-- 邮件收发(ADR-013):账号(配置 + 密封凭证 + 游标 + 跨进程租约)、入站留痕、逐订阅方投递留痕、出站留痕。
--
-- 腾讯企业邮箱两条接入路(IMAP/SMTP · 企业微信邮件 API)都没有带内容的推送,只能轮询拉:
-- 两个后端连同一个库时,一个信箱同一时刻只许一个进程在拉 —— `polling_until` 与
-- `sys.task.advancing_until` 同款(一条 SQL 判 + 占,带过期时间,进程崩了不锁死)。
-- 入站两把唯一键:重复拉到(时钟偏 / UIDVALIDITY 重锚 / wecom 十分钟重叠窗)一律静默跳过。
-- 入站 / 出站表对账号**不设外键**:账号删了留痕还在。
create table if not exists sys.mail_account (
  id                text primary key,
  name              text not null,
  kind              text not null check (kind in ('imap-smtp', 'wecom')),
  address           text not null default '',
  display_name      text not null default '',
  enabled           boolean not null default true,
  is_default        boolean not null default false,
  poll_interval_sec integer not null default 30 check (poll_interval_sec between 10 and 3600),
  channel_id        text,
  backfill_from     timestamptz,
  settings          jsonb not null default '{}'::jsonb,
  secret_cipher     text,
  cursor            jsonb,
  last_polled_at    timestamptz,
  last_poll_error   text,
  last_inbound_at   timestamptz,
  polling_until     timestamptz,
  created_at        timestamptz not null default now(),
  updated_at        timestamptz not null default now()
);
create unique index if not exists mail_account_name_key on sys.mail_account (name);
-- 默认发件账号至多一个 —— 用例先把别的置 false,这道索引兜底
create unique index if not exists mail_account_one_default on sys.mail_account ((true)) where is_default;
create index if not exists mail_account_due_idx on sys.mail_account (enabled, last_polled_at);

create table if not exists sys.mail_inbound (
  id             text primary key,
  account_id     text not null,
  message_id     text not null,
  provider_ref   text not null,
  in_reply_to    text,
  reference_ids  jsonb not null default '[]'::jsonb,
  from_addr      text not null default '',
  from_name      text not null default '',
  to_list        jsonb not null default '[]'::jsonb,
  cc_list        jsonb not null default '[]'::jsonb,
  subject        text not null default '',
  text_body      text,
  html_body      text,
  sent_at        timestamptz,
  received_at    timestamptz not null,
  attachments    jsonb not null default '[]'::jsonb,
  raw            bytea,
  raw_note       text not null default '',
  size           integer not null default 0,
  created_at     timestamptz not null default now()
);
create unique index if not exists mail_inbound_message_key on sys.mail_inbound (account_id, message_id);
create unique index if not exists mail_inbound_provider_key on sys.mail_inbound (account_id, provider_ref);
create index if not exists mail_inbound_time_idx on sys.mail_inbound (received_at desc);

create table if not exists sys.mail_inbound_delivery (
  mail_id     text not null references sys.mail_inbound(id) on delete cascade,
  subscriber  text not null,
  state       text not null check (state in ('dispatching', 'done', 'failed', 'skipped')),
  error       text,
  started_at  timestamptz not null default now(),
  finished_at timestamptz,
  primary key (mail_id, subscriber)
);

create table if not exists sys.mail_outbound (
  id              text primary key,
  account_id      text not null,
  message_id      text not null,
  idempotency_key text,
  to_list         jsonb not null,
  cc_list         jsonb not null default '[]'::jsonb,
  bcc_list        jsonb not null default '[]'::jsonb,
  subject         text not null,
  text_body       text,
  html_body       text,
  in_reply_to     text,
  reference_ids   jsonb not null default '[]'::jsonb,
  attachments     jsonb not null default '[]'::jsonb,
  state           text not null check (state in ('sending', 'sent', 'failed')),
  error           text,
  provider_ref    text,
  requested_by    jsonb not null default '{}'::jsonb,
  created_at      timestamptz not null default now(),
  sent_at         timestamptz
);
create unique index if not exists mail_outbound_idem_key on sys.mail_outbound (idempotency_key) where idempotency_key is not null;
create index if not exists mail_outbound_time_idx on sys.mail_outbound (created_at desc);