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

usage() {
  cat <<'EOF'
Usage:
  migrate_workbench_tables.sh --host HOST --port PORT --user USER --password PASSWORD --source meeting_im --target workbench [--backup-dir DIR]

Migrates im_workbench-owned tables from the shared IM database into the standalone workbench database.
The target tables are dropped and recreated from the source dump. Source and target table dumps are
written before any target changes.
EOF
}

HOST=""
PORT="3306"
USER=""
PASSWORD=""
SOURCE_DB="meeting_im"
TARGET_DB="workbench"
BACKUP_DIR=""

while [[ $# -gt 0 ]]; do
  case "$1" in
    --host) HOST="$2"; shift 2 ;;
    --port) PORT="$2"; shift 2 ;;
    --user) USER="$2"; shift 2 ;;
    --password) PASSWORD="$2"; shift 2 ;;
    --source) SOURCE_DB="$2"; shift 2 ;;
    --target) TARGET_DB="$2"; shift 2 ;;
    --backup-dir) BACKUP_DIR="$2"; shift 2 ;;
    -h|--help) usage; exit 0 ;;
    *) echo "unknown argument: $1" >&2; usage >&2; exit 2 ;;
  esac
done

if [[ -z "$HOST" || -z "$USER" || -z "$PASSWORD" || -z "$SOURCE_DB" || -z "$TARGET_DB" ]]; then
  usage >&2
  exit 2
fi

TABLES=(
  im_workbench_apps
  im_org_departments
  im_org_members
  im_org_visibility_overrides
  im_attendance_rules
  im_attendance_shifts
  im_attendance_records
  im_attendance_checkins
  im_attendance_appeals
  im_meetings
  im_meeting_participants
  im_meeting_note_files
  im_daily_reports
  im_monthly_reports
  im_mailbox_config
  im_mailbox_submissions
  im_feedback_config
  im_feedback_submissions
  wb_ai_capability_config
  wb_ai_document
  wb_ai_idempotency_record
  wb_ai_meeting_summary
  wb_ai_prompt_template
  wb_ai_record
  wb_ai_table_analysis
  wb_ai_task
  wb_ai_task_step
  wb_ai_usage_log
)

timestamp="$(date +%Y%m%d%H%M%S)"
if [[ -z "$BACKUP_DIR" ]]; then
  BACKUP_DIR="./tmp/workbench_migration_${HOST}_${PORT}_${timestamp}"
fi
mkdir -p "$BACKUP_DIR"

MYSQL=(mysql -h "$HOST" -P "$PORT" -u "$USER" "-p$PASSWORD" --default-character-set=utf8mb4)
MYSQLDUMP=(mysqldump -h "$HOST" -P "$PORT" -u "$USER" "-p$PASSWORD" --default-character-set=utf8mb4 --single-transaction --skip-add-locks --set-gtid-purged=OFF)

echo "backup dir: $BACKUP_DIR"
echo "checking source tables..."
"${MYSQL[@]}" -N -e "SELECT TABLE_NAME FROM information_schema.TABLES WHERE TABLE_SCHEMA='${SOURCE_DB}'" > "$BACKUP_DIR/${SOURCE_DB}_tables.txt"

existing_tables=()
for table in "${TABLES[@]}"; do
  if grep -qx "$table" "$BACKUP_DIR/${SOURCE_DB}_tables.txt"; then
    existing_tables+=("$table")
  else
    echo "warning: source table ${SOURCE_DB}.${table} does not exist, skipping" >&2
  fi
done

if [[ ${#existing_tables[@]} -eq 0 ]]; then
  echo "no source tables found" >&2
  exit 1
fi

echo "creating target database if needed..."
"${MYSQL[@]}" -e "CREATE DATABASE IF NOT EXISTS \`${TARGET_DB}\` DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci"

echo "backing up source tables..."
"${MYSQLDUMP[@]}" "$SOURCE_DB" "${existing_tables[@]}" > "$BACKUP_DIR/${SOURCE_DB}_workbench_tables.sql"

target_existing=()
for table in "${existing_tables[@]}"; do
  if "${MYSQL[@]}" -N -e "SELECT COUNT(*) FROM information_schema.TABLES WHERE TABLE_SCHEMA='${TARGET_DB}' AND TABLE_NAME='${table}'" | grep -qx "1"; then
    target_existing+=("$table")
  fi
done
if [[ ${#target_existing[@]} -gt 0 ]]; then
  echo "backing up existing target tables..."
  "${MYSQLDUMP[@]}" "$TARGET_DB" "${target_existing[@]}" > "$BACKUP_DIR/${TARGET_DB}_workbench_tables_before.sql"
fi

drop_sql="SET FOREIGN_KEY_CHECKS=0;"
for table in "${existing_tables[@]}"; do
  drop_sql+="DROP TABLE IF EXISTS \`${TARGET_DB}\`.\`${table}\`;"
done
drop_sql+="SET FOREIGN_KEY_CHECKS=1;"

echo "dropping target tables..."
"${MYSQL[@]}" -e "$drop_sql"

echo "importing source dump into target..."
sed -E \
  -e "s/^\s*CREATE DATABASE .*//" \
  -e "s/^\s*USE \`${SOURCE_DB}\`;//" \
  -e "s/^\s*USE ${SOURCE_DB};//" \
  -e "/^\s*LOCK TABLES /d" \
  -e "/^\s*UNLOCK TABLES;/d" \
  "$BACKUP_DIR/${SOURCE_DB}_workbench_tables.sql" | "${MYSQL[@]}" "$TARGET_DB"

echo "row count comparison:"
printf "%-34s %12s %12s\n" "table" "source" "target"
failed=0
for table in "${existing_tables[@]}"; do
  src_count="$("${MYSQL[@]}" -N -e "SELECT COUNT(*) FROM \`${SOURCE_DB}\`.\`${table}\`")"
  dst_count="$("${MYSQL[@]}" -N -e "SELECT COUNT(*) FROM \`${TARGET_DB}\`.\`${table}\`")"
  printf "%-34s %12s %12s\n" "$table" "$src_count" "$dst_count"
  if [[ "$src_count" != "$dst_count" ]]; then
    failed=1
  fi
done | tee "$BACKUP_DIR/row_counts.txt"

if [[ "$failed" -ne 0 ]]; then
  echo "row count mismatch" >&2
  exit 1
fi

echo "migration complete"