmox_sync POST "$api_url/nodes/$node/qemu/$1/status/start"

  while :; do
    response=$(proxmox GET "$api_url/nodes/$node/qemu/$1/status/current")
    status=$(echo "$response" | jq -r .data.status)
    case $status in
      running) sleep 1 ;;
      stopped) break ;;
      *) printf " unexpected status: \`\%s\`\n" "$status"; exit 2 ;;
    esac
  done

  printf 'done installing VM %d.\n' "$1"
)

################################################################################
## Start VM

start_vm () {
  printf 'Starting VM %d...\n' "$1"

  proxmox_sync POST "$api_url/nodes/$node/qemu/$1/config" \
    ide2=='none,media=cdrom' \
    net0=='virtio,bridge=vnet1305'

  proxmox_sync POST "$api_url/nodes/$node/qemu/$1/status/start"

  printf 'done starting VM %d.\n' "$1"
}

################################################################################
## Main loop

printf 'Provisioning VMs%s with:\n' "$vm_ids"
printf '  sockets: %d\n' "$sockets"
printf '  cores: %d\n' "$cores"
printf '  memory: %d\n' "$memory"

provision_vm () {
  build_iso "$1"
  upload_iso "$1"
  create_vm "$1"
  install_vm "$1"
  start_vm "$1"
  remove_iso "$1"
}

for vm_id in $vm_ids; do
  provision_vm "$vm_id" &
done
wait

printf 'done provisioning VMs%s.\n' "$vm_ids"

################################################################################
## Cleanup

rm -Rf $tmpdir