-- 应收账单：订单占用状态 + 单日期截止日迁移
-- 适用于已经执行过 ar/ar_bill.sql、price/bill.sql 的数据库。
-- 若数据库中的应收明细仍使用旧来源ID列名，请先执行 ar_bill_source_id_rename.sql。
-- 请在业务低峰期执行；本脚本只做字段、索引和历史状态初始化，不删除账单明细。
SET NAMES utf8mb4;
SET @db_name := DATABASE();

-- 1. 给正式账单增加账单名称。历史账单使用账单号生成默认名称。
SET @has_bill_name := (
    SELECT COUNT(*)
    FROM information_schema.COLUMNS
    WHERE TABLE_SCHEMA = @db_name
      AND TABLE_NAME = 'ar_bill'
      AND COLUMN_NAME = 'bill_name'
);
SET @sql := IF(@has_bill_name = 0,
    'ALTER TABLE ar_bill ADD COLUMN bill_name VARCHAR(100) NULL COMMENT ''账单名称'' AFTER bill_no',
    'SELECT 1');
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

UPDATE ar_bill
SET bill_name = CONCAT('应收账单-', bill_no)
WHERE bill_name IS NULL OR TRIM(bill_name) = '';

SET @sql := 'ALTER TABLE ar_bill MODIFY COLUMN bill_name VARCHAR(100) NOT NULL COMMENT ''账单名称''';
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

-- 2. 给来源计费订单增加应收账单占用状态。
SET @has_column := (
    SELECT COUNT(*)
    FROM information_schema.COLUMNS
    WHERE TABLE_SCHEMA = @db_name
      AND TABLE_NAME = 'prc_order_bill'
      AND COLUMN_NAME = 'ar_bill_status'
);
SET @sql := IF(@has_column = 0,
    'ALTER TABLE prc_order_bill ADD COLUMN ar_bill_status VARCHAR(20) NOT NULL DEFAULT ''UNBILLED'' COMMENT ''应收账单占用状态：UNBILLED/BILLED'' AFTER currency',
    'SELECT 1');
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

SET @has_index := (
    SELECT COUNT(*)
    FROM information_schema.STATISTICS
    WHERE TABLE_SCHEMA = @db_name
      AND TABLE_NAME = 'prc_order_bill'
      AND INDEX_NAME = 'idx_bill_ar_status'
);
SET @sql := IF(@has_index = 0,
    'ALTER TABLE prc_order_bill ADD INDEX idx_bill_ar_status (customer_id, currency, ar_bill_status, biz_date)',
    'SELECT 1');
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

-- 3. 根据已有账单明细回填历史订单状态。作废账单不占用订单。
UPDATE prc_order_bill o
JOIN (
    SELECT DISTINCT d.prc_order_bill_id
    FROM ar_bill_detail d
    JOIN ar_bill b ON b.ar_bill_id = d.ar_bill_id
    WHERE b.status <> 'VOID'
) billed ON billed.prc_order_bill_id = o.bill_id
SET o.ar_bill_status = 'BILLED'
WHERE COALESCE(o.ar_bill_status, 'UNBILLED') <> 'BILLED';

-- 4. 账单唯一性改为“客户 + 币种 + 截止日 + 版本”。
-- 同一截止日的作废账单保留历史，新账单使用递增版本号。
DROP TEMPORARY TABLE IF EXISTS tmp_ar_bill_versions;
CREATE TEMPORARY TABLE tmp_ar_bill_versions AS
    SELECT ar_bill_id,
           ROW_NUMBER() OVER (
               PARTITION BY customer_id, currency, bill_period_end
               ORDER BY create_time, ar_bill_id
           ) AS version_no
    FROM ar_bill;

UPDATE ar_bill a
JOIN tmp_ar_bill_versions v ON v.ar_bill_id = a.ar_bill_id
SET a.bill_version = v.version_no;
DROP TEMPORARY TABLE tmp_ar_bill_versions;

SET @has_old_unique := (
    SELECT COUNT(*)
    FROM information_schema.STATISTICS
    WHERE TABLE_SCHEMA = @db_name
      AND TABLE_NAME = 'ar_bill'
      AND INDEX_NAME = 'uk_ar_bill_customer_period'
);
SET @sql := IF(@has_old_unique > 0,
    'ALTER TABLE ar_bill DROP INDEX uk_ar_bill_customer_period',
    'SELECT 1');
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

SET @has_new_unique := (
    SELECT COUNT(*)
    FROM information_schema.STATISTICS
    WHERE TABLE_SCHEMA = @db_name
      AND TABLE_NAME = 'ar_bill'
      AND INDEX_NAME = 'uk_ar_bill_customer_cutoff_version'
);
SET @sql := IF(@has_new_unique = 0,
    'ALTER TABLE ar_bill ADD UNIQUE KEY uk_ar_bill_customer_cutoff_version (customer_id, currency, bill_period_end, bill_version)',
    'SELECT 1');
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

SET @has_cutoff_index := (
    SELECT COUNT(*)
    FROM information_schema.STATISTICS
    WHERE TABLE_SCHEMA = @db_name
      AND TABLE_NAME = 'ar_bill'
      AND INDEX_NAME = 'idx_ar_bill_customer_cutoff'
);
SET @sql := IF(@has_cutoff_index = 0,
    'ALTER TABLE ar_bill ADD INDEX idx_ar_bill_customer_cutoff (customer_id, currency, bill_period_end)',
    'SELECT 1');
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

-- 5. 详情页按账单加载费用时使用的排序索引。可重复执行，不会重复创建。
SET @has_detail_fee_index := (
    SELECT COUNT(*)
    FROM information_schema.STATISTICS
    WHERE TABLE_SCHEMA = @db_name
      AND TABLE_NAME = 'ar_bill_detail_fee'
      AND INDEX_NAME = 'idx_ar_detail_fee_order'
);
SET @sql := IF(@has_detail_fee_index = 0,
    'ALTER TABLE ar_bill_detail_fee ADD INDEX idx_ar_detail_fee_order (detail_id, fee_no, detail_fee_id)',
    'SELECT 1');
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;