-- Split message body by conversation type. Snowflake MsgId remains PK / sort / sync cursor.

CREATE TABLE IF NOT EXISTS private_message (
    id               BIGINT PRIMARY KEY COMMENT 'Snowflake MsgId，主键、排序键、同步游标',
    conversation_id  BIGINT NOT NULL COMMENT '所属单聊会话 id',
    sender_id        BIGINT NOT NULL COMMENT '发送者 user_id；系统消息为 0',
    receiver_id      BIGINT NOT NULL DEFAULT 0 COMMENT '接收者 user_id；系统消息为 0',
    client_msg_id    VARCHAR(64) NOT NULL COMMENT '客户端消息 id，与 sender+会话 组成幂等键',
    message_type     SMALLINT NOT NULL COMMENT '消息类型：1文本 2图片 3语音 4视频 5表情 6GIF 7文件 8位置 9系统',
    content          BLOB NOT NULL COMMENT '序列化后的消息体（JSON 字节），禁止存原始 string；媒体只存对象存储 key',
    status           TINYINT NOT NULL DEFAULT 1 COMMENT '1=正常 2=已撤回 3=审核隐藏',
    created_at       DATETIME(3) NOT NULL COMMENT '服务端入库时间',
    UNIQUE KEY uk_sender_conv_client_msg (sender_id, conversation_id, client_msg_id),
    KEY idx_conversation_id (conversation_id, id),
    KEY idx_receiver_id (receiver_id, id)
) COMMENT='单聊消息正文。PK=MsgId；与 group_message 分表存储';

CREATE TABLE IF NOT EXISTS group_message (
    id               BIGINT PRIMARY KEY COMMENT 'Snowflake MsgId，主键、排序键、同步游标',
    conversation_id  BIGINT NOT NULL COMMENT '所属群会话 id',
    group_id         BIGINT NOT NULL DEFAULT 0 COMMENT '群号 groups.id，便于按群查询',
    sender_id        BIGINT NOT NULL COMMENT '发送者 user_id；系统消息为 0',
    client_msg_id    VARCHAR(64) NOT NULL COMMENT '客户端消息 id，与 sender+会话 组成幂等键',
    message_type     SMALLINT NOT NULL COMMENT '消息类型：1文本 2图片 3语音 4视频 5表情 6GIF 7文件 8位置 9系统',
    content          BLOB NOT NULL COMMENT '序列化后的消息体（JSON 字节），禁止存原始 string；媒体只存对象存储 key',
    status           TINYINT NOT NULL DEFAULT 1 COMMENT '1=正常 2=已撤回 3=审核隐藏',
    created_at       DATETIME(3) NOT NULL COMMENT '服务端入库时间',
    UNIQUE KEY uk_sender_conv_client_msg (sender_id, conversation_id, client_msg_id),
    KEY idx_conversation_id (conversation_id, id),
    KEY idx_group_id (group_id, id)
) COMMENT='群聊消息正文。PK=MsgId；群热路径不写 MySQL inbox 行';

CREATE TABLE IF NOT EXISTS messages (
    id               BIGINT PRIMARY KEY COMMENT 'Snowflake MsgId，主键、排序键、同步游标',
    conversation_id  BIGINT NOT NULL COMMENT '所属会话 id',
    sender_id        BIGINT NOT NULL COMMENT '发送者 user_id',
    client_msg_id    VARCHAR(64) NOT NULL COMMENT '客户端消息 id，与 sender+会话 组成幂等键',
    message_type     SMALLINT NOT NULL COMMENT '消息类型：1文本 2图片 3语音 4视频 5表情 6GIF 7文件 8位置 9系统',
    content          BLOB NOT NULL COMMENT '序列化后的消息体（JSON 字节），禁止存原始 string；媒体只存对象存储 key',
    status           TINYINT NOT NULL DEFAULT 1 COMMENT '1=正常 2=已撤回 3=审核隐藏',
    created_at       DATETIME(3) NOT NULL COMMENT '服务端入库时间',
    UNIQUE KEY uk_sender_conv_client_msg (sender_id, conversation_id, client_msg_id),
    KEY idx_conversation_id (conversation_id, id)
) COMMENT='迁移中转表。0011 拷贝到 private_message / group_message 后删除';

INSERT IGNORE INTO private_message (id, conversation_id, sender_id, client_msg_id, message_type, content, status, created_at)
SELECT m.id, m.conversation_id, m.sender_id, m.client_msg_id, m.message_type, m.content, m.status, m.created_at
FROM messages m
INNER JOIN conversations c ON c.id = m.conversation_id AND c.type = 1;

INSERT IGNORE INTO group_message (id, conversation_id, sender_id, client_msg_id, message_type, content, status, created_at)
SELECT m.id, m.conversation_id, m.sender_id, m.client_msg_id, m.message_type, m.content, m.status, m.created_at
FROM messages m
INNER JOIN conversations c ON c.id = m.conversation_id AND c.type = 2;

INSERT IGNORE INTO private_message (id, conversation_id, sender_id, client_msg_id, message_type, content, status, created_at)
SELECT m.id, m.conversation_id, m.sender_id, m.client_msg_id, m.message_type, m.content, m.status, m.created_at
FROM messages m
LEFT JOIN conversations c ON c.id = m.conversation_id
WHERE c.id IS NULL;

DROP TABLE IF EXISTS messages;