#!/usr/bin/env bash
set -euo pipefail

usage() {
  cat <<'EOF'
Usage:
  ZBX_URL=https://zabbix.example.com ZBX_TOKEN=xxxx \
    scripts/export.sh [--force] <output.yaml> <template-name> [<template-name> ...]

Specifying multiple template names exports them into a single YAML file.
To include linked templates, list their names explicitly.

Environment variables:
  ZBX_URL    Zabbix URL (for example, https://zabbix.example.com)
  ZBX_TOKEN  API token
EOF
}

force=0
if [[ "${1:-}" == "--force" ]]; then
  force=1
  shift
fi

if [[ $# -lt 2 ]]; then
  usage
  exit 1
fi

out="$1"
shift
names=("$@")

if [[ -z "${ZBX_URL:-}" || -z "${ZBX_TOKEN:-}" ]]; then
  echo "ERROR: Set ZBX_URL and ZBX_TOKEN." >&2
  exit 1
fi

command -v curl >/dev/null 2>&1 || {
  echo "ERROR: curl is required." >&2
  exit 1
}
command -v jq >/dev/null 2>&1 || {
  echo "ERROR: jq is required." >&2
  exit 1
}

api_url="${ZBX_URL%/}"
if [[ "$api_url" != */api_jsonrpc.php ]]; then
  api_url="$api_url/api_jsonrpc.php"
fi

if [[ -e "$out" && $force -eq 0 ]]; then
  echo "ERROR: Output already exists: $out (use --force to overwrite)" >&2
  exit 1
fi

api_call() {
  local payload="$1"
  curl -sS --fail-with-body \
    -H "Authorization: Bearer ${ZBX_TOKEN}" \
    -H 'Content-Type: application/json' \
    -d "$payload" \
    "$api_url"
}

ids=()
for name in "${names[@]}"; do
  payload="$(jq -n --arg name "$name" '{
    jsonrpc: "2.0",
    method: "template.get",
    params: {
      output: ["templateid", "host"],
      filter: {host: $name}
    },
    id: 1
  }')"

  if ! response="$(api_call "$payload")"; then
    echo "ERROR: API request failed: $api_url" >&2
    exit 1
  fi

  if jq -e '.error' >/dev/null 2>&1 <<<"$response"; then
    echo "ERROR: template.get failed: $name" >&2
    jq -r '.error.data // .error.message' <<<"$response" >&2
    exit 1
  fi

  id="$(jq -r '.result[0].templateid // empty' <<<"$response")"
  if [[ -z "$id" ]]; then
    echo "ERROR: Template not found: $name" >&2
    exit 1
  fi

  ids+=("$id")
  echo "Resolved: $name -> $id" >&2
done

ids_json="$(printf '%s\n' "${ids[@]}" | jq -R . | jq -s .)"
payload="$(jq -n --argjson ids "$ids_json" '{
  jsonrpc: "2.0",
  method: "configuration.export",
  params: {
    options: {templates: $ids},
    format: "yaml"
  },
  id: 1
}')"

if ! response="$(api_call "$payload")"; then
  echo "ERROR: API request failed: $api_url" >&2
  exit 1
fi

if jq -e '.error' >/dev/null 2>&1 <<<"$response"; then
  echo "ERROR: configuration.export failed" >&2
  jq -r '.error.data // .error.message' <<<"$response" >&2
  exit 1
fi

yaml="$(jq -r '.result' <<<"$response")"
mkdir -p "$(dirname "$out")"
printf '%s\n' "$yaml" > "$out"
echo "Created: $out"