#!/usr/bin/env bash

# This script is triggered by the NATS JetStream consumer on the Control Center.
# It reads a Forgejo webhook JSON payload from STDIN and orchestrates the
# Staging VM OpenTofu lifecycle.

set -euo pipefail

# Read JSON payload from STDIN
PAYLOAD=$(cat)

# Extract fields using jq
ACTION=$(echo "$PAYLOAD" | jq -r '.action // empty')
PR_NUMBER=$(echo "$PAYLOAD" | jq -r '.pull_request.number // empty')

if [ -z "$ACTION" ] || [ -z "$PR_NUMBER" ] || [ "$PR_NUMBER" == "null" ]; then
    printf "Invalid or missing action/pr_number in payload. Exiting.\n"
    exit 0
fi

# We only care about PR events
if [[ "$ACTION" != "opened" && "$ACTION" != "reopened" && "$ACTION" != "synchronized" && "$ACTION" != "closed" ]]; then
    printf "Ignoring PR action: %%s\n" "$ACTION"
    exit 0
fi

# Ensure workspace directory exists for this PR
WORKSPACE="/var/lib/hypervisor-gitops/staging-pr-${PR_NUMBER}"
OPENTOFU_SRC="/var/lib/hypervisor-gitops/nix-config/opentofu/staging-env"

# TrueNAS API variables
TRUENAS_URL=${TRUENAS_URL:-"https://192.168.0.11"}
TRUENAS_API_KEY=${TRUENAS_API_KEY:-""}
ZFS_DATASET=${ZFS_DATASET:-"tank/production"}

get_latest_snapshot() {
    # Fetch the latest snapshot for the dataset from TrueNAS API
    # Assumes TRUENAS_API_KEY is exported in the environment by SOPS
    curl -sS -k -X GET \
        -H "Authorization: Bearer ${TRUENAS_API_KEY}" \
        -H "Accept: application/json" \
        "${TRUENAS_URL}/api/v2.0/zfs/snapshot?id~=${ZFS_DATASET}%%25&limit=1&sort=-creation" | jq -r '.[0].id'
}

printf "Processing PR #%%s (Action: %%s)\n" "$PR_NUMBER" "$ACTION"

if [[ "$ACTION" == "closed" ]]; then
    if [ ! -d "$WORKSPACE" ]; then
        printf "Workspace %%s does not exist. Nothing to destroy.\n" "$WORKSPACE"
        exit 0
    fi
    printf "Destroying Staging Environment for PR #%%s...\n" "$PR_NUMBER"
    cd "$WORKSPACE"
    tofu destroy -var="pr_number=${PR_NUMBER}" -auto-approve
    
    # Cleanup
    cd /
    rm -rf "$WORKSPACE"
    printf "Staging Environment Destroyed.\n"
    exit 0
fi

# Provisioning (opened, reopened, synchronized)
printf "Setting up Staging Environment for PR #%%s...\n" "$PR_NUMBER"

if [ ! -d "$WORKSPACE" ]; then
    mkdir -p "$WORKSPACE"
    cp -r "$OPENTOFU_SRC"/* "$WORKSPACE"/
fi

cd "$WORKSPACE"

# Fetch latest TrueNAS snapshot dynamically
LATEST_SNAPSHOT=$(get_latest_snapshot)

if [ -z "$LATEST_SNAPSHOT" ] || [ "$LATEST_SNAPSHOT" == "null" ]; then
    printf "Failed to retrieve the latest TrueNAS snapshot. Aborting.\n"
    exit 1
fi

printf "Latest Snapshot ID: %%s\n" "$LATEST_SNAPSHOT"

# Apply OpenTofu
tofu init -upgrade
tofu apply -var="pr_number=${PR_NUMBER}" -var="truenas_snapshot_id=${LATEST_SNAPSHOT}" -auto-approve

printf "Staging Environment Provisioned successfully.\n"