'use strict';

const dayjs = require('dayjs');
const cloudDb = require('../config/cloudDatabase');
const database = require('../config/database');
const { applyAftersalesRefundExportOverrides } = require('./aftersalesRefundExportOverride');

const SYNC_VERSION = 'aftersales-refund-union-v2';
const INSERT_BATCH_SIZE = 500;

const TARGET_COLUMNS = [
  'stat_date',
  'source_key',
  'source_table',
  'as_id',
  'outer_as_id',
  'o_id',
  'so_id',
  'type',
  'node',
  'order_labels',
  'shop_name',
  'freight',
  'refund',
  'payment',
  'free_amount',
  'total_refund_money',
  'shop_status',
  'question_type',
  'process_result',
  'status',
  'created',
  'modified',
  'l_id',
  'confirm_date',
  'creator_name',
  'original_order_no',
  'original_courier_name',
  'original_waybill_no',
];

function normalizeDate(value, fallback = dayjs().subtract(1, 'day').format('YYYY-MM-DD')) {
  const parsed = dayjs(value || fallback);
  if (!parsed.isValid()) {
    throw new Error(`Invalid date: ${value}`);
  }
  return parsed.format('YYYY-MM-DD');
}

function listDatesInRange(startDate, endDate) {
  const start = dayjs(normalizeDate(startDate));
  const end = dayjs(normalizeDate(endDate || startDate));
  if (end.isBefore(start, 'day')) {
    throw new Error(`Invalid date range: ${startDate} -> ${endDate}`);
  }

  const dates = [];
  let cursor = start;
  while (!cursor.isAfter(end, 'day')) {
    dates.push(cursor.format('YYYY-MM-DD'));
    cursor = cursor.add(1, 'day');
  }
  return dates;
}

function decimalOrZero(value) {
  const number = Number(value);
  return Number.isFinite(number) ? number : 0;
}

function textOrEmpty(value) {
  return value === null || value === undefined ? '' : String(value);
}

function toInsertRow(row) {
  return TARGET_COLUMNS.map((column) => {
    if (['freight', 'refund', 'payment', 'free_amount', 'total_refund_money'].includes(column)) {
      return decimalOrZero(row[column]);
    }
    if (['created', 'modified', 'confirm_date'].includes(column)) {
      return row[column] || null;
    }
    if (column === 'stat_date') {
      return normalizeDate(row[column]);
    }
    return textOrEmpty(row[column]);
  });
}

const UNION_SQL = `
WITH unified_refunds AS (
  SELECT
    CONVERT(varchar(10), CONVERT(date, created), 120) AS stat_date,
    N'jst_returnAndRefundInfo' AS source_key,
    N'dbo.jst_returnAndRefundInfo' AS source_table,
    CAST(as_id AS nvarchar(80)) AS as_id,
    CAST(outer_as_id AS nvarchar(120)) AS outer_as_id,
    CAST(o_id AS nvarchar(80)) AS o_id,
    CAST(so_id AS nvarchar(120)) AS so_id,
    CAST(type AS nvarchar(50)) AS type,
    CAST(node AS nvarchar(100)) AS node,
    CAST(order_labelsText AS nvarchar(max)) AS order_labels,
    CAST(shop_name AS nvarchar(255)) AS shop_name,
    TRY_CONVERT(decimal(18,2), freight) AS freight,
    TRY_CONVERT(decimal(18,2), refund) AS refund,
    TRY_CONVERT(decimal(18,2), payment) AS payment,
    TRY_CONVERT(decimal(18,2), free_amount) AS free_amount,
    (
      COALESCE(TRY_CONVERT(decimal(18,2), freight), 0)
      + COALESCE(TRY_CONVERT(decimal(18,2), refund), 0)
      - COALESCE(TRY_CONVERT(decimal(18,2), payment), 0)
      - COALESCE(TRY_CONVERT(decimal(18,2), free_amount), 0)
    ) AS total_refund_money,
    CAST(shop_status AS nvarchar(100)) AS shop_status,
    CAST(question_type AS nvarchar(255)) AS question_type,
    CAST(result AS nvarchar(255)) AS process_result,
    CAST(status AS nvarchar(100)) AS status,
    CONVERT(varchar(19), created, 120) AS created,
    CONVERT(varchar(19), modified, 120) AS modified,
    CAST(l_id AS nvarchar(120)) AS l_id,
    CONVERT(varchar(19), confirm_date, 120) AS confirm_date,
    CAST(creator_name AS nvarchar(100)) AS creator_name,
    CAST(N'' AS nvarchar(255)) AS original_order_no,
    CAST(N'' AS nvarchar(120)) AS original_courier_name,
    CAST(N'' AS nvarchar(120)) AS original_waybill_no
  FROM dbo.jst_returnAndRefundInfo WITH (NOLOCK)
  WHERE shop_site <> N'拼多多'
    AND CONVERT(date, created) = @statDate

  UNION ALL

  SELECT
    CONVERT(varchar(10), CONVERT(date, created), 120) AS stat_date,
    N'jst_qmcust_refundlist' AS source_key,
    N'dbo.jst_qmcust_refundlist' AS source_table,
    CAST(as_id AS nvarchar(80)) AS as_id,
    CAST(outer_as_id AS nvarchar(120)) AS outer_as_id,
    CAST(o_id AS nvarchar(80)) AS o_id,
    CAST(so_id AS nvarchar(120)) AS so_id,
    CAST(type AS nvarchar(50)) AS type,
    CAST(node AS nvarchar(100)) AS node,
    CAST(order_label AS nvarchar(max)) AS order_labels,
    CAST(shop_name AS nvarchar(255)) AS shop_name,
    TRY_CONVERT(decimal(18,2), freight) AS freight,
    TRY_CONVERT(decimal(18,2), refund) AS refund,
    TRY_CONVERT(decimal(18,2), payment) AS payment,
    TRY_CONVERT(decimal(18,2), free_amount) AS free_amount,
    (
      COALESCE(TRY_CONVERT(decimal(18,2), freight), 0)
      + COALESCE(TRY_CONVERT(decimal(18,2), refund), 0)
      - COALESCE(TRY_CONVERT(decimal(18,2), payment), 0)
      - COALESCE(TRY_CONVERT(decimal(18,2), free_amount), 0)
    ) AS total_refund_money,
    CAST(shop_status AS nvarchar(100)) AS shop_status,
    CAST(question_type AS nvarchar(255)) AS question_type,
    CAST(N'' AS nvarchar(255)) AS process_result,
    CAST(status AS nvarchar(100)) AS status,
    CONVERT(varchar(19), created, 120) AS created,
    CONVERT(varchar(19), modified, 120) AS modified,
    CAST(l_id AS nvarchar(120)) AS l_id,
    CONVERT(varchar(19), confirm_date, 120) AS confirm_date,
    CAST(creator_name AS nvarchar(100)) AS creator_name,
    CAST(N'' AS nvarchar(255)) AS original_order_no,
    CAST(N'' AS nvarchar(120)) AS original_courier_name,
    CAST(N'' AS nvarchar(120)) AS original_waybill_no
  FROM dbo.jst_qmcust_refundlist WITH (NOLOCK)
  WHERE CONVERT(date, created) = @statDate

  UNION ALL

  SELECT
    CONVERT(varchar(10), CONVERT(date, created), 120) AS stat_date,
    N'jst_refund_pdd_fz_view' AS source_key,
    N'dbo.jst_refund_pdd_fz_view' AS source_table,
    CAST(as_id AS nvarchar(80)) AS as_id,
    CAST(outer_as_id AS nvarchar(120)) AS outer_as_id,
    CAST(o_id AS nvarchar(80)) AS o_id,
    CAST(so_id AS nvarchar(120)) AS so_id,
    CAST(type AS nvarchar(50)) AS type,
    CAST(node AS nvarchar(100)) AS node,
    CAST(order_labels_str AS nvarchar(max)) AS order_labels,
    CAST(shop_name AS nvarchar(255)) AS shop_name,
    TRY_CONVERT(decimal(18,2), freight) AS freight,
    TRY_CONVERT(decimal(18,2), refund) AS refund,
    TRY_CONVERT(decimal(18,2), payment) AS payment,
    TRY_CONVERT(decimal(18,2), free_amount) AS free_amount,
    (
      COALESCE(TRY_CONVERT(decimal(18,2), freight), 0)
      + COALESCE(TRY_CONVERT(decimal(18,2), refund), 0)
      - COALESCE(TRY_CONVERT(decimal(18,2), payment), 0)
      - COALESCE(TRY_CONVERT(decimal(18,2), free_amount), 0)
    ) AS total_refund_money,
    CAST(shop_status AS nvarchar(100)) AS shop_status,
    CAST(question_type AS nvarchar(255)) AS question_type,
    CAST(result AS nvarchar(255)) AS process_result,
    CAST(status AS nvarchar(100)) AS status,
    CONVERT(varchar(19), created, 120) AS created,
    CONVERT(varchar(19), modified, 120) AS modified,
    CAST(l_id AS nvarchar(120)) AS l_id,
    CONVERT(varchar(19), confirm_date, 120) AS confirm_date,
    CAST(creator_name AS nvarchar(100)) AS creator_name,
    CAST(N'' AS nvarchar(255)) AS original_order_no,
    CAST(N'' AS nvarchar(120)) AS original_courier_name,
    CAST(N'' AS nvarchar(120)) AS original_waybill_no
  FROM dbo.jst_refund_pdd_fz_view
  WHERE CONVERT(date, created) = @statDate
)
SELECT *
FROM unified_refunds
ORDER BY created ASC, source_key ASC, as_id ASC;
`;

async function writeSyncLog({ statDate, rowCount, status, errorMessage = '' }) {
  await database.local.query(
    `INSERT INTO aftersales_refund_detail_sync
      (stat_date, sync_version, row_count, status, error_message, synced_at)
     VALUES (?, ?, ?, ?, ?, NOW())
     ON DUPLICATE KEY UPDATE
       sync_version = VALUES(sync_version),
       row_count = VALUES(row_count),
       status = VALUES(status),
       error_message = VALUES(error_message),
       synced_at = NOW()`,
    [statDate, SYNC_VERSION, rowCount, status, errorMessage.slice(0, 1000)]
  );
}

async function insertRows(rows) {
  if (rows.length === 0) {
    return;
  }

  const columnSql = TARGET_COLUMNS.map((column) => `\`${column}\``).join(', ');
  for (let index = 0; index < rows.length; index += INSERT_BATCH_SIZE) {
    const batch = rows.slice(index, index + INSERT_BATCH_SIZE).map(toInsertRow);
    await database.local.query(
      `INSERT INTO aftersales_refund_detail_read (${columnSql}) VALUES ?`,
      [batch]
    );
  }
}

async function refreshAftersalesRefundDetailDate(inputDate) {
  const statDate = normalizeDate(inputDate);
  console.log(`[aftersales-refund-detail] sync start ${statDate}`);

  try {
    const rows = await cloudDb.query(UNION_SQL, { statDate });
    await database.local.query('DELETE FROM aftersales_refund_detail_read WHERE stat_date = ?', [statDate]);
    await insertRows(rows);
    await applyAftersalesRefundExportOverrides(statDate);
    await writeSyncLog({ statDate, rowCount: rows.length, status: 'success' });
    console.log(`[aftersales-refund-detail] sync done ${statDate}, rows=${rows.length}`);
    return { statDate, rowCount: rows.length };
  } catch (error) {
    await writeSyncLog({
      statDate,
      rowCount: 0,
      status: 'failed',
      errorMessage: error.message || String(error),
    }).catch((logError) => {
      console.warn('[aftersales-refund-detail] sync log failed:', logError.message || logError);
    });
    throw error;
  }
}

async function refreshAftersalesRefundDetailRange(startDate, endDate = startDate) {
  const results = [];
  for (const statDate of listDatesInRange(startDate, endDate)) {
    results.push(await refreshAftersalesRefundDetailDate(statDate));
  }
  return results;
}

module.exports = {
  SYNC_VERSION,
  refreshAftersalesRefundDetailDate,
  refreshAftersalesRefundDetailRange,
};