#!/usr/bin/env bash

clickhouse_query() {
  local container="$1"
  local user="$2"
  local password="$3"
  local query="$4"

  docker exec "$container" clickhouse-client --user "$user" --password "$password" --query "$query"
}

render_clickhouse_schema() {
  local schema_file="$1"

  if head -n 1 "$schema_file" | grep -q '\\n'; then
    perl -0pe 's{\\n}{\n}g; s{\\t}{\t}g; s{\\\x27}{\x27}g' "$schema_file"
    return
  fi

  cat "$schema_file"
}

dump_clickhouse_container() {
  local backup_dir="$1"
  local service_name="$2"
  local container="$3"
  local user="$4"
  local password="$5"
  local output_dir="$backup_dir/clickhouse/$service_name"
  local table_list="$output_dir/tables.tsv"
  local database
  local table
  local engine
  local safe_name

  backup_require_command docker
  backup_require_container "$container"
  mkdir -p "$output_dir/schema" "$output_dir/data" "$backup_dir/reports"

  backup_log "Dumping ClickHouse metadata and Native data: $container"
  clickhouse_query "$container" "$user" "$password" \
    "select database, name, engine from system.tables where database not in ('INFORMATION_SCHEMA','information_schema','system') order by database, if(positionCaseInsensitive(engine, 'View') > 0, 1, 0), name format TSV" \
    >"$table_list"

  while IFS=$'\t' read -r database table engine; do
    [[ -n "$database" && -n "$table" ]] || continue
    safe_name="${database}__${table}"
    clickhouse_query "$container" "$user" "$password" "show create table \`${database}\`.\`${table}\` FORMAT RawBLOB" >"$output_dir/schema/${safe_name}.sql"
    if [[ "$engine" != *View* ]]; then
      clickhouse_query "$container" "$user" "$password" "select * from \`${database}\`.\`${table}\` format Native" >"$output_dir/data/${safe_name}.native"
    fi
    clickhouse_query "$container" "$user" "$password" "select '${database}.${table}:' || toString(count()) from \`${database}\`.\`${table}\`" \
      >>"$backup_dir/reports/${service_name}-row-counts.txt"
  done <"$table_list"
}

restore_clickhouse_container() {
  local backup_dir="$1"
  local service_name="$2"
  local container="$3"
  local user="$4"
  local password="$5"
  local input_dir="$backup_dir/clickhouse/$service_name"
  local table_list="$input_dir/tables.tsv"
  local database
  local table
  local engine
  local safe_name
  local restored_databases=""

  backup_require_command docker
  backup_require_container "$container"
  backup_require_path "$table_list"

  backup_log "Restoring ClickHouse tables: $container"
  while IFS=$'\t' read -r database table engine; do
    [[ -n "$database" && -n "$table" ]] || continue
    if ! grep -qw -- "$database" <<<"$restored_databases"; then
      docker exec "$container" clickhouse-client --user "$user" --password "$password" \
        --query "drop database if exists \`${database}\`"
      docker exec "$container" clickhouse-client --user "$user" --password "$password" \
        --query "create database if not exists \`${database}\`"
      restored_databases="${restored_databases:+$restored_databases }$database"
    fi
  done <"$table_list"

  while IFS=$'\t' read -r database table engine; do
    [[ -n "$database" && -n "$table" ]] || continue
    safe_name="${database}__${table}"
    backup_require_path "$input_dir/schema/${safe_name}.sql"
    render_clickhouse_schema "$input_dir/schema/${safe_name}.sql" \
      | docker exec -i "$container" clickhouse-client --user "$user" --password "$password" --multiquery
    if [[ "$engine" != *View* ]]; then
      backup_require_path "$input_dir/data/${safe_name}.native"
      docker exec -i "$container" clickhouse-client --user "$user" --password "$password" \
        --query "insert into \`${database}\`.\`${table}\` format Native" <"$input_dir/data/${safe_name}.native"
    fi
  done <"$table_list"
}

dump_baron_clickhouse() {
  dump_clickhouse_container "$1" "baron_clickhouse" "baron_clickhouse" "${CLICKHOUSE_USER:-baron}" "${CLICKHOUSE_PASSWORD:-password}"
}

dump_ory_clickhouse() {
  dump_clickhouse_container "$1" "ory_clickhouse" "ory_clickhouse" "${ORY_CLICKHOUSE_USER:-ory}" "${ORY_CLICKHOUSE_PASSWORD:-orypass}"
}

restore_baron_clickhouse() {
  restore_clickhouse_container "$1" "baron_clickhouse" "baron_clickhouse" "${CLICKHOUSE_USER:-baron}" "${CLICKHOUSE_PASSWORD:-password}"
}

restore_ory_clickhouse() {
  restore_clickhouse_container "$1" "ory_clickhouse" "ory_clickhouse" "${ORY_CLICKHOUSE_USER:-ory}" "${ORY_CLICKHOUSE_PASSWORD:-orypass}"
}