-- Chat schema and seed data for mini-program
-- Target: MySQL 8+

CREATE DATABASE IF NOT EXISTS mini_program
  DEFAULT CHARACTER SET utf8mb4
  COLLATE utf8mb4_unicode_ci;

USE mini_program;

SET FOREIGN_KEY_CHECKS=0;
DROP TABLE IF EXISTS chat_message;
DROP TABLE IF EXISTS chat_conversation_member;
DROP TABLE IF EXISTS chat_conversation;
DROP TABLE IF EXISTS chat_user_auth;
DROP TABLE IF EXISTS chat_user;
SET FOREIGN_KEY_CHECKS=1;

CREATE TABLE IF NOT EXISTS chat_user (
  id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  nickname VARCHAR(64) NULL,
  avatar_file_key VARCHAR(255) NULL COMMENT 'Stored file key, not URL',
  status TINYINT UNSIGNED NOT NULL DEFAULT 1 COMMENT '1-active 2-disabled 3-deleted',
  last_login_at DATETIME(3) NULL,
  created_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
  updated_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3) ON UPDATE CURRENT_TIMESTAMP(3),
  PRIMARY KEY (id),
  KEY idx_status (status),
  KEY idx_created_at (created_at)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE IF NOT EXISTS chat_user_auth (
  id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  user_id BIGINT UNSIGNED NOT NULL,
  auth_type TINYINT UNSIGNED NOT NULL COMMENT '1-wechat_miniapp_openid 2-wechat_unionid 3-phone_sms 4-email_magic_link 5-oauth 6-username_password',
  auth_identifier VARCHAR(191) NOT NULL COMMENT 'openid/unionid/phone/email/oauth-sub/username',
  password_hash CHAR(64) NULL COMMENT 'sha256 hex for demo only; production should use bcrypt/argon2',
  credential_json JSON NULL COMMENT 'Extra auth payload, e.g. app_id/provider/phone_area',
  is_primary TINYINT UNSIGNED NOT NULL DEFAULT 1 COMMENT '1-primary login identity 0-secondary',
  status TINYINT UNSIGNED NOT NULL DEFAULT 1 COMMENT '1-active 2-disabled 3-revoked',
  last_login_at DATETIME(3) NULL,
  created_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
  updated_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3) ON UPDATE CURRENT_TIMESTAMP(3),
  PRIMARY KEY (id),
  UNIQUE KEY uk_auth_type_identifier (auth_type, auth_identifier),
  KEY idx_user_status (user_id, status),
  KEY idx_last_login_at (last_login_at),
  CONSTRAINT fk_user_auth_user
    FOREIGN KEY (user_id) REFERENCES chat_user(id)
    ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE IF NOT EXISTS chat_conversation (
  id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  user_low_id BIGINT UNSIGNED NOT NULL COMMENT 'Smaller user_id in direct chat pair',
  user_high_id BIGINT UNSIGNED NOT NULL COMMENT 'Larger user_id in direct chat pair',
  status TINYINT UNSIGNED NOT NULL DEFAULT 1 COMMENT '1-active 2-archived',
  last_seq BIGINT UNSIGNED NOT NULL DEFAULT 0,
  message_count BIGINT UNSIGNED NOT NULL DEFAULT 0,
  last_message_preview VARCHAR(255) NULL,
  last_message_at DATETIME(3) NULL,
  created_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
  updated_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3) ON UPDATE CURRENT_TIMESTAMP(3),
  PRIMARY KEY (id),
  UNIQUE KEY uk_direct_pair (user_low_id, user_high_id),
  KEY idx_last_message_at (last_message_at),
  KEY idx_user_low_id (user_low_id),
  KEY idx_user_high_id (user_high_id),
  CONSTRAINT fk_conv_user_low
    FOREIGN KEY (user_low_id) REFERENCES chat_user(id)
    ON DELETE CASCADE,
  CONSTRAINT fk_conv_user_high
    FOREIGN KEY (user_high_id) REFERENCES chat_user(id)
    ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE IF NOT EXISTS chat_message (
  id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  conversation_id BIGINT UNSIGNED NOT NULL,
  seq BIGINT UNSIGNED NOT NULL COMMENT 'Conversation-local incremental sequence',
  sender_user_id BIGINT UNSIGNED NULL COMMENT 'Null means assistant/system sender',
  role TINYINT UNSIGNED NOT NULL COMMENT '1-user 2-assistant 3-system 4-tool',
  content_type TINYINT UNSIGNED NOT NULL COMMENT '1-text 2-audio 3-image 4-json',
  content_text MEDIUMTEXT NULL,
  content_json JSON NULL,
  media_file_key VARCHAR(255) NULL COMMENT 'Stored file key, not URL',
  media_duration_ms INT UNSIGNED NULL,
  client_msg_id VARCHAR(64) NULL COMMENT 'Idempotency key from client',
  created_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
  deleted_at DATETIME(3) NULL,
  PRIMARY KEY (id),
  UNIQUE KEY uk_conv_seq (conversation_id, seq),
  UNIQUE KEY uk_conv_client_msg (conversation_id, client_msg_id),
  KEY idx_conv_created (conversation_id, created_at),
  KEY idx_sender_created (sender_user_id, created_at),
  CONSTRAINT fk_msg_conv
    FOREIGN KEY (conversation_id) REFERENCES chat_conversation(id)
    ON DELETE CASCADE,
  CONSTRAINT fk_msg_sender_user
    FOREIGN KEY (sender_user_id) REFERENCES chat_user(id)
    ON DELETE SET NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

INSERT INTO chat_user (
  id,
  nickname,
  avatar_file_key,
  status,
  last_login_at,
  created_at,
  updated_at
)
VALUES
  (
    1,
    'Parent A',
    'avatars/parent-a.png',
    1,
    '2026-03-25 09:58:00.000',
    '2026-03-25 09:00:00.000',
    '2026-03-25 09:58:00.000'
  ),
  (
    2,
    'Parent B',
    'avatars/parent-b.png',
    1,
    '2026-03-25 10:01:00.000',
    '2026-03-25 09:20:00.000',
    '2026-03-25 10:01:00.000'
  ),
  (
    3,
    'Parent C',
    'avatars/parent-c.png',
    1,
    '2026-03-25 21:11:00.000',
    '2026-03-25 20:30:00.000',
    '2026-03-25 21:11:00.000'
  );

INSERT INTO chat_user_auth (
  id,
  user_id,
  auth_type,
  auth_identifier,
  password_hash,
  credential_json,
  is_primary,
  status,
  last_login_at,
  created_at,
  updated_at
)
VALUES
  (
    1,
    1,
    6,
    'test1',
    SHA2('123', 256),
    JSON_OBJECT('provider', 'local_account'),
    1,
    1,
    '2026-03-25 09:58:00.000',
    '2026-03-25 09:00:00.000',
    '2026-03-25 09:58:00.000'
  ),
  (
    2,
    2,
    6,
    'test2',
    SHA2('123', 256),
    JSON_OBJECT('provider', 'local_account'),
    1,
    1,
    '2026-03-25 10:01:00.000',
    '2026-03-25 09:20:00.000',
    '2026-03-25 10:01:00.000'
  ),
  (
    3,
    3,
    6,
    'test3',
    SHA2('123', 256),
    JSON_OBJECT('provider', 'local_account'),
    1,
    1,
    '2026-03-25 21:11:00.000',
    '2026-03-25 20:30:00.000',
    '2026-03-25 21:11:00.000'
  );

INSERT INTO chat_conversation (
  id,
  user_low_id,
  user_high_id,
  status,
  last_seq,
  message_count,
  last_message_preview,
  last_message_at,
  created_at,
  updated_at
)
VALUES
  (
    1,
    1,
    2,
    1,
    5,
    5,
    'user: Thanks, I understand now.',
    '2026-03-25 10:00:40.000',
    '2026-03-25 10:00:00.000',
    '2026-03-25 10:00:40.000'
  );

INSERT INTO chat_message (
  id,
  conversation_id,
  seq,
  sender_user_id,
  role,
  content_type,
  content_text,
  content_json,
  media_file_key,
  media_duration_ms,
  client_msg_id,
  created_at
)
VALUES
  (
    1001,
    1,
    1,
    1,
    1,
    1,
    'Hi, did you finish homework?',
    JSON_OBJECT('lang', 'en'),
    NULL,
    NULL,
    'c1-m1',
    '2026-03-25 10:00:05.000'
  ),
  (
    1002,
    1,
    2,
    2,
    1,
    1,
    'Almost done, one question left.',
    JSON_OBJECT('lang', 'en'),
    NULL,
    NULL,
    'c1-m2',
    '2026-03-25 10:00:12.000'
  ),
  (
    1003,
    1,
    3,
    NULL,
    2,
    1,
    'I can help explain the last question.',
    JSON_OBJECT('tone', 'assistant'),
    NULL,
    NULL,
    'c1-m3',
    '2026-03-25 10:00:20.000'
  ),
  (
    1004,
    1,
    4,
    1,
    1,
    1,
    'Great, explain how to solve it.',
    JSON_OBJECT('lang', 'en'),
    NULL,
    NULL,
    'c1-m4',
    '2026-03-25 10:00:30.000'
  ),
  (
    1005,
    1,
    5,
    2,
    1,
    1,
    'Thanks, I understand now.',
    JSON_OBJECT('lang', 'en'),
    NULL,
    NULL,
    'c1-m5',
    '2026-03-25 10:00:40.000'
  );