-- 银城大喇叭最小消息与阅读审计：仅租户公开已发布消息，不复用 sys_notice。
-- 可重复执行；不包含定向目标、附件、AI 摘要或问答上下文。

CREATE TABLE IF NOT EXISTS `aihr_broadcast_message` (
  `id` bigint NOT NULL AUTO_INCREMENT COMMENT '消息ID',
  `tenant_id` varchar(20) NOT NULL COMMENT '租户编号',
  `title` varchar(200) NOT NULL COMMENT '消息标题',
  `content` text NOT NULL COMMENT '消息正文',
  `status` varchar(20) NOT NULL DEFAULT 'PUBLISHED' COMMENT 'PUBLISHED/WITHDRAWN',
  `published_by` bigint NOT NULL COMMENT '发布人用户ID',
  `published_time` datetime NOT NULL COMMENT '发布时间',
  `publish_request_key` varchar(100) DEFAULT NULL COMMENT '发布幂等键',
  `publish_request_hash` char(64) DEFAULT NULL COMMENT '发布载荷SHA-256',
  `withdrawn_by` bigint DEFAULT NULL COMMENT '撤回人用户ID',
  `withdrawn_time` datetime DEFAULT NULL COMMENT '撤回时间',
  `withdraw_reason` varchar(500) DEFAULT NULL COMMENT '撤回原因',
  `create_time` datetime NOT NULL COMMENT '创建时间',
  `update_time` datetime NOT NULL COMMENT '更新时间',
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_aihr_broadcast_message_publish_request` (`tenant_id`, `published_by`, `publish_request_key`),
  KEY `idx_aihr_broadcast_message_public` (`tenant_id`, `status`, `published_time`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='银城大喇叭租户公开消息';

-- 兼容已执行过 B0 建表的环境：历史消息没有请求键或撤回原因，保留 NULL。
SET @has_broadcast_publish_request_key := (
  SELECT COUNT(*) FROM information_schema.COLUMNS
  WHERE table_schema = DATABASE() AND table_name = 'aihr_broadcast_message'
    AND column_name = 'publish_request_key'
);
SET @broadcast_ddl := IF(
  @has_broadcast_publish_request_key = 0,
  'ALTER TABLE aihr_broadcast_message ADD COLUMN publish_request_key varchar(100) DEFAULT NULL COMMENT ''发布幂等键'' AFTER published_time',
  'SELECT 1'
);
PREPARE aihr_broadcast_stmt FROM @broadcast_ddl; EXECUTE aihr_broadcast_stmt; DEALLOCATE PREPARE aihr_broadcast_stmt;

SET @has_broadcast_publish_request_hash := (
  SELECT COUNT(*) FROM information_schema.COLUMNS
  WHERE table_schema = DATABASE() AND table_name = 'aihr_broadcast_message'
    AND column_name = 'publish_request_hash'
);
SET @broadcast_ddl := IF(
  @has_broadcast_publish_request_hash = 0,
  'ALTER TABLE aihr_broadcast_message ADD COLUMN publish_request_hash char(64) DEFAULT NULL COMMENT ''发布载荷SHA-256'' AFTER publish_request_key',
  'SELECT 1'
);
PREPARE aihr_broadcast_stmt FROM @broadcast_ddl; EXECUTE aihr_broadcast_stmt; DEALLOCATE PREPARE aihr_broadcast_stmt;

SET @has_broadcast_withdraw_reason := (
  SELECT COUNT(*) FROM information_schema.COLUMNS
  WHERE table_schema = DATABASE() AND table_name = 'aihr_broadcast_message'
    AND column_name = 'withdraw_reason'
);
SET @broadcast_ddl := IF(
  @has_broadcast_withdraw_reason = 0,
  'ALTER TABLE aihr_broadcast_message ADD COLUMN withdraw_reason varchar(500) DEFAULT NULL COMMENT ''撤回原因'' AFTER withdrawn_time',
  'SELECT 1'
);
PREPARE aihr_broadcast_stmt FROM @broadcast_ddl; EXECUTE aihr_broadcast_stmt; DEALLOCATE PREPARE aihr_broadcast_stmt;

SET @has_broadcast_publish_request_index := (
  SELECT COUNT(*) FROM information_schema.STATISTICS
  WHERE table_schema = DATABASE() AND table_name = 'aihr_broadcast_message'
    AND index_name = 'uk_aihr_broadcast_message_publish_request'
);
SET @broadcast_publish_request_index_valid := (
  SELECT COUNT(*) FROM (
    SELECT index_name
    FROM information_schema.STATISTICS
    WHERE table_schema = DATABASE() AND table_name = 'aihr_broadcast_message'
      AND index_name = 'uk_aihr_broadcast_message_publish_request'
    GROUP BY index_name
    HAVING MIN(non_unique) = 0
       AND COUNT(*) = 3
       AND SUM(sub_part IS NOT NULL) = 0
       AND GROUP_CONCAT(column_name ORDER BY seq_in_index SEPARATOR ',') =
           'tenant_id,published_by,publish_request_key'
  ) valid_broadcast_publish_request_index
);
SET @broadcast_ddl := CASE
  WHEN @broadcast_publish_request_index_valid > 0 THEN 'SELECT 1'
  WHEN @has_broadcast_publish_request_index > 0 THEN
    'ALTER TABLE aihr_broadcast_message DROP INDEX uk_aihr_broadcast_message_publish_request, ADD UNIQUE KEY uk_aihr_broadcast_message_publish_request (tenant_id, published_by, publish_request_key)'
  ELSE
    'ALTER TABLE aihr_broadcast_message ADD UNIQUE KEY uk_aihr_broadcast_message_publish_request (tenant_id, published_by, publish_request_key)'
END;
PREPARE aihr_broadcast_stmt FROM @broadcast_ddl; EXECUTE aihr_broadcast_stmt; DEALLOCATE PREPARE aihr_broadcast_stmt;

-- 只追加首发快照；B1 没有修订入口，应用代码不会更新或删除版本记录。
CREATE TABLE IF NOT EXISTS `aihr_broadcast_version` (
  `id` bigint NOT NULL AUTO_INCREMENT COMMENT '消息版本ID',
  `tenant_id` varchar(20) NOT NULL COMMENT '租户编号',
  `message_id` bigint NOT NULL COMMENT '消息ID',
  `version` int NOT NULL COMMENT '消息版本，首版为1',
  `title` varchar(200) NOT NULL COMMENT '消息标题快照',
  `content` text NOT NULL COMMENT '消息正文快照',
  `published_by` bigint NOT NULL COMMENT '发布人用户ID',
  `published_time` datetime NOT NULL COMMENT '发布时间',
  `create_time` datetime NOT NULL COMMENT '快照创建时间',
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_aihr_broadcast_version` (`tenant_id`, `message_id`, `version`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='银城大喇叭消息不可变版本快照';

CREATE TABLE IF NOT EXISTS `aihr_broadcast_read` (
  `id` bigint NOT NULL AUTO_INCREMENT COMMENT '阅读记录ID',
  `tenant_id` varchar(20) NOT NULL COMMENT '租户编号',
  `message_id` bigint NOT NULL COMMENT '消息ID',
  `user_id` bigint NOT NULL COMMENT '阅读用户ID',
  `first_read_time` datetime NOT NULL COMMENT '首次阅读时间',
  `create_time` datetime NOT NULL COMMENT '创建时间',
  `update_time` datetime NOT NULL COMMENT '更新时间',
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_aihr_broadcast_read` (`tenant_id`, `message_id`, `user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='银城大喇叭阅读审计';

-- 与租户事实表保持同一排序规则，兼容历史库 general_ci 与新 MySQL 8 库 0900_ai_ci。
SET @broadcast_target_collation := (
  SELECT collation_name FROM information_schema.columns
  WHERE table_schema = DATABASE() AND table_name = 'aihr_knowledge_info' AND column_name = 'tenant_id'
  LIMIT 1
);
SET @broadcast_target_collation := COALESCE(@broadcast_target_collation, @@collation_database);

SET @broadcast_message_collation := (
  SELECT table_collation FROM information_schema.tables
  WHERE table_schema = DATABASE() AND table_name = 'aihr_broadcast_message'
  LIMIT 1
);
SET @broadcast_ddl := IF(
  @broadcast_message_collation = @broadcast_target_collation,
  'SELECT 1',
  CONCAT('ALTER TABLE aihr_broadcast_message CONVERT TO CHARACTER SET utf8mb4 COLLATE ', @broadcast_target_collation)
);
PREPARE aihr_broadcast_stmt FROM @broadcast_ddl; EXECUTE aihr_broadcast_stmt; DEALLOCATE PREPARE aihr_broadcast_stmt;

SET @broadcast_version_collation := (
  SELECT table_collation FROM information_schema.tables
  WHERE table_schema = DATABASE() AND table_name = 'aihr_broadcast_version'
  LIMIT 1
);
SET @broadcast_ddl := IF(
  @broadcast_version_collation = @broadcast_target_collation,
  'SELECT 1',
  CONCAT('ALTER TABLE aihr_broadcast_version CONVERT TO CHARACTER SET utf8mb4 COLLATE ', @broadcast_target_collation)
);
PREPARE aihr_broadcast_stmt FROM @broadcast_ddl; EXECUTE aihr_broadcast_stmt; DEALLOCATE PREPARE aihr_broadcast_stmt;

SET @broadcast_read_collation := (
  SELECT table_collation FROM information_schema.tables
  WHERE table_schema = DATABASE() AND table_name = 'aihr_broadcast_read'
  LIMIT 1
);
SET @broadcast_ddl := IF(
  @broadcast_read_collation = @broadcast_target_collation,
  'SELECT 1',
  CONCAT('ALTER TABLE aihr_broadcast_read CONVERT TO CHARACTER SET utf8mb4 COLLATE ', @broadcast_target_collation)
);
PREPARE aihr_broadcast_stmt FROM @broadcast_ddl; EXECUTE aihr_broadcast_stmt; DEALLOCATE PREPARE aihr_broadcast_stmt;

-- 兼容已执行过 B0 建表的环境：原有消息只补一次 v1 快照。
INSERT INTO aihr_broadcast_version (
  tenant_id, message_id, `version`, title, content, published_by, published_time, create_time
)
SELECT m.tenant_id, m.id, 1, m.title, m.content, m.published_by, m.published_time, m.create_time
FROM aihr_broadcast_message m
WHERE NOT EXISTS (
  SELECT 1
  FROM aihr_broadcast_version v
  WHERE v.tenant_id = m.tenant_id
    AND v.message_id = m.id
    AND v.`version` = 1
);

SET @broadcast_target_collation := NULL;
SET @broadcast_message_collation := NULL;
SET @broadcast_version_collation := NULL;
SET @broadcast_read_collation := NULL;
SET @has_broadcast_publish_request_key := NULL;
SET @has_broadcast_publish_request_hash := NULL;
SET @has_broadcast_withdraw_reason := NULL;
SET @has_broadcast_publish_request_index := NULL;
SET @broadcast_publish_request_index_valid := NULL;
SET @broadcast_ddl := NULL;