#!/bin/bash

# For my use, debian for the little one, ubuntu for the big ones

# From .env, following values:
# LINODE_API_KEY  (used for all Linode API calls below, via curl)
# WHICH_DOMAIN
# ROOT_PASS
source .env
# All Linode API requests use the API key sourced from .env above:
#   curl -H "Authorization: Bearer $LINODE_API_KEY" https://api.linode.com/v4/...
#ROOT_PASS=$(for w in {1..3}; do echo -n $(cat /usr/share/dict/words | grep -v "'" | sed -n $(echo "$(cat /usr/share/dict/words | grep -v "'" | wc -l) * $RANDOM / 32768 + 1" | bc)p); done)
#ROOT_PASS="StartRootPass5678"
SCRIPT_ACTION=$1
LINODE_LABEL=$2
LOGFILE="./linodes.log"

# Pre-existing Valheim volume, attached to every Linode at creation time.
# The filesystem (mkfs.ext4) was already created; see voldirections.txt.
VOLUME_ID="18073448"
VOLUME_NAME="ValVol202609"
VOLUME_DEVICE="/dev/disk/by-id/scsi-0Linode_Volume_$VOLUME_NAME"
VOLUME_MOUNT="/mnt/$VOLUME_NAME"

# Cloud Firewall applied to every Linode at creation time. It must allow the
# Valheim ports (2456-2457/udp) and, if you still need SSH, port 22.
FIREWALL_ID="165767433"

# StackScript that mounts the volume on first boot (see stackscript.md).
# Enter the numeric StackScript ID manually after creating it in the Linode UI.
#STACKSCRIPT_ID="2225110"
# Normal:
#STACKSCRIPT_ID="2225140"
# More resources (1.5):
STACKSCRIPT_ID="2225166"

if [[ "$SCRIPT_ACTION" == "" || "$SCRIPT_ACTION" == "--help" || "$SCRIPT_ACTION" == "-?" ]]; then
  echo "Linode helper script: create-linode.sh <action> <label> [args]"
  echo "Create:  create-linode.sh c <new label>"
  echo "         (fixed size: 8GB shared, newest Debian image;"
  echo "          attaches and mounts volume $VOLUME_NAME)"
  echo "Destroy: create-linode.sh d <label>"
  echo "Connect: create-linode.sh x <label>"
  echo "         create-linode.sh x <label> get <remote source> <local dest>"
  echo "         create-linode.sh x <label> put <local source> <remote dest>"
  echo "Update record: create-linode.sh a <label> <subdomain>"
  echo "         (updates the existing A record, creates one if missing)"
  echo "List:    create-linode.sh l"
  echo "         (lists all Linodes, no label needed)"
fi

# Create
if [[ "$SCRIPT_ACTION" == "c" ]]; then

  # Fixed size: 8GB shared, newest Debian image
  INSTANCE_SIZE="g6-standard-4"
  INSTANCE_IMAGE="linode/debian13"

  # The StackScript (see stackscript.md) runs as root on first boot and mounts
  # the volume, so no SSH session is needed to configure it.
  curl -s -H "Content-Type: application/json" \
    -H "Authorization: Bearer $LINODE_API_KEY" \
    -X POST -d '{
          "label": "'$LINODE_LABEL'",
          "region": "us-central",
          "type": "'$INSTANCE_SIZE'",
          "image": "'$INSTANCE_IMAGE'",
          "root_pass": "'$ROOT_PASS'",
          "authorized_users": ["ni7ne_midpriv"],
          "stackscript_id": '$STACKSCRIPT_ID',
          "firewall_id": '$FIREWALL_ID'
        }' \
    https://api.linode.com/v4/linode/instances | jq .

  # Wait for the Linode to finish provisioning instead of blindly sleeping.
  # Poll the status until it reports "running", which is the state required
  # before the volume can be attached. 60 attempts x 10s = 10 minute ceiling.
  INSTANCE_STATUS=""
  for _ in $(seq 1 60); do
    INSTANCE_STATUS=$(curl -s -H "Authorization: Bearer $LINODE_API_KEY" https://api.linode.com/v4/linode/instances | jq -r '.data[] | select(.label == "'$LINODE_LABEL'") | .status')
    if [[ "$INSTANCE_STATUS" == "running" ]]; then
      break
    fi
    echo "Waiting for $LINODE_LABEL to reach running (status: ${INSTANCE_STATUS:-unknown})..."
    sleep 10
  done

  if [[ "$INSTANCE_STATUS" != "running" ]]; then
    echo "ERROR: $LINODE_LABEL did not reach running (last status: ${INSTANCE_STATUS:-unknown})." >&2
    exit 1
  fi

  INSTANCE_IP=$(curl -s -H "Authorization: Bearer $LINODE_API_KEY" https://api.linode.com/v4/linode/instances | jq '.data[] | select(.label == "'$LINODE_LABEL'") | .ipv4[]' | sed -e "s/\"//g")
  INSTANCE_ID=$(curl -s -H "Authorization: Bearer $LINODE_API_KEY" https://api.linode.com/v4/linode/instances | jq '.data[] | select(.label == "'$LINODE_LABEL'") | .id' | sed -e "s/\"//g")
  echo "Instance IP: $INSTANCE_IP"
  echo "Instance ID: $INSTANCE_ID"

  # Attach the pre-existing Valheim volume (see voldirections.txt).
  # The volume must be attached to a running Linode; the image boots on create.
  curl -s -H "Content-Type: application/json" \
    -H "Authorization: Bearer $LINODE_API_KEY" \
    -X POST -d '{
          "linode_id": '$INSTANCE_ID',
          "persist_across_boots": true
        }' \
    https://api.linode.com/v4/volumes/$VOLUME_ID/attach | jq .

  # Give the volume a moment to appear on the instance before the StackScript
  # (which runs on first boot) mounts it.
  sleep 15

  echo "$(date -Iminutes) --- Id:$INSTANCE_ID --- IP:$INSTANCE_IP Summoned $LINODE_LABEL with volume $VOLUME_ID." >>$LOGFILE
  echo "Started with root pass $ROOT_PASS"

fi

# List
if [[ "$SCRIPT_ACTION" == "l" ]]; then
  curl -s -H "Authorization: Bearer $LINODE_API_KEY" \
    https://api.linode.com/v4/linode/instances | jq .
fi

# Destroy
if [[ "$SCRIPT_ACTION" == "d" ]]; then
  INSTANCE_IP=$(curl -s -H "Authorization: Bearer $LINODE_API_KEY" https://api.linode.com/v4/linode/instances | jq '.data[] | select(.label == "'$LINODE_LABEL'") | .ipv4[]' | sed -e "s/\"//g")
  INSTANCE_ID=$(curl -s -H "Authorization: Bearer $LINODE_API_KEY" https://api.linode.com/v4/linode/instances | jq '.data[] | select(.label == "'$LINODE_LABEL'") | .id' | sed -e "s/\"//g")
  echo "Destroying ID:$INSTANCE_ID Hit Ctrl-C in the next 10 seconds to cancel."
  sleep 15

  # Shut the Linode down cleanly before deleting it, so systemd stops the
  # Docker container and the Valheim server gets the chance to save the world
  # rather than being cut off mid-write.
  echo "Shutting down ID:$INSTANCE_ID..."
  curl -s -H "Authorization: Bearer $LINODE_API_KEY" \
    -X POST https://api.linode.com/v4/linode/instances/$INSTANCE_ID/shutdown | jq .

  # Give the shutdown time to finish before the instance is deleted.
  sleep 30

  curl -s -H "Authorization: Bearer $LINODE_API_KEY" \
    -X DELETE https://api.linode.com/v4/linode/instances/$INSTANCE_ID
  echo "$(date -Iminutes) --- Id:$INSTANCE_ID --- IP:$INSTANCE_IP Destroyed $LINODE_LABEL." >>$LOGFILE
fi

# Connect
if [[ "$SCRIPT_ACTION" == "x" ]]; then

  REMOTE_ACTION=$3
  SCP_SOURCE=$4
  SCP_DEST=$5

  INSTANCE_IP=$(curl -s -H "Authorization: Bearer $LINODE_API_KEY" https://api.linode.com/v4/linode/instances | jq '.data[] | select(.label == "'$LINODE_LABEL'") | .ipv4[]' | sed -e "s/\"//g")
  if [[ "$REMOTE_ACTION" == "get" ]]; then
    echo "get </~/source> <localdest>"
    scp $INSTANCE_IP:/home/finn/$SCP_SOURCE $SCP_DEST
  fi

  if [[ "$REMOTE_ACTION" == "put" ]]; then
    echo "put <localsource> </~/dest>"
    scp $SCP_SOURCE $INSTANCE_IP:/home/finn/$SCP_DEST
  fi

  if [[ "$REMOTE_ACTION" == "" ]]; then
    echo "Connecting: $INSTANCE_IP"
    ssh -o "StrictHostKeyChecking no" root@$INSTANCE_IP
  fi

fi

# Update record
if [[ "$SCRIPT_ACTION" == "a" ]]; then

  INSTANCE_IP=$(curl -s -H "Authorization: Bearer $LINODE_API_KEY" https://api.linode.com/v4/linode/instances | jq '.data[] | select(.label == "'$LINODE_LABEL'") | .ipv4[]' | sed -e "s/\"//g")

  NI_SUBDOMAIN=$3
  DOMAIN_RECORDS=$(curl -s -H "Authorization: Bearer $LINODE_API_KEY" \
    https://api.linode.com/v4/domains/$WHICH_DOMAIN/records)

  # Only A records are managed by this action, so filter out the rest
  # (CNAME, MX, TXT, ...) when showing the current state.
  echo "Previous value:"
  echo "$DOMAIN_RECORDS" | jq '.data[] | select(.type == "A")'

  sleep 3

  # Update the A record that already exists for this subdomain rather than
  # adding another one; a record is only created when there is nothing to
  # update. DNS names are case-insensitive, so compare them that way.
  RECORD_IDS=$(echo "$DOMAIN_RECORDS" | jq -r --arg name "$NI_SUBDOMAIN" \
    '.data[] | select(.type == "A" and ((.name // "") | ascii_downcase) == ($name | ascii_downcase)) | .id')
  RECORD_ID=$(echo "$RECORD_IDS" | head -n 1)
  DUPLICATE_IDS=$(echo "$RECORD_IDS" | tail -n +2)

  echo "Updating records with ip $INSTANCE_IP..."

  #ni7ne:
  if [[ -n "$RECORD_ID" ]]; then
    curl -s -H "Content-Type: application/json" \
      -H "Authorization: Bearer $LINODE_API_KEY" \
      -X PUT -d '{
            "type": "A",
            "name": "'$NI_SUBDOMAIN'",
            "target": "'$INSTANCE_IP'",
            "ttl_sec": 14400
          }' \
      https://api.linode.com/v4/domains/$WHICH_DOMAIN/records/$RECORD_ID | jq .

    # Duplicates left behind by earlier runs would keep resolving to an old
    # IP, so remove everything except the record that was just updated.
    for DUPLICATE_ID in $DUPLICATE_IDS; do
      echo "Deleting duplicate A record $DUPLICATE_ID for $NI_SUBDOMAIN..."
      curl -s -H "Authorization: Bearer $LINODE_API_KEY" \
        -X DELETE https://api.linode.com/v4/domains/$WHICH_DOMAIN/records/$DUPLICATE_ID
    done
  else
    curl -s -H "Content-Type: application/json" \
      -H "Authorization: Bearer $LINODE_API_KEY" \
      -X POST -d '{
            "type": "A",
            "name": "'$NI_SUBDOMAIN'",
            "target": "'$INSTANCE_IP'",
            "ttl_sec": 14400
          }' \
      https://api.linode.com/v4/domains/$WHICH_DOMAIN/records | jq .
  fi

  echo "Update complete."

fi